Hello forum,
I'd like to tap your experience and creativity since I am in the process of meditating about my next speaker project. Be warned though, it might get a little exotic (and maybe ambitious).
Since this is a project description, I think it might be good to give you some background, so you know where I'm coming from and what I'm aiming for.
Starting point:
I'm currently listening to a pair of computer controlled 3-way speakers that I designed with a friend in 2010 to take part in a diy hobby loudspeaker developer contest. It was designed around Acourate and tried to demonstrate what was possible with digital technology. We accepted a few compromises back then.
Hifi-Music-World 2010 - Messebericht - DIY-Forum - Frank-Landmesser.de
Scroll to the bottom to see Zoé.
General concept: drivers with substantial cone area in a very small footprint. Zoé measures just 24 cm wide, 42 (top) / 52 cm deep (bottom) and 95,5 cm tall. Yet it houses
38 mm tweeter: Ciare 1.38 TW2
20 cm mid-woofer B&C 8NW51
38 cm bass Beyma 15G450N (mounted on the side, playing in something like 30+ litres net).
Linear phase crossovers and room correction are provided by AudioVero Acourate software. Initially with 200 dB/octave Neville-Thiele XOs, now with proprietary filters developed by Uli Brüggemann, Acourate's programmer. Similar steepness though.
The cabinets were build in record time by my buddy, to get finished speakers in time for the competition. For years I thought about exchanging it for a new housing with more wallthickness and a nicer finish.
However, if I spent money on a nicer cabinet, I could as well improve the concept a bit to overcome some of the limitations of the system:
For years I thought about ways how to improve the concept in the current footprint and design, but finally I came to the conclusion to keep Zoé as it is and start from scratch with a completely new design for the next digital speaker.
I have sets of mid drivers that I wanted to use in a design for many years. It might be time to build something around them now:
Beyma 102Nd/N
https://www.beyma.com/speakers/Fichas_Tecnicas/102NdN.pdf
25 cm mid drivers with a BL of 25,4 Tm, driving 33 g Mms in an 11 mm deep gap with a 12 mm long VC. This results in Qes of 0,09 and a monstrous efficiency rating of 103 dB/2,83 V/1 m.
I plan to use two per side.
Symmetrical driver placement for good measure...
The challenge is finding the right partners for the upper frequencies. While I don't care much about their efficiency (as long as they are not on a completely different page than the mid monsters), I am looking for decent surface area and low moving mass.
That quickly brought me to small PA drivers or even AMTs for high-mids and a ribbon tweeter. Here are two quick drafts of how this could look like:
I'm curious to read your thoughts and ideas.
I'd like to tap your experience and creativity since I am in the process of meditating about my next speaker project. Be warned though, it might get a little exotic (and maybe ambitious).
Since this is a project description, I think it might be good to give you some background, so you know where I'm coming from and what I'm aiming for.
Starting point:
I'm currently listening to a pair of computer controlled 3-way speakers that I designed with a friend in 2010 to take part in a diy hobby loudspeaker developer contest. It was designed around Acourate and tried to demonstrate what was possible with digital technology. We accepted a few compromises back then.
Hifi-Music-World 2010 - Messebericht - DIY-Forum - Frank-Landmesser.de
Scroll to the bottom to see Zoé.
General concept: drivers with substantial cone area in a very small footprint. Zoé measures just 24 cm wide, 42 (top) / 52 cm deep (bottom) and 95,5 cm tall. Yet it houses
38 mm tweeter: Ciare 1.38 TW2
20 cm mid-woofer B&C 8NW51
38 cm bass Beyma 15G450N (mounted on the side, playing in something like 30+ litres net).
Linear phase crossovers and room correction are provided by AudioVero Acourate software. Initially with 200 dB/octave Neville-Thiele XOs, now with proprietary filters developed by Uli Brüggemann, Acourate's programmer. Similar steepness though.
The cabinets were build in record time by my buddy, to get finished speakers in time for the competition. For years I thought about exchanging it for a new housing with more wallthickness and a nicer finish.
However, if I spent money on a nicer cabinet, I could as well improve the concept a bit to overcome some of the limitations of the system:
The tweeter hardly reaches 15 kHz. A trade-off for its massive cone area and Mms.
Beamwidth/directivity continuity might be a bit flawed because of the big step from a 20 cm mid driver to a dome tweeter.
While Zoé plays really nice now, I can't get rid of the feeling that I might get more mid/high resolution with smaller, lighter drivers.
For years I thought about ways how to improve the concept in the current footprint and design, but finally I came to the conclusion to keep Zoé as it is and start from scratch with a completely new design for the next digital speaker.
