12 New Drivers Measured at Zaph Audio

[Rick Craig]

Rick,

What would you recommend for a mid under, say, $75?

How 'bout for dipole use?

Thanks!

Really depends upon what the other drivers are and what frequency range you want to cover. For dipole use do you plan to go active or passive? There are some new drivers coming in 2007 that may be really good (talked to someone in the industry a few days ago).

[jdybnis]

Hi Steve,
I also haven't figured out the 11.5 mm of xmax. Based on posts, it's a better mid than a woofer. So why would it need 11.5 mm of xmax?
Jim

According to this review the AA6.5 really a better woofer than mid. http://www.diymobileaudio.com/forum/...ead.php?t=4814

I think we're just discussing midrange performance because that's where zaph's measurements started us out.

[peterS]

Hi Steve,



I also haven't figured out the 11.5 mm of xmax. Based on posts, it's a better mid than a woofer. So why would it need 11.5 mm of xmax?

My $.02 worth....

Jim

split coil gives a higher xmax length as much of the two coil arnt in the gap

[cotdt]

Wow so many informative responses here noting things which affect the sound that I've never even considered. Which means I've got to remeasure all my driver's responses with higher resolution!

And you guys owe it to yourselves to try the Poly AA 6.5. Fans of non-pistonic drivers will really love it, and it sounds good in general too. Pistonic drivers sound more realistic but not as laid-back.

[TacoD]

And you guys owe it to yourselves to try the Poly AA 6.5. Fans of non-pistonic drivers will really love it, and it sounds good in general too. Pistonic drivers sound more realistic but not as laid-back.

Different concepts can work imho, I like the audiotechnoloy drivers a lot but I also can approve pistonic drivers (hmm Accuton sounds to fake for me, but Seas Excel...). For me it's the total package which is important, not only one specific set of measurements.

[madscience]

Greetings everyone!

Since I'm new to this forum, I would like to shortly introduce myself: I am a master student of nanosciences at the University of Basel. As you could have guessed, I'm also an audio DIY enthusiast. My finished projects so far include power amplifiers, preamplifiers, an active crossover, subwoofers and bookshelf speakers. I have a calibrated measurement microphone at hand in conjunction with a computer-based measurement system (newest version of Speaker Workshop).

Now, to get to the point: It looks like the Ascendant Audio Poly 6.5 woofer plays in the same league as the big boys (Scan Speak, Usher, etc.). At 35 bucks this would sound too good to be true. Now, my problem is that I live in Switzerland. The mentioned woofer is not available here . Would someone be willing to hook me up with a pair of the woofers? I would pay the full costs, of course. In return, I would make thorough measurements and publish them on this forum.

best regards,

Daniel

[Drew]

Would someone be willing to hook me up with a pair of the woofers? I would pay the full costs, of course. In return, I would make thorough measurements and publish them on this forum.

best regards,

Daniel

Hi Daniel,

I might be willing to help you out. Shipping would be from the SF Bay Area - maybe it would be a bit cheaper from someone on the East Coast?

[madscience]

I might be willing to help you out. Shipping would be from the SF Bay Area - maybe it would be a bit cheaper from someone on the East Coast?

I think it shouldn't make much of a difference (says he from past experience). What makes shipping costly is the fact that it is over-seas. However, packages sent by US air mail (take around a week to arrive) are a bearable compromise between delivery time and cost. That said, I am definitely interested. I tried to estimate the shipping cost on the USPS website and it turned out to be around 30 US dollars. Adding the shipping within the US, I'm estimating a total of roughly 50 US dollars. Although this hurts a bit, the low price of the drivers (hopefully) makes up for it.
The order procedure could be as follows: once I'm provided a US adress, I can order and pay myself. Then I would send money for shipping from the US to Switzerland.

I can easily be contacted at: d.schaffhauser@gmx.ch.

[Mazeroth]

madscience,

This was just posted over at the Parts Express forum:

http://www.pesupport.com/cgi-bin/config.pl?read=325158

It looks like one of the drivers came bent, which was more than likely a manufacturing flaw. What you *could* try to do is have the guys at Ascendant visually inspect the drivers you're going to order to make sure you get flawless ones, seeing how you're out of the country.

[aprilia88]

I am not quite sure that I understand what is meant when when you guys are talking about no fast bass. Are you talking about speakers (sizes not mattering) or fundamentaly that 40hz is 40hz and that is all there is to it? If you are talking abo

[cjd]

I am not quite sure that I understand what is meant when when you guys are talking about no fast bass. Are you talking about speakers (sizes not mattering) or fundamentaly that 40hz is 40hz and that is all there is to it? If you are talking abo

Hmm, something cut you off?

"fast" bass is not specifically a function of a driver - or at least, the things people hear and associate with fast bass.

Anyone wanting the Ascendant drivers, I would wait for a second opinion (i.e. let Curt finish his look-over) I may have to drive out next week and pay Chad a visit if he's around.

C

[peterS]

Hmm, something cut you off?

"fast" bass is not specifically a function of a driver - or at least, the things people hear and associate with fast bass.



C

i dissagree entirely
it is a function of Le
im sure there are other factors at higher octives which i think you allude to not to mention stored energy but Le is very very important

[madscience]

Hmm, something cut you off?

Anyone wanting the Ascendant drivers, I would wait for a second opinion (i.e. let Curt finish his look-over) I may have to drive out next week and pay Chad a visit if he's around.

