Hello everyone,
I'm excited to finally be posting here after being a long-time lurker. I've been working on a few small projects, but now I'm aiming for something bigger and could really use your support and input.
For my 4-way build, I already have a few drivers in that I'd like to use:
BMS 18n850v2
Accuton c50-8-044
Scan Speak R2904/700005
However, I'm looking for some recommendations for a suitable mid-woofer/midrange driver that would complement the ones I already have. The drivers will be mounted on a fairly wide baffle, around 60cm in width and crossed via DSP.
I would greatly appreciate any suggestions or recommendations you all might have. Thanks so much for your help!
I'm excited to finally be posting here after being a long-time lurker. I've been working on a few small projects, but now I'm aiming for something bigger and could really use your support and input.
For my 4-way build, I already have a few drivers in that I'd like to use:
BMS 18n850v2
Accuton c50-8-044
Scan Speak R2904/700005
However, I'm looking for some recommendations for a suitable mid-woofer/midrange driver that would complement the ones I already have. The drivers will be mounted on a fairly wide baffle, around 60cm in width and crossed via DSP.
I would greatly appreciate any suggestions or recommendations you all might have. Thanks so much for your help!
Hey Lehnok,
I love the sounds produces by large cones moving a small distance and believe its far superior to small cones moving a large distance ie over the vital 100 Hz to 800 Hz (vocals, cello, strings piano etc) a 15 or 12 inch or even a 10 inch is waaaay better than any small coned driver regardless of the cone material diamond/carbon/ceramic/" unobtainium" or snake oil material.
As you have a big baffle you can fit superb Pro drivers, also your DSP ( I assume fully active active amplification on all drivers?) allows you to use sealed box alignment and Eq to suit room and system/listening preferences.
My personal top drivers (currently available) for this range are;
15 inch the fabulous Beyma 15P 80 Fe/N https://www.beyma.com/speakers/Fich...ers-data-sheet-low-mid-frequency-15P80FeN.pdf It sounds sublime in 30 to 40 litres sealed box.
12 inch Beyma https://www.beyma.com/en/products/c/low-mid-frequency/112P80FEV28/altavoz-12p80fe-v2-8-oh/ similar to the 15 inch just not quite as dynamic or extended at the low end. I have never used the Neo magnet version but others say its also a great sounding driver.
PHL 10 inch https://www.phlaudio.com/fileadmin/user_upload/phl_audio/3860NdSM_SpecSheet.pdf I have not used this new V2 Neo magnet version but the I loved the previous ferrite magnet version which had remarkable resolution.
10 inch Volt 2500.4 https://voltloudspeakers.co.uk/speaker/bm2500-4-10inch/ Sweet sounding and works in very small / shallow sealed box, also lovely in open baffle.
Hope this helps
Cheers
Alex.
I love the sounds produces by large cones moving a small distance and believe its far superior to small cones moving a large distance ie over the vital 100 Hz to 800 Hz (vocals, cello, strings piano etc) a 15 or 12 inch or even a 10 inch is waaaay better than any small coned driver regardless of the cone material diamond/carbon/ceramic/" unobtainium" or snake oil material.
As you have a big baffle you can fit superb Pro drivers, also your DSP ( I assume fully active active amplification on all drivers?) allows you to use sealed box alignment and Eq to suit room and system/listening preferences.
My personal top drivers (currently available) for this range are;
15 inch the fabulous Beyma 15P 80 Fe/N https://www.beyma.com/speakers/Fich...ers-data-sheet-low-mid-frequency-15P80FeN.pdf It sounds sublime in 30 to 40 litres sealed box.
12 inch Beyma https://www.beyma.com/en/products/c/low-mid-frequency/112P80FEV28/altavoz-12p80fe-v2-8-oh/ similar to the 15 inch just not quite as dynamic or extended at the low end. I have never used the Neo magnet version but others say its also a great sounding driver.
PHL 10 inch https://www.phlaudio.com/fileadmin/user_upload/phl_audio/3860NdSM_SpecSheet.pdf I have not used this new V2 Neo magnet version but the I loved the previous ferrite magnet version which had remarkable resolution.
