Speaker with 25hz +-3db

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marrduk24

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Speaker with 25hz +-3db
« on: 5 Sep 2018, 06:02 am »
Rick

Recently got to listen to PMC MB2. Probably one of my fav auditions so far. Heft in the bass even at low volume, really sweet & clean mid range and very air & smooth High notes (I am particularly sensitivity to even tad bit hot high notes ). However these speakers would never meet WAF :)

I was going though old threads on your forum and came across this thread from you

“ I have a specific set of drivers that would be excellent in a 38"-40" high cabinet (plus about 2"-3" for a base w/spikes), 10.5" wide, and 11"-13" deep. Bass extension would be -3db / 35hz passive or down to 20-25hz with active equalization. Dual 8" woofers, 7" midbass, 2" Accuton dome mid, a new ribbon tweeter for $7,000/pair shipped to the CUSA. Includes a 4-way passive crossover or a Mini-DSP 4x10HD for fully active operation. A hybrid is also possible with Hypex or MiniDSP plate amps.”

Keen to get your view on

1. Going with something like Tempesta and getting a pair of High quality subs vs a speaker like the one you described above.

2.  Given Scanspeak has released a 11” driver (28W), would you rather do a hybrid 3 way (28W + 18M + SS Be). What would f3 of that be in a 40”x12”x16” cabinet?

« Last Edit: 5 Sep 2018, 12:41 pm by marrduk24 »

c_note

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Re: Speaker with 25hz +-3db
« Reply #1 on: 5 Sep 2018, 02:39 pm »
The Scan-speak 11' driver looks fantastic.  An option you may want to consider would be a closed box, active application with a little bass boost in the 40 hz region.  In a very compact box--say, one-and-a-half cubic feet--you could get an F3 probably in the mid 30's and an F6 probably in the high 20s. 

I personally think closed box systems have better pitch definition than ported speakers, and the small enclosure size would be a huge plus.  Google "Selah Audio Galena" as a possible enclosure option.

Re: midrange drivers, the Morel TSCM634 is spectacular--as good as it gets, in my opinion.  I suspect the Satori MR16PNW would offer 95% of the performance at a substantially lower price point, however.  Both would be fantastic options.  Pair with a great beryllium tweeter and you would have a world-class speaker that could compete with anything out there for under $15K.

Good luck in your speaker journey!

marrduk24

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Re: Speaker with 25hz +-3db
« Reply #2 on: 5 Sep 2018, 08:28 pm »
I am not at all an expert in this but I get F3 of 27 hz in a Portrd box. Dimensions of 40”x12”x15” and internal volume (excluding port, midrange enclosure and driver displacement ) of 60 litres. I am guessing that’s just based on passive design.



Rick Craig

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Re: Speaker with 25hz +-3db
« Reply #3 on: 6 Sep 2018, 09:21 pm »
I am not at all an expert in this but I get F3 of 27 hz in a Portrd box. Dimensions of 40”x12”x15” and internal volume (excluding port, midrange enclosure and driver displacement ) of 60 litres. I am guessing that’s just based on passive design.

I'm a little confused - I read on another forum where you already had chosen someone to build your speakers? Was that me?

marrduk24

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Re: Speaker with 25hz +-3db
« Reply #4 on: 7 Sep 2018, 12:19 am »
That great designer will be you :)

Rick I am at this stage still considering various options - buy used gear, an off the shelf design by you or Jim or custom with you.

I didn’t want the trolls on the form distract the conversation with comments around how as a newbie I have no idea and hence DIY is not for me (which it is not). That’s why I just said assume I am going to be working with someone master at this art without naming anyone.

Rick Craig

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Re: Speaker with 25hz +-3db
« Reply #5 on: 7 Sep 2018, 08:12 pm »
That great designer will be you :)

Rick I am at this stage still considering various options - buy used gear, an off the shelf design by you or Jim or custom with you.

I didn’t want the trolls on the form distract the conversation with comments around how as a newbie I have no idea and hence DIY is not for me (which it is not). That’s why I just said assume I am going to be working with someone master at this art without naming anyone.

Thanks for the clarification. I take it that you like the bass from the PMC  over anything else so far?

marrduk24

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Re: Speaker with 25hz +-3db
« Reply #6 on: 7 Sep 2018, 08:42 pm »
Do you mean PMC MB1? PMC Twenty5.26 was ok but I did like MB1 a lot.

