To summarise what might be a longish post, I'm looking for a collaborator to design a pair of large format, wide-bandwidth studio monitors. As this is arguably not a pure 'DIY'/non-profit endeavour, professional/monetary considerations will be worked out before any input is sought.
I have introduced myself and what I'm about to say a few times before, but here I go again.
I run a music studio (with my partner at work), and I build audio studios for a living. My listening rooms rooms are very highly damped - known as 'non environment' or 'hemi-anechoic' rooms. There is little to no 'room gain'. An 8" studio monitor just about manages to do the job, but for any serious visceral impact/scale, a large format pair of speakers is a must. There are no large format monitors available at under $15K or so, and the expense increases significantly by the time it gets here to India.
So, I have been building large format speakers for some of my rooms - I have built 'Econowaves', 'Pi Speakers' and 'SEOS' based speakers from designs proven in the DIY world. For some of these designs, I have bought drivers and parts from abroad (Including an AE TD15H which my cat just destroyed and a pair of Exodus/Anarchy subs, the servicing of which is going to be a PITA).
Servicing and spares when I buy gear from abroad is a nightmare. And ant any time, your consignment may be held up at customs indefinitely, and you might be charged an arbitrary fee to get your stuff cleared.
As it happens, there are a number of 'Pro Audio' speaker companies represented in India. Eminence, B&C and Beyma I have used a few times before, I believe Faital Pro, BMS and a few others are also here... strangely, their pricing is competitive with USA/European pricing - possibly because of reduced customs levies on "spare parts", when imported by the distributors here who have an organized system of dealing in larger quantities. These guys have warranties, spares, repair centres etc., so working with what is available locally is a much more viable option.
Even though I am proud of the speakers I've built as they are working hard everyday in a few studios, I know that they all have serious flaws, and I don't have the bandwidth or wherewithal to really "design" a pair of serious speakers.
I have been working on a few ideas (driver/electronics combinations) and I am putting together a document detailing what I have found so far, what I am looking for and what I am willing to offer.
The design will be of a tri-amp'd DSP driven system capable of putting out at least 110 dB continuous, at a cost of <$3K in parts (including electronics), per pair.
Full disclosure - I wrote to Troels G who politely declined. I wanted to approach John of Zaph Audio, but I didn't, because he has made it publicly clear that he doesn't want to be contacted. I want to reach out to "GM" (who always makes valuable contributions, my ideal collaborator!) who, it seems, also does not want to be contacted... so I have to go public like this!
Who will consider joining me in my endeavour? Either PM me or make me a recommendation for someone who might be interested... It should be obvious that the money and scale involved will not be big, but I believe my offer will be transparent and fair... so for somebody who is already an enthusiast and can spare some time, this would be a good fit...
Sincerely,
audiothings.
I have introduced myself and what I'm about to say a few times before, but here I go again.
I run a music studio (with my partner at work), and I build audio studios for a living. My listening rooms rooms are very highly damped - known as 'non environment' or 'hemi-anechoic' rooms. There is little to no 'room gain'. An 8" studio monitor just about manages to do the job, but for any serious visceral impact/scale, a large format pair of speakers is a must. There are no large format monitors available at under $15K or so, and the expense increases significantly by the time it gets here to India.
So, I have been building large format speakers for some of my rooms - I have built 'Econowaves', 'Pi Speakers' and 'SEOS' based speakers from designs proven in the DIY world. For some of these designs, I have bought drivers and parts from abroad (Including an AE TD15H which my cat just destroyed and a pair of Exodus/Anarchy subs, the servicing of which is going to be a PITA).
Servicing and spares when I buy gear from abroad is a nightmare. And ant any time, your consignment may be held up at customs indefinitely, and you might be charged an arbitrary fee to get your stuff cleared.
As it happens, there are a number of 'Pro Audio' speaker companies represented in India. Eminence, B&C and Beyma I have used a few times before, I believe Faital Pro, BMS and a few others are also here... strangely, their pricing is competitive with USA/European pricing - possibly because of reduced customs levies on "spare parts", when imported by the distributors here who have an organized system of dealing in larger quantities. These guys have warranties, spares, repair centres etc., so working with what is available locally is a much more viable option.
Even though I am proud of the speakers I've built as they are working hard everyday in a few studios, I know that they all have serious flaws, and I don't have the bandwidth or wherewithal to really "design" a pair of serious speakers.