I have sets of mid drivers that I wanted to use in a design for many years. It might be time to build something around them now:
Beyma 102Nd/N
https://www.beyma.com/speakers/Fichas_Tecnicas/102NdN.pdf
25 cm mid drivers with a BL of 25,4 Tm, driving 33 g Mms in an 11 mm deep gap with a 12 mm long VC. This results in Qes of 0,09 and a monstrous efficiency rating of 103 dB/2,83 V/1 m.
I plan to use two per side.
Symmetrical driver placement for good measure...
The challenge is finding the right partners for the upper frequencies. While I don't care much about their efficiency (as long as they are not on a completely different page than the mid monsters), I am looking for decent surface area and low moving mass.
That quickly brought me to small PA drivers or even AMTs for high-mids and a ribbon tweeter. Here are two quick drafts of how this could look like:
I'm curious to read your thoughts and ideas.
MmtmM is tough with large drivers. Smallest drivers with similar sensitivity include the B&C 5MDN38 and the Faital Pro M5N8-80. Best bet for a tweeter is the Bliesma T34.
Or
Go with a large format compression driver on a horn like the XT1464 or PR614 and cross around 700hz. Faital HF1440 looks like a good option to reach a clean 20khz.
Or
Go for a prosound coaxial between 6"-10".
Or
Go with a large format compression driver on a horn like the XT1464 or PR614 and cross around 700hz. Faital HF1440 looks like a good option to reach a clean 20khz.
Or
Go for a prosound coaxial between 6"-10".
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Or go with a real large format CD (like a 2") and horn/waveguide that can cross over at 500Hz or lower. You will need a tweeter for >4kHz.
Really like the Zoe....very nice in such a small package.
Also like the forward thinking re linear phase and steep xovers.
Whole project, well done ! 🙂
The Beyma 102Nd/N looks killer. Where do you find them on the Beyma website? Never seen that kind of efficiency spec before.
My 2cents advice,
...is that my starting speaker design spec is what kind off SPL do I want, with what kind on frequency extension, both high and low.
Once that's settled, i can start to think about pattern, room, environment, etc.
Anyway, so what are your spl and freq extension goals?
Like what are you planning to fit under the (maybe 2) 102Nd/N's per side ?
That's a lot of mid-range grunt.
It's always the very highs and very lows that define a speaker i think...
mids seem to be the easy part....
I like to solve the extremes ....subs and VHF first....and then fill in then holes....
Also like the forward thinking re linear phase and steep xovers.
Whole project, well done ! 🙂
The Beyma 102Nd/N looks killer. Where do you find them on the Beyma website? Never seen that kind of efficiency spec before.
My 2cents advice,
...is that my starting speaker design spec is what kind off SPL do I want, with what kind on frequency extension, both high and low.
Once that's settled, i can start to think about pattern, room, environment, etc.
Anyway, so what are your spl and freq extension goals?
Like what are you planning to fit under the (maybe 2) 102Nd/N's per side ?
That's a lot of mid-range grunt.
It's always the very highs and very lows that define a speaker i think...
mids seem to be the easy part....
I like to solve the extremes ....subs and VHF first....and then fill in then holes....
I have a pair of the Beyma 102Nd/N as well, used them for 15 years in a midbass horn. My new system concept (also digital active, but with an IIR controller) revolves around Limmer 870 with RCF MR8N301 and a 1" CD above that. Limmer also has a coaxial version of the 870 - I decided against it based on looks 😱 wonder if that was the right decision.
Anyway my first impression of the RCF driver is excellent.
@mark100 the 102Nd/N is obsolete, not available anymore.
The compression driver going very low only works with a few drivers that can pull this off and a very large horn, think 60 x 60 cm mouth like B&C ME464 . E.g. a BMS coax in Limmer 033 didn't "do it" for me (although it looks useable from 600 Hz) at all compared to a 042 with PHL (in an audition of Dieter Achenbach's speakers).
Anyway my first impression of the RCF driver is excellent.
@mark100 the 102Nd/N is obsolete, not available anymore.
The compression driver going very low only works with a few drivers that can pull this off and a very large horn, think 60 x 60 cm mouth like B&C ME464 . E.g. a BMS coax in Limmer 033 didn't "do it" for me (although it looks useable from 600 Hz) at all compared to a 042 with PHL (in an audition of Dieter Achenbach's speakers).
BMS4590 in any wg that controls directivity down to 800Hz or so. 2x6nd430-8 in mtm crossed at 800Hz to BMS and some 15" bass crossed at 150-200Hz (didn't bother to suggest this because the options are countless).
Thanks guys!
Gonna try to reply to your messages in chronological order:
Ernie,
yes, Bliesma tweeters look great! They're also German made, not far from here. However, I have my mind set on ribbons at the moment and plan to run a few tests with an actual unit soon. (A post for that is currently in review.)