It wasn’t just the bass. I liked the whole package in a way I haven’t for 6-7 other speakers I have auditioned - it had heft in bass at low volume, really sweet mid-range (but still had very clean seperation) and airy highs. Through all the auditions I have realised my head gets very irritated if the highs notes are even tiny bit hot. I have also seen I am attracted to speakers that have very clean sound where you can clearly separate each instrument.

Other speakers I have auditioned include PMC Twenty5.26, Dynaudio Contour 60, Paradigm Persona 3F, KEF Refernece 5, Focal Sopra 2, B&W 802, Sonus Faber Amati.

Rick Craig

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Re: Speaker with 25hz +-3db
« Reply #7 on: 7 Sep 2018, 09:04 pm »
Do you mean PMC MB1? PMC Twenty5.26 was ok but I did like MB1 a lot.

It wasn’t just the bass. I liked the whole package in a way I haven’t for 6-7 other speakers I have auditioned - it had heft in bass at low volume, really sweet mid-range (but still had very clean seperation) and airy highs. Through all the auditions I have realised my head gets very irritated if the highs notes are even tiny bit hot. I have also seen I am attracted to speakers that have very clean sound where you can clearly separate each instrument.

Other speakers I have auditioned include PMC Twenty5.26, Dynaudio Contour 60, Paradigm Persona 3F, KEF Refernece 5, Focal Sopra 2, B&W 802, Sonus Faber Amati.

Thanks for the info. I checked on that particular design and it wouldn't meet your criteria of -3dB @25hz. Not to say it wouldn't have decent bass extension but it would certainly fall short of that spec.

marrduk24

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Re: Speaker with 25hz +-3db
« Reply #8 on: 8 Sep 2018, 03:47 am »
Rick

Can’t seem to find the F3 of MB2.

Anyway I also looked at specs for Dynaudio C4, another speaker I have liked (say 7.5/10) and that has F3 < 30hz too.

So going back to original options, keen to get your view on


1. Going with something like Tempesta and getting a pair of High quality subs vs a speaker that goes to Under 30hz

2.  If full range speaker, I want height to be under 45 and width within 12”. Keen to get your view on hybrid vs fully passive and what could each design look like.

Separately I am also hoping to try Rockport Atria in the next month or so.  Here is what I have tried so far:

1. Paradigm 3F : it did not feel very clean. Plus my hearing is really sensitive to high notes and I feel I can’t tolerate any level of brightness.
2. KEF Reference 5: there was nothing obvious missing but somehow it didn’t feel like I got the three elements I was looking for: heft in the bass at low volume, clean & sweet mids and airy top notes
3. PMC Twenty5.26 and Contour 60 - there wasn’t a clear winner. I preferred bass of Contour but midrange of PMC. Didn’t love High notes of any of these two
4. Focal Sopra 2 and B&W 802 D3: Focal felt tight and precise. However lacked the soundstage of B&W. B&W had great wide soundstage. However didn’t quite have the separation of Focal. I also found focal to be a bit boomy, but that could just be the room.

Rick Craig

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Re: Speaker with 25hz +-3db
« Reply #9 on: 8 Sep 2018, 02:02 pm »
Rick

Can’t seem to find the F3 of MB2.

Anyway I also looked at specs for Dynaudio C4, another speaker I have liked (say 7.5/10) and that has F3 < 30hz too.

So going back to original options, keen to get your view on


1. Going with something like Tempesta and getting a pair of High quality subs vs a speaker that goes to Under 30hz

2.  If full range speaker, I want height to be under 45 and width within 12”. Keen to get your view on hybrid vs fully passive and what could each design look like.

Separately I am also hoping to try Rockport Atria in the next month or so.  Here is what I have tried so far:

1. Paradigm 3F : it did not feel very clean. Plus my hearing is really sensitive to high notes and I feel I can’t tolerate any level of brightness.
2. KEF Reference 5: there was nothing obvious missing but somehow it didn’t feel like I got the three elements I was looking for: heft in the bass at low volume, clean & sweet mids and airy top notes
3. PMC Twenty5.26 and Contour 60 - there wasn’t a clear winner. I preferred bass of Contour but midrange of PMC. Didn’t love High notes of any of these two
4. Focal Sopra 2 and B&W 802 D3: Focal felt tight and precise. However lacked the soundstage of B&W. B&W had great wide soundstage. However didn’t quite have the separation of Focal. I also found focal to be a bit boomy, but that could just be the room.

