AudioCircle

Audio/Video Gear and Systems => Open Baffle Speakers => Topic started by: BrassEar on 22 Apr 2008, 05:20 pm

Title: DIY Emerald Physics CS2 Clones
Post by: BrassEar on 22 Apr 2008, 05:20 pm
Research so far indicates the following components in the CS2:

4 x 15-inch Eminence Alpha-15A Drivers

2 x Selenium D220Ti-8 1" Titanium Horn Driver

2 x 12" Round Waveguide 1" Threaded

48 x 18.5 x 2.5-inch baffle

Behringer DCX2496, 1 kHz xover, 48 db/octave. One would have to replicate the DSP settings that Emerald is using on the Behringer. Does anyone have any additional info on this?
Title: Re: DIY Emerald Physics CS2 Clones
Post by: Dmason on 22 Apr 2008, 05:52 pm
Why replicate, when you can improve?

Something like

4X AE Speakers IB15   www.aespeakers.com
2X B&C DE250 compression driver www.bcspeakers.com
2X DDS 90' Waveguide  www.ddshorns.com 

Software based, low latency active crossover with future upgradeability

www.thuneau.com   

That is just for starters. Removing the crossover from 1000Hz in itself would make for a vast improvement, IMO. Using a dedicated wideband driver between 200-4000Hz would be another, and if one intended to do a 2.5 way, I would strongly recommend avoiding completely, metallic diaphragms in compression drivers, favouring those with polyester units, which are ALOT easier on the ears, and the good ones these days require no equalization. The metal units are designed for high output, long throw applications, using alot of power AND equalization. But if I were to clone the Emerald, I would likely use those components. The AE bass drivers and the T Huneau XO, for sure. -Which I intend to use, as well as the DDS waveguide horn, whose geometry was calculated by Dr Earl Geddes apparently. The pro audio B&C, and Beyma wideband/midband drivers look VERY interesting.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: ebag4 on 22 Apr 2008, 06:29 pm
Those AE IB15s are nice drivers.  I use 4 of the previous generation in my IB for my HT.  THe units I have used the chrome phase plugs that AE uses in some of their other drivers currently.  Here is a pic of the AE IB15s in my IB:

http://home.comcast.net/~infinitelybaffled/page3IB-Gallery3.html

Mine is the second system down.  Fantastic bass!
Title: Re: DIY Emerald Physics CS2 Clones
Post by: BrassEar on 22 Apr 2008, 07:08 pm
>>You mean like this?
>>Jeff

YES!!!!!
What drivers did you use? And are you using the Behringer xover?

TIA
Title: Re: DIY Emerald Physics CS2 Clones
Post by: rajacat on 22 Apr 2008, 07:32 pm
Hmmmm....these designs are very interesting. Now I just have to find the time. :scratch: Definitely the woodworking aspects of OB construction are less complex, cheaper and less time consuming than box speakers. It would be really nice to have solid wood baffles.

Roy
Title: Re: DIY Emerald Physics CS2 Clones
Post by: JeffB on 22 Apr 2008, 07:34 pm
jkelly,

Those look nice.
Are the baffles supported by any braces on the back?
Or is there simply a slot in the base they slip into?
Title: Re: DIY Emerald Physics CS2 Clones
Post by: ebag4 on 22 Apr 2008, 07:37 pm
.... Definitely the woodworking aspects of OB construction are less complex, cheaper and less time consuming than box speakers.

Roy

That depends on the OB, these took me longer than any box speakers I ever built:

(http://www.audiocircle.com/image.php?id=12942)

Of course YMMV :wink:
Title: Re: DIY Emerald Physics CS2 Clones
Post by: Russell Dawkins on 22 Apr 2008, 07:40 pm
They look great - how do they sound?

If the upper baffle were tapered, wider at the top, like the Lyngdorf DP 1s (which apparently sound great as part of his radical system), these would be reminiscent of an exclamation point! I say radical because with a 300 Hz crossover to the "sub" the woofer is not really a "sub" and is an integral part of the design.

http://tinyurl.com/5waw6r
Title: Re: DIY Emerald Physics CS2 Clones
Post by: ebag4 on 22 Apr 2008, 08:01 pm
Hi Russell,
I checked out the Lyngdorf site, those are pretty cool, thanks for pointing them out.  My 15s aren't truly a subwoofer either, they are crossed at 200hz.  As for the sound, I am really enjoying them.  I have been using them for about 4 months.  I love the OB alignment, it's sound is effortless.  This is about the 5th OB speaker I have built and so far these are the most "full range" although there is an intimacy that a full/wide range driver gives you that I sometimes miss.

My apologies to the OP, I seem to have taken this thread off track, now back to the original topic.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: Victor on 22 Apr 2008, 08:45 pm
I am also in the process of cloning the CS2's. They are not available in the Netherlands, but I have allready all the drivers, the waveguide and the the DCX 2496.  The only thing I am looking for, are the settings of the crossover. I am looking for somebody who can mail me the config file for the DCX 2496.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: BrassEar on 22 Apr 2008, 09:06 pm
I am also in the process of cloning the CS2's. They are not available in the Netherlands, but I have allready all the drivers, the waveguide and the the DCX 2496.  The only thing I am looking for, are the settings of the crossover. I am looking for somebody who can mail me the config file for the DCX 2496.

Can you confirm that the drivers that I listed are correct for the stock CS2's?

Regarding the xover settings, I thought I read somewhere that this information is included in the CS2 user guide. Maybe someone who owns the CS2's could post that?
Title: Re: DIY Emerald Physics CS2 Clones
Post by: BradJudy on 22 Apr 2008, 09:33 pm
That depends on the OB, these took me longer than any box speakers I ever built:

(http://www.audiocircle.com/image.php?id=12942)

Of course YMMV :wink:

Very nice.  I can envision the next step up with two 15" drivers and a speaker designed to look like an acoustic guitar.  :D
Title: Re: DIY Emerald Physics CS2 Clones
Post by: Ric Schultz on 22 Apr 2008, 09:48 pm
Drivers are correct.  However, as Dave said....there are far better choices.

The CS2 settings are not in the user guide.

I am sure Clayton feels his Behringer settings are proprietary.  He has spent a lot of time there.  You are a naughty boy if you email these settings to someone.....go to your room!  However, you can do a pretty good job yourself. Position the speakers in the room as you would to listen, with the axis crossing slightly in front of the listening position.  Set the xover at 1000hz (48db per octave) and get/borrow/buy/rent a measurement tool......the Behringer equalizer with calibrated mic will do (I also have a "bouncing ball" Audio Control third octave thang that is very easy to see, but the Behringer equalizer/mic will show you the same thang).  Play pink noise and notice the deviation from flat.....now using the EQs in the Behringer xover set them until pink noise measures flat at listening position.  You might want to play with delay as well.  Of course, you might like a setting other than flat.  Have fun!
Title: Re: DIY Emerald Physics CS2 Clones
Post by: TomS on 22 Apr 2008, 11:32 pm
I also consider the DCX settings proprietary to Emerald Physics unless Clayton says otherwise.  While I appreciate the DIY angle as much as anyone, it simply isn't appropriate to copy them from a legitimately purchased EP DCX and provide them to someone who has not purchased the speakers.  I've been asked several times by mail and PM already, and refused to do this  :nono:
Title: Re: DIY Emerald Physics CS2 Clones
Post by: jkelly on 23 Apr 2008, 01:14 am
>>You mean like this?
>>Jeff

YES!!!!!
What drivers did you use? And are you using the Behringer xover?

TIA


I used the Parts Express package.
I plan to play with a 1st order passive design with a L pad but will most likely go the active route.

I am also starting a second cabinet to redo my B200 and Alpha 15.

I plan to have a removable mdf plate on the top third that will allow me to build different
full range driver panels (B200, 103, 108) that I can swap in and out.



Title: Re: DIY Emerald Physics CS2 Clones
Post by: dorokusai on 23 Apr 2008, 02:00 am
Awesome. I'd love to hear about them in contrast to the EP product.

Mark
Title: Re: DIY Emerald Physics CS2 Clones
Post by: ttan98 on 23 Apr 2008, 02:30 am
Jkelly,

I for one welcome you to give us a progress report of how you go with this CS2 clone project.

cheers..
Title: Re: DIY Emerald Physics CS2 Clones
Post by: BrassEar on 23 Apr 2008, 04:31 pm
I also consider the DCX settings proprietary to Emerald Physics unless Clayton says otherwise.  While I appreciate the DIY angle as much as anyone, it simply isn't appropriate to copy them from a legitimately purchased EP DCX and provide them to someone who has not purchased the speakers.  I've been asked several times by mail and PM already, and refused to do this  :nono:

Yea, that seems fair. I think Clayton has already disclosed more about the design than most people would. What is most amazing about the CS2s is the quality of their overall presentation using fairly cheap drivers. I think I will take the Dr. Mason approach and instead of cloning the CS2s, just build something better.

My apologies to Emerald Physics and Clayton if I was inciting something unethical.  :oops:
Title: Re: DIY Emerald Physics CS2 Clones
Post by: TomS on 23 Apr 2008, 05:27 pm
I also consider the DCX settings proprietary to Emerald Physics unless Clayton says otherwise.  While I appreciate the DIY angle as much as anyone, it simply isn't appropriate to copy them from a legitimately purchased EP DCX and provide them to someone who has not purchased the speakers.  I've been asked several times by mail and PM already, and refused to do this  :nono:

Yea, that seems fair. I think Clayton has already disclosed more about the design than most people would. What is most amazing about the CS2s is the quality of their overall presentation using fairly cheap drivers. I think I will take the Dr. Mason approach and instead of cloning the CS2s, just build something better.

My apologies to Emerald Physics and Clayton if I was inciting something unethical.  :oops:
No worries at all.

I think in true the spirit of DIY, if you can learn by measuring yourself, tweaking, substituting, and trying alternatives to make a design better yet, then full steam ahead.  Clayton took the risk of starting with off the shelf parts anyway, other than the tuning itself.  I've seen lots of great suggestions here already, so it should be interesting to see what everyone comes up with!  Those prototypes look mighty nice for sure.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: Dmason on 23 Apr 2008, 06:19 pm
I always support the idea of DIY innovation, however, the idea of cloning Clayton's thang, verbatim, is not on. There is a very sacred principle of intellectual property here, and I would like to know that that will be respected. The finished product Clayton has come up with is smooth as glass, and ALOT of people like it. Incidently, I think the asking price is more than fair

..It is pretty easy stuff to come up with a tuning for anyone's "cloned" rig here without all that, and the intelligence quotient on AC is pretty damn high, I would say; plenty of help about. How about something original?

 While I wish Clayton, and EP all the success they genuinely deserve, and endless hours of boxless magic to those happy owners, the dual big-cone + treble idea is not new, and in my opinion, it is an inherently flawed design, trying to mate big cones to small diaphragms.. I am not targeting EP here, but including JAMO, Hawthorne Duet, and any other of this kind.

