V8ImpSS

Just adding a head unit and continuing to use the monsoon system will not change anything because the same amplification is being used.

Yea you would leave your rears as is, then the amp literally wires up in between the factory amp and speakers...speaker line level going in and out

Those RMS ratings are for a sub in a properly designed enclosure, they can't handle as much when in a free air application like you've got.

That Alpine MRP-F300 would give you 75w's RMS x4 @2 ohms, plenty for it to be loud and sound good on both your front speakers and subs

LS1SSZ28

iTrader: (5)

Im not sure my Front door speakers are capable of 75rms

V8ImpSS

Yes they can, wattage means almost nothing, if the amp gain is set correctly you'll be fine. Each one of my tweeters have 80w rms going to them...

WhiteBird00

iTrader: (4)

Yes and no. Yes, changing the head unit continues to use the Monsoon amp. No, the change is not small. The factory head unit is a distortion machine with limited control of sound shaping. The Monsoon amp is somewhat underpowered but it is very good at what it does... amplifying the audio signal without introducing its own distortion. Give it clean input and you'll be amazed at how good it can sound. Replacing the factory head unit results in a significant improvement in sound quality and is probably the #1 thing you can do to improve the Monsoon system (even before changing speakers).

Sorry, I don't understand what you're trying to convey here. Audio signal is either speaker level (amplified) or line level (pre-amp)... it can't be both. For most aftermarket amps you'll have to also get an aftermarket head unit since most amps accept only line level input (RCA) not speaker level.

V8ImpSS

By adding a new amp you can adjust the gains so it reaches it highest "volume" before the signal from the head unit becomes distorted. But swapping out the head unit and sending a cleaner signal to the amp won't make his subs hit harder...we're talking about benefits besides SQ.

I meant speaker level (amplified) my bad. That Alpine ive mentioned here several times has a built in hi to low.