I have been working on a few ideas (driver/electronics combinations) and I am putting together a document detailing what I have found so far, what I am looking for and what I am willing to offer.
The design will be of a tri-amp'd DSP driven system capable of putting out at least 110 dB continuous, at a cost of <$3K in parts (including electronics), per pair.
Full disclosure - I wrote to Troels G who politely declined. I wanted to approach John of Zaph Audio, but I didn't, because he has made it publicly clear that he doesn't want to be contacted. I want to reach out to "GM" (who always makes valuable contributions, my ideal collaborator!) who, it seems, also does not want to be contacted... so I have to go public like this!
Who will consider joining me in my endeavour? Either PM me or make me a recommendation for someone who might be interested... It should be obvious that the money and scale involved will not be big, but I believe my offer will be transparent and fair... so for somebody who is already an enthusiast and can spare some time, this would be a good fit...
Sincerely,
audiothings.
Why does it have to be kept within PM, wouldn't it be better and fair to keep the project going as open source and you can donate those funds you had in mind to diyAudio instead?
I was wondering, have you considered buying something like Behringer B2031A and then adding a powered sub?
Is there an official product that you would like to have DIYed with similar technology?
I was wondering, have you considered buying something like Behringer B2031A and then adding a powered sub?
Is there an official product that you would like to have DIYed with similar technology?
You have some ideas about room damping, this goes together with the speakers. (If you used so much damping that the walls went away then you could use any speakers)... I could see whoever does this also designing or re-designing the room damping/interface and speakers.
If you are still willing to use Hypex Fusion amps, I would be willing to collaborate with you on the Hypex filter design part. I do not have enough experience to be your sole collaborator... you will need at least one other well-experienced person to help.
What kind of speaker architecture are you preferring? Something with direct radiator mid and tweeter (like ATC or Barefoot), or are you leaning toward something like a JBL 4367?
What kind of speaker architecture are you preferring? Something with direct radiator mid and tweeter (like ATC or Barefoot), or are you leaning toward something like a JBL 4367?
Thank you for your response. There are a few things here:
* I have to get this done reasonably quickly. Cat has chewed the rubber surrounds of one of my two TD15H subs... I make a living out of this, and I would like to keep my demo room/studio sounding great, without excuses. I cannot get my AE TD15H sub refurbished at a workable cost... and I also cannot offer the experience of my listening room to my clients unless my speakers are performing as intended...
* I have many limitations... for example, the drivers electronics I can afford to import/buy locally... Also, my rooms are closer to anechoic chambers than regular domestic listening setups... Would it really be a sensible 'open source' project if the use case scenario is so narrow?
* It is not my intention to make money out of selling speakers... but if I start building speakers for my clients so that my rooms perform to their potential, I will have to be compensated for my time and effort, not necessarily for the "design" of the speakers... Being that this forum is a not-for-profit community (as I understand), it would be unfair to take advice from a community (for a specific professional purpose) and not return anything of value for the community to take back.
One can look up the last few posts I have created on this forum... I would have been happy to let this stay in the public domain, if I had got sufficient inputs... If I do hook up with a design collaborator, I will still be happy to release whatever designs emerge into the public domain, if it is OK by that person, and that person does not charge me for it.
MrKlinky, thank you. Yes, according to my way incomplete understanding, a sealed sub should sound 'tight' and 'fast', when compared a ported one. I am attempting to build the tightest/fastest sounding control rooms, so to speak, so your suggestion is very relevant. Whether it can be accomplished within the said limitations is yet to be seen. QSC's Reference Monitor System is the closest I have found, and it deviates in several ways from what I have in mind...
AllenB, these are not 'some ideas'... Non environment rooms were not invented by me, and they are reasonably well documented. Most people have not been in such rooms and do not understand how they sound.
Your quote
makes no sense to me. I am sure that most small domestic speaker systems depend on 'room gain' to deliver an enjoyable experience. I know it is not possible, but I wish you could hear an average 8" speaker in my room and become aware of how unexciting it sounds.
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That may work well for recreational hobby pursuits, but a real design effort needs a team leader, and a focused and committed team of individuals, preferably as small a team as possible. I understand why he wants a private collaboration.
I shy away from the term 'fast' like the plague, however it is a fact that sealed enclosures have a considerably faster step response decay time compared with ported, tapped horn, and horn-loaded drivers, and are considerably more accurate, however they are very inefficient. I find it hard to listen to anything other than sealed sub enclosures, anything else sounds lazy and blurred to me.
