PDA

View Full Version : Acend Drivers and Crossovers



davef
12-02-2003, 07:30 AM
Hi sc300t,

I will do my best here to address your questions:

>Please correct me if I'm mistaken. I think the CBM-170 and CMT-340 share the same woofers but different tweeters.

Different tweeters AND different woofers. Although the woofers physically look the same, their parameters and impedance are quite different.

>Woofer:
AUDAX AM170Z2 6-1/2" SHIELDED AEROGEL WOOFER $76.50 each
This is the only audax 6.5" woofer that has aerogel AND phase plug AND shielded. The woofer mount looks slightly different, but the actual woofer itself looks the same.

Both of our 6.5" Aerogel woofers are custom made for us. You can not purchase these from anyone but us. The AM170Z2 is similar looking, but yet it is quite different from the woofer in our CBM-170. The ONLY similarities are the cone material and phase plug. T/S params, motor assembly, voice coil and former are different.

Tweeter for CMT-340
>AUDAX TW025A12 3/4" TEXTILE DOME TWEETER $34.60 each
This is the only soft dome tweeter that has the face plate for wider dispersion.

Similar but also different, however, our tweeter used in the CMT-340 does share the same faceplate. Also keep in mind that this tweeter (the TW025A12) is not shielded and the one built for us certainly is. There are other important differences as well but the tweeter you make reference to is a fine tweeter as well.

>I am not 100% sure about the tweeters, but isnt CBM-340 using the 3/4" tweeter instead of the 1" as advertised?

The tweeter we use in the CMT-340 is a 1" tweeter. The TW025A12 you mention is also a 1" tweeter, not 3/4". The "25" in the TW025A12 represents 25mm, which is equivalent to 1".

>my most important question is the crossover. The CBM-170 is known for the complex and advanced crossover. All sections are second order and they form fourth order. What about the CMT-340 crossover? Is it better than the CBM-170?

Actually some sections of the CBM-170 crossover are 2nd order electrical, others are 4th order electrical. The CMT-340 crossover is as complex as the CBM-170 but to say one crossover is "better" than another doesn't make sense. The CBM-170 crossover is optimized for the CBM-170, and at the same time, the CMT-340 crossover is optimized for its usage as well. Both crossovers function equally well for each of their specific duties.

If you are planning on trying to build your own CBM-170 or CMT-340, I recommend against this. The woofers and crossovers are proprietary and without these components and the necessary advanced measuring equipment we use (as well as experience), you will not be able to reproduce the remarkable flat and linear response of these speakers, which is our speakers trademark.

Hope this helps.











Good Sound To You!

David Fabrikant
www.ascendacoustics.com

sc300t
12-02-2003, 07:41 AM
Hi Dave,

Thanks for the help. That answers everything. I am going to order a set of CMT-340 L/R/C next week (right now just waiting on my refund money from axiom audio). The reason I returned the axiom speakers is because it's too bright. I hope ascend is not so bright (at least ascend use soft dome instead of metal dome).

Couple more questions:

1. Is the tweeter on the CMT-340 more sensitive than the one on CBM-170? If it does, will it produce more detail on the high frequency? Does it really produce wider soundstage with the new design (compared to CBM-170's tweeter?

2. As my understanding, The CMT-340 L/R is basically the same as the CMT-340 C except the tweeter will be rotated 90 degrees (for vertical mounting). What about the crossover? Is it changed (or maybe tuned) for L/R application? What exactly is the difference between the crossover on the L/R and the C?

3. What is EXBAC?

4. Any plans on manufacturing bipolar speakers for surround?

Thank you.

BradJudy
12-02-2003, 01:35 PM
I'll answer 2 & 3 for David. EXBAC is the extended baffle compensation in the crossover of the CMT-340C intended to correct for the extended baffle effect of placing a center channel on top of a TV. This is not present in the L/R versions as they do not need this correction.

I hope you like your Ascends.

David: Anything new in the works for the Holiday season?

sc300t
12-03-2003, 12:16 AM
BradJudy,

Thanks for the answers. So, the CMT-340 L/R crossover is basically the same as the CMT-340 C without the EXBAC?

Dave, what about the question 1 and 4? Thanks.

curtis
12-03-2003, 12:38 AM
I will take a stab at 1 and 4.

I have comapared the CMT-340 to the CBM-170 (I own both). I do detect just a little more detail in the higher frequencies, to me, barely noticeable. The CMT-340 on a whole, definitely presents a wider soundstage. The detail on both speakers is excellent.

Dave has mentioned in another thread that he is thinking about developing a surround speaker, what type he is not sure of.

-curtis

Brian Bunge
12-03-2003, 02:13 AM
Curtis,

Maybe we can talk David into letting me try out a pair of CMT-340's. I could send them back along with a pair of maple cabinets to match your stands! [8D]

Brian Bunge
Rutledge Audio Design

davef
12-03-2003, 10:03 AM
Thanks for answering some of sc300t's questions! Here are formal replies:

1. Is the tweeter on the CMT-340 more sensitive than the one on CBM-170? If it does, will it produce more detail on the high frequency? Does it really produce wider soundstage with the new design (compared to CBM-170's tweeter?

>No, the tweeter sensitivity between the two is the same. The CMT-340 has higher sensitivity due to the fact that it has dual 6.5 woofers wired in parallel. This accounts for the 3dB higher sensitivity spec of the CMT-340. Sensitivity will not affect the amount of "detail" one hears from a tweeter. Low distortion and a lower resonance frequency will achieve more detail. Yes, the 340 tweeter does indeed have a wider dispersion pattern.

>2. As my understanding, The CMT-340 L/R is basically the same as the CMT-340 C except the tweeter will be rotated 90 degrees (for vertical mounting). What about the crossover? Is it changed (or maybe tuned) for L/R application? What exactly is the difference between the crossover on the L/R and the C?

The 340 main version is optimized within the crossover for vertical placement whereas the center version is optimized for horizontal placement on top of a baffle.

>3. What is EXBAC?

It is our designation for E)xtended BA)ffle C)ompensation. It is a circuit within the CMT-340c's crossover that helps compensates for the negative acoustic effects created by placing a speaker on a large baffle (such as a TV.) This has the benefit of increasing the clarity of the midrange response.

Take care!





Good Sound To You!

David Fabrikant
www.ascendacoustics.com