10 inch Volt 2500.4 https://voltloudspeakers.co.uk/speaker/bm2500-4-10inch/ Sweet sounding and works in very small / shallow sealed box, also lovely in open baffle.
Hope this helps
Cheers
Alex.
Hey Alex,
Thank you so much for your response!
I completely agree with you about the impact of big cones and how impressive they can sound in good speakers.
Regarding my setup, I'm planning to use 4 stereo amp units and MiniDsp Flex, which I'm pretty excited about.
I must admit, your suggestions have piqued my interest because I hadn't considered anything larger than 8 inches for my mid driver. So, here comes my next question: Do you think it would make sense to cross the Beyma 15 with the Accuton 2-inch driver? Or do you think I should start looking for another driver to replace the Accuton?
Thanks again for being so supportive!
All the best,
Konrad
Thank you so much for your response!
I completely agree with you about the impact of big cones and how impressive they can sound in good speakers.
Regarding my setup, I'm planning to use 4 stereo amp units and MiniDsp Flex, which I'm pretty excited about.
I must admit, your suggestions have piqued my interest because I hadn't considered anything larger than 8 inches for my mid driver. So, here comes my next question: Do you think it would make sense to cross the Beyma 15 with the Accuton 2-inch driver? Or do you think I should start looking for another driver to replace the Accuton?
Thanks again for being so supportive!
All the best,
Konrad
For me, if I was starting with a clean slate for cabinet and drivers plus I had a DSP crossover/Eq plus up to eight channels of amplification I would aim for a high sensitivity, all sealed box design.
I also prefer broad but shallow cabinets which can be placed right up against the front wall of my listening room (either side of a 65 inch OLED TV screen) so that movies, TV and music content all sounds great as I combine a dedicated two channel rig with a Denon AVR with Auro 3D software.... Forget Dolby Atmos, Auro 3D is different concept. https://www.auro-3d.com/
Cost no object option 4 way:
Bass - 20Hz to 80Hz - 18 inch Precision Devices https://www.precision-devices.com/w...PD-1850-3-Techincal-Specifications-020221.pdf
Mid bass - 80Hz to 500Hz - Beyma 15P80 Fe/N
Midrange - 300Hz to 2 KHz -
Treble - 2KHz > Beyma TPL 200 (No horn!)
I have attached some sims and my thoughts on the sound/use of the pd 1850 and Beyma drivers... I will do some more sims tomorrow on some upper midrange to cover the 500 Hz to 2,000Hz band.
Cheers
A.
I also prefer broad but shallow cabinets which can be placed right up against the front wall of my listening room (either side of a 65 inch OLED TV screen) so that movies, TV and music content all sounds great as I combine a dedicated two channel rig with a Denon AVR with Auro 3D software.... Forget Dolby Atmos, Auro 3D is different concept. https://www.auro-3d.com/
Cost no object option 4 way:
Bass - 20Hz to 80Hz - 18 inch Precision Devices https://www.precision-devices.com/w...PD-1850-3-Techincal-Specifications-020221.pdf
Mid bass - 80Hz to 500Hz - Beyma 15P80 Fe/N
Midrange - 300Hz to 2 KHz -
Treble - 2KHz > Beyma TPL 200 (No horn!)
I have attached some sims and my thoughts on the sound/use of the pd 1850 and Beyma drivers... I will do some more sims tomorrow on some upper midrange to cover the 500 Hz to 2,000Hz band.
Cheers
A.
Actually this would be my choice of upper midrange driver, https://www.phlaudio.com/fileadmin/user_upload/phl_audio/1120_SpecSheet.pdf
I have not used it but I have used its predecessor, a 16 Ohm ferrite magnet version the PHL 1130 and its sooooo good, really detailed and resolving but still dynamic and supple.
So my four drivers would be:
PD 1850 bass
Beyma 15P80 Fe/N
PHL 1752
Beyma TPL 200 (No horn)
Good luck and remember your mileage may vary!
I have not used it but I have used its predecessor, a 16 Ohm ferrite magnet version the PHL 1130 and its sooooo good, really detailed and resolving but still dynamic and supple.
