Vifa Woofers For Subwoofer :) [Archive] - Audio & Video Forums


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11-02-2005, 10:44 AM
I have two Vifa M22WR-09-06 9" Woofers.
I whant to build a subwoofer from them.
Can you tell me if this is a good idea to use this two drivers for a Cloused box subwoofer design.
I have a AR.COM bookshelfs and i am listening for music most of the time.
Thank you very much..
Znom - 6 Ohms
Fs - 26Hz
Vas - 55L
Qms - 2.73
Qes - 0.38
Qts - 0.33
Re - 4.3 Ohms
Xmax - 6.5mm (one way linear)
BL - 8.8Tm
Sens. - 88dB 1w/1m
FR - 30-1000 Hz
150w RMS/600wp (transient)

225mm (9") frame diameter
187mm (7.4") cutout diameter

11-02-2005, 11:35 AM
Hi Alex,
If what you've provided is accurate (and I think it is), I calculate best results in a 30 L vented box with a 2" ID port that is 6" long.
To be honest, sealed subwoofers that are smaller than 12" usually have to cost a lot of money to make good, deep bass, so ported is best for these woofers. (hey nothing wrong with that, the port let's you use the air inside the cabinet to make bass for free).

Make 2 boxes for them, 30L. They can be a perfect cube (13.75" each side measured to the outside) using 0.75" MDF.

Place the subwoofers by each of your's so you have dual subwoofers in stereo mode. These should be a pretty good budget subwoofer. You should be able to find subwoofer plate amplifiers that have 70 to 100 watts for cheap. That's all you'll need for these since you'll have 2.

They should really add some bottom end punch to the's. I calculate F3 around 30Hz, but it will be a bit lower than that in your room, maybe 26 or 27 Hz.

Let me know how you make out.

11-02-2005, 11:47 AM
WAW that was fas!
Great answer thanks.
I consider to buy one Sub Amp, and use this two woofers in one box, i do not think i whant to use two boxes becouse of a space and wires runing thrugh.
Please can you colculate again for a one box :D
Thanks ;)

11-02-2005, 12:18 PM
The problem with using 1 box is how you connect the woofers.

If you wire them in series, you will double the impedance. Not good, that cuts down your amplifier power by 1/2 and means you will have to buy a much more powerful amp. That'll cost you some more money, which probably isn't worth it. Not only that, your box will have to be double the size. 60 L .

If you wire them in parallel, you will cut the impedance down by 1/2. This is probably worse, since the Re is about 4.3 ohms. Unless you know of a good 2 ohm stable plate amplifier for cheap, you won't want to do this either. You'll fry most of those sub amps I'd think. Again, you'd need a bigger box, too.

So two 30 L boxes, or one 60 L box. Your call. I think the two subs will space the response out in the room much better, and make a more even, consistent sound.

Or just go with 1 of them for now. Even one should take over for the's below 50Hz and add a some bottom end kick.

11-02-2005, 12:22 PM
Thank you very very much...