The magic is in the message with speakers, and this is why the purest, "purist?" approach deviates from this concept, -abit- at least, and would include a dedicated wideband driver from below Middle C, (250Hz) or ideally, 150Hz, to at least two octaves above high C, which would be 2000Hz, with 3500Hz + being nice. There are several very musical options that reach cleanly much higher than that. This way, there are no bass frequency-induced IM distortions placed on the WB cone. The treble radiator can be tied in where the two driver's polar responses match, the higher up, the less critical an issue this becomes. Bass is just plain easy to implement, and can be done on just about any budget.

My own idea which has been brewing awhile has more to do with a sort of nearfield OB set up, using a single Lamdba IB15 per side, a 6-8 inch wideband mid driver, possibly the new Tone Tubby 6.5, or whizzerless EF8, both of which look VERY interesting, pending published specs, and unsmoothed FR measurements, ...but get some without the whizzer, which has been indicated as a possibility, [think group buy] and tie in some teensytweet that was copacetic with the hempster. The higher up you go, the less you need to concern yourself with the "quality" of the treble driver... Below 40Hz or so, use a fast, sealed sub, to fill in the fundamentals. This way you could have a low profile 18 X 30 sized OB well proven down to 40Hz even on an 18 X 18 baffle, a la Dave Leonard, Bob in St Louis, et al, all complete with dedicated drivers for their respective passbands, and no contamination in the middle. -And a sub, as an option. One high powered plate amp will do fine for both channels, providing lethal amounts of smack and slam. Once relieved of bass duty, even the most modest wideband driver, like my beloved 1997 Pioneer car 6 X 9's, and the most modest single ended tube amp will become real little monsters, with decently sensitive mains drivers.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: BrassEar on 26 Sep 2008, 10:12 pm
Position the speakers in the room as you would to listen, with the axis crossing slightly in front of the listening position.  Set the xover at 1000hz (48db per octave) and get/borrow/buy/rent a measurement tool......the Behringer equalizer with calibrated mic will do (I also have a "bouncing ball" Audio Control third octave thang that is very easy to see, but the Behringer equalizer/mic will show you the same thang).  Play pink noise and notice the deviation from flat.....now using the EQs in the Behringer xover set them until pink noise measures flat at listening position.  You might want to play with delay as well.  Of course, you might like a setting other than flat.  Have fun!

Thanks for the info Ric. Am I dense or are there only a few settings which could be involved?

1. Clearly the xover is set at 48 dB/octave around 1 kHz.
2. A shelving EQ filter must be applied to the low end to compensate for the OB design of the woofer setup.
3. Levels for the compression driver must be balanced with the woofers.
4. EQ must be applied to the compression driver/horn combo for flat on axis response.
5. Possible delay to the compression driver to compensate for  alignment.

Am I missing anything obvious here?
Title: Re: DIY Emerald Physics CS2 Clones
Post by: gainphile2 on 27 Sep 2008, 03:11 pm

1. Clearly the xover is set at 48 dB/octave around 1 kHz.
2. A shelving EQ filter must be applied to the low end to compensate for the OB design of the woofer setup.
3. Levels for the compression driver must be balanced with the woofers.
4. EQ must be applied to the compression driver/horn combo for flat on axis response.
5. Possible delay to the compression driver to compensate for  alignment.

Am I missing anything obvious here?

On #2, there should be two compensation: dipole rolloff 6db/oct and driver compensation. Dipole rolloff is fairly easy except we need to remember there is a hump before it which needs to be tamed using notch filter.

Driver compensation should replicate something like Linkwitz biquad so the 40Hz hump is tamed and the FR is flat towards 20Hz. I have been playing around with eminence 15 and the xmax is fairly easy to exceed.

6. There should be plenty of notches around. With my 45mm baffle I have dipole peak at around 300Hz and driver breakup at 2kHz per datasheet but this is fairly easy to correct if using DCX2496. I am using op-amps and it's a real pain to get measurement then build the circuits.

Btw. I have not heard the CS2 but not really sure that dipole + horn/waveguide combination would actually work? It would be dipole only up to 1kHz, and SL repeatedly mentioned that live reproduction can only be achieved if the radiation pattern is uniform across frequency ranges? Would love to hear how you go.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: zybar on 27 Sep 2008, 03:35 pm

1. Clearly the xover is set at 48 dB/octave around 1 kHz.
2. A shelving EQ filter must be applied to the low end to compensate for the OB design of the woofer setup.
3. Levels for the compression driver must be balanced with the woofers.
4. EQ must be applied to the compression driver/horn combo for flat on axis response.
5. Possible delay to the compression driver to compensate for  alignment.

Am I missing anything obvious here?

On #2, there should be two compensation: dipole rolloff 6db/oct and driver compensation. Dipole rolloff is fairly easy except we need to remember there is a hump before it which needs to be tamed using notch filter.

Driver compensation should replicate something like Linkwitz biquad so the 40Hz hump is tamed and the FR is flat towards 20Hz. I have been playing around with eminence 15 and the xmax is fairly easy to exceed.

6. There should be plenty of notches around. With my 45mm baffle I have dipole peak at around 300Hz and driver breakup at 2kHz per datasheet but this is fairly easy to correct if using DCX2496. I am using op-amps and it's a real pain to get measurement then build the circuits.

Btw. I have not heard the CS2 but not really sure that dipole + horn/waveguide combination would actually work? It would be dipole only up to 1kHz, and SL repeatedly mentioned that live reproduction can only be achieved if the radiation pattern is uniform across frequency ranges? Would love to hear how you go.

The CS2's work extremely well.

George
Title: Re: DIY Emerald Physics CS2 Clones
Post by: BrassEar on 27 Sep 2008, 03:39 pm

Btw. I have not heard the CS2 but not really sure that dipole + horn/waveguide combination would actually work? It would be dipole only up to 1kHz, and SL repeatedly mentioned that live reproduction can only be achieved if the radiation pattern is uniform across frequency ranges? Would love to hear how you go.

SL should go a hear the EP CS2. IMHO, they are better than the Orions in most respects. I just firmly believe that the weaknesses in the CS2 (harshness from the titanium driver and congestion from the WG?) can be easily eliminated. I am cloning them with respect to baffle, Xover, and Alpha 15's but I am using a 15-inch WG with a BMS compression driver. I will posts results and pix when I am done but don't hold yer breath.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: tubamark on 27 Sep 2008, 11:52 pm
. . . . . I am cloning them with respect to baffle, Xover, and Alpha 15's but I am using a 15-inch WG with a BMS compression driver. I will posts results and pix when I am done but don't hold yer breath.

Where did'ja find a 15" waveguide?
Price?
curious,

-- Mark
Title: Re: DIY Emerald Physics CS2 Clones
Post by: gainphile2 on 29 Sep 2008, 05:29 am

SL should go a hear the EP CS2. IMHO, they are better than the Orions in most respects. I just firmly believe that the weaknesses in the CS2 (harshness from the titanium driver and congestion from the WG?) can be easily eliminated. I am cloning them with respect to baffle, Xover, and Alpha 15's but I am using a 15-inch WG with a BMS compression driver. I will posts results and pix when I am done but don't hold yer breath.

You've heard both speakers? Could you please describe where each excels ? I can only dream of building an Orion, $2 grand drivers only and still needs 8 amplification :cry: ... so I was looking to build CS2 clone. In fact I have 4 Alpha 15 already which is very expensive to ship to Australia. But after playing around with the Alpha I conclude that this driver is not easily tamed to work up to 1kHz using analog filters. Let alone trying to equalise the horn. Maybe that's why the DCX was necessary. But then again just learning from my experience, without anaechoic chamber this could also be very trivial.

From DIY point of view Orion has more chance of a success but price prohibitive. CS2 is much simpler and cheaper to implement ... but there is no proven DIY settings out there (yet). The good thing is if someone is successful, implementation is "just an upload" away ....  :thumb:
Title: Re: DIY Emerald Physics CS2 Clones
Post by: dweekie on 29 Sep 2008, 11:06 am

SL should go a hear the EP CS2. IMHO, they are better than the Orions in most respects. I just firmly believe that the weaknesses in the CS2 (harshness from the titanium driver and congestion from the WG?) can be easily eliminated. I am cloning them with respect to baffle, Xover, and Alpha 15's but I am using a 15-inch WG with a BMS compression driver. I will posts results and pix when I am done but don't hold yer breath.

You've heard both speakers? Could you please describe where each excels ? I can only dream of building an Orion, $2 grand drivers only and still needs 8 amplification :cry: ... so I was looking to build CS2 clone. In fact I have 4 Alpha 15 already which is very expensive to ship to Australia. But after playing around with the Alpha I conclude that this driver is not easily tamed to work up to 1kHz using analog filters. Let alone trying to equalise the horn. Maybe that's why the DCX was necessary. But then again just learning from my experience, without anaechoic chamber this could also be very trivial.

From DIY point of view Orion has more chance of a success but price prohibitive. CS2 is much simpler and cheaper to implement ... but there is no proven DIY settings out there (yet). The good thing is if someone is successful, implementation is "just an upload" away ....  :thumb:


It is really difficult to wade through all the opinions of various speakers.  I've read that the Geddes Summa was better than the Orion, which was better than the Hawthorne Sterling Silver Iris, which was better than the Emerald Physics CS2, which was better than the Orion, and we just cycle through over and over again. I've heard some highly touted speakers where I was the only one out of the whole room that couldn't stand to listen to them.  It's a tough world when everyone has a different pair of ears.....
Title: Re: DIY Emerald Physics CS2 Clones
Post by: gainphile2 on 29 Sep 2008, 11:31 am
Yes, that's why I did not ask which one is better but rather what qualities differentiate those design  aa. Of course if I was in the US I'd just go to RMAF and decide for myself  :drool:

Btw. I'm not sure what's with Gedes horn/waveguide. They still use box with all its inherent issues. But OB + horn like CS2, now that I really need to hear sometimes.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: dweekie on 29 Sep 2008, 12:07 pm
Yes, that's why I did not ask which one is better but rather what qualities differentiate those design  aa. Of course if I was in the US I'd just go to RMAF and decide for myself  :drool:

Btw. I'm not sure what's with Gedes horn/waveguide. They still use box with all its inherent issues. But OB + horn like CS2, now that I really need to hear sometimes.