So my four drivers would be:
PD 1850 bass
Beyma 15P80 Fe/N
PHL 1752
Beyma TPL 200 (No horn)
Good luck and remember your mileage may vary!
Hello Lehnok!
I have done a quick research about the drivers, the tough one in my eyes is the Accuton c50-8-044 driver - older model, not in stock anymore in all major shops in Europe. The kick bass - low midrange driver needs to fit with the ceramic dome type with the quite low 1W / 1m SPL of 89dB. For me a good approach is to see in the Google universe what other professionals are doing with this. I found one of those that in my opinion knows quite well what he is doing, here: http://www.troelsgravesen.dk/SP44.htm
I think the cost no object option is to look for an Accuton driver that makes it down to 120 - 150 Hz, but the Accuton stuff is really expensive. I am not sure whether a large high SPL paper cone will fit into the Accuton 2 inch inverse dome. A good choice for paper cones with low Rms low distortion design is always Acoustic Elegance, like this here: https://aespeakers.com/shop/td/td8m/. With the export cost to Europe and the shipping the U.S. stuff with no distributor in Europe isn't cheap though.
Hope it helps, Stefano
I have done a quick research about the drivers, the tough one in my eyes is the Accuton c50-8-044 driver - older model, not in stock anymore in all major shops in Europe. The kick bass - low midrange driver needs to fit with the ceramic dome type with the quite low 1W / 1m SPL of 89dB. For me a good approach is to see in the Google universe what other professionals are doing with this. I found one of those that in my opinion knows quite well what he is doing, here: http://www.troelsgravesen.dk/SP44.htm
I think the cost no object option is to look for an Accuton driver that makes it down to 120 - 150 Hz, but the Accuton stuff is really expensive. I am not sure whether a large high SPL paper cone will fit into the Accuton 2 inch inverse dome. A good choice for paper cones with low Rms low distortion design is always Acoustic Elegance, like this here: https://aespeakers.com/shop/td/td8m/. With the export cost to Europe and the shipping the U.S. stuff with no distributor in Europe isn't cheap though.
Hope it helps, Stefano
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Hi Lehnok, the 30 minutes timeout reached i have to post in a new thread.
To increase the sensitivity of the 2 inch inverse dome driver you should consider to adopt some kind of a wave guide approach, a quick calculation shows that a 16 cm deep 22 cm circular mouth area waveguide could make it, with a tractrix contour even less deep with 12 - 14 cm. There are also options for waveguides for the Scan-Speak tweeters, here: http://www.troelsgravesen.dk/ScanSpeak-waveguides.htm I know a guy here in Germany that is able to make very nice wooden wave guides almost for everything, here: https://www.lautsprechermanufaktur-heyder.de/en-us/lmh-horns Here the cost no object option is about the elliptical e-Trak horns as a waveguide, they are really excellent looking works of art. The midrange waveguide for the 2 inch dome tweeter without a phase plug require a quite low cut off to the tweeter, so that a wave guide for the tweeter is needed too. So either no wave guide at all or both for high midrange and tweeter.
Hope again it helps, Stefano
To increase the sensitivity of the 2 inch inverse dome driver you should consider to adopt some kind of a wave guide approach, a quick calculation shows that a 16 cm deep 22 cm circular mouth area waveguide could make it, with a tractrix contour even less deep with 12 - 14 cm. There are also options for waveguides for the Scan-Speak tweeters, here: http://www.troelsgravesen.dk/ScanSpeak-waveguides.htm I know a guy here in Germany that is able to make very nice wooden wave guides almost for everything, here: https://www.lautsprechermanufaktur-heyder.de/en-us/lmh-horns Here the cost no object option is about the elliptical e-Trak horns as a waveguide, they are really excellent looking works of art. The midrange waveguide for the 2 inch dome tweeter without a phase plug require a quite low cut off to the tweeter, so that a wave guide for the tweeter is needed too. So either no wave guide at all or both for high midrange and tweeter.
Hope again it helps, Stefano
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The Scan-Speak R2904 as a ring radiator is predestinated for a waveguide, the phase plug is already built in the tweeter. Quite the opposite for the ceramic dome, i oversaw that it has the protection grid that might be difficult to remove.
https://hificompass.com/sites/default/files/documents/c50-8-044.pdf
https://www.hifisound.de/out/media/...QZJq1ep8e+x1kamLz98RbfJO/Ry7q+zTPgXOIng==.pdf
https://hificompass.com/sites/default/files/documents/c50-8-044.pdf
https://www.hifisound.de/out/media/...QZJq1ep8e+x1kamLz98RbfJO/Ry7q+zTPgXOIng==.pdf
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Hey Stefano,
Thanks for all your insights. You were spot-on about the Accuton driver. I got these drivers, along with some others, brand new a while back from a speaker builder. He said they might not be the prettiest, but their performance is top-notch! 😄
As you mentioned, the sensitivity of this driver is on the lower side, so I've been thinking of trying a waveguide approach to tackle that. Luckily, I have 3D printing and CNC capabilities, so experimenting won't be a problem.
Removing the grille on the Accuton driver was a bit tricky, but I couldn't stand the "Car Audio" look, so I went for it. Apparently, Accuton added the grille because the cone is quite brittle and prone to damage.
Besides Troels' project, I haven't come across anyone else using this driver in their builds, unfortunately.
As for matching it with another Accuton driver like the AS190-9-251, I gotta be honest, it's not worth the price of over 1000 Euro. Scan-Speak's 22W/8857T-00 is one-third of the cost and does a great job! :O
Seas drivers look a lot like those from Acoustic Elegance. I'm curious if they perform similarly. Time to do some research!
Anyway, you're right, Stefano, the Accuton driver can be a bit tricky to work with. My initial idea was to go for a 3-way design for simplicity, using a PA midrange driver between 200 and 2700 Hz, like the PA 18 SOUND 8NMB420 or something more exotic like the Audio Technology C-Quenze 23 I 52 17 06.
But the idea of a nice 4-way with a big mid, as mentioned by Alex and done by Troels in his Loudspeaker 1&2, is quite tempting. I'm considering it too.
Thanks again for all your help!
Cheers,
Thanks for all your insights. You were spot-on about the Accuton driver. I got these drivers, along with some others, brand new a while back from a speaker builder. He said they might not be the prettiest, but their performance is top-notch! 😄
As you mentioned, the sensitivity of this driver is on the lower side, so I've been thinking of trying a waveguide approach to tackle that. Luckily, I have 3D printing and CNC capabilities, so experimenting won't be a problem.
Removing the grille on the Accuton driver was a bit tricky, but I couldn't stand the "Car Audio" look, so I went for it. Apparently, Accuton added the grille because the cone is quite brittle and prone to damage.
Besides Troels' project, I haven't come across anyone else using this driver in their builds, unfortunately.
As for matching it with another Accuton driver like the AS190-9-251, I gotta be honest, it's not worth the price of over 1000 Euro. Scan-Speak's 22W/8857T-00 is one-third of the cost and does a great job! :O
Seas drivers look a lot like those from Acoustic Elegance. I'm curious if they perform similarly. Time to do some research!
Anyway, you're right, Stefano, the Accuton driver can be a bit tricky to work with. My initial idea was to go for a 3-way design for simplicity, using a PA midrange driver between 200 and 2700 Hz, like the PA 18 SOUND 8NMB420 or something more exotic like the Audio Technology C-Quenze 23 I 52 17 06.
But the idea of a nice 4-way with a big mid, as mentioned by Alex and done by Troels in his Loudspeaker 1&2, is quite tempting. I'm considering it too.
Thanks again for all your help!
Cheers,
BMS driver has got enough of a potential to cross to accuton at a reasonable x/o frequency. First test your speaker design skills by making it a 3 way.
I wholeheartedly support the idea of experimenting with the 3-way design; however, I must admit that I hold reservations regarding the potential sound quality it may produce. Nevertheless, considering it as a science project, I see no reason not to give it a try.
cheers,
Konrad
cheers,
Konrad
Re the BMS 18 inch drivers....Personally I would never use this driver at all, but if you already have them (can you sell them or trade them in?) the best use is in a sealed box below 80Hz. They do not have light weight cones, so low midrange is not going to be good, esp at low SPL in a domestic setting.
