Built a handful of nice systems over the years, mostly active systems using a 4 channel amp and a dsp with a sub that had its own amp. No reason not to use 4 ohm speakers.

Until now with this nightmare BMW. I love my 328, and when the sound system is finished, I'll love that, too, but getting there is really taxing my knowledge. Lack of space (convertible) only adds to my issues.

Started with a HiFi, replaced the front mids and tweeter with Morel's Hybrid set up. Big improvement. Bought one of Technics harnesses for adding an amp. Was going to use an Alpine PDX I have. Planning on leaving the rear speaker alone. Here's were my trouble is: It's a 4 amp, channel 1 goings to right door, channel 2 goes to left door. That leaves channels 3 and 4 for the underseat 8" woofers (was going to stick with Morels) Running channel 3 to right underseat and channel 4 to the other underpowers them. However, running the 3rd channel (+) to the (L) underseat and the (-) to the (R) underseat and the 4th channel (+) to the (R) underseat and the (-) to the (L) underseat greatly increases power to both as long as they're 2 ohm speakers (the Morels 8" come in both 4 ohm and 2 ohm).

I know there's a name for this but even with my 20 y/o copy of the Car Stereo CookBook, I'm still confused. Is my above description close? Can the Alpine APX run 4 ohm and 2 ohm at the same time.

Or should I just go with lower rated speakers to go with the power coming out of the amp?

Did you download the Amp Manual?

thanks

the manual, that is. Very confusing.

In the mean time, the new Morel speakers are 4 ohm while the OEM underseat 8" speakers are 2 ohm, right? Don't amps like either 2 OR 4 ohm speakers? Right now the OEM amp is running both. Isn't it damaging to the amp to power the ohm they're not made to run? Running both 2 and 4 at the same time can't be good, either. As long as it's not damaging to the speakers, right? RIGHT?