Since you have 4 alphas already, have you considered some of the other projects posted in the past other than compression drivers?  The MJK project with Jordans and Alpha or the B200 wth Alphas come to mind.  If you feel there is weakness at 1K in the alphas, the full range driver mix might be worth your while. 
Title: Re: DIY Emerald Physics CS2 Clones
Post by: mightym on 29 Sep 2008, 11:19 pm
If you haven't looked already, there's a long, long, but informative thread over at AudioKarma, called the econo wave guide thread.  If I were to attempt to clone the Emerald Physics CS2, I would look seriously at this for the top end.   The idea was * you supply the woofer, Here's the topend...*  From all accounts, it doesn't sound like a " horn ", but has verrry smoooth, and detailed sound.  I'm working on a rebuild of an old set of Realistic cabs that literally had the woofers kicked in, I plan to use the Econo-waveguide in them.

www.audiokarma.org/forums/showthread.php?t=150939


What kind of trouble are you having Re: the Eminence Alpha 15A's up to 1K?  since the Eminence Alpha's are on sale at PE for $52 freight paid ( Shh, don't tell anyone ), I had been thinking of a clone project of my own.

The info I was able to find looked to be 94Db +/- 2Db to (just) past 1K.

John
Title: Re: DIY Emerald Physics CS2 Clones
Post by: gainphile2 on 30 Sep 2008, 12:16 am
The design was Eminence 15 + a fullrange, as experiment only. My thinking was if I can't do it with easily implemented Full Range, there is no way I can make the horn to work.

frequency response is fine and can be measured and corrected. But it just does not sound right to cross at 1kHz. Perhaps due to time alignment etc. which is not easily done using analog filters. best result is to cross really low and then I did not need to correct the FR and transition between drivers is not too sensitive to the ear.

I believe these factors were the reason a DSP is necessary as they can correct them fairly aggresively. But spending AUD450 for DCX2496 without proven settings and an anaechoic chamber is not something I want to gamble on.

My 'final' prototype now runs a fullrange and the Eminence acts like a sub.

I still believe CS2 has the best and functional looking OB so far. Considering the price it looks like a really good value (in the US).
Title: Re: DIY Emerald Physics CS2 Clones
Post by: gainphile2 on 30 Sep 2008, 12:55 am

btw... I just found out the 12" waveguides has been discontinued from PartsExpress  :cry:
Title: Re: DIY Emerald Physics CS2 Clones
Post by: mightym on 30 Sep 2008, 01:35 am
Too bad,

I looked the waveguide up, and they were recommending crossover at 1200 Hz.  I don't think you could make them work without the DSP.  But then what do I know...Emerald Physics says on their webpage that they crossed below 1000 Hz....

The Econo waveguide is designed to cross in the region of 1400 Hz., the Eminence Alpha 15A's have a nasty big peak above 1000 Hz.  even with a 24 Db crossover ( passive ), you'd have a bit of trouble NOT having a fair peak, or would spend lots of time and $ perfecting the woofer filter.


John
Title: Re: DIY Emerald Physics CS2 Clones
Post by: gainphile2 on 30 Sep 2008, 02:06 am
I did 24/db LR filter (active) and added notch filter (also active) at that 2k peak. It actually worked well.

I did encounter problems with bloated 300Hz and 500Hz -- again without anaechoic chamber this might be just room effect.

I wonder if doing measurements outside would be a valid one ?

If we can replicate the DSP using analog filters I think it would be great (and better than AD -DA perhaps).

This is nearfield measurement of an eq-ed Eminence 15 to compensate dipole roll-off. I forgot whether it had the 1kHz xo or not. That 2kHz peak can be removed fairly easily. Does anyone have a measurement of Selenium + 12" waveguide ?

(http://i188.photobucket.com/albums/z72/widhibrata/audio/05eminencefull-rangewitheqnearfield.jpg)
Title: Re: DIY Emerald Physics CS2 Clones
Post by: BrassEar on 30 Sep 2008, 03:13 am

Where did'ja find a 15" waveguide?
Price?
curious,

-- Mark

http://www.gedlee.com/Summa.htm (http://www.gedlee.com/Summa.htm)
Title: Re: DIY Emerald Physics CS2 Clones
Post by: BrassEar on 30 Sep 2008, 03:16 am
frequency response is fine and can be measured and corrected. But it just does not sound right to cross at 1kHz. Perhaps due to time alignment etc. which is not easily done using analog filters.

With the Behringer DCX it is very easy to set the xover, slope, gains, and eq. But how does one measure and correct the time alignment issues?
Title: Re: DIY Emerald Physics CS2 Clones
Post by: BrassEar on 30 Sep 2008, 03:18 am
FWIW, a pair of Alphas on an OB the size of the CS2 were very easy to measure and EQ. The only reason that you can't run it full range is the 2K spike. It is actually very smooth right up to 1.4K. If you xover there at 48 dB/octave I think it sounds excellent.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: BrassEar on 30 Sep 2008, 03:25 am
Does anyone have a measurement of Selenium + 12" waveguide ?

(http://i188.photobucket.com/albums/z72/widhibrata/audio/05eminencefull-rangewitheqnearfield.jpg)

I assume for informational purposes only? I find that Selenium to be bright, hard, and congested near the xover region and is what really holds the CS2 back IMO.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: gainphile2 on 30 Sep 2008, 04:46 am
frequency response is fine and can be measured and corrected. But it just does not sound right to cross at 1kHz. Perhaps due to time alignment etc. which is not easily done using analog filters.

With the Behringer DCX it is very easy to set the xover, slope, gains, and eq. But how does one measure and correct the time alignment issues?

I saw DCX screen before where you can introduce delays. In theory one just measure the distance between woofer and tweeter coils, and calculate in ms. the time difference.  My understanding DCX has two types: Long and short delays. I don't know more details.

With analog allpass, the phase correction is much more difficult to design, and even then the results can be argued/debated.

This is what I meant:

Quote
Adjustable delay for all inputs and outputs allow manual or automatic correction for room temperature, phase and arrival time differences
Title: Re: DIY Emerald Physics CS2 Clones
Post by: mgalusha on 30 Sep 2008, 01:31 pm
Quote
I saw DCX screen before where you can introduce delays. In theory one just measure the distance between woofer and tweeter coils, and calculate in ms. the time difference.  My understanding DCX has two types: Long and short delays. I don't know more details.

The DCX has the capability to do set this automatically if a measurement microphone is connected to it's "C" input. I haven't tried it but the DSP can do it.

If you are setting delay times manually you can set them by distance or time.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: BrassEar on 30 Sep 2008, 04:03 pm
Quote
I saw DCX screen before where you can introduce delays. In theory one just measure the distance between woofer and tweeter coils, and calculate in ms. the time difference.  My understanding DCX has two types: Long and short delays. I don't know more details.

The DCX has the capability to do set this automatically if a measurement microphone is connected to it's "C" input. I haven't tried it but the DSP can do it.

If you are setting delay times manually you can set them by distance or time.

Many thanks to both gainphile2 and mgalusha for these insights! I will post photos and results when I am close to finishing this project.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: BrassEar on 14 Oct 2008, 07:06 pm
You've heard both speakers? Could you please describe where each excels ? I can only dream of building an Orion, $2 grand drivers only and still needs 8 amplification :cry: ... so I was looking to build CS2 clone.

I have heard both the Orions and the CS2s but NOT in the same room or with the same equipment. I would never say anything bad about the Orions, they are truly amazing but they do lack the efficiency and dynamics of the CS2. On the other hand, I find the CS2 to be bright and hard. Whether this is due to the titanium compression driver, the PE conical horn, or too low a crossover point, I don't know. Since a CS2 clone with better drivers, horns, and higher crossover is much easier and cheaper to build than an Orion clone, this is the direction that I am going.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: zybar on 14 Oct 2008, 08:07 pm
You've heard both speakers? Could you please describe where each excels ? I can only dream of building an Orion, $2 grand drivers only and still needs 8 amplification :cry: ... so I was looking to build CS2 clone.

I have heard both the Orions and the CS2s but NOT in the same room or with the same equipment. I would never say anything bad about the Orions, they are truly amazing but they do lack the efficiency and dynamics of the CS2. On the other hand, I find the CS2 to be bright and hard. Whether this is due to the titanium compression driver, the PE conical horn, or too low a crossover point, I don't know. Since a CS2 clone with better drivers, horns, and higher crossover is much easier and cheaper to build than an Orion clone, this is the direction that I am going.

A modified DCX goes along way towards eliminating the brightness and hardness which you speak of. 

George
Title: Re: DIY Emerald Physics CS2 Clones
Post by: BrassEar on 15 Oct 2008, 06:51 pm
A modified DCX goes along way towards eliminating the brightness and hardness which you speak of. 

George

Thanks George, I intend to try that.

BTW, my comments probably sound way too critical on the CS2. To be clear - I LOVE the CS2. I actually find them to be a breakthrough product, especially at their price point. To come within striking distance of $10-20K speakers is amazing.

I am personally out to prove or disprove my theory regarding these speakers which is..... take the stock CS2 design and use a better waveguide and compression driver and you could have a speaker that will challenge almost any speaker at any price.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: gainphile2 on 16 Oct 2008, 12:50 am

I have heard both the Orions and the CS2s but NOT in the same room or with the same equipment. I would never say anything bad about the Orions, they are truly amazing but they do lack the efficiency and dynamics of the CS2. On the other hand, I find the CS2 to be bright and hard. Whether this is due to the titanium compression driver, the PE conical horn, or too low a crossover point, I don't know. Since a CS2 clone with better drivers, horns, and higher crossover is much easier and cheaper to build than an Orion clone, this is the direction that I am going.

Thanks for that insight. I am in the same position as you as an Orion is way out of reach financially. I'm happier than ever now to proceed with my cloning project. Will soon try to locate the selenium and horn.

The DCX cost $500 here in australia, so I may try getting by with analogue filters. At the moment I have played around with a pair of my eminence 15 and have some good idea how to tame it.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: ttan98 on 16 Oct 2008, 02:19 am

Thanks for that insight. I am in the same position as you as an Orion is way out of reach financially. I'm happier than ever now to proceed with my cloning project. Will soon try to locate the selenium and horn.

The DCX cost $500 here in australia, so I may try getting by with analogue filters. At the moment I have played around with a pair of my eminence 15 and have some good idea how to tame it.

Gainphile,

I have 10" Dayton spherical Horn(similar to CS2) and Selenium titanium DE220Ti compression driver, a pair of each, if you are interested contact me.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: BrassEar on 16 Oct 2008, 04:16 pm
Will soon try to locate the selenium and horn.
FWIW, I would NOT use the same selenium driver and PE conical horn unless you are perfectly happy with the sound of the stock CS2. Clayton recently revealed here that he is using the DDS waveguide and BMS driver on his flagship CS1.

I am now experimenting with the DDS waveguide and the B&C DE250 but I have heard the Beyma drivers are the ones to beat (just ask Duke of AudioKenesis).
Title: Re: DIY Emerald Physics CS2 Clones
Post by: Magnetar on 16 Oct 2008, 05:23 pm
Will soon try to locate the selenium and horn.
FWIW, I would NOT use the same selenium driver and PE conical horn unless you are perfectly happy with the sound of the stock CS2. Clayton recently revealed here that he is using the DDS waveguide and BMS driver on his flagship CS1.

