Arash Posted July 11, 2014 Share Posted July 11, 2014 (edited) actually I want to buy a pair of BMS 4592-mid and I'm in maze about what impedance to get. 16 ohm need 3bd less attenuation and a 11-12db tap of a auto-transformer I wind can do the job. 8 ohms needs 3 more dBs of attenuation. I'll use them on a Khorn or LS (I still haven't made up my mind) on the other hand I may build elliptical tractrix horn to use with 4592s and 4550 tweeter put them on top of an active bass bin. in that case the lower impedance means lower wattage needed to drive them. I don't know what to do. can anyone help me which one to chose and why? in case I can wind a special auto-transformer with -14 or -15 db taps, then what? Edited July 11, 2014 by Arash Quote Link to comment Share on other sites More sharing options...
Deang Posted July 11, 2014 Share Posted July 11, 2014 Google "8 ohm or 16 ohm compression driver" With the 16 ohm version, you will be -12 or -13. 1 Quote Link to comment Share on other sites More sharing options...
mboxler Posted July 11, 2014 Share Posted July 11, 2014 Are you referring to the BMS 4552 compression tweeter (113 dB at 1 watt)? Quote Link to comment Share on other sites More sharing options...
Arash Posted July 11, 2014 Author Share Posted July 11, 2014 (edited) Are you referring to the BMS 4552 compression tweeter (113 dB at 1 watt)? actually I've access to BMS product for -65% lower than ordinary price. doesn't make any difference which model to get about tweeter. 4592-mid shows a hump at 3Khz region. 4592-ND (coax) is more linear. I assume something is wrong with the measurement or at hump is not a horn effect. how about using 4592-ND Coax as a midrange? I can leave the tweeter idle. any idea? 4592-Mid: 4592-ND (Coax): Edited July 11, 2014 by Arash Quote Link to comment Share on other sites More sharing options...
mark1101 Posted July 11, 2014 Share Posted July 11, 2014 I have a pair of 4592ND coax that I run on K-402s. It's a dual driver (coaxial) setup that comes with a crossover board that presents 8 ohms to the amp. I like these drivers a lot. They ARE HOT and will need attentuation. After trying many drivers, these are the closest to the TAD 4002s (beryliums) that I have run into. Quote Link to comment Share on other sites More sharing options...
Deang Posted July 11, 2014 Share Posted July 11, 2014 (edited) .. Edited July 11, 2014 by DeanG Quote Link to comment Share on other sites More sharing options...
Arash Posted July 11, 2014 Author Share Posted July 11, 2014 I have a pair of 4592ND coax that I run on K-402s. It's a dual driver (coaxial) setup that comes with a crossover board that presents 8 ohms to the amp. I like these drivers a lot. They ARE HOT and will need attentuation. After trying many drivers, these are the closest to the TAD 4002s (beryliums) that I have run into. thanks for the opinion 4592-ND coax seems to be more linear than the mid version although I think something is wrong with that hump. what is your idea about using the coax version as a midrange and leave the hf diagram idle? I'll use Beyma CP-25 with 4592 on a Khorn or LS as CP-25 provides more controlled dispersion pattern making the final sound more directivity uniform. is there any technical reason we can't use the coax version just as a mid-range? Quote Link to comment Share on other sites More sharing options...
mboxler Posted July 11, 2014 Share Posted July 11, 2014 Sorry...didn't realize you were referring to the coax model. Since both the mid and tweeter drivers are rated at 112 to 118 dB, you will need to pad the tweeter by the same amount as the mid to match the bass bin. If you were to bi-amp, and build a 2nd order 6k crossover from the mid to the high, you could attenuate the entire 400 Hz + signal to the crossover by 12 dB, and drive the bass at max volume. That's pretty much what I'm doing, using Decware SET amps. I'm using the 4592nd-mid with a separate tweeter. Mike 1 Quote Link to comment Share on other sites More sharing options...
mark1101 Posted July 11, 2014 Share Posted July 11, 2014 Is the curve shown for the 4592-mid on a horn or is it a raw curve? The curve shown of the 4592ND coaxial says it is on a horn, That may be your hump issue. 1 Quote Link to comment Share on other sites More sharing options...
mark1101 Posted July 11, 2014 Share Posted July 11, 2014 I can't state any technical reason but I would not use the coaxial version and then only use 1 portion of it. You may be able to............I just wouldn't. Quote Link to comment Share on other sites More sharing options...
mark1101 Posted July 11, 2014 Share Posted July 11, 2014 ah.......I see the 4592-mid curve was on a CD horn. That's the hump. Don't worry about it. The coaxial driver does the same thing on a CD horn (at my house ). 1 Quote Link to comment Share on other sites More sharing options...