Whether you like the genre or not, a very good test of a subs' transient decay is the double bass drum pedal used by bands like Metallica. The long decay time of a ported enclosure for example reproduces this as a drawn-out phhhhhtttttt, instead of the almost machine gun-like sound of sealed enclosures.
Whether you like the genre or not, a very good test of a subs' transient decay is the double bass drum pedal used by bands like Metallica. The long decay time of a ported enclosure for example reproduces this as a drawn-out phhhhhtttttt, instead of the almost machine gun-like sound of sealed enclosures.
The QSC reference monitor system looks exactly like what I would have recommended. A decent sized 2" waveguide (like a PRV WG45-50) and a Celestion AXI2050 coaxial or B&C DCX50 coaxial CD, or perhaps a 1.4" waveguide (like a Faital LTH142) and a B&C DCX454 coaxial CD. In either case mated to a JBL 2206 or 2226. Maybe even a pair if you would like to control vertical dispersion below 500Hz in your room (but by the sound of it that might be unnecessary). All crossed over actively (DSP). A few subwoofers sprinkled around the room, of course.
Perhaps a Danley Synergy horn might be more your taste, but that would probably be prohibitively expensive for you to get and does not have the look that many want.
Perhaps a Danley Synergy horn might be more your taste, but that would probably be prohibitively expensive for you to get and does not have the look that many want.
hifijim has an excellent build thread on an all sealed boxes SB_Acoustics 3-way design using the DSP on Hypex Fusion FA253 amps.
(Hypex Fusion FA253 amps + SB34NRX75-6 + SB17CAC35-4 + SB26CDC-C000-4)
Many believe that these aluminum cones produce "the raw truth" tone which is often favored in a studio... helps you to create a mix in the studio's direct+reverberant soundstage which is reproduced in most living rooms. The 12" SB34NRX75-6 has T/S parameters optimized for sealed operation.
New active 3-Way, Hypex and SB
=============
If this build was just for your personal listening enjoyment, I would suggest you research coaxial compression drivers in waveguide like the SEOS24 and the JBL M2 to remove most room effects from your listening position.
(Hypex Fusion FA253 amps + SB34NRX75-6 + SB17CAC35-4 + SB26CDC-C000-4)
Many believe that these aluminum cones produce "the raw truth" tone which is often favored in a studio... helps you to create a mix in the studio's direct+reverberant soundstage which is reproduced in most living rooms. The 12" SB34NRX75-6 has T/S parameters optimized for sealed operation.
New active 3-Way, Hypex and SB
=============
If this build was just for your personal listening enjoyment, I would suggest you research coaxial compression drivers in waveguide like the SEOS24 and the JBL M2 to remove most room effects from your listening position.
Thanks for the kind words...
Audiothings and I have conversed in an earlier thread. We sort of came to the conclusion that a system similar to mine would almost meet his requirements, but not quite.
I don't think mine will quite do that. I think I am about 3 dB short...
If he used a pair of SB34 drivers, and a pair of SB17CAC drivers, I think he could surpass 110 dB. The cost for the 10 drivers would be ~ $1200, and the two Hypex FA253 amps would be ~ $1200, so it is well within his budget. He may need a tweeter with more power handling than the SB26CDC, we would have to think about that. And if he wants a waveguide tweeter, I am not the person to offer advice on that.
Thank you hifijim. Your build was quite inspirational. I do intend to use Hypex amps (I think that your's is the only build build where I have seen them being put to optimal use... I and will keep you in the loop when things move ahead. Please accept my gratitude for contributing so kindly.
In an ideal world, I would go for something like this... 🙂 Three way speakers with a 3" dome mid-range and dual 9" woofers putting out 115 dB continuous (each), complemented with an 18" sub reaching well into the low 20s.
But in the real world, I'm looking at something like this:
I have in mind a couple of alternatives to the Lab12c. But a modular system based around a sealed mf/hf driver (Beyma 8CX300Fe) and a subwoofer per side is where I'm at, right now... The addition of a second subwoofer pair driven by their own (Hypex FA501) amp should yield an SPL potential of +6dB...
@ hifijim, your last post with the dual 12" SB drivers is also not far from where I would like to be... but two things keep me from moving in that direction:
1) The absence of a long term reliable vendor for SB Acoustics, in India.
2) My current speaker soffit, which is 17" w x 17" d x ~60" h... (I can possibly get around this by stacking the 12" woofers vertically, but the lack of availability in India is still a deal-breaker.
