Brazilian woofer specs

[njepitt]

Hi Everyone,

I've been looking into biamping my system, and the guys on the Pass Labs forum have given me a reasonably clear idea of a circuit for the crossover. My present system uses a diy F5 powering a pair of B&W monitors, which sound great, but for orchestral music I feel it could use more in the bass. I intend to leave the present system as the mid-high part, and to put a pair of woofers/subwoofers in separate cabinets, independently amplified (how is still to be decided...). I imagine a crossover point about 300Hz, although that isn't written in stone, and I am definitely looking for something for music, mostly classical and jazz, not HT, and I don't need bone-crushing SPL. I'd like to go pretty low, but there is no absolute need to be flat to 20Hz.

My problem with the speakers is that since I live in Brazil, and freight and import taxes are beyond anything reasonable (I'll spare you all my rant...) importing woofers is out of the question, so if I'm going to do this I will have to use local products. There's plenty to choose from, but little information as to what would work well in the situation I am looking for. (If I wanted to install them in my car I could get all the advice I could possibly want...) After checking around I have found this driver

Eros Alto-falantes

which is available at a more-or-less reasonable price (there's also a 12" version). It seems to be quite a close match for this one:

Parts-Express.com:*Dayton ST255-8 10" Series II Woofer | woofer st255-8 10" woofer midbass dayton series II series 2 dayton audio dayton loudspeaker

so it's useful as a reference point. Does anyone have any experience of either of these, or if they are plain wrong for my purpose, can anyone give me an example of a US or European driver that would be better, or alternatively more appropriate T-S parameters, so I can continue searching out a Brazilian near-equivalent?

Many thanks for any help.

Cheers

Nigel

[Inductor]

Selenium speakers are very fine
SELENIUM

[aud1out]

Always liked what I see from Selenium (but have not used).

Out of the blue, someone who does not diy thru these forums remarked how woofers/drivers from Brazilian are good quality. He did not know the brands tho.

[Moondog55]

Some car woofers/sub-woofers work really well.

As a starting point why not look for a driver with an Fs of 25 or lower and a Qts of around 0.33/0.42 which should work in a sealed box with reasonable efficiency.

I thought Bravox were made in Brazil.
Also i would go for a woofer double the diameter of the midrange driver so if the B&W has a 6 inch diver I'd use a 12inch woofer

[njepitt]

Hi Guys,

Thanks for all the replies. Yes, Selenium and Bravox are made in Brazil, but (at least so far) I haven't found anything that looks "right", although I spent some time on their websites (In fact Selenium would be my first choice, since they have a very good rep, and I know where I can get my ahnds on them at a fair price. I'm quite happy to move up to 12", if I can find the right driver). The Selenium woofers I've looked at all seem to be designed for PA work, and have higher Fs, for instance at 50Hz; the best I could see is this one:

http://www.selenium.com.br/site/asse..._pdfManual.pdf

In the case of Bravox they are all car audio drivers, which I am not against on principle, but am concerned won''t work so well for what I want. There is this, for instance,

Bravox

although this is likely outside my budget.

With either Bravox or Selenium it would help if anyone had model numbers, since I am not really sure what I ought to be looking for. Failing that, some other hypothetical T-S parameters would help narrow it down. (Qts of around
0.33/0.42 as moondog55 suggested is a good starting point - how about Qms/Qts or Vas, and so forth?)

Noone commented yet on the Eros driver I posted a link to. Should I read silene as meaning no-one is impressed? (Qts is about where moondog55 suggested at 0.376, but it's a 10" driver. It's 12" big brother has Qts=0.488...) Also, anything that helps with the idea of using a car woofer/subwoofer would be a help, because there is a HUGE selection available, although many of them would have to be hidden from view on account of WAF...

Well, as I said before all help is much appreciated.

Cheers

Nigel

[Moondog55]

That has an Fs / Fo which is far to high for serious bass music

[njepitt]

Originally Posted by Moondog55

That has an Fs / Fo which is far to high for serious bass music

Which one? The selenium? How about the Bravox?

[njepitt]

Maybe this one is a little more like it?

Bravox

[Jerrand]

Hey nigel, i too live in Brazil and here is really hard to find good material for DiY !!! Looking at the Selenium site, this is the model that came the closest to the initial specs the Moondog said !!!

SELENIUM

[njepitt]

Hi Everyone,

I've managed to find some info about some woofers by NAR audio, which appear to be closer to what I am looking for. Both are 12", although they have some 10" models also. (I probably can't get these locally, but I can mail-order from within Brazil, which is nearly as good...)

Specs on the 12SW-3 (two voice coil 2x6R, a little pricy...)

Qts=0.318, Qes=0.347, Qms=3.908, Vas=175.5l, Fs=23.4Hz, Xmax=13mm

Specs on the 12SW-2 (one voice coil 4R...)

Qts=0.516, Qes=0.592, Qms=4.024, Vas=190l, Fs=23.8Hz, Xmax=7.5mm

These look more-or-less what moondog55 was suggesting below. Any thoughts? (I am sort of hoping the cheaper one looks good, but somehow I know it is unlikely....;-))

If anyone thinks the 10" speakers are up to the job I can post the T-S.
(I actually found a link (in portuguese) to a diy folded transmission line using the 10" 10SW-3, which wouldn't be out of the question as far as WAF goes).

Thanks for any help

Nigel