Deang Posted July 11, 2014 Share Posted July 11, 2014 (edited) The published curve says it was done on a "2230 Horn". The room will dominate, and either swamp or exaggerate peaks and dips, sometimes as much as 10dB or more at the listening position. We have plots out here somewhere with that driver on horns that collapse the vertical - anyone remember the thread? Edited July 11, 2014 by DeanG 1 Quote Link to comment Share on other sites More sharing options...
babadono Posted July 11, 2014 Share Posted July 11, 2014 If you use the coax driver both the mid and highs will be coming out the same horn obviously. I tried the BMS 4592 coax on GotHover's eliptrac horn lens and did not like the results. I went to the mid driver only on the eliptrac and a seperate driver and horn for the highs. Perhaps if you have the proper equipment, both measurement and EQ, you can make the coax behave OK. Quote Link to comment Share on other sites More sharing options...
Arash Posted July 11, 2014 Author Share Posted July 11, 2014 (edited) thanks dudes for info about that hump. I think I'll go for a 16 ohm mid version. or 8 ohms?! If you use the coax driver both the mid and highs will be coming out the same horn obviously. I tried the BMS 4592 coax on GotHover's eliptrac horn lens and did not like the results. I went to the mid driver only on the eliptrac and a seperate driver and horn for the highs. Perhaps if you have the proper equipment, both measurement and EQ, you can make the coax behave OK. I have the measurement equipment but I'm not going to use EQ and active Xover. using active network will let me use 4592 outstanding efficiency as I can actively driver woofer to come along with hf horn but IMO efficiency is good to some extent. when we go extremly hight (+110db/w/m) we will restrict out choice of amplifier because you need only a fraction of a watt and that amp which has an accurate first watt becomes a moot point. 104db/w is an acceptable level IMHO Edited July 11, 2014 by Arash Quote Link to comment Share on other sites More sharing options...
Arash Posted July 11, 2014 Author Share Posted July 11, 2014 BMS is a great company but something is annoying about their products. most of the frequency curves they offer is measured in hi wattage! how the bloody hell should I find out for how for example a 15" woofer will performs in normal listening levels?! take this for example: link Quote Link to comment Share on other sites More sharing options...
mark1101 Posted July 14, 2014 Share Posted July 14, 2014 I am using the 4592ND coaxial with the passive network it came with and have that connected to an ALK ESN at 500Hz.. This board has the ALK autoformer on it that adjusts every 1Db. So I have an extreme slope between the K402 horn and the woofer cabinet (DBB) at 500Hz. and much less slope between the BMS drivers. I believe I have the attenuation on the 402 horn set for -3Db. I am also using a DBX 1231 EQ in the system to EQ the K402 horn. This is a must have as far as I'm concerned. You can't run a 402 horn without some sort of EQ. I used a mic and RTA to adjust the EQ to closely match the horn response to that of my MCM setup which is across the room (also in my avatar). This setup is driven by my Benchmark DAC-2 into the DBX EQ and then into a McIntosh MC-2100...........and this is a wonderful sounding setup. 1 Quote Link to comment Share on other sites More sharing options...
Gorm Posted July 14, 2014 Share Posted July 14, 2014 I have the 16 ohm version 4592-mid attached to the Eliptrac 400 in my Super Cornscalas, I love them. They are connected to to ALK ES500 crossovers. 1 Quote Link to comment Share on other sites More sharing options...
Arash Posted July 14, 2014 Author Share Posted July 14, 2014 I have the 16 ohm version 4592-mid attached to the Eliptrac 400 in my Super Cornscalas, I love them. They are connected to to ALK ES500 crossovers. I've seen your CS images on the net. they are fantastic. I'll use them with CP-25 tweeters. Quote Link to comment Share on other sites More sharing options...
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