My Fiance's father has a little M&K 2.1 system from the early 80's that includes a VX-7 subwoofer. It's a little 8" with what I think is a 50w plate amplifier. When playing certain notes it makes a vibrating sound that I can't figure out. I pulled the driver and it's not the voice coil scratching, and it's not anything rattling around in the cabinet. Despite not being able to figure out what the issue was, we figured that the driver is over 20 years old, has been well enjoyed, the foam surround can't last that much longer, and it wouldn't hurt to just replace it. The problem is that M&K are no longer in business, the original drivers are basically impossible to find (and we don't want to buy a complete sub with cab just to part it out), and I can't find specs on it. We measured the driver and it came back at 2 ohms, and I was thinking of just getting a DVC 4 ohm and wiring it up in parallel. However, I haven't been able to find any cheap DVC woofers. I know it would receive less power, but is there anything bad about putting a 4 ohm driver in there instead? Does anyone has specs on this thing or other suggestions as far as picking a driver goes? He wants to spend as little as possible and I think I found something that is cheap and will work decently: 8" Shielded Poly Cone Woofer 4 Ohm. Thanks friends.