big system w/ monsoon hu advice, please

[71firebirdls1]

i've searched a little on here, but still have some questions... here is what i'm wanting to do. i have '71 firebird with an '01 TA dash and monsoon head unit. i want to gut out the backseat of the '71 firebird and put four subs (2-12s and 2-10s all at 2ohms) and power it with a 4-channel amp (rockford fosgate or whatever with 150-200W RMS per channel and low distortion at 2ohms) and keep the monsoon hu. i also bought aftermarket 2ohm speakers to replace the two front '01 speakers.

now the sound doesn't need to be a pacemaker or anything, it's not for compitions, and is mostly for looks, but still needs to sound great. i know i need to get a converter for the rca cables and that the monsoon hu is 500W peak.

1) do i need to worry about the output voltage of the monsoon hu? is this hu pretty decent? is it 15-20 RMS per channel?

2) does the factory '01 amp supply poer to all 10 speakers? can i leave the factory in to run the speakers and also put in the fosgate for the subs?

3) is putting the subs in the backseat not going to be very loud/powerful? is doing a sealed set-up best for this or a bandpass set-up better? i want to keep most of the factory speakers working.

any help would be great!

www.ExtremeFirebird.com

[White Rascal]

Mixing and matching different size subs is a bad idea. You could end up having cancellation doing this which would defeat the whole purpose of having subs.

1) No, the POS Monsoon HU is a total piece of garbage. When my car's stereo was still stock I hooked it up to my oscilloscope and took some measurements with a calibrated test CD and found that it distorts it's output at only 23 clicks of the volume control. Try that with your HU and you'll find that that setting isn't very loud at all. The higher you turn it up the worse the distortion gets.

2) The POS factory amp is also a waste of your time. It uses speaker level inputs instead of line level RCA inputs. So you are sending a badly distorted signal from the POS HU into this POS amp that is adding even more distortion of it's own on top of the distorted input signal. This is why the factory speakers are constantly blowing all the time.

3) A sealed box is the way to go. While bandpass subs are the loudest and hit the hardest of all subwoofer enclosures they are large and difficult to design properly. A BP enclosure would be better off in a van or other large vehicle.

Personally I think you should re-think this entire project. Doing what you have in mind now will only lead to headaches further on down the road.

[71firebirdls1]

well, i think i'm going use a line output converter with internal summing (from http://www.mobileaudiocontrol.com/pr...uct_Id=222456# or http://mobile.jlaudio.com/products_c...hp?prod_id=369) for the monsoon hu. that should really clean it up. how would i hook up the monsoon amp (to power all the '01 speakers) and run an aftermarket amp to power four subs?

[White Rascal]

Why bother using what amounts to band-aids for your stereo system? