As I mentioned earlier, I am somewhat of a bad carpenter... but I need to learn, otherwise I am just in the wrong hobby. If I pay everyone else to build for me all the time, I'll go broke even faster than I otherwise would. 😀 😉
Instead of tackling a huge 7 cubic foot vented enclosure, though, I've been thinking about trying to pull off a much smaller sealed one. I was originally going to use two 12" woofers, bu I'd have to buy them, which would cost extra, and I am a little tight on finds right now. I am also unsure that I'll be able to find any baltic birch plywood to build out of. My local Lowe's and Home Depot only have 3/4" 7-ply birch plywood, as far as I know. This is not exactly what I was wanting... Anyway, I was modeling in WinISD to see what kind of response curve I'd get in a 15" internal cubed enclosure. The volume is roughly 1.95 cubic feet, but after the driver is added, its probably significantly less. No amp will be in there at the moment. I had planned on a Linkwitz transform circuit to EQ the low end up a tad. But, all this modeling ran me into a problem.
The T/S specs listed on the Acoustic Visions website are:
Fs: 26.8Hz
Qms: 7.9
Qes: 0.32
Qts: 0.30
Vas: 132L
Re: 3.6-ohms
BL: 22.1
Sd: 804 cm^2
Xmax: 25.85mm
Pmax: 1000W
SPL: 91dB
But, the DUMAX Specs are considerably different and cause a lot of change in WinISD. The sensitivity goes down using the DUMAX specs, and the box models differently. Also, ThomasW measured the inductance of the driver to be about 2.78mH, which didn't have much of an effect on the curve (thanks again Thomas). But, because the specs are different and the two instances don't model the same, the LT values differ, which throws that off a tad... So, which specs would I be most correct going with? Thanks all
Instead of tackling a huge 7 cubic foot vented enclosure, though, I've been thinking about trying to pull off a much smaller sealed one. I was originally going to use two 12" woofers, bu I'd have to buy them, which would cost extra, and I am a little tight on finds right now. I am also unsure that I'll be able to find any baltic birch plywood to build out of. My local Lowe's and Home Depot only have 3/4" 7-ply birch plywood, as far as I know. This is not exactly what I was wanting... Anyway, I was modeling in WinISD to see what kind of response curve I'd get in a 15" internal cubed enclosure. The volume is roughly 1.95 cubic feet, but after the driver is added, its probably significantly less. No amp will be in there at the moment. I had planned on a Linkwitz transform circuit to EQ the low end up a tad. But, all this modeling ran me into a problem.
The T/S specs listed on the Acoustic Visions website are:
Fs: 26.8Hz
Qms: 7.9
Qes: 0.32
Qts: 0.30
Vas: 132L
Re: 3.6-ohms
BL: 22.1
Sd: 804 cm^2
Xmax: 25.85mm
Pmax: 1000W
SPL: 91dB
But, the DUMAX Specs are considerably different and cause a lot of change in WinISD. The sensitivity goes down using the DUMAX specs, and the box models differently. Also, ThomasW measured the inductance of the driver to be about 2.78mH, which didn't have much of an effect on the curve (thanks again Thomas). But, because the specs are different and the two instances don't model the same, the LT values differ, which throws that off a tad... So, which specs would I be most correct going with? Thanks all
needtubes said:
The ones you carefully measure yourself. It is not hard, just tedious to do it the old fashioned way. All you need is a tone generator program, a ~300-600 ohm resistor and a multimeter.
http://www.epanorama.net/documents/audio/speaker_parameters.html
another way, with different requirements:
http://sound.westhost.com/tsp.htm
Or you can build a wallin jig and use speaker workshop 😉
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