Hi,
Bms Coax i heard 12c382, 12c362, 15c262, 15c362, one of the 8" too but i can't remember the ref ( wasn't cheap iirc).
In fact i only think good things about the 12" and 15" i heard i was less impressed by the 8", probably because i listen to an 8" coax on a dayly basis.
I heard them in their field of use, as stage monitors ( 'wedge' or 'fill', small top) driven by loudspeaker management units ( pro dsp). Processing is imo needed for them to shine ( time alignment/fir complementary xover). And don't expect them to be 2 ways Tannoy: they need a third sub/low dedicated way.
So if you are ok with active architecture with at least 3 ways and dsp powered system it's a matter of application and preferences between references.
15" Bms sounds nice and loud. If i had to make a two way i would use the 362, it would be the closest to a system15 Dmt but shorter on low end.
I have a sweetspot on 12". I really liked both, 12c362 and 382. 382 xover can be a tad lower in freq but it needs steep slope imo (the woofer drop like a bomb past 1khz). Well maybe i'm biased by looking to much at the datasheet and had my mind already made when i played with it? . 362 was comparatively easier to deal with, with IIR.
There is a Bms 'sound' in common to all. Maybe from the compression driver i suppose? They are detailed but smooth at same time. It's difficult to put words on it. Woofer part of 382 seemed more vivid to me than the memory i have from 362 but it might be bias as 382 membrane have carbon on it and i expect things from carbon drivers.... so difficult to tell without direct comparison. I would probably go for the 382 though.
Before covid i've seen an infomercial where Bms talked about different versions based on 382, one being less PA and more monitoring oriented. It seems to had been forgoten. Too bad.
Bms Coax i heard 12c382, 12c362, 15c262, 15c362, one of the 8" too but i can't remember the ref ( wasn't cheap iirc).
In fact i only think good things about the 12" and 15" i heard i was less impressed by the 8", probably because i listen to an 8" coax on a dayly basis.
I heard them in their field of use, as stage monitors ( 'wedge' or 'fill', small top) driven by loudspeaker management units ( pro dsp). Processing is imo needed for them to shine ( time alignment/fir complementary xover). And don't expect them to be 2 ways Tannoy: they need a third sub/low dedicated way.
So if you are ok with active architecture with at least 3 ways and dsp powered system it's a matter of application and preferences between references.
15" Bms sounds nice and loud. If i had to make a two way i would use the 362, it would be the closest to a system15 Dmt but shorter on low end.
I have a sweetspot on 12". I really liked both, 12c362 and 382. 382 xover can be a tad lower in freq but it needs steep slope imo (the woofer drop like a bomb past 1khz). Well maybe i'm biased by looking to much at the datasheet and had my mind already made when i played with it? . 362 was comparatively easier to deal with, with IIR.
There is a Bms 'sound' in common to all. Maybe from the compression driver i suppose? They are detailed but smooth at same time. It's difficult to put words on it. Woofer part of 382 seemed more vivid to me than the memory i have from 362 but it might be bias as 382 membrane have carbon on it and i expect things from carbon drivers.... so difficult to tell without direct comparison. I would probably go for the 382 though.
Before covid i've seen an infomercial where Bms talked about different versions based on 382, one being less PA and more monitoring oriented. It seems to had been forgoten. Too bad.
It is sort of fun to see how the response of SB Rosso 65CDN-T driver on an EXAR 400 horn looks like with FIR filtering (driver passband linearization + crossover) targeted at producing a flat 'ish' listening window response (with LR4 highpass at 600Hz).. 🙂
I just keep wondering.. How would it sound like if the pattern width was a tiny bit wider across the bandwidth.. 🙂
I just keep wondering.. How would it sound like if the pattern width was a tiny bit wider across the bandwidth.. 🙂
One of the top modules planned with the dual 15-inch W371A type bass-mid module is a synergized/MEH ed Tritonia waveguide.. 😀 with the mid drivers on the MEH radiating in a cardioidish pattern
The other top module is the EXAR 400 horn.