Their Mms of 240 g with 25 Bl = a "slow" 9.4 ratio.
The lower cost Precision Devices 1850- 3 (with a huge 5 inch voice coil and superb low power compression of just 1.6 dB at rated power) has a lower Mms of 215g and 31 Bl giving a class leading ratio of just 6.9.
Their Mms of 240 g with 25 Bl = a "slow" 9.4 ratio.
The lower cost Precision Devices 1850- 3 (with a huge 5 inch voice coil and superb low power compression of just 1.6 dB at rated power) has a lower Mms of 215g and 31 Bl giving a class leading ratio of just 6.9.
PS
I once bought an amplifier from a DIY guy who had the most amazing DIY three way speakers which he called the "1812 Overture"
It was the PD 1850 Mk 2 (2016 or 2017 I think) in a sealed box covering bass up to 80Hz, then crossing over to a Beyma 15 P80 Fe and a Beyma TPL 200.... But, the TPL was suspended in front the dust cap of the 15 P80 on 5mm diameter copper rods bent into a "U Bend" shape which screwed into the cabinet sides.
The TPL rear chamber was replaced with a 3D printed "Tear Drop" shaped housing which put the front of the TPL about 20 cm in front of the dust cap, the rear of the TPL housing was a sharp point which looked like it touched the dust cap(!) but he said was actually 1 cm away.
They sounded amazing.....! I bought the amp (a DIY 300B SET with about 8 watts ) but the amp has never sounded as good on any other speakers I have tried it on... Even on TPL 200 drivers which I use...There was a magic in that CoAx that is quite unique.
I once bought an amplifier from a DIY guy who had the most amazing DIY three way speakers which he called the "1812 Overture"
It was the PD 1850 Mk 2 (2016 or 2017 I think) in a sealed box covering bass up to 80Hz, then crossing over to a Beyma 15 P80 Fe and a Beyma TPL 200.... But, the TPL was suspended in front the dust cap of the 15 P80 on 5mm diameter copper rods bent into a "U Bend" shape which screwed into the cabinet sides.
The TPL rear chamber was replaced with a 3D printed "Tear Drop" shaped housing which put the front of the TPL about 20 cm in front of the dust cap, the rear of the TPL housing was a sharp point which looked like it touched the dust cap(!) but he said was actually 1 cm away.
They sounded amazing.....! I bought the amp (a DIY 300B SET with about 8 watts ) but the amp has never sounded as good on any other speakers I have tried it on... Even on TPL 200 drivers which I use...There was a magic in that CoAx that is quite unique.
BMS has got perfect T/S parameters for a vented cabinet ( good bass performance without EQ). The manufacturer knew exactly what to do, and the tripple demodulating rings serve their purpose also.
Audiophiles would like us to believe in a system of "fast and slow" which we know is a nonsense. We also know certain important decisions have got to be made. You can have a (s)lower spl driver that plays bass right or you can have a higher spl driver with poorer bass, unless you apply EQ and catapult all that philosophy to oblivion.
Audiophiles would like us to believe in a system of "fast and slow" which we know is a nonsense. We also know certain important decisions have got to be made. You can have a (s)lower spl driver that plays bass right or you can have a higher spl driver with poorer bass, unless you apply EQ and catapult all that philosophy to oblivion.
Hello there,
i have taken a look to spec sheet from BMS:
https://www.bmsspeakers.com/fileadm...ium/bms_18n850v2_2011-04_neodymium_woofer.pdf
BMS declare application of the driver as infra-woofer from 20 to 200 Hz - no midrange. The graph shows the behavior of the frequency response and the corresponding 2nd and 3rd harmonic distortion curves at 1000 W (89,4V) - this is very very impressive. With the right amplifier you can probably produce in a normal listening room so much pressure that the glasses will be pressed out of the window frames. It is more likely that you need a 3 way satellite + subwoofer design. Crossover point from subwoofer to the kick bass no higher than 200 Hz, a 10 inch mid bass will do.
