M4 specs
Here are the specs. A monster of a driver. I must have them, my pleads have been answered!
I think I will drive it with a 1W Class A amplifier! 😀
Here are the specs. A monster of a driver. I must have them, my pleads have been answered!
I think I will drive it with a 1W Class A amplifier! 😀
One thing is very peculiar: They couple the convex side of the diaphragm to the horn throat.
The throat is usually coupled to the other side of the diaphragm for good reasons !
Regards
Charles
The throat is usually coupled to the other side of the diaphragm for good reasons !
Regards
Charles
Hmm, for HIFI use, a ~1.8kHz XO point is not where I want to put one regardless of all the consumer/DIY designs that put one in our most acute hearing BW.
GM
GM
not quite as much low-end bandwidth but better distortion for a given freq.
http://www.bmspro.com/products/4591.html
http://www.bmspro.com/products/4591.html
ScottG said:
I dunno, from glancing at the specs, no comparison I think. The M4 goes down an extra octave and the distortion figures are extremely low. They are given for 10% output and 100%. If I am reading this correctly this means at 20W and 200W program power, not 1W/1M as the BMS product. I draw from this that we got 114dB at 1W, therefore 131 dB at 1M for 20W with less than 1.5% second harmonic (at 1KHz!) and, well MUCH less third harmonic distortion, which would be the evil one here. It looks like less than 2% 3rd harm. distortion at 200W= 137 dB SPL! ..and it goes down to 300 Hz 😱
I gather you would probably need a minimum of 8 high regular pro low midrange direct radiators to come even close to this performance in SPL and their combined distortion figure could not come even close.
******* awesome specs, but the thing could sound like a trashcan. Correct me please if I am wrong. 😉
Big Gun,
Are you speaking from experience, or are you looking at the charts?
I am having a hard time with these little smoothed charts, I need to get better glasses... 😀
Don't get me wrong though, the BMS stuff looks as if it is VERY affordable!
Are you speaking from experience, or are you looking at the charts?
I am having a hard time with these little smoothed charts, I need to get better glasses... 😀
Don't get me wrong though, the BMS stuff looks as if it is VERY affordable!
The BMS does indeed appear to be rated at level (i.e. 118 db) where the 2nd harm. distortion figures are less than .5% from 250 to 1kHz and less than 1% above 1kHz (with 3rd order at less than .1% at all freq.s). (Note: the distortion graphing is raised in level substantially.) As far as what happens when power input is increased - I don't know. So I could be wrong about the distortion statement.
Additionally I couldn't find any info on the smoothing going on for the BMS driver - so again its hard to say if one driver has a smother response than the other.
What I will say is that the community driver is NOT a midrange driver - the evident break-up above 2kHz suggests that the driver needs a VERY steep crossover around this freq. (or lower). (i.e. its a lower midrange driver.) On the otherhand it does go an octave lower. Unfortunetly this means that another mid-driver is still needed if your going to use the community driver.
On the otherhand the BMS driver goes quite high in freq. - extending past the midrange with very little break-up. Practically speaking this means that the BMS driver will be FAR easier to integrate into a viable design.
I'm also not terribly fond of impeadance increasing as far as it does in the community driver, it makes me wonder what the phase-angle is doing.
Additionally I couldn't find any info on the smoothing going on for the BMS driver - so again its hard to say if one driver has a smother response than the other.
What I will say is that the community driver is NOT a midrange driver - the evident break-up above 2kHz suggests that the driver needs a VERY steep crossover around this freq. (or lower). (i.e. its a lower midrange driver.) On the otherhand it does go an octave lower. Unfortunetly this means that another mid-driver is still needed if your going to use the community driver.
On the otherhand the BMS driver goes quite high in freq. - extending past the midrange with very little break-up. Practically speaking this means that the BMS driver will be FAR easier to integrate into a viable design.
I'm also not terribly fond of impeadance increasing as far as it does in the community driver, it makes me wonder what the phase-angle is doing.
ScottG said:
Hello Scott,
RE: M4, I was actually more impressed about its reach into the midbass frequency bands, essentially covering the entire vocal fundamental range! Community suggests to run ONE horn in conjunction with TEN bass drivers and FOUR high frequency horns (@25% efficiency each). NOT exactly high on the SAF! 😀
OTOH, this should be the perfect mate for THYLANTYR and his 6(?) SA ribbon tweeters per side. 😱
COMMUNITY aside, you got me curious about the BMS stuff and would like to ask you if you have heard any of it? It seems a hell of a deal! Your insight is much appreciated, I am thinking of getting in touch with their US distributor in Utah.
On the matter of the M4, do you really consider 2kHz to be low midrange? No question that this kind of horn would not be run with a first order passive crossover LOL. I would think a L-R 24dB/oct. or perhaps even a 48dB/oct., run as part of an active three or even four-way system, perhaps with some of the BMS extended horn drivers on top. 😀
Greetings
P.S.: distortions ARE low (see measurements!)