I am now experimenting with the DDS waveguide and the B&C DE250 but I have heard the Beyma drivers are the ones to beat (just ask Duke of AudioKenesis).

The Beyma CP380 is pretty darn good, none of the metallic sound found in most compression drivers.

The Parts Express horns aren't very good - it would be hard to judge compression driver quality using them.

Still, the best 1" driver I have found is the no-longer-in business Emilar 175 series. I have used TAD, Altec, Beyma, BMS, JBL, B&C, Radian 1" drivers and others.

Some OB with Emilar and 21" bass:

(http://img157.imageshack.us/img157/1981/obfrt2dp8.jpg)

(http://img157.imageshack.us/img157/3725/obsidebm1.jpg)

(http://img361.imageshack.us/img361/557/obtwoqj3.jpg)
Title: Re: DIY Emerald Physics CS2 Clones
Post by: AK on 16 Oct 2008, 05:50 pm
Magnetar, do you have impedance curve from that 21in pyle woofer?
Title: Re: DIY Emerald Physics CS2 Clones
Post by: Magnetar on 16 Oct 2008, 06:03 pm
Magnetar, do you have impedance curve from that 21in pyle woofer?


I will be measuring them again in the next few days. maybe a by the end of next weekend. I'm using a pair in the new bass line array panels - hopefully will have time to get working soon.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: gainphile2 on 16 Oct 2008, 11:56 pm
Will soon try to locate the selenium and horn.
FWIW, I would NOT use the same selenium driver and PE conical horn unless you are perfectly happy with the sound of the stock CS2. Clayton recently revealed here that he is using the DDS waveguide and BMS driver on his flagship CS1.

I am now experimenting with the DDS waveguide and the B&C DE250 but I have heard the Beyma drivers are the ones to beat (just ask Duke of AudioKenesis).

Thanks again. Any link where I can get pricing for the DDS waveguide ?
Title: Re: DIY Emerald Physics CS2 Clones
Post by: mgalusha on 17 Oct 2008, 02:39 am
DDS Website: http://www.ddshorns.com/catalog.php?page=ENG190Pro

US Speaker carries them: http://www.usspeaker.com/dds%20cfd-eng-1-90pro-1.htm
Title: Re: DIY Emerald Physics CS2 Clones
Post by: BrassEar on 17 Oct 2008, 04:11 pm
DDS Website: http://www.ddshorns.com/catalog.php?page=ENG190Pro

US Speaker carries them: http://www.usspeaker.com/dds%20cfd-eng-1-90pro-1.htm

Good links. FYI, I don't think DDS sells directly. They use US Speaker and Assistance Audio for sales channels. US Speaker charges more but they actually will sell and deliver you product. I gave up on Assistance audio after several phone calls and emails, they apparently don't want my business or my money.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: BrassEar on 27 Oct 2008, 05:46 pm
I hope I am not beating a dead thread to death but I finally got my CS2 clones up and running.

FYI:

4 Alpha 15As
2 DDS waveguides
2 B&C DE250
2 foam plugs
1 DXC2496

The good news is that even without any EQ the sound is pretty amazing.  The DE250 in the DDS 10-inch waveguide with Geddes foam plug makes for the best highs I have ever heard. Currently crossing over at 1.2K, LR48. Next step is to use TrueRTA with the Behringer mic to apply proper EQ and time alignment.

Only downside thus far is that I am not getting the bass that I heard from the CS2. I assume that EQ will fix this.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: jkelly on 27 Oct 2008, 06:39 pm
Can you provide some detail on making/buying the foam plugs?
Would you have a pic?

Did you cut out a big diamond to stuff in the horn?

thanks,

Jeff
Title: Re: DIY Emerald Physics CS2 Clones
Post by: BrassEar on 27 Oct 2008, 06:59 pm
Can you provide some detail on making/buying the foam plugs?
Would you have a pic?

The foam is VERY specific. I did a fair amount of research and bought it here. I had to use 3M adhesive spray to glue the layers together and then trim to fit the waveguide.

On this page, scroll down to REGICELL Foam, Recommended for Speakers and Filters. You must use 30 PPI foam.

http://www.foamandupholstery.com/out_door_foam.htm (http://www.foamandupholstery.com/out_door_foam.htm)

I will try to post some pix soon.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: gainphile2 on 31 Oct 2008, 04:42 am
Good progress there BrassEars .. hope you can post pictures.

I have obtaned 10" PE waveguides, so the next step is to get the Seleniums. Unfortunately Aussie dollar has crashed and I have to wait a while now for better economic situation  :|

The plan is to cross at around 1.5k using analogue xo.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: jkelly on 1 Nov 2008, 10:15 pm
I have two of the Seleniums available if it makes any sense to ship from NJ.

Jeff
Title: Re: DIY Emerald Physics CS2 Clones
Post by: gainphile2 on 2 Nov 2008, 03:01 am
I have two of the Seleniums available if it makes any sense to ship from NJ.

Jeff


How much are you asking? I'll try to see what's the shipping estimate with USPS.
Title: Re: DIY Emerald Physics CS2 Clones - Photos
Post by: BrassEar on 4 Nov 2008, 05:25 pm
Here are some photos of the project. The physical build and cosmetic stuff is about 99% complete. Now the real hard part starts with RTA and EQ tweaking on the Behringer.  :o

http://members.cox.net/brassear/emerald-physics-clones/ (http://members.cox.net/brassear/emerald-physics-clones/)
Title: Re: DIY Emerald Physics CS2 Clones
Post by: dweekie on 4 Nov 2008, 07:14 pm
Looks very nice! 
Title: Re: DIY Emerald Physics CS2 Clones - Photos
Post by: jkelly on 4 Nov 2008, 10:00 pm
Here are some photos of the project. The physical build and cosmetic stuff is about 99% complete. Now the real hard part starts with RTA and EQ tweaking on the Behringer.  :o

http://members.cox.net/brassear/emerald-physics-clones/ (http://members.cox.net/brassear/emerald-physics-clones/)

Wow - they really look great!

I have a couple of questions. 

Is the back of the waveguide covered with any material?

The foam plug - how do you determine the width of it.  I thought that maybe it fills
the whole horn but it looks like a lightbulb screwed into the mouth.

Does it go into the mouth of the waveguide?

Thanks and great work.

Title: Re: DIY Emerald Physics CS2 Clones
Post by: Ric Schultz on 4 Nov 2008, 10:18 pm
Looks great......however, any grill cloth will veil the sound and including on the woofs.  You absolutely must contrain layer damp the frames of the woofs....huge....humungus difference.  You really want to wire your amps directly to the drivers, so the cloth on the back should be gone too.  A single set of binding posts and the extra wire will veil the sound.   All these things I have tried.  You will probably need to delay the treble a slight bit.  The woofs take at least 200 hours of very hard playing to come into their own.  The surrounds and spider are very stiff.......so takes a while.  Have fun!
Title: Re: DIY Emerald Physics CS2 Clones - Photos
Post by: BrassEar on 4 Nov 2008, 10:42 pm
Is the back of the waveguide covered with any material?
Nope, stock DDS waveguide. These are strange in that the fronts are beautifully finished and the rears look like a child finished them.

The foam plug - how do you determine the width of it.  I thought that maybe it fills
the whole horn but it looks like a lightbulb screwed into the mouth.
Does it go into the mouth of the waveguide?

I just used spray adhesive to glue multiple layers together and then cut that 3-inch thick chunk in a circle. I then had to manually shave or cut it down to represent a funnel that fit inside the WG. It comes about a half inch in front of the throat. If you were not using a grille you could extend the foam out beyond the mouth of the waveguide. I believe Geddes does this on his speakers.  I don't think the foam plug dimensions are that critical as any foam in the WG would help as far as what I read on Earl's patent.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: BrassEar on 4 Nov 2008, 10:49 pm
You absolutely must contrain layer damp the frames of the woofs....huge....humungus difference. 

Sorry Ric but I must be dense, can you elaborate on this? How do I constrain layer damp the frames of the woofers? Do you mean apply some damping compound to those cheapo stamped steel frames to stop them from ringing like telephones?  :lol:

You really want to wire your amps directly to the drivers, so the cloth on the back should be gone too. 
I wired some 14GA directly to the drivers and that cable will connect directly to the amps.

You will probably need to delay the treble a slight bit. 

The auto time align on the Behringer indicated 30 mm tweeter delay (.09 ms). Does that sound close?

Thanks for the suggestions! The next major step after getting these RTA'd and EQ'd will be to upgrade the Behr. I think I know who can do that for me!
Title: Re: DIY Emerald Physics CS2 Clones
Post by: Ric Schultz on 5 Nov 2008, 07:17 am
Yes, apply a constranined layer damping material to the woofer frames.  Michael Percy sells EAR SD40AL.  This damping material has an aluminum layer on top.  You cut it to size with scissors and peel off the clear layer underneath and stick it on....self sticking.  Works incredibly.  Damp all the struts on each woofer.....way better sound.

Yes, that amount of delay sounds about right.  You can easily change it and listen.

I am glad you are hardwiring.....mucho good.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: fine on 22 Nov 2008, 05:28 pm
 aa
Title: Re: DIY Emerald Physics CS2 Clones
Post by: BrassEar on 4 Dec 2008, 05:03 pm
Just a minor update here....

Please see Richard's "New Insights: Going beyond HiFi... "good" design and the "known" ~" thread (page 3) for my latest trials with these clones.  I just might go passive first order on these but I need a few weeks of pure listening to make that call.  The Behringer is an amazing device for the $$ but I now have more respect than ever for what Clayton has accomplished with this unit and his speakers. 

I don't like the sound of the DDS waveguide/B&C DE250 with high order slopes and just going for flat in-room response does not sound as natural as a simple coil and cap arrangement here. What is truly shocking is how flat the first order setup actually measures in room with TrueRTA.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: ecir38 on 5 Dec 2008, 12:37 am
Here's the link

http://www.audiocircle.com/index.php?topic=56536.msg559905#msg559905

Look forward to hearing more about this when the time comes.

BR
Title: Re: DIY Emerald Physics CS2 Clones
Post by: gainphile2 on 5 Dec 2008, 12:30 pm
Holy cow the universe have aligned  :o. While awaiting for AUD to strengthen so I can get reasonable price for seleniums I have... run the Eminence Alpha FULL RANGE for about a month. I since had no desire to pursue cloning the CS2 it sounds so real, so good. The high is simple dome tweeter. I reserved the lower part for additional Alpha but don't need them and also not keen to lower the acoustic center.

(http://i188.photobucket.com/albums/z72/widhibrata/audio/DSC_6888-1.jpg)


I still pass it through active XO for the bass compensation and notice no sound degradation. This is measurement from *listening position*, in-room. Ignore the SPL level I did not calibrate them.