C

It would be nice to see Zaph's results reproduced. I am especially interested in the harmonic distortion behavior at higher levels.
As I mentioned before, as soon as I get the chance to get my hands on a pair of them I will do elaborate measurements and post them on this forum.

By the way, some people might think that the AA 6.5 is not entirely suitable for bass reproduction. However, odd order distortion levels are comparable to Scan Speak / Usher drivers. 2nd order distortion is actually much less obtrusive than one might think...
The only problem is see is the somewhat high Qts value. But there are ways to get real bass from sealed cabinets...

[cotdt]

It would be nice to see Zaph's results reproduced. I am especially interested in the harmonic distortion behavior at higher levels.
As I mentioned before, as soon as I get the chance to get my hands on a pair of them I will do elaborate measurements and post them on this forum.

By the way, some people might think that the AA 6.5 is not entirely suitable for bass reproduction. However, odd order distortion levels are comparable to Scan Speak / Usher drivers. 2nd order distortion is actually much less obtrusive than one might think...
The only problem is see is the somewhat high Qts value. But there are ways to get real bass from sealed cabinets...

x2! please test them at high output since low-output harmonic distortion testing kind of defeats the whole purpose, especially since you can't extrapolate the results to higher output. also, these high excursion motors like XBL^2 or split-coil topologies have some noise at higher output that Seas motors do not have, and harmonic distortion tests don't tell the story, but multitone tests would.

[madscience]

also, these high excursion motors like XBL^2 or split-coil topologies have some noise at higher output that Seas motors do not have, and harmonic distortion tests don't tell the story, but multitone tests would.

are you talking about mechanical noise not originating from the membrane? I've experienced artifacts in my CSS FR125S, but they're due to the fact that they have a phase plug and thus cause air leakage. But I suppose the Seas drivers would suffer from the same problem, or not?

[cotdt]

are you talking about mechanical noise not originating from the membrane? I've experienced artifacts in my CSS FR125S, but they're due to the fact that they have a phase plug and thus cause air leakage. But I suppose the Seas drivers would suffer from the same problem, or not?

Yes I am talking about the same mechanical noise. I'm not sure where it originates from, but all XBL^2 motors and certain other high excursion motors have it, while the Seas and Dayton motors you can play at higher output before mechanical noise develops.

[jdybnis]

Zaph's ratings are up

Zaph updated his page with subjective ratings of the 6.5"-7" drivers .

[brucemck2]

Any speculation on how the Accuton might fare vs. this group ... thinking about it, or perhaps the magnesium Seas, as part of a line array with Fountek ribbons.

[gitarretyp]

Any speculation on how the Accuton might fare vs. this group ... thinking about it, or perhaps the magnesium Seas, as part of a line array with Fountek ribbons.

You mean something along these lines? :T

[brucemck2]

Yes, along those lines.

[augerpro]

I noticed Usher uses the 8948A in it's top models. Now we need to get one of those tested since it's almost the same price as teh 8945A/P at PE.

And a Visiton ti100, KE25, al130, al180, and, and...man this stuff never ends. And Seas has new stuff it's rolling out. Getting pretty hard to choose at the >$100 area, many great drivers.

[Feyz]

They use 8948A as a midrange in their 3-4way models where a bigger woofer covers the low end. From the pdf's from Usher's site, 8948A has an Fs of 45Hz, where as 8945A/P has Fs' at low 30s. It has a bit higher sensitivity also, so makes sense as the mid choice vs their other 7" drivers for them. But as a dedicated midrange there are many options to consider for us. I think the 8945A/P (8945P is my favourite) really shines if you want a 2 way close to full range with lots of power handling and low distortion that doesn't require a subwoofer for most music. They had their BeO tweeter data posted at one point, they no longer have it. That looked like a very nice one both in FR and distortion plots, though PE don't have it (yet, may be they will?).

[madscience]

Yes, indeed it would be nice to have the Usher 8948A tested. Personally, I'm interested in it because it seems to have significantly lower Vas than the other Usher drivers. Therefore it could be an excellent choice for compact 2-way systems. The resonance frequency is also low enough to obtain sufficient low-bass response from a small bass-reflex enclosure.

Some words about the Ascendant Audio 6.5:

In my opinion, it is a real stand-out performer because it has really low distortion over the entire spectrum. Price/performance-wise it clearly beats all other tested drivers. Too bad, I can't get my hands on those (only available to the US).

[DearS]

The Usher 8948A is on sale for $75 at Partsexpress, A really good deal. Hope to see them in more DIY systems. :T

[madscience]

It looks like the 8945A is on sale, not the 8948A.

[augerpro]

Zaph has some new drivers tested. The new Seas reed cones look pretty good. Although at their price they may be in the same situation as the Peerless Nomex, spend a little more for the Exclusives or spend less and go with Dayton RS.

The distortion profile of the ER15RLY is extremely similar to the Nomex 832873...interesting. Response is a little more extended though. I wonder what Z at Xmax looks like? From my limited knowledge of motors the Nomex appears to be a bit asymmetrical, I wonder if the Seas is better?

[cotdt]

the ER15RLY is very interesting. i have some slow-order filters i would love to try with it.

[Jed]

the ER15RLY is very interesting. i have some slow-order filters i would love to try with it.

CA15 is equal in performance if looking at distortion. The ER15 is very smooth and if it was between these 2 drivers I'd go with the ER15 as well. The ER18 received a nice performance boost with its excel inspired motor, minus one faraday ring.

[TacoD]

Seas woofers have Klippel optimized motors, the Nextel woofers are very symmetric (Voicecoil magazine measurements).