The small high-mid driver in my sketch is a PHL 950Nd. Also a nice small PA unit from a highly regarded manufacturer, like your suggestions.
I shy away from PA compression drivers because of their usually very ugly impedance curves. It seems there is a lot happening in these membranes, chambers and horns. It's also really hard to find one that reaches 20 kHz cleanly, let alone exceed that substantially. And while I don't hear over 18k, I do think that a tweeter that's capable of delivering 40 kHz can also follow transient signals better. That's the main motivation behind the lean towards ribbons with super light membranes.
I actually have a pair of Beyma 8XC20 still in their original cartons. Wanted to test them for a long time. But the CD issues apply to them as well. Another project for the long winter nights maybe. 😀
Mark,
thank you for your nice words! The true achievement here has to go to Uli. His measurement and filtering software is a killer tool. And constantly getting improved, too.
The 102s are monsters. Unfortunately discontinued for a long time already. I got mine years ago from a dealer who wanted to clear his stock. However, there are still reconing kits around. If you want a set of 102Nds, try to contact Beyma in Spain directly, I can imagine they still have some units around.
So search the "Discontinued Products" area on the Beyma website:
LOUDSPEAKER 102Nd/N 8 OH
We have seen the classical high fs hifi mid driver vanishing. PA mids followed soon with the shift towards line array systems. Even small drivers are engineered for high Xmax now. Compared to that the 102s and their big brothers 122Nd (I have a pair of those, too 🙄 ) are dinosaurs. Originally designed to drive huge PA mid horns, I think.
SPL?
I want effortless 85 dB at the listening spot. Maybe 10 dB headroom for good measure. More is just a nice to have, but not necessary. Amp power is not an issue. The bass drivers will get a class D, for the tweeters a class A is planned. An active setup gives you all kinds of freedom.
Frequency extension?
25 Hz to 40 kHz
Bass is easy. Just provide enough cone area, the software does the rest (if backed up by sufficient amping). Room acoustics allow 25 Hz, that's what I have already. In my roughly 30 m2 living room (with a substantially high ceiling though), Zoé could even handle 15 Hz, but there's no music down there. That's just a number.
40 kHz is the real challenge.
I have 4 pcs Beyma 18P80Fe laying around here for the first test. In a way I thik they follow a similar concept than the 102s: low Mms, high Qms and massive Qes of 0,189. No chance of getting any serious bass from that in a passive speaker.
Doubling the number of 12"s if necessary is not an issue. I could also decide to mount a single 21" per side. Tried that before as CB subs with an open baffle 3-way, but that was long ago in a much larger listening room. I do miss these two super compact 160 l subs sometimes, their effortless low end was addictive (room modes as low as 18 and 24 Hz help).
Give the midrange is handled well, I agree with you. I think that my 85 dB appear louder than they really are because the low end can keep up with the high/mid SPL and is not lagging behind. It's time aligned and plays in super small closed enclosures (working against stiff air cushions), giving it good manners right down to 25 Hz.
Gatedriver,
Interesting!
Midbass implies, that you didn't use a bass driver for a low end? The 102s had to work from the ground up? What tweeters did you use? What was your impression of the drivers and the setup?
I have a loudspeaker buddy some 40 km away who designs his own horns. He went through countless versions and also switched to digital filtering with Acourate a while ago. I could ask him to make custom horns for me, but still think that horns are not the right way for me and my listening room.
Zvu,
yeah, the BMS 4590. Fascinating drivers. But IIRC, my horn buddy tested them and ended up selling them. He wasn't really happy. I have to interview him again what didn't meet his expectations.
Gonna try to reply to your messages in chronological order:
Ernie,
yes, Bliesma tweeters look great! They're also German made, not far from here. However, I have my mind set on ribbons at the moment and plan to run a few tests with an actual unit soon. (A post for that is currently in review.)
The small high-mid driver in my sketch is a PHL 950Nd. Also a nice small PA unit from a highly regarded manufacturer, like your suggestions.
I shy away from PA compression drivers because of their usually very ugly impedance curves. It seems there is a lot happening in these membranes, chambers and horns. It's also really hard to find one that reaches 20 kHz cleanly, let alone exceed that substantially. And while I don't hear over 18k, I do think that a tweeter that's capable of delivering 40 kHz can also follow transient signals better. That's the main motivation behind the lean towards ribbons with super light membranes.
I actually have a pair of Beyma 8XC20 still in their original cartons. Wanted to test them for a long time. But the CD issues apply to them as well. Another project for the long winter nights maybe. 😀
Mark,
thank you for your nice words! The true achievement here has to go to Uli. His measurement and filtering software is a killer tool. And constantly getting improved, too.