Front view
Back view
Hopefully I get a chance to try out all this.. 🙂
The other top module is the EXAR 400 horn.
Front view
Back view
Hopefully I get a chance to try out all this.. 🙂
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A quick and very dirty Tritonia-based MEH prototype and preliminary measurements 😀
This is not the actual Tritonia. It is a scaled down version with about 30ish cm width that Mabat had published on ATH thread. The original one is about 43cm in width. Since this is a prototype, I decided to go with this smaller one as it was relatively easier to 3D print
HF: SB audience Rosso 65 CDN-T
MF: 2 x Tymphany TC9FD8 in parallel (8x B&C 4NDF16 drivers already in hand.. 😉 )
Mids radiate out through elliptical-shaped ports into the horn. Total port area per side = approx. 1/12th of driver SD
Distance between centre of horn throat and centre of each ellipse = 6cm (approx)
Right now the mids are open-back. Need to close it and test Next. But till then here are two sets of measurements of the Mids and CD taken separately from about 10cm from horn mouth and 1m away from horn mouth.
Measurements from 10cm away from horn mouth
Measurements from 1m away from horn mouth
The below distortion results are unreliable but still here it is..
Rosso CD distortion from 1m away
Same for 2xTC9FD in parallel on the horn
More measurements with closed back mids and polars to come next when I get time.. 😀
PS: Both drivers were measured with different input voltages as I accidentally turned the amp volume control after I took measurements of the CD on horn
I wanted to fix the mids and the ports on the top and bottom of the horn instead of on the sides.. I mistakenly put them on sides while designing and saw the mistake only after 3D printing.. Also, seems like i was half asleep while doing the design since the driver cutout and screw holes for mids were missed and eventually I had to tape everything together for this experiment.. 😀
This is not the actual Tritonia. It is a scaled down version with about 30ish cm width that Mabat had published on ATH thread. The original one is about 43cm in width. Since this is a prototype, I decided to go with this smaller one as it was relatively easier to 3D print
HF: SB audience Rosso 65 CDN-T
MF: 2 x Tymphany TC9FD8 in parallel (8x B&C 4NDF16 drivers already in hand.. 😉 )
Mids radiate out through elliptical-shaped ports into the horn. Total port area per side = approx. 1/12th of driver SD
Distance between centre of horn throat and centre of each ellipse = 6cm (approx)
Right now the mids are open-back. Need to close it and test Next. But till then here are two sets of measurements of the Mids and CD taken separately from about 10cm from horn mouth and 1m away from horn mouth.
Measurements from 10cm away from horn mouth
Measurements from 1m away from horn mouth
The below distortion results are unreliable but still here it is..
Rosso CD distortion from 1m away
Same for 2xTC9FD in parallel on the horn
More measurements with closed back mids and polars to come next when I get time.. 😀
PS: Both drivers were measured with different input voltages as I accidentally turned the amp volume control after I took measurements of the CD on horn
I wanted to fix the mids and the ports on the top and bottom of the horn instead of on the sides.. I mistakenly put them on sides while designing and saw the mistake only after 3D printing.. Also, seems like i was half asleep while doing the design since the driver cutout and screw holes for mids were missed and eventually I had to tape everything together for this experiment.. 😀
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You could also try a cardioid solution like your sica-coax!
A cardioid MEH. That sounds very innovative ... has that ever been done before?
@stv : Yes that is the idea I had in mind from start.. 🙂 I was thinking closed back to establish a. baseline..
@hifijim: I am sure somebody would have tried the idea out.. It might just be that it might not be an efficient use of mid drivers for high SPL applications and people would have stuck to the idea of larger horns and closed back mid based MEHs of the idea was to extend pattern control lower.. 🙂
@hifijim: I am sure somebody would have tried the idea out.. It might just be that it might not be an efficient use of mid drivers for high SPL applications and people would have stuck to the idea of larger horns and closed back mid based MEHs of the idea was to extend pattern control lower.. 🙂
I am thinking if I can substitute the Rosso CD with a 1inch CD like the B&C DE 360 (need to buy) or the tymphany DFM 2535/2544 R (both of which I have in hand) to replace Rosso CD on this MEH experiment..