(http://i188.photobucket.com/albums/z72/widhibrata/audio/05v13design.jpg)
Title: Re: DIY Emerald Physics CS2 Clones
Post by: scorpion on 5 Dec 2008, 04:05 pm
Gainphile2,

Your measurements conform quite a bit to what I has measured for th Alphas fullrange, the build up at 2 kHz may or may not exsist and I think it is much milder than official FR measurements show. I  also listened to the Alpha fullrange but placed much near the floor and I liked what I heard but didn't go further. Are these speakers better than your Plutos ? Then this is really interesting. What are your panel and mounting measures ? I do would like to run a simulation of your setup ! Where is the tweeter coming in ? :)

/Erling
Title: Re: DIY Emerald Physics CS2 Clones
Post by: BrassEar on 5 Dec 2008, 05:59 pm
I still pass it through active XO for the bass compensation and notice no sound degradation. This is measurement from *listening position*, in-room. Ignore the SPL level I did not calibrate them.

Gainphile2 - what active XO are you using? I am surprised that they sound that good being so close to the rear wall. I have mine about 3 feet from the rear wall and they sound spacious and very clean.

Maybe we should start a new "Full Range Alpha" Circle. This is one amazing driver. Thanks for sharing.  BTW, I still think two are better than one.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: scorpion on 5 Dec 2008, 08:20 pm
Gainphile2,

In fact, you won't be sacrifacing anything by taking in a lower Alpha. Just let this go bass only and you will not be needing any bass lift.
I can say this for my ongoing project is 2 Alphas on a 40 cm wide baffle, flat down to 40 Hz + some other drivers, no EQ. More detail later.

/Erling
Title: Re: DIY Emerald Physics CS2 Clones
Post by: gainphile2 on 6 Dec 2008, 11:42 am
Gainphile2,

Your measurements conform quite a bit to what I has measured for th Alphas fullrange, the build up at 2 kHz may or may not exsist and I think it is much milder than official FR measurements show. I  also listened to the Alpha fullrange but placed much near the floor and I liked what I heard but didn't go further. Are these speakers better than your Plutos ? Then this is really interesting. What are your panel and mounting measures ? I do would like to run a simulation of your setup ! Where is the tweeter coming in ? :)

/Erling

The 2k peak does appear if I measure *nearfield* so I had played around with notch filter to smooth it out. But then they don't sound "right". Only after I read this maniac at Lampizator.eu I got the "awakening".  Basically he said never to measure nearfield or 1m etc. as then they will sound like your typical showroom speakers. Measure only at listening position as then the room is accounted for! What a genius.

My guess is at listening position the 2k peak is already well-diffused by the room it became irrelevant.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: gainphile2 on 6 Dec 2008, 11:48 am
I still pass it through active XO for the bass compensation and notice no sound degradation. This is measurement from *listening position*, in-room. Ignore the SPL level I did not calibrate them.

Gainphile2 - what active XO are you using? I am surprised that they sound that good being so close to the rear wall. I have mine about 3 feet from the rear wall and they sound spacious and very clean.

Maybe we should start a new "Full Range Alpha" Circle. This is one amazing driver. Thanks for sharing.  BTW, I still think two are better than one.

The XO is simple lowpass-shelving as per SL's site. One op-amp. I forgot what the frequencies were I think it was 250Hz - 11Hz. but will try to re-document and post here. It was one of those experiement which bound to "fail" so I did no documentation. If you look at my site gainphile.blogspot.com I usually document things very thoroughly. What a turn of event though   :thumb:.

That picture was quite old and yes - too close to the wall. The final distance from the wall is now 85cm (inside) and 90cm (outside) so they're bit toed-in. The soundstage is best if they are simply parallel to the wall but then I would be listening to the tweeters off-axis.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: gainphile2 on 6 Dec 2008, 11:59 am
Are these speakers better than your Plutos ? Then this is really interesting. What are your panel and mounting measures ? I do would like to run a simulation of your setup ! Where is the tweeter coming in ? :)
/Erling

In short: Yes. But the Pluto have their own quality. With such large panel sometimes I have the impression that the "Stage" is blocked by these panel. Something like looking at a concert but then you have 2 people standing in front of you. It's a weird sensation how these OBs fool your brain. With the Pluto this sensation do not exist thus I felt "the concert" is all for myself.

Where the Pluto fails: Bass quality and sensitivity.

The baffle is 45cm x 112cm. Woofer at 63cm and Tweeter 91cm. I forgot what Tweeter freq. is but it's 3.3uF parralel with 2.2uF + L .56mH  (2nd order).

Title: Re: DIY Emerald Physics CS2 Clones
Post by: scorpion on 6 Dec 2008, 11:57 pm
gainphile2,

Here are two simulations of your Alpha15 baffle. 1st as is is now:

(http://www.audiocircle.com/image.php?id=17257)

2nd with a second Alpha lower crossed LP at 300 Hz , 12dB/octave:

(http://www.audiocircle.com/gallery/albums/userpics/50000/2Alpha15%2C_the_top_one_fullrange.JPG)

No EQ in any case.

/Erling
Title: Re: DIY Emerald Physics CS2 Clones
Post by: richidoo on 7 Dec 2008, 12:07 am
Looks like those FR simulation graphs were created with Quarter-Wave (http://quarter-wave.com/) software, created by AC'er Martin King.  :thumb:
Title: Re: DIY Emerald Physics CS2 Clones
Post by: gainphile2 on 7 Dec 2008, 09:16 am
Wow that's a good program (MJK I suppose)?  It seems that my eq can do the same as the additional Alpha with no eq but they both roll off rather quickly below 40Hz which is Fs. I wonder now if they can be pushed towards high 20s when a pair is used  aa

I ran a test of harmonics distortion and 30Hz is still reasonable but 20Hz is not. At 20Hz I can hear tones whare there should be silence. I'm wondering how CS2 can obtain -3dB at 20Hz.

At 40Hz:
(http://i188.photobucket.com/albums/z72/widhibrata/audio/dist_03_40hz-1.jpg)


At 30Hz:
(http://i188.photobucket.com/albums/z72/widhibrata/audio/dist_02_30hz-1.jpg)


At 20Hz:
(http://i188.photobucket.com/albums/z72/widhibrata/audio/dist_01_20hz-1.jpg)

Title: Re: DIY Emerald Physics CS2 Clones
Post by: scorpion on 7 Dec 2008, 11:51 am
Of course it's MJK's MathCad models, the best software we have for these simulations. MJK himself has published a lot of Alpha simus so I don't think he will mind.
Two woofers will certainly help bass but this 20 Hz figure is a bit in the blue, it will never be put to test in reality. Two woofers will help lowbass powerhandling and contribute to extension.

What SPL level is your Spectrum measurement ? 40 Hz looks quite reasonable, 2nd harmonic a bit below 10% and 3rd well below 3% distortion perhaps as low as 1%. 30 Hz is alright too I think although 3rd harmonic is equal to the 2nd. Now think what 2 units and no EQ will do !  :)

/Erling
Title: Re: DIY Emerald Physics CS2 Clones
Post by: BrassEar on 8 Dec 2008, 08:17 pm
I am not so much concerned about the low end extension of the Alphas when they sound this good down to around 40 Hz or so. These have the open, magical sound of Magnepan bass without the low efficiency and limited headroom. The best of both worlds really.

I would roll the Alpha off at some point though. Although it sounds very good full range, just play a solo piano recording and you can hear what almost sounds like ringing or blurring of the piano tones. I don't think it is room related. When I threw a .51 choke in series with my two Alphas, they now sound slightly rolled off but still magical.

I almost think I stumbled on a discovery here, mating almost full range alphas with a waveguide loaded compression driver - all using simple first order passive xovers! I honestly have never heard better sound.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: doak on 9 Dec 2008, 01:35 am
I am not so much concerned about the low end extension of the Alphas when they sound this good down to around 40 Hz or so. These have the open, magical sound of Magnepan bass without the low efficiency and limited headroom. The best of both worlds really.

I would roll the Alpha off at some point though. Although it sounds very good full range, just play a solo piano recording and you can hear what almost sounds like ringing or blurring of the piano tones. I don't think it is room related. When I threw a .51 choke in series with my two Alphas, they now sound slightly rolled off but still magical.

I almost think I stumbled on a discovery here, mating almost full range alphas with a waveguide loaded compression driver - all using simple first order passive xovers! I honestly have never heard better sound.

Very interesting indeed.   Thanks for posting your progress.

IMO the digital crossover of the EP CS2 is not only what "makes them work" but is also their "Achilles heel".  Spending several hundred dollars or more to upgrade it doesn't make much sense to me ---- "going analog" does though. 

Best of Luck!
Title: Re: DIY Emerald Physics CS2 Clones
Post by: BrassEar on 9 Dec 2008, 05:19 am
IMO the digital crossover of the EP CS2 is not only what "makes them work" but is also their "Achilles heel".  Spending several hundred dollars or more to upgrade it doesn't make much sense to me ---- "going analog" does though. 

I think you are exactly right about the Behringer and the CS2.

I guess these are no longer EP CS2 clones. They are more like an Earl Geddes/AudioKenesis design with OB bass. I am hooked on waveguides/compression drivers + OB bass.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: scorpion on 9 Dec 2008, 07:25 am
You are certainly right here. The Alphas manage bass quite on their own without any EQ and they will play down into the 30'ies without any help.
I have DE250 coming after Christmas and the Dayton waveguide. It will be interesting to test together with my 4 Alphas. But what this fullrange wave also is opening up is a pairing of the Alphas and for instance Neo3PDR directly at about 2 kHz, like GR Research's OBs, lots of interesting options. .51 will begin rolling off at about 1200 Hz so it should be open for a lot of crossings.

/Erling
Title: Re: DIY Emerald Physics CS2 Clones
Post by: doak on 9 Dec 2008, 04:39 pm

I think you are exactly right about the Behringer and the CS2.

I guess these are no longer EP CS2 clones. They are more like an Earl Geddes/AudioKenesis design with OB bass. I am hooked on waveguides/compression drivers + OB bass.


Well, you're in VERY good company there!  :wink:
Title: Re: DIY Emerald Physics CS2 Clones
Post by: BrassEar on 9 Dec 2008, 05:43 pm
I have DE250 coming after Christmas and the Dayton waveguide. It will be interesting to test together with my 4 Alphas. But what this fullrange wave also is opening up is a pairing of the Alphas and for instance Neo3PDR directly at about 2 kHz, like GR Research's OBs, lots of interesting options. .51 will begin rolling off at about 1200 Hz so it should be open for a lot of crossings.

The DE250 in the DDS waveguide presents the best mids/highs I have ever heard. I have owned Quads, Maggies with ribbons, Vandersteens, NHTs, KEFs, Martin Logan CLS, etc. and nothing comes close. There is zero thermal compression going on and this is something you just have to hear to appreciate.

I agree, using the Alphas up to 1K or so opens up a world of options.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: scorpion on 10 Dec 2008, 09:33 am
BrassEar,

One question, how do you attach the foam plug to the waveguide ?

