QuestionHello. I'd like to install two front car speakers @ 75W RMS / 225W Peak, two rear speakers @ 110W RMS / 330W Peak, a 250W RMS bass unit, and a head unit @ 20W RMS / 50 Peak x 4 channel. I'm curious as to how powerful of an amp to buy is and what to hook it up to and what to be powered by the hed unit? Thanks.
AnswerHi John,
Most of your questions are mostly a case of personal opinion.
First and foremost, whether or not a speaker needs an amp is usually a better decision to make based on the speaker's cone size.
Smaller speakers (say <= 5 1/4") are acceptable to run off of a headunit, as making highs really loud doesn't take much actual power.
Whereas anything bigger than that, you might want to put on an amplifier.
But it all comes down to how much you can afford and personal preference.
Personally, with that very set up, I would power the 75w fronts off of the headunit, and then buy a 4 channel amp, put the rears on its first two channels, and then run the subwoofer bridged off of its other two channels (making sure I bought an amp that can support that sort of thing, of course. :))
Also, wattage is also a personal opinion thing. You won't blow a speaker by giving it too little wattage, and hooking up 100w speakers to a 300w amp won't make them blow up provided the 300w amp is set up correctly to only provide as much power as the speakers can handle.
Now of course, having a huge difference in wattage between speakers and amplifier is usually a waste of one or the other.
If you have 2 100w speakers and a 250w sub hooked up to one amp, you simply need to find an amp that can provide ~100w per channel, and ~250w bridged across 2 channels.
Good luck,
Justin