It makes it difficult to make a good comparison when there's not much evidence of the measured performance. I'm kind of shocked that PMC only listed a frequency range with no +/- dB let alone response graphs. Being that they market heavily to the recording industry it's surprising. I can pretty much look at quoted specs and tell you if they are fairly accurate, especially if I know the drivers involved.

-3dB @25hz (a true 25hz, not with room gain added in for advertising) is really tough to achieve in a fully passive speaker without a larger woofer and big cabinet. It's possible with an 8" driver but the sensitivity will be very low with a moderate cabinet size. If the woofer is designed for a smaller cabinet then the moving mass of the cone and other parts really makes it difficult to drive. The bass may go deep but the control / definition isn't very good.

Moving up to a 9.5" (like the Satori W024) improves the sensitivity but it takes a fairly large cabinet to have a box tuning without peaking. This is bettered by the Scan-Speak 11" (more excursion and surface area) but again with a fairly large cabinet. The Scan-Speak has more limited upper end response than the Satori so the choice of midrange is more important; however, there is a good group of mids that will work fine with the woofer. If your target is 25hz the larger woofer with more excursion always wins in a passive speaker.

So,yes, the passive 3-way can be done as long as you're tolerant of a bigger cabinet. The alternative is using an active bass section which allows more flexibility - sealed box, smaller cabinet, wider choice of drivers, etc.  The DSP amps also give you the ability to do room correction/EQ which is a huge factor. No matter how good a passive design is I have witnessed many times over a listening room wreaking havoc on the bass with large peaks. If you don't have any EQ correction available in your front end equipment then a speaker with active DSP is your best solution.

The Tempesta with outboard subs or integrated into a single cabinet is an excellent choice. The Epico could be done the same way as well. The floorstanding option would be within the dimensions you need.

mresseguie

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Re: Speaker with 25hz +-3db
« Reply #10 on: 8 Sep 2018, 04:00 pm »
It makes it difficult to make a good comparison when there's not much evidence of the measured performance. I'm kind of shocked that PMC only listed a frequency range with no +/- dB let alone response graphs. Being that they market heavily to the recording industry it's surprising. I can pretty much look at quoted specs and tell you if they are fairly accurate, especially if I know the drivers involved.

-3dB @25hz (a true 25hz, not with room gain added in for advertising) is really tough to achieve in a fully passive speaker without a larger woofer and big cabinet. It's possible with an 8" driver but the sensitivity will be very low with a moderate cabinet size. If the woofer is designed for a smaller cabinet then the moving mass of the cone and other parts really makes it difficult to drive. The bass may go deep but the control / definition isn't very good.

Moving up to a 9.5" (like the Satori W024) improves the sensitivity but it takes a fairly large cabinet to have a box tuning without peaking. This is bettered by the Scan-Speak 11" (more excursion and surface area) but again with a fairly large cabinet. The Scan-Speak has more limited upper end response than the Satori so the choice of midrange is more important; however, there is a good group of mids that will work fine with the woofer. If your target is 25hz the larger woofer with more excursion always wins in a passive speaker.

So,yes, the passive 3-way can be done as long as you're tolerant of a bigger cabinet. The alternative is using an active bass section which allows more flexibility - sealed box, smaller cabinet, wider choice of drivers, etc.  The DSP amps also give you the ability to do room correction/EQ which is a huge factor. No matter how good a passive design is I have witnessed many times over a listening room wreaking havoc on the bass with large peaks. If you don't have any EQ correction available in your front end equipment then a speaker with active DSP is your best solution.

The Tempesta with outboard subs or integrated into a single cabinet is an excellent choice. The Epico could be done the same way as well. The floorstanding option would be within the dimensions you need.

I don't mean to interrupt, but this is great and very helpful (to me) information, Rick. Thank you!

Michael

marrduk24

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Re: Speaker with 25hz +-3db
« Reply #11 on: 8 Sep 2018, 10:09 pm »
Rick, Very helpful.

I came up with 25hz largely based on two designs I have been eyeing :)

http://www.josephaudio.com/p3specs


http://rockporttechnologies.com/atria-ii/

Though I have to admit I don’t really have full appreciate for these technical specs. eg I auditioned Focal Sopra 2 (f3 of 34hz) and B&W 802 (f3 of 17) and I found Sopra to have plenty of base and didn’t feel it was lacking in that department compared to B&W.