/Erling
Title: Re: DIY Emerald Physics CS2 Clones
Post by: Victor on 10 Dec 2008, 02:36 pm
Last weekend I started with my CS2 clone project. I have the Alpha 15’s, the Dayton waveguide and the Selenium DT220i
I have a DCX 2496 and some amps: a T amp, a Sansui AU222, a Behringer EP 2500 and a Music Angel KT88

Before I started putting the speakers on a baffle, I just laid them on a old matras and let them play for a few days. I used the Alpha without any coil, just full range. For the tweeter I used a 2 uF capacitor. It sounded very promising, extremely fast and open.

So, I expected a lot form the baffles. First I have tried the above mentioned passive version with just the vintage Sansui AU 222. It sounded o.k. but not that great, it was rather shouty and peaky. The main problem is of course the sensitivity mismatch of the units. I tried to get a more balanced sound by using a vintage Technics parametric equaliser. The sound improved a lot.

Then I tried the active approach. The DXC 2496 was used with all sorts of XO points and shelves. I used the AU 222 for the Alpha’s and a T amp for the tweeters. It became clear that the Alpha’s do have a serious problem with resolution in the midrange. For some of us it may be acceptable, but I am not happy with it. The CS 2 use 48db at 1000hz. Crossing it at a higher frequency degraded the resolution.

I played with it for a whole afternoon, it sounded impressive but I was not satisfied with it. However I think I have to improve the rigidness and damping of the baffles before I can call my speakers a serious CS 2 clone.

I will also try another tweeter. I have a pair of Philips RSQ8P’s and am interested to see if it’s possible to make an (active) match with the Alpha’s.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: BrassEar on 10 Dec 2008, 05:44 pm
One question, how do you attach the foam plug to the waveguide ?
Erling:

Just a light touch of 3M adhesive spray on the inside of the foam. Shove it in the WG and hold for 30 seconds. Worked perfectly. In hindsight, I probably should have spent more time sanding the foam to perfectly fill the shape of the WG. I may re-do this down the road. The foam is one of those "tweaks" that is a dramatic improvement and I am not one for tweaks in general.

Please report back here with your thoughts.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: BrassEar on 10 Dec 2008, 05:50 pm
It became clear that the Alpha’s do have a serious problem with resolution in the midrange. For some of us it may be acceptable, but I am not happy with it. The CS 2 use 48db at 1000hz. Crossing it at a higher frequency degraded the resolution.

I am currently trying to zero in on where to low pass the Alpha. Right now I am at first order around 1200 Hz. It's a trade off in that full range they sound more "live" but you do lose resolution in the midrange and a slight honkiness when run full range.

I have a friend who is going down a similar road with Alphas/PE WG/BMS drivers and crossing over passively and then using an analog graphic EQ to smooth things out. I will try to get him to post here.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: gainphile2 on 25 Dec 2008, 11:53 am
The honkiness when run full-range is due to that 2kHz peak. I did measurement and level it using notch filter f=1.8kHz, Q=5.4, depth= -8db and then it sounds fine. There is also a dipole peak at 400Hz.

My problem is I dont have a proper compression driver yet (expensive with current aus rate exchange) so a typical 1" dome tweeter is used and is quite strained. But from around 30Hz to 3kHz it's fine. I think a completely analog CS2 clone is possible albeit differences. If lucky perhaps can utilise only one amp.

I was also not happy with the overall polar response with only 1 tweeter firing forward and added another one firing from the back out-of phase. It  is now more coherent and "correct". Not sure how I would implement this when the CD and waveguide is on hand.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: Lazz on 26 Dec 2008, 01:32 am
BrassEar, you say {I honestly have never heard better sound}. Can you tell me what speakers you have heard and are comparing them to as I'm trying to get an idea of ob sound and performance.Thx Lazz.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: BrassEar on 26 Dec 2008, 05:59 am
Lazz - I have owned various Magnepans, Martin Logans, Vandersteens, NHT, Quads, B&W, etc. I never have liked cones and I always thought horns sounded terrible. Waveguides, compression drivers, and OB bass has changed everything for me. Now, multi subs are completing my new world order of audio.

For these reasons I think people like Earl Geddes, Duke of AudioKenesis, and Clayton of Emerald Physics are at the cutting edge of audio and the commercial mags and reviewers are clueless.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: David Weil on 26 Dec 2008, 10:18 pm
Clueless? Or writing for a living in favor of the companies who pay the ads in their magazines?
Title: Re: DIY Emerald Physics CS2 Clones
Post by: BrassEar on 26 Dec 2008, 11:41 pm
Clueless? Or writing for a living in favor of the companies who pay the ads in their magazines?

Excellent point.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: poseidonsvoice on 27 Dec 2008, 04:28 am
Clueless? Or writing for a living in favor of the companies who pay the ads in their magazines?

You hit the nail on the head on that one  :banghead:

or was it a brick wall,depending on the way you look at it  :dunno:

Anand.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: chakija on 27 Dec 2008, 09:24 pm
Guys,
just one question about those who use Alpha full range and satisfied with results...
Are those with black or silver sticker on magnet ???
I have both and i can say that black version is much, muuuuch more linear than sliver one ! No sign of shouting from them ,but silver sticker alpha shouts like hell  :duh:
Title: Re: DIY Emerald Physics CS2 Clones
Post by: gainphile2 on 28 Dec 2008, 05:50 am
I have the "black" version and it shouts too. But never compared with "silver one".

The shoutiness is easily tamed with notch filter as my previous post.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: Graham Maynard on 28 Dec 2008, 09:35 am
What is the difference, the cone ?

Is it same shape and spec but coated differently, as if tropicalised ?
Title: Re: DIY Emerald Physics CS2 Clones
Post by: fine on 28 Dec 2008, 10:53 am
I have the Black.
http://www.audiocircle.com/index.php?action=gallery;area=browse;album=1672
Title: Re: DIY Emerald Physics CS2 Clones
Post by: chakija on 28 Dec 2008, 12:32 pm
Well, i think it's the dust cap coating...
It seems little more stiffer on black alpha.
Also cone surrounding is with more traces of glue  :scratch:
I had alpha 6" and magnet is identical with black version of 15''. Size and shape is same but there r some tiny differences comparing to silver alpha, like vent gap protecting grill, or finishing radius etc...
I compared them again, and difference is very obvious !
Silver alpha makes your ear bleed when run in FR, and black alpha is much more tamed and with little different bass (little more detailed, and with better slam) !
Today i will try to compare them with my old silver alpha 15''... 
@fine
your speakers are marvelous, and one of the reason i bought another pair of 15''   :thumb:
Title: Re: DIY Emerald Physics CS2 Clones
Post by: gainphile2 on 29 Dec 2008, 12:01 am
Indeed those are really nice pair of speakers. Perhaps you could share us a how-to finishing  aa.

Yesterday I crossed the alphas at 1kHz with 24db active XO while keeping the notch (it's not steep enough to get rid of the peak). It sounds much cleaner than running it full range. The disadvantage is now I need 2 amps (which I had anyway).
Title: Re: DIY Emerald Physics CS2 Clones
Post by: ecir38 on 29 Dec 2008, 02:16 am
fine, do you have a link to the spikes on those speakers?

BR
Title: Re: DIY Emerald Physics CS2 Clones
Post by: fine on 30 Dec 2008, 10:21 am
Thank you if you like it :)
The spikes was made on CNC from stainless steel.Each ob have below footprint a ceramic square (500mm x 500mm) and 15mm thick print support with 3mm absorber material below to not scratch the floor.
The front baffle is from 45mm MDF + oak veneer + more than 16 coats of lacquer hand maded.
After that ... some serious work with 2000 granulation of sand paper & cold water + car polish (very fine one) and some teflon oil to make that shine look.All of the work-hand maded,manually.
The crossover for Supravox is on 250hz passive (single cap) and for Alpha's is active one.I also experimented with supertweeter Fostex T925A alnico motor on the top.The integration was wery good but not an "must be".Today I don't need any kind of supertweeter extension.Supravox do that job very good indeed.
The detail on Supra is amaizing and not need aditional components to mud the sound.
The amplifier for Alpha's is also DIY with lateral mosfets and for Supra DIY tube monoblocks.
The entire system is fire up with DIY preamp.
I will try passive cross. to woofers....12-15H coil to see what is happening.Any suggestions?
Check my gallery:
http://www.audiocircle.com/index.php?action=gallery;area=browse;album=1671
http://www.audiocircle.com/index.php?action=gallery;area=browse;album=1673
http://www.audiocircle.com/index.php?action=gallery;area=browse;album=1627


I have experimented a few days ago with Paudio BM8CXA (8" coaxial) and with 3 tweeters:
Selenium 220TI
Selenium 2500TI
BMD 450S
The passive cross on them was on 1,1khz IV and I order on 6khz.
Also I tryed I order on 8" woofer.
The results don't satisfy me.The sound is very mud,lack of details and overall was far away from Supravox.
Another experiment these days was replacing the Supra with Altec 811 horn + 806 driver.The cuttoff was on aprox. 800-900hz...original crossover.
The maximum sensitivity on Altec is about the same with Supravox...96-97db.
The details on Altec was a little soft and silky and a few steps back, somewhere close to the wall.
The feeling on Supravox was "right in my face" the vocalist was "here..here with me".Allmost I touch the instruments.Microdetails was there.
The single "weak link" on the Supravox was when I go up the volume.. ...aprox. 45W ...(on 96db spl)...the sound became ugly agglomerate,harsh and unpleasant....but on 30W is amaizing.
 96db and 30W is more than enough for most "normal" people.
On jazz or classic music the instruments on Altec horns was something on the back seats comparing with Supra on the baffle but very easy listening on higher volume.
I change 806 with Selenium 220TI,2500Ti-neodimium and BMD450-S ferofluid from PAudio.
The 2500 is a little dark,220TI something dull and 450 in between...
All these drivers have the mark -"metal inside"- was not my cup of tea ,something still missing comparing with Supravox.I don't tryed the drivers on other horns.
Comparing face to face,the ob's side by side that was my impression.I know the conclusion maybe was too early and probabily have some phase problems but I couldn't make them sound coherent.

Have a nice night between the 2008-2009. :thumb:
Title: Re: DIY Emerald Physics CS2 Clones
Post by: BrassEar on 8 Jan 2009, 10:49 pm
Yesterday I crossed the alphas at 1kHz with 24db active XO while keeping the notch (it's not steep enough to get rid of the peak). It sounds much cleaner than running it full range.

After damping the Alpha baskets and the rear of the DDS WGs with FATMAT, I am now using a borrowed Behringer CX3400 but with a twist. Low passing the Alphas at 930 Hz, LR 4th order with a gap until I roll in the DE250/WG around 1.2K Hz. This cleans up the mids and the Alpha in general and I don't really hear the dip. I would need a larger WG to take this combo down to 930 or so to match the Alpha. The reason for the CX3400 is that it includes a CD horn EQ switch that boosts the 4KHz and up range for typical horn response. I like it.  I am using multiple small subs so I don't need to EQ the Alphas ala Emerald Physics.