The mids seem to go as high as 1.5kHz or so.. Hence it looks like a waste of the Rosso CD.. Also, The B&C DE360 looks so clean (for a compression driver) upto 20kHz that I have not seen anything like it.. I also have 8 x 4NDF34 waiting to be used as a synergy mids instead of the TC9FD drivers..
With all the above potential driver changes, I want to keep the original size of the Tritonia Waveguide or slightly larger (430mm x 3xx mm) and use it with a 1inch driver so that once I put it in a baffle and add roundovers around the edges, it will come to a total of about 520mm in width, which is exactly thr width of my 15inch driver cabinets.. It looks like I will have to custom-make a waveguide using ATH if I am to go with these changes..
The mids seem to go as high as 1.5kHz or so.. Hence it looks like a waste of the Rosso CD.. Also, The B&C DE360 looks so clean (for a compression driver) upto 20kHz that I have not seen anything like it.. I also have 8 x 4NDF34 waiting to be used as a synergy mids instead of the TC9FD drivers..
With all the above potential driver changes, I want to keep the original size of the Tritonia Waveguide or slightly larger (430mm x 3xx mm) and use it with a 1inch driver so that once I put it in a baffle and add roundovers around the edges, it will come to a total of about 520mm in width, which is exactly thr width of my 15inch driver cabinets.. It looks like I will have to custom-make a waveguide using ATH if I am to go with these changes..
JBL M2 uses a robust CD down to 800Hz in a horn. Below that F you will loose horn effect anyways (depending on size)
The benefit of MEH realízes only in rather large size, even SH50 is on the limit IMO (SH50 is a stage monitor).
The benefit of MEH realízes only in rather large size, even SH50 is on the limit IMO (SH50 is a stage monitor).
My idea behind trying out this MEH sort of design to experiment with two aspects:
1) Have the controlled directivity of my Sica coax speakers/or better and extend it to even lower frequencies using the dual 15inch woofer module
2) Retain/Better the dynamics of my EXAR400+ Satori WO24P system
Since the dual 15inch woofer module provides some amount of directivity control down in the 100Hz to 300Hz region, the idea is to have a top module that satisfies the above goals..
All that said, it is not because I am feeling like I am missing out on something on the EXAR400 system, but the curiousity about how would it sound like if its polar pattern was a little wider that drives this design.. 😀
Hence the idea is to have the cardioidish rear radiation from the mids attached on the MEH (either 4 per side on the horn or 2per horn and 2extra pattern shaping mids on the outside of the box that holds the horn).. MEH kind of driver configuration also gives me the benefits of a point source..
1) Have the controlled directivity of my Sica coax speakers/or better and extend it to even lower frequencies using the dual 15inch woofer module
2) Retain/Better the dynamics of my EXAR400+ Satori WO24P system
Since the dual 15inch woofer module provides some amount of directivity control down in the 100Hz to 300Hz region, the idea is to have a top module that satisfies the above goals..
All that said, it is not because I am feeling like I am missing out on something on the EXAR400 system, but the curiousity about how would it sound like if its polar pattern was a little wider that drives this design.. 😀
Hence the idea is to have the cardioidish rear radiation from the mids attached on the MEH (either 4 per side on the horn or 2per horn and 2extra pattern shaping mids on the outside of the box that holds the horn).. MEH kind of driver configuration also gives me the benefits of a point source..
Great!
I have to say this is one of the most instructive and interesting threads I have seen here on diyAudio - thanks @vineethkumar01!
Don't forget you have front-rear cancellation going on that makes it look like there is little low end from the mids. 4 4NDF34's per side, sealed, should be good down to 100-150 Hz for home use. I'll bet that much of that "un-smoothness" you see on the mid response is due to reflections from that open back. they really want to be in a stuffed enclosure. Its really encouraging how high their response goes. It means you are free to choose a CD for its high end response, not one that supports a low XO.
