Audio Concepts DV12

[peterdesmidt]

I have four Audio Concepts DV-12 woofers. Would they make decent candiates for us in a floor/basement IB? The parameters are:

Impedance: 8 ohms nominal/coil
Size/Inches: 12"
RMS Power: 100 Watts/Channel
System Power: 200 Watts/Channel
Sensitivity: 89 db/1W/1M
SD meters sq: .0540
DCR: 6.28 Ohms/Coil
Inductance: 1.44 mh/coil
Xmax: 10 mm
Voice Coil: 50 mm
Fs: 16.4 Hz
Mmd: 84 grams
Bl: 9.1
Qms: 9.399
Qes: .325
Qts: .314
VAS: 432 liters

[chrisbee]

Even if they were 18" drivers everybody would say 10mm Xmax is just too low to risk with an IB. You will hit the endstops on the first dynamic bass effect. There is nothing to resist excessive cone movement with an IB.

Using 12" drivers you just haven't the displacement necessary for a real IB to move enough air to make the exercise worthwhile.

If you had twelve or more of these drivers perhaps it would be worth a try in a small room where you aren't sitting very far from the manifold. By using lots of 12" drivers you can still build up a reasonable displacement.

Using 15" or 18" drivers it is far easier to get the air moving at low frequencies. Imagine waving a large board in your hands compared with a small one. The large board can move an awful lot more air compared with the small one.

[ThomasW]

If the room is small, and modest output is the only thing needed, then yes they'd work. They're best suited for a ported box.

[peterdesmidt]

Hi Guys,

Thanks for the input! The specs above were pulled off the web, and not from AC Concepts. Doing some digging, I found the original spec sheet. (I'm proud of myself, since I bought them in 1993.) Here are the "officicial" specs, I don't know if this new info changes your recommendations.

BL: 7.80 tm
FS: 17hz
QMS: 5.101
Qes: .481
Qts: .44
Vas: 380 liters
Cms: 902.0436
Mms: 80.340 grams
Mmd: 73.024
Xmax (linear one way): 10.54mm
Voice coil Diameter: 2"
Vocie coil height: 30.61mm
Air Gap Height: 9.525mm
Voice Coil Inductance: 2mh
Voice Coil Resistance: 3.11 ohms

And this is what AC said about them: "The DV12 is ideal for sealed or aperiodic enclosures of 2 to 5 cubic feet. The DV12 also makes an excellent bandpass woofer and works well in fourth order alignments."

[ThomasW]

Mike Dzurko designs and builds good drivers.

These however aren't the best choice for an IB sub, since the Xmax is so short.

[peterdesmidt]

Thanks! It's better to find out the bad news now then after the IB is built. I'm a little confused, though, as to why AC calls this a "super long throw" woofer. Is Xmas usually specified by one-way exursion, say from the mid point to the front, or is it specified from the front travel limit to the rear travel limit?

[PeterW]

It usually measured as half of the total linear excursion. Some people like to hype their drivers by saying things like "this woofer has an amazing 10mm of one way excursion!"
This is typical product marketing, if you did not know that 10 mm is a very low xmax number for a subwoofer, you could be tricked into beliving that the 10mm was big. If you have >25mm one way excursion, it is a very good number. There are very few subs that can sustain linear travel with over 30mm of one way travel.