Also to note is that I don't know of a single widely accepted large format studio monitor that is fully sealed. There are some Pelonis Monitors which can presumably contend, but I have never even heard of anybody who has heard them. The Barefoot MasterStack12 would also contend, but they don't mention SPLs (why?), they cost $50K a pair, and a side firing woofer will not work in my room as the speakers will be flush mounted with the front wall. (As it happens, the Barefoots also use Hypex amps 🙂.
I like your cat.
I have heard of the non-environment idea, please correct me if I am wrong. This was designed to put speakers in a quasi-free field. It was designed by people frustrated that they could not put in their own speakers without redesigning the control room, so they reduced the effect of the room.
If speakers sound different with and without the room then their polar behaviour may be inconsistent.
I have heard of the non-environment idea, please correct me if I am wrong. This was designed to put speakers in a quasi-free field. It was designed by people frustrated that they could not put in their own speakers without redesigning the control room, so they reduced the effect of the room.
I don't use the term 'room gain'. Do you mean reverberation in this case? Speakers without room reflections (sometimes) sound boring like headphones. This will happen to all speakers if you take them outside, or treat the room to make it behave like free field. In a domestic environment you want to keep the back wall live.
If speakers sound different with and without the room then their polar behaviour may be inconsistent.
Hello,
AllenB, non environnement / zero environnement design is T. Hidley's baby. The idea come from observation of previous Hidley's room design had 'issue' ( they all have... but in this case Stevie Wonder was disturbed so it needed a 'redesign' or a paradygm shift ) despite being widely accepted by proworld as 'standard' mixing rooms. It happened around early 80's after T.Hidley's 4 or 5 years break from audio. It came with 'subsonic' concept with certified '20hz' capable rooms too.
The point isn't to use whatever loudspeaker you want but to make room 'disappear' to have the highest accuracy and portability of mixs between rooms. In Tom Hidley's incarnation monitors are invariably Kinoshita's effort most of the time RM7 or 8.
IF the acoustic principle are stricly applied it won't suit many loudspeakers ( highly reflecting front wall) as they require inwall.
AllenB, non environnement / zero environnement design is T. Hidley's baby. The idea come from observation of previous Hidley's room design had 'issue' ( they all have... but in this case Stevie Wonder was disturbed so it needed a 'redesign' or a paradygm shift ) despite being widely accepted by proworld as 'standard' mixing rooms. It happened around early 80's after T.Hidley's 4 or 5 years break from audio. It came with 'subsonic' concept with certified '20hz' capable rooms too.
The point isn't to use whatever loudspeaker you want but to make room 'disappear' to have the highest accuracy and portability of mixs between rooms. In Tom Hidley's incarnation monitors are invariably Kinoshita's effort most of the time RM7 or 8.
IF the acoustic principle are stricly applied it won't suit many loudspeakers ( highly reflecting front wall) as they require inwall.
Thank you Krivium.
audiothings idea that the sound is boring due to lack of reverberation might be unfortunate, but this is not a domestic situation.
I'm not certain whether this means there would be less or more critical room interaction, however for consistency I'd suspect it would be necessary for less room interaction to avoid speaker axial inconsistencies as that is one of the main differences between speakers.
audiothings idea that the sound is boring due to lack of reverberation might be unfortunate, but this is not a domestic situation.
The better option, this and properly oriented walls, gives as close to free-field in a given space even before room treatment.
I'm not sure if your comment is about the highly reflective front wall but it is needed because the room is so much damped that it isn't confortable for human beings without it! Iow it is reflecting not for the loudspeakers ( they have directional control from 480hz with Kinoshita's anyway) but for engineers and musicians!
Absorption is wideband and cover all walls (except front and floor - floor is either wood or concrete/ marble in this room i've being in) through the use of what Hidley call 'hangers' which are large panels of rockwools angled and piled in suspension every 20 to 30 cm located on room boundary.
The term 'box full of rockwool' i suspect come from this particular design.
Phillip Newell was involved in the development of the principle and made an almost complete explanation of the principle in his book 'recording studio acoustic' on Focal Press.
They both ( Hidley and Newell) use horn loaded mtm loudspeakers in this kind of room ( but Newell used his own design afaik).