Going from passive to active xover is a tradeoff in texture. I wish I could just throw a switch and go from active to passive as they both have their merits.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: gainphile2 on 9 Jan 2009, 04:01 am
BrassEar,

Why not using the DCX2496? They can equalize the horn as well can't they?
Title: Re: DIY Emerald Physics CS2 Clones
Post by: BrassEar on 9 Jan 2009, 05:46 pm
Why not using the DCX2496? They can equalize the horn as well can't they?

I still have it but I could never get rid of some noise problems with the unit. Maybe I need to research how to properly set the gains. I think I will eventually give up on passive as you do need a certain amount of eq for these drivers.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: zapper7 on 14 Feb 2009, 04:32 pm
Brassear,
On the foam plug, I take the foam and layer it (like a laminate glu-lam beam) from 1/2 inch away from the throat of the WG to how far from the mouth of the WG?
I try to shape it wexactly like the WG, and use a small amount of spray adhesive to secure it to the WG when finished, right?
I assume you should not compress the foam by pressing it into the WG, right?
Sorry for all the questions, but I agree with you on the hardness or shoutiness of the speaker.
Thanks   Z
Title: Re: DIY Emerald Physics CS2 Clones
Post by: Victor on 15 Feb 2009, 08:21 am
I am getting verry happy with the results of the CS 2 clone using this setup
http://freerider.dyndns.org/anlage/LeCleach.htm.
The crossover for the Alpha's is lowered and the corssover for the DT 220/waveguide is higher.
Using it with the DCX 2496 is very simple and easy to compare to the original 48 db settings
No noise problems for me, using just a potentiometer after the output of the DCX.
 
Title: Re: DIY Emerald Physics CS2 Clones
Post by: dmiller on 15 Mar 2009, 12:19 am
Why not using the DCX2496? They can equalize the horn as well can't they?

I still have it but I could never get rid of some noise problems with the unit. Maybe I need to research how to properly set the gains. I think I will eventually give up on passive as you do need a certain amount of eq for these drivers.

Generally noise comes from running the input too low. Gain should be 0 and level should be as high as possible without clipping. The DCX only works really well with volume being done after the digital stage. In a pro setup volume wouldn't be controlled before the unit.

How are the clone projects going? I'm about to start a cs2 clone test with horns I have that can be crossed at 800hz.  I'm thinking about 12" woofers with boxed subs crossed at 50hz. Any suggestions?
Title: Re: DIY Emerald Physics CS2 Clones
Post by: Ric Schultz on 11 Jun 2009, 09:33 am
I have added a page on my website discussing mods and or building your own Emerald Physics 2 type of speaker with more info to come.  I have done almost everything discussed there so speak with direct knowledge.  Very cool, very cheap for what you get.  http://www.tweakaudio.com/EVS-2/Modding_the_Emerald_Physics_spe.html  Have fun.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: scorpion on 21 Jul 2009, 05:06 pm
Thank's a lot Ric for your write up. Extremly useful. Hope that you can manage photos soon. I'm in the process to test this setup as a follow up to my MJAO baffles. (Perhaps a bit contrary to jkelly).  However it is awfully expensive, if you don't live in some 'right' contry in, Europe to get parts from Parts-Express, however small their weight so I have to live with the brass threaded part of the Dayton horns. Though I had a success of getting cheap Vifa D27TGs and also B&C 250s. I also think I have located a supplier of 30 PPI foam to test with the waveguide (aquarium supplier, everything should be tested). With regard to your suggestions I find no other difficulty as I alreday have the DCX2496. You don't expliciltly mention but in the back of the Alpha15s there is a large metal surface round the spider that also has to covered by felt.

/Erling
Title: Re: DIY Emerald Physics CS2 Clones
Post by: Ric Schultz on 21 Jul 2009, 05:50 pm
Erling,
Funny, was just going to post in your thread.  What I wanted to add is that it is seriously important to time align the drivers.  In your MJAO speaker all the drive units are mounted on the front of the baffle.  This will result in the treble hitting your ears first, then the midrange and finally the woof....not good.  Usually the best sound is for the higher frequency driver to be slightly behind lining up their voice coils.....anotherwords....first line up the voice coils and then move the mid or tweeter back a little more.  You could make a test pair of baffles with a shelf on top of the woofs and also mount the midrange and tweeter on their own baffles (felted, of course) and then space them back on top till you get it right...it is obvious....Using naturally recorded music in space that is full range it will be super easy to hear when the midrange is right to the woof and when the tweet is right on too.  Then you can make your finished baffles with the midrange mounted from the rear through a large waveguide and also do the same with the tweet.  You would want to felt around the mid and high drivers as well.  You could also use very small baffles for the mid and highs since they are not doing anything below 300hz anyway.  The sound will be much improved and if you try this then you can tell us what the set back distances are.  I think your basic speaker is incredible and will be talking about it on my website as I think it may be the best bang for the buck in an open baffle single amp speaker. 

I will have some photos later this week from someone who just built the CS2 clones with the Vifa and just felted the whole inside of the waveguide with good effect.

The parts express waveguides are cheap.....you really need to cut off the threaded part or you are really never going to get good sound. 

One of my buddies thought that felting too much on the inside of the struts, etc. of the woofers actually closed down the sound too much.  I am sure this is a system thing.  Yes, I would felt all I could and then remove some, if necessary.

I will try to add the pics this week.  I will then add info about your speaker, my own box speaker and using the VMPS midrange planar panel.  My own box speaker is a $45 woof with no xover and the Vifa with just a cap and resistor on its own baffle on top of the speaker and time aligned, felted, damped and hardwired.  Overall better than my highly modified Gallo 3.1s that I used to have. Can be built for $300.....a super monitor!

Enjoy,
Ric
Title: Re: DIY Emerald Physics CS2 Clones
Post by: Telstar on 21 Jul 2009, 09:50 pm
Very nice ideas, Ric. I'm looking for the pictures, cuz English is not my first language and some technical names are hard to understand for me.

Feel free to provide "felting advice" to my Hempatics build if you wish :)
Title: Re: DIY Emerald Physics CS2 Clones
Post by: scorpion on 21 Jul 2009, 10:03 pm
Ric,

Before going into too much discussion. Is this a thing incorporated into the DCX programme of EP CS2 and earlier models ?

/Erling
Title: Re: DIY Emerald Physics CS2 Clones
Post by: JDUBS on 21 Jul 2009, 11:47 pm
I will then add info about your speaker, my own box speaker and using the VMPS midrange planar panel.  My own box speaker is a $45 woof with no xover and the Vifa with just a cap and resistor on its own baffle on top of the speaker and time aligned, felted, damped and hardwired.  Overall better than my highly modified Gallo 3.1s that I used to have. Can be built for $300.....a super monitor!

Enjoy,
Ric

Ric, would really love to hear more details about your monitor!!  Probably best for a separate thread, but sounds very interesting.

Thanks.
Jim
Title: Re: DIY Emerald Physics CS2 Clones
Post by: scorpion on 22 Jul 2009, 01:30 pm
Ric,

It's sinking in. I will be honored and flattered if you present the MJAO baffle on your web. I suppose you have had the opportunity to hear it somehow.
It's good and not very expensive to build but to judge it betweeen a lot of good OBs is not easy and I certainly appreciate your comments.

Regarding time alignment, interest are now focussing on these smaller points of design in strive for perfection. Rudolf has some interesting threads here with both physical placement of drivers as well as measurments to seek best placement of mid/top baffles in relation to an H-baffle.

It is of course not a MJAO poblem it is a problem that is shared by 99 % of all loudspeakers. But your thoughts and findings make me curious to test.
In fact I already have been thinking in this direction by separating bass and mid/top baffles. Using the Alphas as a base for experiment with various drivers, I have to improve my woodworking but I certainly like the outline you present. And if effects are as pronounced as your argument, it will be an interesting journey and a point of no return.

Thank you for the inspiration !  :)

/Erling
Title: Re: DIY Emerald Physics CS2 Clones
Post by: Ric Schultz on 22 Jul 2009, 11:34 pm
I have added some preliminary pics of a friends clones on my site.  I will try to get him to take some closeups of the tweeter to waveguide mounting and also the felting on the waveguide.  He is using the basic program for the CS2 but he has not redone the eq for this tweet nor time aligned it.  Xover is 48db per octave at 1K.  He is going to have me mod his Behringer and after that, with the eq and time aligning just right, should be in super heaven.  Already, he feels he has the best speaker he has ever had.  He is using Bel Canto Ref 1000s on the bottom and will be getting a Pass F5 clone for the top (currently using a receiver on top).

Today Friday 7-24 I added some more info on baffles, 3 and 4 way possibilities and a crude drawing for a super brace to the website.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: Victor on 8 Sep 2009, 10:00 pm
I started all over again, with the Alpha 15's and the DT220 + waveguides. Just like the original CS2.

Using the DCX 2296 48db xover at 1k.

With True RTA I first equalized the tweeter. Without eq  they are not flat from 1k; they are rising steep from 1 k to 1k6 and are rather uneven further up their range.

I put my mike at 1 meter in front of the waveguide and eq them as flat as could be done form 1 k to 20k. 

Then I eqd the Alpha's., there where peaks/problems at 420 and 840 hz and 1680 hz.

Then I measured them combined and adjusted the level.

I  delayed the tweeter 5 centimeter.

When this was done I eq'd the complete speaker with True RTA

Finally I fine eq'd them by listening to all sorts of music.

The results are amazing. This is really a great speaker, big sounding, very detailed, involving, dynamic, etc.

It takes a lot of time but it's worth the effort.

System used for the test: Logitech Transporter, Behringer SRC 2496, DEQ2496, DCX 2496, Europower 2500 for the Alpha's and Dared MP5 for the tweeters.

Currently I am just testing the system in a room of 40 sqm, bur I will try the speakers in my much larger livingroom of 1200 sqm next week. Then I will also add my concrete subwoofers , with Kilomax 18's  that are integrated in the floor of my living room, below 50 hz.


Title: Re: DIY Emerald Physics CS2 Clones
Post by: guest4954 on 9 Sep 2009, 10:15 pm
Without offence or jealousy:
What kind of living room do you have?: ...in my much larger livingroom of 1200 sqm...

Michiel
Title: Re: DIY Emerald Physics CS2 Clones
Post by: Russell Dawkins on 9 Sep 2009, 10:21 pm
yes! If I'm not mistaken, 1200 sq m is 10,800 sq ft. That would be a small aircraft hangar!
Title: Re: DIY Emerald Physics CS2 Clones
Post by: Victor on 10 Sep 2009, 04:35 pm
oops. it's not a hanger I meant 120 sqm ofcourse.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: scorpion on 16 Sep 2009, 08:18 pm
I have to report some findings about this EP cloning.

