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The BMS mid driver upgrade


Max2

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On the BMS units I've measured, the 8 Ohm version (plotted) measured better than the 16 Ohm.

 

Blue plot is the BMS on a 300Hz horn, no network, raw response from the analyzer.  Microphone about 8ft from throat.

 

Green 4th order band-pass with -6dB corner frequencies at 300Hz and 3.6kHz.  

 

Purple is with -10dB attenuation. 

 

Filter took numerous iterations ("tweaks") between analyzer and the simulator.  Nice response realized however and it can operate at high sound pressures without audible strain.  I would not recommend using a high-pass network on this unit at all.

 

There's better sounding alternatives that are lower cost.

 

Can you expand on the alternatives you mention John?  Thanks

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B&C DE250

 

 

This is what I would recommend for a tweeter or a BMS 4550 on a QSC waveguide from Parts Express. It's in my avatar and looks like a "mini me" K-402.

 

 

that QSC horn sure looks fine (baby K-402~ :P ) but I've compared B&C DE500 combined to that horn with a CP-25. DE500 is very similar to DE250 but with a Neo magnet. CP-25 sounded more open and detailed. DE500 behind a Seos 12 horn was more sweet to ear than QSC. also better controlled dispersion pattern. after all, the best tweet I've ever heard so far is Fostex Fostex T500. this small tweeter sounds badly good! never heard anything better in term of micro detail and tonal accuracy. sure this opinion is subjective.

Edited by Arash
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  • 2 weeks later...

 

 

B&C DE250

 

 

This is what I would recommend for a tweeter or a BMS 4550 on a QSC waveguide from Parts Express. It's in my avatar and looks like a "mini me" K-402.

 

 

that QSC horn sure looks fine (baby K-402~ :P ) but I've compared B&C DE500 combined to that horn with a CP-25. DE500 is very similar to DE250 but with a Neo magnet. CP-25 sounded more open and detailed. DE500 behind a Seos 12 horn was more sweet to ear than QSC. also better controlled dispersion pattern. after all, the best tweet I've ever heard so far is Fostex Fostex T500. this small tweeter sounds badly good! never heard anything better in term of micro detail and tonal accuracy. sure this opinion is subjective.

 

Not having heard them side by side, I would probably agree with you, but the Seos Option was not on the table at my time of purchase. Besides when you throw prices in the equation, the price/performance ration isn't there with the other options you suggest, especially the Fostex, The best horn system I've ever heard was the Sadurni and it used a $1,000 Fostex. When I hear Nora Jones "Come Away With Me" on those horns at Axpona, it was an emotional experience. Best imaging and "live cymbals" sound I've ever heard.

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B&C DE120 1" Neodymium Mylar Compression Driver 8 Ohm 2/3-Bolt
 

 

It's titanium, not mylar. Former owner me be.

 

 

Parts Express screwed it up then as I copied directly from their web site. :huh:

 

http://www.parts-express.com/bc-de120-1-neodymium-mylar-compression-driver-8-ohm-2-3-bolt--294-5809

 

 

For those that may want titanium diaphragm material vs. the mylar, upon further investigation, as I suspected, it looks like Parts Express carries the driver with both types of diaphragm material. B)

 

http://www.parts-express.com/bc-de120tn-1-neodymium-titanium-compression-driver-8-ohm-2-3-bolt--294-5810

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B&C DE120 1" Neodymium Mylar Compression Driver 8 Ohm 2/3-Bolt
 

 

It's titanium, not mylar. Former owner me be.

 

 

Parts Express screwed it up then as I copied directly from their web site. :huh:

 

http://www.parts-express.com/bc-de120-1-neodymium-mylar-compression-driver-8-ohm-2-3-bolt--294-5809

 

They have made errors before, but maybe it's me that stands corrected. sorry. My measurements in the Dave's conical tweeter show a rising high end. They were certainly detailed enough, but now that they are gone, I can't open one up to see. Probably doesn't matter anyhow.

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This is from B&C, definitely a Mylar diaphragm. 

 

I was not aware of the Titanium option for these.

 

http://www.bcspeakers.com/products/hf-driver/archive/de120

 

 

DE120

Current alternative DE110
  • 40 W continuous program power capacity
  • 1" horn throat diameter
  • 36 mm (1.4 in) aluminium voice coil
  • Mylar diaphragm
  • 1500 - 18000 Hz response
  • 106 dB sensitivity

 

 

Dave

Edited by GotHover
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B&C DE250

 

 

This is what I would recommend for a tweeter or a BMS 4550 on a QSC waveguide from Parts Express. It's in my avatar and looks like a "mini me" K-402.

 

 

that QSC horn sure looks fine (baby K-402~ :P ) but I've compared B&C DE500 combined to that horn with a CP-25. DE500 is very similar to DE250 but with a Neo magnet. CP-25 sounded more open and detailed. DE500 behind a Seos 12 horn was more sweet to ear than QSC. also better controlled dispersion pattern. after all, the best tweet I've ever heard so far is Fostex Fostex T500. this small tweeter sounds badly good! never heard anything better in term of micro detail and tonal accuracy. sure this opinion is subjective.

 

Not having heard them side by side, I would probably agree with you, but the Seos Option was not on the table at my time of purchase. Besides when you throw prices in the equation, the price/performance ration isn't there with the other options you suggest, especially the Fostex, The best horn system I've ever heard was the Sadurni and it used a $1,000 Fostex. When I hear Nora Jones "Come Away With Me" on those horns at Axpona, it was an emotional experience. Best imaging and "live cymbals" sound I've ever heard.

 

Any thoughts on the DE10 versus the DE250 with either the QSC or Seos when sensitivity is not an issue (active set up)?  Is there some throat angle issue?  I kind of like the idea of mylar, along with the Community M200. 

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I just got the QSC waveguide and am pairing it with the Dayton D250P. In listening last night with my wife and daughter we were all rather stunned at the sound. Big step forward from the Selenium D220/HM2525 combo, which is surprising because the Seleniums were a step forwatd from my Crites tweeters. A very natural sound, I could really hear the hall on some recordings.

Edited by tromprof
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The best horn system I've ever heard was the Sadurni and it used a $1,000 Fostex

 

what Sadurni has used is exactly what I mentioned as the best tweets I ever heard. better than all Avantgarde, Cessaro, Acapella, Odeon and many other mega dollar horn speaker I've heard so far.

 

fter all, the best tweet I've ever heard so far is Fostex Fostex T500
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In reference to the BMS "HE". What is the shorting ring? How does this improve the driver?

 

If you buy into it

 

The very long version

 

http://www.hifiakademiet.dk/User_files/fedd9fa85cbf2dee95f4281933f6e920.pdf

 

 

 

The short

 

http://techtalk.parts-express.com/showthread.php?213312-From-the-archives-Faraday-ring-explanation-by-quot-Feyz-quot

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