Here is an example of an Hidley's design including 20hz and N.E.( hangers are located behind the black fabric, and the two slots on frontwall are the subs out ( push pull design) :
Google Image Result for https://dt7v1i9vyp3mf.cloudfront.net/styles/news_large/s3/imagelibrary/B/BOP_07-J3X_OXH.FUYwfAAVt_W5oKFzD7XMEpOx.jpg
About inwall i agree. The other positive point being it increase headroom in low end ( or absolute max spl. Depend how you see it). Without talking about diffraction of course which another main point).
Absorption is wideband and cover all walls (except front and floor - floor is either wood or concrete/ marble in this room i've being in) through the use of what Hidley call 'hangers' which are large panels of rockwools angled and piled in suspension every 20 to 30 cm located on room boundary.
The term 'box full of rockwool' i suspect come from this particular design.
Phillip Newell was involved in the development of the principle and made an almost complete explanation of the principle in his book 'recording studio acoustic' on Focal Press.
They both ( Hidley and Newell) use horn loaded mtm loudspeakers in this kind of room ( but Newell used his own design afaik).
Here is an example of an Hidley's design including 20hz and N.E.( hangers are located behind the black fabric, and the two slots on frontwall are the subs out ( push pull design) :
Google Image Result for https://dt7v1i9vyp3mf.cloudfront.net/styles/news_large/s3/imagelibrary/B/BOP_07-J3X_OXH.FUYwfAAVt_W5oKFzD7XMEpOx.jpg
About inwall i agree. The other positive point being it increase headroom in low end ( or absolute max spl. Depend how you see it). Without talking about diffraction of course which another main point).
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So Sterling Sound have T. Jouanjouan's designed room now. Interesting he is becoming the Hidley of our time.
Audiothing you contemplate two very differents design. Both are known to works ( great) but with different renderings.
Anyway about sealed i have yet to see a studio monitor with closed subs. Neither studio systems i have heard or seen were closed for sub: either TL or BR.
For other ways ( low or mid) well yes sealed exist.
The 'fast' sound come from the impulse/transient response of closed box: q of 0,707 is the middle compromise point for low end extension, spl and transient for a given driver. It doesn't excel in every point but is a nice working compromise. If you want to favour transient response ( and bandwidth extension but less louder than 0.707) go with 0.577.
It may even be easier to integrate to a typical room too as it usually complement well the 'room gain' profile (of course it vary from built technique, room size and loudspeakers...).
Make it close to optimal for transient and reduce groupdelay below audibility threshold of the band to be reproduced and you'll have 'fast' sound evenwith BR. Or restrict bandpass!
Audiothing you contemplate two very differents design. Both are known to works ( great) but with different renderings.
Anyway about sealed i have yet to see a studio monitor with closed subs. Neither studio systems i have heard or seen were closed for sub: either TL or BR.
For other ways ( low or mid) well yes sealed exist.
The 'fast' sound come from the impulse/transient response of closed box: q of 0,707 is the middle compromise point for low end extension, spl and transient for a given driver. It doesn't excel in every point but is a nice working compromise. If you want to favour transient response ( and bandwidth extension but less louder than 0.707) go with 0.577.
It may even be easier to integrate to a typical room too as it usually complement well the 'room gain' profile (of course it vary from built technique, room size and loudspeakers...).
Make it close to optimal for transient and reduce groupdelay below audibility threshold of the band to be reproduced and you'll have 'fast' sound evenwith BR. Or restrict bandpass!
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Audiothings what freq do you plan to cross your coax? Because 110db continuous will be a challenge for an 8" even crossed at 150hz ( could work better around 250hz with 'steep' ( higher than 18db/octave/third order) slope xover however). Have you already worked the Center to center spacing of coax and woofer too? It will help define xover freq too in case of Mtm.
I would upsize to 10" or 12" for this kind of spl..
Your first layout i like and is not far from Seatonsound's 'the catalyst'.
Should work very nice with same xover points. The 250hz fc in case of 'Catalyst' help to make it a point source (almost full bandwidth) with the added bonus to lessen floor bounce ( same thing happen with Kinoshita RM range). Very clever design to study.
If you can find pictures of coax subcabinet construction of catalyst it is worth taking a look at it and get inspired imho.
I would upsize to 10" or 12" for this kind of spl..
Your first layout i like and is not far from Seatonsound's 'the catalyst'.
Should work very nice with same xover points. The 250hz fc in case of 'Catalyst' help to make it a point source (almost full bandwidth) with the added bonus to lessen floor bounce ( same thing happen with Kinoshita RM range). Very clever design to study.
If you can find pictures of coax subcabinet construction of catalyst it is worth taking a look at it and get inspired imho.
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