I have been challanged by Ric Schultz to time align my MJAO passive 3-way OB, see: earlier in this thread. I will come back to this soon after my vacation about the 25th October.
In the mean time I have been experimenting with my 2 Alphas and the Vifa D27TG35-06 going active with DCX2496. I received two Vifas after a long wait and recognized that they could be put in my MS-100CHQ cut outs in the MJAO baffle. I also performed the tweak suggested by Ric and cut off the back of the Vifa's dual chamber.

Well, what to say. This speaker as now presented 2 Alphas and the Vifa D27TG35-06 crossed at 950 Hz active is so far the best OB I have experienced.
The Alphas bass/middle may be a bit too dark in direct comparison, with for instance the MJAO, but still very good and certainly benefitting from the active drive. On the whole they put out a performance second to very few in direct comparison. And I have a hint how to perhaps overcome this weakness of a bit darkness. The Vifa however is extremely good. You can't really imagine how precise and detailed this tweeter presents itself, it is amazing. The whole speaker benifits from this and altogether you get a sound and image quite superb. The active driving of course is really responsible for this. You may be astonished how little energy really is transmitted by the tweeter at 950 Hz and above and how big an impact it really does when active. No EQ was applied to the tweeter. My concern now, will the waveguide really 'improve' the Vifas ? No other of the proposed bass tweaks were performed. The link to Ric's 'Modding' page is: http://www.tweakaudio.com/EVS-2/Modding_the_Emerald_Physics_spe.html .

There are some pictures accompaning these statements: First the baffle with the Vifas put in place:

(http://www.audiocircle.com/image.php?id=22072)

then the tweaked Vifa tweeter:

(http://www.audiocircle.com/image.php?id=22073)

and last a measurement of the tweeter frequency response at 50 cm in front and in back, the higer output is from the front, 1 KHz crossover, 10 dB division:

(http://www.audiocircle.com/image.php?id=22071)

/Erling


Title: Re: DIY Emerald Physics CS2 Clones
Post by: scorpion on 19 Sep 2009, 10:57 pm
Commenting a bit more about this setup.  I use two Behringer units. First every signal is AD-ed and/or if digital from the beginning, upsampled to 96 kHz 24 bit in a SRC2496 before entering the DCX2496. These units fit as hand in glove. The SRC2496 is an AD/DA and also upsampling device very much underrated I think. What's eventually going on in the DCX is certainly benefitting from this pre procedure.

For the DCX2496 I have mounted 3 bass filters, one BP at 60 Hz at + 2 dB with a Q of 2.0 and a similar BP at 132 Hz + 2 dB and 2.0 Q and last a BP filter at 368 with - 4 dB and a Q-value of 4. This is all the filters I have mounted and they should be more or less optimal in my room. No tweeter filter. The crossover between the Alphas and the Vifa27 is at 937 Hz LR 48 dB/oct. I tried to listen to music at very high volume to establish this. There are differing specifications now for the Vifa unit if you compare what is written on the Tympany site or what is published for the units presumably produced in Denmark before the transfer to Chinese production. I have however applied the suggested Zobel of 7.0 ohm + 1 mH + 69 uF over the Vifas, to what help I do not really know.

The Alphas are a tiny bit on the dark side so I don't think that felt on the inside of the chassis is really called for. Damping the outside might still be a good idea. The Vifas might very well be as near perfection as you can come, at least for the price, when tweaked for dipole performance as suggested by Ric Schultz. The forward/backward power relationship is perfect.

I have done extensive listening to two records that I am very familiar of their recording venues. The first is the famous Audiophile record 'Jazz at the Pawnshop 1' recorded in the Stockholm club named Stampen. I often visited that place in the 70'ies so I have a good knowledge of the sound and atmosphere. These speakers put out noting but the real thing. Quite amazing. The other record is the BIS SACD presentation of Norrköping Symphony Orchestra and Ronald Brautigam playing Beethoven Piano Concertos, in this case No 1 & 3, from the Louis De Geer Concert Hall in Norrköping. This hall is now 15 years old and I have visited it during all the seasons about twice a month for concerts so I know a bit how it sounds. And also this record, however multi-miced evidently, does give you an impression of how it would sound as a regular concert performance. In all very enthralling, indeed.

/Erling
Title: Re: DIY Emerald Physics CS2 Clones
Post by: Russell Dawkins on 20 Sep 2009, 07:21 am
A good tip about the SRC2496, Scorpion. That's the second time I have heard this said, so now it is time to try to find one, used of course.

Thanks for this and also for the large number of information-rich posts you have made over the years.
Is your DCX2496 stock?
Title: Re: DIY Emerald Physics CS2 Clones
Post by: scorpion on 20 Sep 2009, 10:12 pm
Both units are stock as of now. But I have three AK4396s lying around and I will do Scott Endler's proposed output mod when I can find someone able to put these tiny things in place for me and then complete with a 6-channel volume control. I think that the stockversion is quite adequate, but exchanging with newer chips and bypassing a lot of output-electronics is probably a good idea. I bought the two units at the same time and have run them like this all the time.

By the way the somewhat obcessed Lukasz Fikus has gone crazy about the SRC on his Lampizator web: http://www.lampizator.eu/LAMPIZATOR/TRANSPORT/behringer/Behringer.html .  :)

/Erling
Title: Re: DIY Emerald Physics CS2 Clones
Post by: jkelly on 23 Sep 2009, 07:39 pm
Erling,

Can you describe the process you used to cut off the back of the tweeter?
How far back from the end did you cut?  What tool did you use to cut?

Thanks,

Jeff
Title: Re: DIY Emerald Physics CS2 Clones
Post by: jkelly on 24 Sep 2009, 11:39 am
Erling,

How does the Vifa sound with just one Alpha 15"?
I may try replacing the B200 / single Alpha 15" system with the Vifa and active crossing it at 950.

Jeff
Title: Re: DIY Emerald Physics CS2 Clones
Post by: scorpion on 25 Sep 2009, 09:19 pm
Jeff,

I used a hacksaw to cut off the last millimeters from the plastic back.

From the comparison with the MJAO I am actually thinking of introducing my B200 in this setup moving the Vifa crossing up a bit and really go active.

/Erling

Title: Re: DIY Emerald Physics CS2 Clones
Post by: benzene on 26 Sep 2009, 09:30 am
Erling:
Sorry to cut into this thread. I realized that you're real good  :thumb: at those technical stuff , eg. frequency graph measurement & etc. I would like to ask you if i only have the DCX2496, and i wanna try out the auto align for time delay setting, which type of microphone is better? Is the auto align setting in DCX2496 reliable?
I'm currently trying to get the sound right on my OB.
And how do we determine whether what EQ we need to apply in the DCX2496 to make the sound right?
I'm sorry if this seems like some stupid questions, as i just started into this hobby for a year & still learning without any electronic background knowledge.  :oops:
Thanks in advance.
Title: Re: DIY Emerald Physics CS2 Clones
Post by: scorpion on 1 Oct 2009, 03:40 pm
Sorry Benzene,

I am far away from home on vacation, therefore no answer.
With dipoles you cannot time-align but with physical placement of speakers. No digital alignment will do any good.

To determine EQ I have used a simple homemade mic from Panasonic WA-61 module. It works very well. Measurement system is ARTA, available at the net.

/Erling
Title: Re: DIY Emerald Physics CS2 Clones
Post by: sfdoddsy on 13 Oct 2009, 09:56 am
This may help:

http://www.musicanddesign.com/Dipole-offset.html

Title: Re: DIY Emerald Physics CS2 Clones
Post by: Ric Schultz on 14 Oct 2009, 11:15 pm
I know I am repeating myself here, but here goes:

You must time align all drivers.  The Behringer can do this very simply....once your system is in pretty high tweaksville, you should be able to hear the smallest amount of time alignment distance allowed in the Behringer.....delaying it forward or backwards...it should be easy to hear.  The Vifa tweet with the back cut off is not a true dipole.  The felt blocks most sound from coming out the rear.  It does have some sound coming out the rear but nothing like what is coming out the front.  Please time align....you can do this physically or electrically but it makes a huge difference.....in all speakers.

You must felt around any driver (in any speaker) used from 1K on up.  The diffraction will smear the sound and make it brighter.  Cover everything except the actual part of the driver that moves.

You must constrain layer dampen the baffle.  A single piece of plywood or MDF is going to muddy the sound super duper.  2 15 inch drivers have all the bass and warmth you could ever want.  You don't need baffle noise.  A brace all the way up the back will help even more as well as mounting the woofs via their magnets.  Highly refined particle board is better than MDF....but still you want at least two layers with Green Glue or other damping glue in between.

You must constrain layer dampen the entire back of the Eminence drivers.....BIIIIIIIIIIIIIIIIIIIIIIIIII IIIIIG difference.  You won't believe how fast these things are when covered with EAR SD40AL (Percy sells it).

Title: Re: DIY Emerald Physics CS2 Clones
Post by: scorpion on 21 Oct 2009, 01:40 pm
Hey Ric, this was only a test setup.

But quite revealing I think. All-thogether with active EQ you can really make the Alphas very authoritative speakers. Certainly very listenable. With this combo I do find the whole sound to be a bit on the dark side even though Vifas was not treated any. Crossover at 937 Hz 48 db/oct. The back output, as shown by my measurements, is not insignificant. But I have tried DCX2496 alignment and you are right there, I can really hear when things are right.

It's a bit funny how good the Alphas sound, but when you listen carefully you would realize that a good midrange would not be out of place. What I miss is the openness a good unit can supply. So here we go !  :)

But as the speakers stand now I could almost have them for the rest of my life, so good is the illusion ! On the Dark side of the Moon ?

/Erling
Title: Re: DIY Emerald Physics CS2 Clones
Post by: scorpion on 6 Nov 2009, 06:22 pm
Hi Ric,

I will take the Alpha15 Vifa combo as pictured to a diy-show arranged by our Swedish Hi-Fi Forum in Uppsala November 14th. All in all I think it is very good but perhaps a bit on the dark side. Units match well in sensitivity wihout waveguide so the only real EQ done is 12 dB/sloped filter from 100 Hz downwards at 6 dB gain, implemented in the DCX2496. The Vifa tweeter is delayed by 20 cms, which by listening is deemed best. Measurements then show  40 - 20000 Hz +- 3dB at sweetspot in my living room. I hope I will have a lot of comments at the show. It is of course not really an EP clone with no waveguide in place.

But I now also fully understand your post earlier. I have been experimenting with the Dayton waveguide and the Vifa is quite another loudspeaker with that.
Very bright as treble is amplified but also wide spread. So damping is called for and also damping of the waveguide like you have proposed should be done. Regarding the Alphas I will damp the back surface left round the spider with felt and also damp legs with bitumen on the outside.

/Erling