The 102s are monsters. Unfortunately discontinued for a long time already. I got mine years ago from a dealer who wanted to clear his stock. However, there are still reconing kits around. If you want a set of 102Nds, try to contact Beyma in Spain directly, I can imagine they still have some units around.
So search the "Discontinued Products" area on the Beyma website:
LOUDSPEAKER 102Nd/N 8 OH
We have seen the classical high fs hifi mid driver vanishing. PA mids followed soon with the shift towards line array systems. Even small drivers are engineered for high Xmax now. Compared to that the 102s and their big brothers 122Nd (I have a pair of those, too 🙄 ) are dinosaurs. Originally designed to drive huge PA mid horns, I think.
SPL?
I want effortless 85 dB at the listening spot. Maybe 10 dB headroom for good measure. More is just a nice to have, but not necessary. Amp power is not an issue. The bass drivers will get a class D, for the tweeters a class A is planned. An active setup gives you all kinds of freedom.
Frequency extension?
25 Hz to 40 kHz
Bass is easy. Just provide enough cone area, the software does the rest (if backed up by sufficient amping). Room acoustics allow 25 Hz, that's what I have already. In my roughly 30 m2 living room (with a substantially high ceiling though), Zoé could even handle 15 Hz, but there's no music down there. That's just a number.
40 kHz is the real challenge.
I have 4 pcs Beyma 18P80Fe laying around here for the first test. In a way I thik they follow a similar concept than the 102s: low Mms, high Qms and massive Qes of 0,189. No chance of getting any serious bass from that in a passive speaker.
Doubling the number of 12"s if necessary is not an issue. I could also decide to mount a single 21" per side. Tried that before as CB subs with an open baffle 3-way, but that was long ago in a much larger listening room. I do miss these two super compact 160 l subs sometimes, their effortless low end was addictive (room modes as low as 18 and 24 Hz help).
Give the midrange is handled well, I agree with you. I think that my 85 dB appear louder than they really are because the low end can keep up with the high/mid SPL and is not lagging behind. It's time aligned and plays in super small closed enclosures (working against stiff air cushions), giving it good manners right down to 25 Hz.
Gatedriver,
Interesting!
Midbass implies, that you didn't use a bass driver for a low end? The 102s had to work from the ground up? What tweeters did you use? What was your impression of the drivers and the setup?
I have a loudspeaker buddy some 40 km away who designs his own horns. He went through countless versions and also switched to digital filtering with Acourate a while ago. I could ask him to make custom horns for me, but still think that horns are not the right way for me and my listening room.
Zvu,
yeah, the BMS 4590. Fascinating drivers. But IIRC, my horn buddy tested them and ended up selling them. He wasn't really happy. I have to interview him again what didn't meet his expectations.
P.S.:
Missed that...
Yup. My horn buddy also told me about the Faital 1440 recently. This CD does look great on paper. We're trying to get hold of a pair, but that turned out to be not so easy.
Missed that...
Yup. My horn buddy also told me about the Faital 1440 recently. This CD does look great on paper. We're trying to get hold of a pair, but that turned out to be not so easy.
I've listened BMS 4592 in Oris Swing and other than needed listening distance of at least 4m, i have nothing to complain about. Crossover can make or brake these drivers. And horn/wg type of course.
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"I'd like to tap your experience and creativity since I am in the process of meditating about my next speaker project. Be warned though, it might get a little exotic (and maybe ambitious)."
My advice is yes, or no. What do you think?
My advice is yes, or no. What do you think?
Shefffield,
If you don't want compression drivers - try Beyma TPL150H.
In my old system the 102Nd was used from 100 to about 600 or so Hz. Closed 15" subs below and a BMS 4552Nd in a big elliptical JMLC horn i made in solid wood above. Must've been one of the first of these horns, before the spreadsheet was distributed.
I would've liked to keep the 102 Nds for my new system, but i'm set on horns and have no time to build something nice right now, with phaseplugs. Hence the 870s.
Who knows, maybe i'll make something similar to your project some day, kinda like an Alcons CRMS ... wide and flat.
The midrange is where the music is.... 😎
I live in Bavaria too, btw.
If you don't want compression drivers - try Beyma TPL150H.
In my old system the 102Nd was used from 100 to about 600 or so Hz. Closed 15" subs below and a BMS 4552Nd in a big elliptical JMLC horn i made in solid wood above. Must've been one of the first of these horns, before the spreadsheet was distributed.
I would've liked to keep the 102 Nds for my new system, but i'm set on horns and have no time to build something nice right now, with phaseplugs. Hence the 870s.
Who knows, maybe i'll make something similar to your project some day, kinda like an Alcons CRMS ... wide and flat.
The midrange is where the music is.... 😎
I live in Bavaria too, btw.