Also that circa 5800 Hz peak coming through the mid ports is common phenomena in MEH and will need to be suppressed
I tried out a slightly larger waveguide derived from Tritonia but with a 1-inch throat using ATH and ABEC
Here is a comparison of infinite baffle vs waveguide in a box with 18mm rounding at the edges
Device width x height = 448.00 x 386.00 mm (17.638 x 15.197")
Device length = 144.00 mm (5.669")
Infinite baffle sims
Normalized response curves from 0 to 90 degrees (Normalization using 10 degrees off-axis curve)
Waveguide in a box version
I am not sure about this.. It looks like the waveguide has a little too much directivity at 1kHz itself.
Even if I have cardioidish radiating mids crossing over around 1.5 kHz to the waveguide, its directivity of around 5-6dB might be less compared to that of the waveguide I think... 🤔
Here is a comparison of infinite baffle vs waveguide in a box with 18mm rounding at the edges
Device width x height = 448.00 x 386.00 mm (17.638 x 15.197")
Device length = 144.00 mm (5.669")
Infinite baffle sims
Normalized response curves from 0 to 90 degrees (Normalization using 10 degrees off-axis curve)
Waveguide in a box version
I am not sure about this.. It looks like the waveguide has a little too much directivity at 1kHz itself.
Even if I have cardioidish radiating mids crossing over around 1.5 kHz to the waveguide, its directivity of around 5-6dB might be less compared to that of the waveguide I think... 🤔
As you have all the machinery of Ath at your disposal, perhaps make it a bit smaller with a larger edge radius. You can also make it less deep, etc. I would also expect the depth of the enclosure to have an effect. Depending on the diameter of the midrange diaphragm, its DI can be higher in the end, increased by its own directivity.
I posted the curves of the waveguide in box wrongly in above post..
Here are the correct curves
Maybe with this kind of directivity from the horn, I don't even need to have cardioidish radiating mids.. Just closed back mids in an MEH configuration crossed over to the woofers might be sufficient I guess..
The dual 15inch woofer module (ideal) directivity below
Maybe the wide-narrow-wide kind of nature of the polar pattern of the waveguide is an issue?
Here are the correct curves
Maybe with this kind of directivity from the horn, I don't even need to have cardioidish radiating mids.. Just closed back mids in an MEH configuration crossed over to the woofers might be sufficient I guess..
The dual 15inch woofer module (ideal) directivity below
Maybe the wide-narrow-wide kind of nature of the polar pattern of the waveguide is an issue?
Attachments
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I am more surprised aboout the DI dip around 4k. Quickly run it on an infinite baffle to check if this issue persists without a box. There lies the real issue with the waveguide, in this avoidable discontinuity.
The other is not resulting from the waveguide alone. The 1k narrowing is usually related to horizontal edge diffraction. If you are going for a narrow pattern, and so it seems, learn from @limacon's, to my knowledge yet to be finished but well simulated and documented two way speaker: https://www.diyaudio.com/community/threads/ath4-waveguide-inspired-multi-way.384410/page-8
According to his testimony, which was given in another thread which I sadly forgot how to find it, to mitigate the narrowing of the pattern required carefully tailoring the enclosure shape and dimensions. This is thus an optimization of all diffraction happening on all edgeds and walls of the enclosure, in respect to the frequency region. Maybe he can give an idea what to look for. The other solution is obviously to go for a free-standing waveguide, and you have been there.
The other is not resulting from the waveguide alone. The 1k narrowing is usually related to horizontal edge diffraction. If you are going for a narrow pattern, and so it seems, learn from @limacon's, to my knowledge yet to be finished but well simulated and documented two way speaker: https://www.diyaudio.com/community/threads/ath4-waveguide-inspired-multi-way.384410/page-8
According to his testimony, which was given in another thread which I sadly forgot how to find it, to mitigate the narrowing of the pattern required carefully tailoring the enclosure shape and dimensions. This is thus an optimization of all diffraction happening on all edgeds and walls of the enclosure, in respect to the frequency region. Maybe he can give an idea what to look for. The other solution is obviously to go for a free-standing waveguide, and you have been there.