Originally posted by bnoon:
Subs fail more from misuse than any other problem. If you've used a sub this way without blowing it, consider yourself lucky.
The magnetic draw will not allow proper voice coil movement because it was designed for power to come thorugh both voice coils. Putting the sub in a larger box designed for one voice coil is a band aid fix until you measurre the new physical and electrical Q of the driver. Anyone know how to do that? Explain it please... and don't quote some box program equation either...
Mr. T asked for a way to wire them up... dnewma04, you did that part by only wiring two VCs, but now you need to tell him how to rebuild his box to fit the new drivers he's created. 
I'm sorry Brad, but all I did, originally, was answer a question that someone had on how the audiobahn's could be be used in a 2, 4, and 8 ohm load. I did NOT recommend using 1 VC because it just doesn't make any sense in his case. He should either wire the VCs in parallel and use the amp in 2 ohm stereo mode, or do a series/parallel connection and wire them to the amp with a 4 ohm mono amp.
Now as far as DVC drivers go, if you short the other coil (run a jumper across it) all of the parameters remain the same except for teh sensitivity of the sub will drop by 3dB and the power handling of the sub will be cut in half. You can also add a resistor to "tune" it to a certain Qtc, or better yet, use a variable resistor across the other coil to allow to "dial in" the qtc to your needs. This is especially valuable in a dipole subwoofer or an infinite baffle arrangement where a highish Qtc is desired as it literally determines the Qts.
How would I test the new paramaters? I would first go to the company that produced the sub to get them. If that wasn't an option, I would throw them on hte woofer tester. You can also test them with some basic electronic tools if you have them, but it is time consuming and you need the tools to do it.
I don't consider myself lucky, I consider myself knowledgeable enough to consider all the available options and choose the one best suited for my application, in this case, it was to sacrifice some output for the money savings I desperately needed at the time. I had a couple of options, use the amp I had and one VC, buy another amp, buy another speaker. I chose to keep what I had and it worked very well. Of course, before I made the decision, I talked to a few (4) engineers/designers and received feedback from numerous members of the DIY community with more years building speakers than I have been alive, and they all agreed that it was a perfectly viable alternative. I assume that first sentence of yours was to imply that I "misused" the sub, which is completely wrong. I also didn't recall saying that I just put the sub in a bigger box as a bandaid. I put it in the box it was intended for, in my case a critically damped sealed box.