i have taken a look to spec sheet from BMS:
https://www.bmsspeakers.com/fileadm...ium/bms_18n850v2_2011-04_neodymium_woofer.pdf
BMS declare application of the driver as infra-woofer from 20 to 200 Hz - no midrange. The graph shows the behavior of the frequency response and the corresponding 2nd and 3rd harmonic distortion curves at 1000 W (89,4V) - this is very very impressive. With the right amplifier you can probably produce in a normal listening room so much pressure that the glasses will be pressed out of the window frames. It is more likely that you need a 3 way satellite + subwoofer design. Crossover point from subwoofer to the kick bass no higher than 200 Hz, a 10 inch mid bass will do.
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For a loudspeaker without waweguide(s), great rule of thumb is to have each next radiator 3 times smaller than previous. As mentioned in Toole’s “Loudspeakers and Rooms”, a combo of 10+3+0.75 in will provide smooth reflections and sound power. Scaling to 18” bass driver, we have 18+6+2+0.75” sequence, 6 in midrange. Maybe a pro driver to match 18” sensitivity.
Ring tweeter directivity is narrowing above 6-7 kHz, I would swap it for 20 mm dome (somewhat rare today) or Accuton C25.
Attempting to marry a 15” mid to 2” ceramic dome is not recommended and will result in a somewhat severe off-axis and sound power hole from about 400 to 1000-1500 Hz (Accuton can’t be crossed much lower due to rather small 0.75 mm excursion).
Ring tweeter directivity is narrowing above 6-7 kHz, I would swap it for 20 mm dome (somewhat rare today) or Accuton C25.
Attempting to marry a 15” mid to 2” ceramic dome is not recommended and will result in a somewhat severe off-axis and sound power hole from about 400 to 1000-1500 Hz (Accuton can’t be crossed much lower due to rather small 0.75 mm excursion).
Greets!
Hmm, using my preferred octave spreads way to choose drivers, ~20-20 kHz = ~10 octaves, so for a (4) way = ~2.5 octaves each:
~20*2^2.5 = ~113 Hz
~113*2^2.5 = ~640 Hz
~640*2^2.5 = ~3620 Hz
~3620*2^2.5 = ~20480 Hz
So at a glance need some driver changes for a (4) way.
Mid bass driver then is ~sqrt(113*640) = 269 Hz mean = ~13543/pi/269 = ~16" eff. diameter = ~18" frame making for a dual 18" 1.5 way for the ~20 - 640 Hz BW. This will ensure much more life-like mids.
The Accuton doesn't go low enough, so ideally ~sqrt(640*3620) = ~1522 Hz mean = ~13543/pi/1522 = ~2.83" eff. diameter = ~4" frame mid, but with baffle size dictating its low end response, which with an 18" woofer is plenty big enough, so already having the Accuton, your call if using dual 18" or single wide BW 18"/> ~800 Hz XO.
https://alexiy.nl/eq_chart/
https://alexiy.nl/eq_chart/ear_sensitivity.htm
Hmm, using my preferred octave spreads way to choose drivers, ~20-20 kHz = ~10 octaves, so for a (4) way = ~2.5 octaves each:
~20*2^2.5 = ~113 Hz
~113*2^2.5 = ~640 Hz
~640*2^2.5 = ~3620 Hz
~3620*2^2.5 = ~20480 Hz
So at a glance need some driver changes for a (4) way.
Mid bass driver then is ~sqrt(113*640) = 269 Hz mean = ~13543/pi/269 = ~16" eff. diameter = ~18" frame making for a dual 18" 1.5 way for the ~20 - 640 Hz BW. This will ensure much more life-like mids.
The Accuton doesn't go low enough, so ideally ~sqrt(640*3620) = ~1522 Hz mean = ~13543/pi/1522 = ~2.83" eff. diameter = ~4" frame mid, but with baffle size dictating its low end response, which with an 18" woofer is plenty big enough, so already having the Accuton, your call if using dual 18" or single wide BW 18"/> ~800 Hz XO.
https://alexiy.nl/eq_chart/
https://alexiy.nl/eq_chart/ear_sensitivity.htm