Exceeding car amplifier ohm rating?

[mightyhorn]

I have a Rockville RXA-F1 amp. My car's 4 front speakers are wired as two parallel pairs. Their combined ohm rating drops their load to 1.7 ohms per channel, which is below the amp's 2 ohm rating. Is this OK?

Extra info in case it matters:

The speakers are all coax
The door speakers are Alpine 6.5", 4 ohm, 50/250W
The dash speakers are JBL 3.5", 3 ohm, 25/75W
I am using an AudioControl LC7i LOC
The sub is powered, so the amp isn't powering it.

Thanks for your help!

 

[americanaudiophile]

It is not OK.
You could blow a fuse in the amp, make it go into protection and turn off, or blow up. If it does work at first it might cause the amp to overheat while playing and shut down.
If you're bridging the 4 channel amp to stereo it's only stable to 4 ohms not two ohms.
If you are only using two channels to drive the front speakers then you could wire a non inductive power resistor in series with the parallel wired speakers to raise the impedance.

 

[mightyhorn]

Thanks for the warnings...I've read similar. I think I've decided to just rewire the dash speakers, but out of parallel, separate from the door speakers. This way, channel 1 will be 4 ohms, and channel 2 will be 3 ohms. Again, channel 3 will be rerouted to my powered sub, away from the amp.

Hopefully this is an acceptable scenario. If not, feel free to put up the red light again.

 

[americanaudiophile]

You could use the amp in your headunit to power the dash speakers.

 

[mightyhorn]

Why didn't I think of that?!? Of course, this would cause a big wattage difference between the door speakers and the dash, but I guess it could work. Still wondering if it would be best to just un-parallel them and rewire them to the amp separately.

I also posed this question to Rockville directly, and they said as long as I don't drive the system too hard, .3 Ohms over rating isn't terrible.

Should I trust this?