Coaxial Wars....Round Two!

cool...shoot the off axis measurements...

Search on diyaudio as there was a build using it last year with the Hypex plate amp with DSP xover.

What I really want to see are some measurements of the two small BMS units, the 8CN552 and the 5CN140.

Buy them (esp the 8") and measure them for me will you, there's a good chap.

Some of the little PHL 6" coaxes look good too, and I've heard 2 designs using the standard mid versions and they are outstanding. Zalytron have some on clearance if interested.

I'm waiting to get some time in the shop to test the PAudio BM8CX and 15CX38 as I already have 4 of each. Both are used in some well received OB speakers from GR Research, along with some of the other BM coxes.

I really hope you can find some suitable candidates here. I have really been interested in a nice coaxial design after seeing the JTR speakers but without the price tag. Although i have to say its probably pretty fair.

What is it ? I always wanted three 15" Tannoys as my mains. Fell in love while doing some pro audio work back in the 80's. Each cabinet had a 15" woofer and a 15" coax. 250 watts per cabinet was enough to get 120db in the smallish studio.

The 8" coax looks cool.

Posting so that I can subscribe.

Do these have crossovers built in or do they give you 2 sets of terminals?

Nice find, I like the looks!

Little article on the 6CX200Nd

http://www.prosoundweb.com/article/b...oaxial_driver/


The woofer has less sensitivity then I would like, there will be serious padding on the HF to create a decent curve. Max Power is lower then I would have thought for a pro audio driver.

Dang! My FlameThrower is in the shop right now.
I guess I'll just be a silent observer, instead.
How much were they?

Problem is that it's only a 6 1/2 driver. An 8 would likely correct those two complaints, a 10" even more!

Beyma-6CX200Nd

in case you aren't aware, the silver iris is another option.

edit: from hawthorne audio (i think)

since it's a beyma I am guessing, $200-300.

It's basically a Beta 15 with a cheap APT crossing at 2500Hz and a Qt too high for decent use in a box. It was designed as a single driver OB unit.

I have an independent FR saved somewhere and it's awful.

$289

http://www.usspeaker.com/homepage.htm

Ouch, especially since the 8CX21 is <$160 from PSS.

Couldnt you fix this with adding additional woofers not coaxials maybe 2 more? And then it may take just a little padding to the HF. I would it wouldbe better with multiple woofers than stand alone right?

No, the sensitivity of the system is limited by the least sensitive element. If that is the Beyma 6" cone, then adding other drivers will cause combing issues at the upper end of it's range assuming they are running together and not x-ed over at come lower freq.

Those are my thoughts too. Im still not sure why Mayhem is always trying to avoid the 8CX21. Its a succesful driver!

Im talking like the JTR's. 2 woofers and a coaxial driver, so adding 2 woofers wouldnt increase the sensitivity of the mids?. Wouldnt you run into combing issues with any speaker using more than 1 woofer not just this? Thats why you cross at a lower frequency for 6.5" it would be 2086hz to reduce combing i thought. Whats that driver crossed at from the HF source as is? Im really curious and am trying to learn so i may be confused here and appreciate the input/correction. Not trying to jack you mayhem just trying to learn about this topic. I just dont know why you couldnt use 2 other 6.5" woofers of the same similar specs even same exact woofer type just without the HF driver.

You'd have to make a 3 way. As it stands using only the coaxial, you're limited to about 90db after BSC. Adding a pair of woofers in parallel and making it a 3 way you're looking at getting close to 93-94 depending on the woofers and BSC.

If you are going to go three-way, you are better off using a different coaxial with higher (mid) sensitivity and then adding a pair of woofers to get you down to 70-80 hertz. That way you can have a system with 95 to 100db sensitivity. In other words a JTR T8.

I hadnt looked at the specs of this particular coaxial so i wasnt neccessarily referring to "IT" just in general. It would be nice to see a knock off of the JTR's done for a fraction of the price. Thats something i would be really interested in.

roger that alpha niner...if you could dig up that frequency response, that would be good data to have in circulation.

Originally Posted by A9X-308 View Post
Ouch, especially since the 8CX21 is <$160 from PSS.

"Those are my thoughts too. Im still not sure why Mayhem is always trying to avoid the 8CX21. Its a succesful driver!"

I'm using them with the B&C XO-1 ($65) for DSX Wide and Height speakers and they sound very nice.

Spec'd at 94 dB and I don't doubt it for a second.

I would have guessed more from comparing them to my previous LCR's (Scanspeak 7"/1").

At $160 each I do not see why it would not be the clear choice for a coaxial speaker design. Who is PSS?

http://www.prosoundservice.com/m9_vi...:item=BC-8CX21

I don't get what's so exciting about this one? It has low surface area (only a 6.5" frame) so forget about dynamics or decently narrow midrange directivity. Adding insult to injury, the tweeter horn covers most of the radiating surface and is unterminated, so one can realistically expect diffraction everywhere.

So why, exactly, does this driver pique your interest while the Tannoy-style concentrics from B&C, et al., don't?

From my perspective, this itsy bitsy mini driver might be interesting to incorporate into an up-firing omni-style surround (a la Duevel or B&O), but that's the only use of which I can think.


If it was in the 1980s, then they were probably the old-style Duals. (I believe the System 215 DMT, with the modern "Tulip waveguide" Dual, came out in 1990 or so.) Do you remember what the tweeter waveguides looked like? Were they propellers or pepper-shaker tops?

As far as the more recent Tannoy Duals, having just last week had a pair of System 15 DMT II's in my home I stand by my earlier assessment that the 12" Duals are a better choice for home use. Even after running Audyssey MultEQ XT, the 15's were audibly rougher in the lower mids than the 12's. (Pre-Audyssey the difference is more pronounced, I think. I write "I think" because with MultEQ XT off I could do a nearly immediate A/B comparison, and the limitations of aural memory + expectations of improvement from MultEQ XT may color my perception there.)

True, some of the difference could be cabinet-related, as I have mine in cabinets with nothing on the baffle to diffract and large roundovers all around, but Tannoy's published measurements for both show the 12's to be smoother as well.

The 15's were more sensitive. To achieve the same levels with the 12's on a 1kHz sine wave I had to move the volume on my 4308ci/A up four clicks, whatever that means. (I think the published difference is 2dB.)

The 15 DMT II's extra dynamic capability may be an asset in very large rooms, but with three 12 DMT II-based mains even listening to music at voice-modulating levels I've yet to hear them sound strained, or even perceptibly "loud." And the 15's are huuuuuuuge. It's really something to see how thoroughly they dwarf the already large 12's.