Anyway thanks a lot for your thoughtful reply Rick. I feel like there is a real risk of me getting it wrong if I start specifying the technical design goals, because I frankly don’t know that much. So if I do custom, it’s probably best that I just specify the sound I like and WAF and let you convert that to a technical design :)


Tyson

Re: Speaker with 25hz +-3db
« Reply #12 on: 8 Sep 2018, 10:50 pm »
I've had some crazy powerful over the top deep bass setups, and IME you really don't need any bass below about 30hz.  I've had subs that would go to 15hz at 100db and really, everything from 15hz to 30hz just makes you feel like you are under water and messes with your inner ear.  A speaker that's capable of true 30hz extension (hits it with power) is all you'll ever need, for music.  Movies, that's another matter ;)

marrduk24

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Re: Speaker with 25hz +-3db
« Reply #13 on: 8 Sep 2018, 11:23 pm »
Thanks Tyson. I am sure even above 30 Many other characteristics matter a lot more than F3 point.

Tyson

Re: Speaker with 25hz +-3db
« Reply #14 on: 9 Sep 2018, 01:15 am »
Thanks Tyson. I am sure even above 30 Many other characteristics matter a lot more than F3 point.

Oh yes.  Rick's mentioned active bass a couple of times - I'd take that suggestion seriously.  One thing people don't think about is the speaker/amplifier match.  A passive 3 way speaker needs a much more serious and powerful amp than a speaker that has an active bass section.  If your "main" amp only has to drive the mids/highs, you don't need a muscle amp and can spend your $$ on a more refined main amp. 

Rocket_Ronny

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Re: Speaker with 25hz +-3db
« Reply #15 on: 9 Sep 2018, 02:30 am »
PMCs are great sounding and imaging speakers. One of the reasons they can charge their lofty prices for simple 2 way speakers, not to mention the 3 ways like you heard. What was the price of them?

I was speaking to a salesman who sold PMC and he felt while they are great the SA Pandion 2 demo pair they had he much preferred. Now that is sky high priced speaker for what it is and would not have bought it if not discounted. BUT... that little bugger uses special scanspeak drivers - I love scanpeaks, a true favorite - and that long throw woofer packs a punch and you would think they almost have sub woofers. They have great WAF given they are so small and don't look like anything.

I too am a fan of active sub sections in speakers. Offers world's of flexibility.

Rocket Ronny

marrduk24

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Re: Speaker with 25hz +-3db
« Reply #16 on: 9 Sep 2018, 11:08 am »
PMC was about $19000. Used about $12k.

I have yet auditioned Rockport Atria but I think that’s about $22k and used $12k.

Can you guys point me to any hybrid/ active designs by one of the well known manufacturers (Wilson, Vandersteen, Magico, Rockport etc)? Just want to get some inspiration.

Letitroll98

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Re: Speaker with 25hz +-3db
« Reply #17 on: 9 Sep 2018, 11:48 am »
I have a suggestion, but I don't think it's proper to suggest other designers on the Selah circle.

steve1580

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Re: Speaker with 25hz +-3db
« Reply #18 on: 9 Sep 2018, 04:33 pm »
Yeah,  wouldn't that be like going to a restaurant and ordering delivery?

Tyson

Re: Speaker with 25hz +-3db
« Reply #19 on: 9 Sep 2018, 09:57 pm »
PMC was about $19000. Used about $12k.

I have yet auditioned Rockport Atria but I think that’s about $22k and used $12k.

Can you guys point me to any hybrid/ active designs by one of the well known manufacturers (Wilson, Vandersteen, Magico, Rockport etc)? Just want to get some inspiration.

They generally don't offer active options.  I think that's for 2 reasons.  First, most of the customers of those speakers really want an over-the-top amplifier anyway, so there's no need to offer a bass-active solution.  Second, if you're a major speaker company, the last thing you want to do is give audiophiles knobs, buttons, or switches of any kind on a speaker.  Most will screw it up and you'll end up spending a lot of time/effort after the sale trying to educate your customers and fix their mistakes. 

Notice I didn't cite "sound quality" as a reason.  That's because IME it's easier to obtain better sound quality and in-room performance with an active bass section.  But as an end user, you have to be comfortable with taking in-room RTA measurements in order to dial in the bass properly. 

Which is why people like Rick are so great - if you (the end user) are willing to spend some time learning how to dial in an active bass speaker, then he's more than willing and able to build one for you.  Or if you want a more traditional passive design, he's exceptionally skilled at those too.  I've heard his speakers many times at RMAF and believe me, his speakers equal (or better) anything that the larger companies put out.