Car Stereos: subwoofer power recommendations, dual voice coil, watts rms

Question
QUESTION: will a 5 channel amplifier with a sub channel of 4 ohms 200 watts output power a sub that is rated at 350 watts rms and 1400 watts max power

ANSWER: Hi George,

200 watts RMS is an acceptable level of power for a subwoofer rated at 350 watts RMS.  (You don't need to pay attention to the "max" power rating for the sub or the amplifier).  Note that the amplifier may produce more power if it's connected to a 2-ohm subwoofer; if your sub is a dual voice coil model, then its impedance would actually be 2 ohms, not 4 ohms, with the voice coils wired in parallel.  However, if you have a single voice coil sub, then you'd want to look at the 4-ohm power rating of the amplifier.

Hope this helps!

Brian

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QUESTION: will 2 pair of speakers rated at 4 ohms, 50 watts rms and 280 watts max power be able to handle an amplifier output of  120 watts x 4 at 4 ohms. Thanks.

ANSWER: George,

If the 120 x 4 specification is an RMS power rating, then it's definitely far too much for the speakers.  That doesn't mean they'll blow as soon as you connect them, however; in fact, for normal music listening, you might be able to get away with this kind of a mismatch.  You'd have to be very cautious, set the amplifier gain control carefully, and be ready to turn it down if the speakers start to sound strained or distorted.  Also, since you're using a separate subwoofer, I'd suggest using the amp's high-pass filter for the front and rear speakers.  Cutting the deep bass tones out of the speakers can help prevent them from being over-powered.

Brian

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QUESTION: Brian can i power my front and rear door speakers that are rated at 4ohms 50 rms and a subwoofer rated at 4 ohms and 350 rms. With an amplifier setting of 50 watts rms x 4 channels + 200 rms x 1 channel 4 ohms. Or do i need to lower the rms rating on the amplifier to below 50 watts rms x 4 channels. I want to power all the speakers off of a 5 channel Power Bass ASA 700.5 amplifier.   Thanks.

Answer
George,

From looking at the amp specs, I think it would be a very good match for your speakers and subs.  You can use a 50x4 RMS amp with speakers rated for 50 watts RMS.  Your subwoofer can handle more than 200 watts, but you can still drive it effectively at that power level.  The amplifier you've chosen should be fine.

Brian