need help with sub/amp and ohm understanding

[soniktoothe]

I am currently thinking about putting a sub in my 2007 M3i sedan. I want to build a custom fiberglass enclosure to put behind the passenger rear wheel well. I really just want a little bottom end to round out my factory stereo. And i want to get something decent for as cheap as possible. Here is what I was contemplating:

Infinity reference DVC(4 ohm per coil) 10":
https://www.ebay.com (commissions earned)

JBL 2 channel amp
https://www.ebay.com (commissions earned)
I know the amp is bridgable according to the info i found on it.

I have never worked with DVC subs before.
Option 1: If I wire each coil with its own channel I would get 60w x 2 to the sub. Probably enough power for me. Though I understand that it could damage the sub if the coils are working against eachother due to stereo input.
Option 2: I could bridge the amp then run the coils in parallel bringing the overall resistence to 2 ohm. Thereby increasing power, but would I fry the amp?
Option 3: I could bridge the amp and run the coils in series bringing the resistence to 8 ohm, deacreasing power. But would I then only have 60 watts total power? Or would I still be pushing 120 watts due to the amp being bridged.

I would really appreciate the help if I could clear these issues up. Thanks!

Jay

 

[Derrick_B]

Both coils need to be on the same channel. If one channel is producing different sound than the other, the coils will end up fighting each other (bad). That amp appears to be stable at 2 ohms bridged, but you'd need to check the manual.

 

[1sty]

You will need to series the voiuce coils which will preset an 8 ohm load to the amplifier when bridged which will give the sub 120 watts.