So, I've helped a bunch of people install car audio equipment, made product suggestions, and done my own work as well. I went through high school planning to major in engineering, and took a digital electronics class. It was great fun.
In my systems, I've gone through a fair amount of parts and finally I installed an Alpine 12" Type-R (1242D) sub rated at 500wRMS/1500wMAX with a Sony XM-ZR1852, 2-channel amp. It was sweet, and a definite upgrade from the Pioneer sub I had in there previously. The Alpine is a 4-ohm dual voice coil sub. When I ordered the sub, that specification stuck in my head. When it arrived and I installed it, I wired it up the way that WASN'T the 2-ohm load configuration, and wired the voice coils in SERIES. I assumed that the overall load would have stayed at 4-ohms. Since I've frequented shows and whatnot, I was impressed with the Type-R but it seemed to be lacking volume and sound quality, but just figured it was my ears and wasn't anything huge. I have the 2-channel Sony bridged to 400wRMS at 4ohms. When comparing systems of people I know, the Type-R kept up but I knew on the inside that it should be crushing all of the Kicker CVRs, Polks, and the like, but it wasn't. I used the gain settings on my headunit to compensate for the lack of volume from the sub. Then, last night came my revelation:
I have a 4-ohm dual voice coil sub with the coils wired in SERIES. That creates an 8ohm load, which means that my speculations were wrong. The amp, seeing the 8ohm load, is only pushing 200wRMS, instead of the 400w I had assumed. I really can't believe I overlooked that..
Now, my situation is that the Sony amp I have isn't 2-ohm stable, so I'm picking up a Kenwood Mono Block KAC-9102D amp from a friend tomorrow. (850wRMS @ 2ohms) And now I won't have to risk clipping the amp anymore!
Hopefully some of you understand the humor in this post!