Attachments
Hmm, human vocals go down to 60Hz, though a bit rolled off. A man's pitch starts around 96Hz, so I assume that's why the earliest PA/theater horns had a 100Hz Fc.
GM
Yep, 250 is ~ middle C on the piano. I dunno about y'all, but I can sing a lot lower than that. 250 is straining.
I don't know why it's so popular these days to cross over at 150-200 to "cover the entire vocal range".
Shocking new development: a 'woofer'. Covers the entire fundamental vocal range: 60-800hz.
GB
I don't know why it's so popular these days to cross over at 150-200 to "cover the entire vocal range".
Shocking new development: a 'woofer'. Covers the entire fundamental vocal range: 60-800hz.
GB
2 kHz is middle to upper mid, BUT you really have to look at the entire bandwidth and what is usable. The usable bandwith of the community driver is lower midrange.
I haven't heard any of BMS's products. There are a few things that captured my attention though, (and note that I'm not at all concerned about spl beyond about 111 peaks (or 105 at the listening chair) - only about sound quality with good eff.).
Number one was the gauss of the driver. Its tough finding this sort of magnet strength in ANY driver - particularly in a ceramic magnet. (even neo. magnets rarely have this sort of gauss.) One of the few places you will find this sort of gauss is in lowther (and lowther-like) drivers. As any lowther afficianado will tell you, the higher the gauss, the higher the sound quality - even though it will typically tilt-up the high freq.s of such a driver.
Number two is the mass of the driver (and for the same reasons as number one above). This can be tricky though, perceptually you'll want increasing mass as freq. decreases for a given sd, otherwise you'll get a "ghost-like" effect for imaging - even with excellent amplification.
Number three is the bandwidth. Try looking for more compression drivers that go much lower; you found one.. and I'm sure GOTO and ALE have some at exhorbitant prices, other than that though I don't think you'll find many drivers that go this low WITH an extended bandwidth. To combine properly with the number 2 reason above I generally prefer 1st order crossovers (electrical). On top of this you have power handling. Because the driver is so eff. you have decibles to burn (but you have to do it right - i.e. magnetic, not resistave). This means you can cross lower than what would normally be sane because the driver will only see a fraction of the power of other drivers (even an inexpensive silicon steel variable autoformer should suffice for padding down this driver).
Number 4, low break-up distortion. The driver was originally constructed for the concentric driver approach with NO crossover for the top of the mid (i.e. crossoverless). Nasty break-up's (in drivers) occur because the driver is rigid and starts acting non-linear, (or no longer like a piston). This is tough to remove even with very steep crossovers (for some reason it seems to effect the signal further on down the freq. spectrum, perhaps not unlike what digital 44kHz does without a filter?).
Number 5, low distortion.
..
Now if I was doing a horn today, my first and last shopping stop would be for the H4594ND.. probably with a Le'Cleach "flair", and not dissimilar to the horn size or filter he uses for his "rig", (though I'd certainly do something different for the lower freq.s). In particular (besides the other driver strengths mentioned) this driver is dual concentric which should help tremendously with imaging (and other drivers that say they handle up to 20kHz are lying.. up past 9kHz these drivers start having a downward tilting response). My low freq. driver pick would have to be the Supravox 400-2000 EXC
http://www.supravox.fr/english version/speakers/intro_hp.html
in a quasi open-baffle/resonant-pipe approach that Ocellia uses.
http://www.ocellia.com/Anglais/ocellia-anglais.html
While the box wouldn't be small.. it wouldn't be humongeous either, and COULD look domestically acceptable.
Just a thought.. (what'a'ya think GM?)
I haven't heard any of BMS's products. There are a few things that captured my attention though, (and note that I'm not at all concerned about spl beyond about 111 peaks (or 105 at the listening chair) - only about sound quality with good eff.).
Number one was the gauss of the driver. Its tough finding this sort of magnet strength in ANY driver - particularly in a ceramic magnet. (even neo. magnets rarely have this sort of gauss.) One of the few places you will find this sort of gauss is in lowther (and lowther-like) drivers. As any lowther afficianado will tell you, the higher the gauss, the higher the sound quality - even though it will typically tilt-up the high freq.s of such a driver.
Number two is the mass of the driver (and for the same reasons as number one above). This can be tricky though, perceptually you'll want increasing mass as freq. decreases for a given sd, otherwise you'll get a "ghost-like" effect for imaging - even with excellent amplification.
