Most HU's have 15-27 watts (RMS) of power per channel. Not too bad if you have very efficient speakers. A Factory HU will give most cars ~90-95dB of SPL to mids and highs.

A good 4 channel for the interiors and a decent Mono amp for the sub is a preferred choice.

If you have a larger sub system installed, additional amping power is always a good option to balance out the mix. Depending on how loud you want the entire system to play (and how much power your intereior speakers can handle) I use roughly an 8:1 ratio ... meaning 800 watts subs, 100 watts to interior speakers per channel.

The other aspect of good balanced SQ (sound quality) system, is to match interior out SPL to subs. Say you target 110dB full range (that's pretty loud) would need 128 watts/channel interiors . (assuming 89dB ref @ 1 watt/1 meter) Cut that by 50%, (64 watts) you'll get 107dB... still very loud.

Also, you may want to seriously consider upgrading the ALT/BAT and BAT/GND wires to #4 gage. Stock wires are usually #6-8 gage. This will help transfer maximum current from ALT to BAT and amps.

 

I'm fairly new to audio. Can someone explain this concept to me?

 

04F-250 stroked - Congrats on the new components, I prefer amping all the speakers through dedicated amps. Since you're going old school (with some freakin sweet amps I might add.. what's the stats on the 225?), I wouldn't worry about trying to use the HU's built-in amp, it's not worth it.. you might also think about buying another 2-channel amp and using the 2150 for a sub since it can put out 600wRMS of true power when bridged.. I love old school amps, aren't they great?


Wow.. I've never heard someone actually try to argue that too little power to the speakers will kill them. I guess I should keep my home theater speakers turned up enough to give my speakers a good work out.. my neighbors are going to be so pissed at me! You won't hurt your speakers by running them with the volume turned down, if anything you're prolonging their life. Your analogy would be good if it were true that speakers had oil between the voice coil and magnet that drained out when you turned the volume down, but it's not true. The voice-coils only heat up when they're in use (caused by friction).. it's impossible to burn up your voice coils by under powering them. If you really want to argue this, then maybe you should learn how a speaker works first. Sorry to bust your chaps.

How does lowering the gain in the amp give you more adjustability than using the head unit? Doesn't it actually.. give you less? If you want to make a change in the fading because a certain CD would sound better with a more "aural" effect, you'd just have to go into the menu on the HU and change it up.. no digging around in the back to turn up the rear speakers for one CD. That's just an example, but still, that's not the reason the gain is on the amp in the first place..

To deisele75 - Some people believe that you should have your soundstage set where it sounds like it's coming from the front of the vehicle.. kind of like being at a concert. Personally I believe this is BS, since I like my sound to envelope me instead of sounding distant. If you're really worried about a "soundstage" then you better get to modifying that car of yours.. the steering wheel needs to be in the middle of the dash and you need to move your seat too.

 

ThankS
i decided to buy a jl audio e4300 to run components. hopefully it'll sound good. On a side note: I just purchased some idq 10" from supercrewsounds.com and will be running them with the ppi pc2150.
P.S. thanks beerstalker for the help! rep points to ya!!!!

 

Sounds like a sweet deal!

 

I think what he is trying to say about underpowering is that, when you try to play a speaker at a higher SPL and you underpower it in the process it destroys the speaker because the amp is trying to create something it can't which causes distortion. When you try to get more out of a amp than it will make then it clips, which causes a flatline in the wave when viewed on an o-scope this flatline is seen to the speaker theorectically as DC even though it is not, which in turn creates extreme heat.

There is no friction in the voice-coil it touches nothing but air.

So it really is better to slightly oversize an amp. If you speakers can handle say 75 W RMS then get an amp that can do 100 W RMS and cut it back a little. That way you are not using a 75 W RMS amp at maximum capacity with the 100 W RMS amp you still have headroom left.