Car audio question: How much can I power from my deck?

[BigToque]

I've got a Pioneer P3100 head unit. Apparently it puts out 45W to each of the 4 channels.

Would this be the Max power going to each channel? Basically meaning that the RMS power going to each speaker is 22.5W?

Now a more 'real-world' type question:

If I put a decent pair of 6x9 speakers, and they could handle up to 100W RMS, does that mean I'm seriously under powering the speakers? At that point, would I need to get an Amplifier just for the speakers?

 

[N8Magic]

Actually, the real usable power coming from that deck is more in the order of 10W/channel (if that). As for your 6X9's, yes, you could power them with the deck, but they won't sound nearly as good as if you were to put an amp in as well. (even a cheap amp)

*edit* I have an Alpine head unit that puts out similar power, and I use it to power the 6X9's in the back of my car. I wish I wouldn't have cheaped out and just bought an amp.

 

[Viperoni]

Actually, you should be hitting roughly 18watts RMS...
read the manual.

And yes, even a cheap amp will sound better than the built in one.
Look at the heatsink on a headunit, and that'll tell you how much power it can put out

I use my Kicker impulse 352xi crossed @ 70hz to run my rear 6x9's as subs :Q