Number three is the bandwidth. Try looking for more compression drivers that go much lower; you found one.. and I'm sure GOTO and ALE have some at exhorbitant prices, other than that though I don't think you'll find many drivers that go this low WITH an extended bandwidth. To combine properly with the number 2 reason above I generally prefer 1st order crossovers (electrical). On top of this you have power handling. Because the driver is so eff. you have decibles to burn (but you have to do it right - i.e. magnetic, not resistave). This means you can cross lower than what would normally be sane because the driver will only see a fraction of the power of other drivers (even an inexpensive silicon steel variable autoformer should suffice for padding down this driver).
Number 4, low break-up distortion. The driver was originally constructed for the concentric driver approach with NO crossover for the top of the mid (i.e. crossoverless). Nasty break-up's (in drivers) occur because the driver is rigid and starts acting non-linear, (or no longer like a piston). This is tough to remove even with very steep crossovers (for some reason it seems to effect the signal further on down the freq. spectrum, perhaps not unlike what digital 44kHz does without a filter?).
Number 5, low distortion.
..
Now if I was doing a horn today, my first and last shopping stop would be for the H4594ND.. probably with a Le'Cleach "flair", and not dissimilar to the horn size or filter he uses for his "rig", (though I'd certainly do something different for the lower freq.s). In particular (besides the other driver strengths mentioned) this driver is dual concentric which should help tremendously with imaging (and other drivers that say they handle up to 20kHz are lying.. up past 9kHz these drivers start having a downward tilting response). My low freq. driver pick would have to be the Supravox 400-2000 EXC
http://www.supravox.fr/english version/speakers/intro_hp.html
in a quasi open-baffle/resonant-pipe approach that Ocellia uses.
http://www.ocellia.com/Anglais/ocellia-anglais.html
While the box wouldn't be small.. it wouldn't be humongeous either, and COULD look domestically acceptable.
Just a thought.. (what'a'ya think GM?)
Power Spectrum of VOX
Both of you are correct to some degree. 😀
To clarify but not necessarily to abdicate my own imprecision, I would like to say that I was referring to popular music mixing in which the voice is usually somewhat constricted to a certain frequency area . While our vocal chords are able to oscillate within a range of about 50 to 5000Hz (and a bass singer can produce notes in the 80Hz range) our vocal tract acts as a resonator and the first modal resonant peak (formant) of the human voice usually lies around 270Hz . I think from this fact most manufacturers place crossover points somewhat below that range. As far as the M4 driver in question is concerned, it claims to cover the "articulation range" of the human voice, fair enough I think.
The attached measurement elucidates the power spectrum of the human voice.
SO, anyone heard this driver yet? 😀
Cheers
Greg B said:
Both of you are correct to some degree. 😀
To clarify but not necessarily to abdicate my own imprecision, I would like to say that I was referring to popular music mixing in which the voice is usually somewhat constricted to a certain frequency area . While our vocal chords are able to oscillate within a range of about 50 to 5000Hz (and a bass singer can produce notes in the 80Hz range) our vocal tract acts as a resonator and the first modal resonant peak (formant) of the human voice usually lies around 270Hz . I think from this fact most manufacturers place crossover points somewhat below that range. As far as the M4 driver in question is concerned, it claims to cover the "articulation range" of the human voice, fair enough I think.
The attached measurement elucidates the power spectrum of the human voice.
SO, anyone heard this driver yet? 😀
Cheers
" I think from this fact most manufacturers place crossover points somewhat below that range."
rarely, instead they do it for a whole host of other reasons usually to do with the drivers they use and the width of the speakers baffle.
and..
while it would be nice for someone to exclaim the sonic virtues of the driver on the board.. with horns its a VERY subjective assesment better left to you. In otherwords contact woodhorn and see if they will allow you to return the driver after 30 days if you don't think its worth it - if so then all you'll be out is shipping and will have a firm grasp on whether you think the product is worth it or not (which you can't really get here).
rarely, instead they do it for a whole host of other reasons usually to do with the drivers they use and the width of the speakers baffle.
and..
while it would be nice for someone to exclaim the sonic virtues of the driver on the board.. with horns its a VERY subjective assesment better left to you. In otherwords contact woodhorn and see if they will allow you to return the driver after 30 days if you don't think its worth it - if so then all you'll be out is shipping and will have a firm grasp on whether you think the product is worth it or not (which you can't really get here).
Nice suggestions Scott, thank you. Of course, before I shell out the shipping and waste a lot of time I thought it might be worth to at least LOOK for some consensus, here.... .😉
Cheers
Cheers
just did a search here on BMS and apparently there is somone here using their drivers..
http://www.diyaudio.com/forums/showthread.php?s=&threadid=12074&highlight=
and about the only descriptive quality said is here:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=1200&perpage=10&highlight=&pagenumber=2
http://www.diyaudio.com/forums/showthread.php?s=&threadid=12074&highlight=
and about the only descriptive quality said is here:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=1200&perpage=10&highlight=&pagenumber=2
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