Where next on my Open Baffle adventure, Advice please.

evozero · « **Reply #60 on:** 15 Mar 2010, 09:26 am »

Hi all / danny,
I have pulled the speakers away from the wall, you are right they sound much better with room to breath.
does this mean I Should remove the resistor now? What about the cap?
Cheers
ian

Rudolf · « **Reply #61 on:** 15 Mar 2010, 11:25 am »

Quote from: evozero on 15 Mar 2010, 09:26 am

does this mean I Should remove the resistor now? What about the cap?

Hi Ian,

keep the cap. It will keep low frequencies from the AN. I believe Danny would like a smaller cap to push the crossover to a higher frequency. But in that case you probably need to fiddle with the 'boost' resistor in the plate amp to balance the low frequency output of the Beta 15. Simply dialing in a new crossover frequency for the H frame won't do:

Throw out the 4.6 Ohm resistor. You will need to turn up the volume of the Beta 15 afterwards.

Did you receive the PE parts already?

Danny Richie · « **Reply #62 on:** 15 Mar 2010, 03:45 pm »

Quote

What you are probably saying is that it sounds more accurate with the 6-7 Ohm resistor 5-10 degrees off axis.

Yes, a slightly smaller resistor brought up the top end a little and towing them off axis slightly brought it back down.

Yes Ian, leave your cap on there to pull off the lows. I'd also play your favorite piece of music that is heavy in the bottom end and bring the power up to the limit of your loudness. Then keep an eye on the Super 8 and its exertion range. If it is getting beat up then you will need to go to a smaller value.

Also, please don't use an electrolytic cap for that value. Use a poly cap or two to get the value that you need and by-pass it with a small value (like a .1uF) to discharge some of that stored energy of those big cap values.

I also just posted some info in my circle on a new sub-woofer plate amp that you guys might be interested in for applications like this.

Danny Richie · « **Reply #63 on:** 15 Mar 2010, 05:57 pm »

Quote

Id sure like to see a polar plot so we can know what it sounds like.

Here you go Dan.

This was with the LR network at the front but without the two notch filters.

DanTheMan · « **Reply #64 on:** 15 Mar 2010, 06:01 pm »

Thanks Danny!

Very cool.

Dan

evozero · « **Reply #65 on:** 17 Mar 2010, 02:37 pm »

Hi all,
Just had a reply from PE on the plate amps;
"hanks for contacting us. I believe this amp uses a Linkwitz-Riley alignment. There really isn't a way to use a DMM to measure where it is being crossed over at. You would need a speaker measuring system to measure where the speaker is being cut off to be accurate."
I have also removed the resistor on the AN8, and think it does sound a little cleaner after adjusting the Beta volume up to the right level.
Still waiting on the parts to arrive, could be another week, really is luck of the draw with customs.
Cheers
Ian

evozero · « **Reply #66 on:** 31 Mar 2010, 01:17 pm »

Hi All,
Guess what? It's Christmas!
New parts have finally arrived, I have amps, inductors, caps and resistors.
Can you guys give me some guidance physically connecting the components, don't want to damage anything. Especially now my speakers have taken such a step forward.
Many thanks
Ian

Danny Richie · « **Reply #67 on:** 31 Mar 2010, 02:40 pm »

Yeah, I'll help you out. Show me what you have if you can.

evozero · « **Reply #68 on:** 31 Mar 2010, 03:45 pm »

Thanks Danny,
I am a little confused after the discussion on the AN8 cross overs.
Parts list; I have the existing 150uf caps as well as the following.

2 x 4.5Ohm resistors
2 x 8hm resistors
2 x 1.5 inductor
2 x 47uf cap

2 x 240w plate amps
Thanks a lot
Ian

Danny Richie · « **Reply #69 on:** 31 Mar 2010, 04:18 pm »

Okay, I am concerned a little bit with the quality of the caps.

We need to protect your full range driver from the low frequency ranges so it won't get beat up, but the entire signal will be passing through whatever cap you use so it needs to be of good quality.

I also always by-pass any large cap value like that with a much smaller one. My favorite has been the little .1uF Gen.2 Sonicap. In 200 VDC they are only $2.70 each so it is not a big expense, but it really helps reduce any cap related smearing.

Can you send any pics of that stuff?

evozero · « **Reply #70 on:** 3 Apr 2010, 10:22 am »

Hi Danny,

I included the .47uf Auricaps and tea light for size comparison. The 150uf currently in line with the AN8 is made by Mundorf and was very expensive.
I have also been a real idiot, i forgot to check if the plate amps run on 240v mains. I just assumed they would be switch-able, doh!
120 VAC, 60 Hz, 400 watts, is the spec listed in the manual.
Should i buy a step down converter unit or an actual transformer with two 120v secondary outputs? i can only find step down unit rated to 200watts, do these plate amps really pull 400watts?
Danny, do you sell the .1uF Gen.2 Sonicap. In 200 VDC?
Many Thanks
Ian

Danny Richie · « **Reply #71 on:** 6 Apr 2010, 02:55 am »

Okay, hook it up like this:

I didn't have the high dollar Mundorf so I used a 100uF Erse in its place so you can get the idea.

If you have some of those small Auricaps like the ones pictured then you could use them as by-pass caps hooked up like shown. This will help out the quality of the sound a lot.

Yes, I do stock the .1uF 200 VDC Sonicaps. They are only $2.70 each. I don't have them up on my site or I would be constantly filling orders for two of them. I'll do anything I can for my customers but would not like to advertise a lot of orders that will make me less than $2.00 profit for all the time and effort of packing them up and providing an invoice.

I also stock all of those other parts and/or anything else you might need.

The size of the Mundorf cap that you have (150uF) might be too large and still allow the driver to be worked too hard in the lower ranges. You'll just have to play it hard and keep an eye on it.

Does this make sense?

evozero · « **Reply #72 on:** 6 Apr 2010, 05:05 pm »

Hi Danny, can i just clarify a few things.
The 100uf you have pictured, I will use the large Dayton 47uf.
Bypass the 47uf with a small cap, i have two tiny AURICAP, .022 µF, 600V as well as the .47uf available?
Should i use the 8 or 4.5 Ohm resistors?
The 150UF Mundorf cap in series with the positive speaker connector?
Thanks very much, just ned to sort out the voltage on the plate amps now.
Cheers
Ian

Danny Richie · « **Reply #73 on:** 6 Apr 2010, 06:32 pm »

Quote

The 100uf you have pictured, I will use the large Dayton 47uf.

I'd try your Mundorf cap in this place at first and see if it blocks enough low frequency information for you.

If it does not then I'd try something along the 100uF range. You could try a pair of those Dayton 47uF caps to make a 94uF value and see how that works.

Quote

Bypass the 47uf with a small cap, i have two tiny AURICAP, .022 µF, 600V as well as the .47uf available?

Whatever value you use there, by-pass it with your small Auricap.

Quote

Should i use the 8 or 4.5 Ohm resistors?

Start with your 4.5 ohm resistor and see how it sounds. Top end too hot, go with a larger value. Top end too soft, go with a smaller value.

Viridian · « **Reply #74 on:** 7 Apr 2010, 10:11 pm »

I don't want to go OT here, but Danny, I'm very interested in what you have done there. I'll contact you on your forum.

Good luck Ian!

Erik

Quote from: Danny on 3 Mar 2010, 02:48 am

Sorry, I am a little late coming to this thread.

I have been there done that already with all of this stuff and know what you are up against. If I would have caught this thread earlier I would might have saved you some trail and error lessons. Sorry...

I also have measured and tested it big brother the Super 12 in open baffle application. So I have a good idea of what you are up against there.

First off, get your baffle size down as small as possible. The surface reflections of a wide baffle will kill your imaging and any transparency aspects of the sound stage. All will sound as if it is playing from the baffle forward.

If you need to, turn your lower woofer sideways so that it doesn't add baffle width.

Try something like this:

Also, I would highly advise against a U shaped frame. Most utilize them with no bracing at all. Then the panel size is such that they flex and resonant wildly. At least the H frame breaks the panels down to half their size. That helps a lot, but can still be a problem. Even a friend of mines Orion's allowed a LOT of low frequency coloration due to panel flexing and resonating. I used 1.25" thick side panels on the Super-V and it still needed to be lines with No Rez to kill the resonances completely and provide a solid bass response.

Another thing that I saw in this thread that was a red flag was this compensation network for the Super 8.

Do NOT use a resistor at the front of the network allowing a full range signal to pass through it. With very little power on it at all, it will burn up in smoke and flames.

evozero · « **Reply #75 on:** 14 Apr 2010, 11:53 am »

Hi Danny / All,
Sorry for the delay in progress, and I apologise if it looks rude. Extremely busy with work.
Danny, I did as you suggested and tried some very bass heavy music. The excursion was more than i expected, with a suprising amount of bass output. So i have used the 47uf with two tiny AURICAP, .022 µF, 600V bypassing.
Also used the Mills 8Ohm resistor with the Jantzen 1.5mh inductor.

As I'm not currently using any resistors, just the Mundorf Cap, do I need one back in situ, or just wire it up like my photo?
Cant wait to try the new xover, just want to check with you guys before blowing anything up.
Many Thanks
Ian

Danny Richie · « **Reply #76 on:** 14 Apr 2010, 12:44 pm »

Hook it up just like you have it wired in your photo.

If the top end is too soft then you can start reducing that resistor value a little to bring it back up.

It is going to sound a little different now if you have gotten used to it the way it was, but it will be much more accurate.

evozero · « **Reply #77 on:** 14 Apr 2010, 01:36 pm »

Thanks Danny,
Ill connect it up and report back later.
Many thanks
Ian

evozero · « **Reply #78 on:** 16 Apr 2010, 10:23 am »

Hi All / Danny,
I have the new crossover installed so a quick report is due.
It is hard to describe the change in sound, but i think the overall sound is much smoother, doesn't shout the midrange. Another change I notice is the sound stage is better defined and much easier to follow musicians, and a new addition is the stage width extending beyond the speakers.
Another great improvement.
Big thanks to Danny!
Cheers
Ian

evozero · « **Reply #79 on:** 10 Jun 2010, 09:05 am »

Hi All,
Now that these speaker have been up and running for a couple of months, I though I would report my findings.
The first and most difficult problem has been WAF, my partner really hates them being so far into the room. I have also covered them in cloth to try and soften the look.

Not perfect, but more acceptable in a domestic environment.

Another problem i have encountered is humming when using the plate amps. I have tried many ways to lower the hum levels, some have been effective, but not enough to remain in my system. Maybe it is just a compatibility issue with my SET valve amp.
So its back to the Sony amp powering the Eminence Beta 15's.

So I have a question for the forum. Rudolf mentioned the low pass should be tuned to 110 Hz to suit the Beta 15's and i am currently using passive 8 Ohms subwoofer filters Crossover frequency 120Hz,12dB/oct. ( 1 inductor & 1 cap).

Can you suggest passive components better suited,making a correct type and value filter?
Over all I am extremely happy with these speakers, just want to get the final bit of tweaking done.
Thanks
Ian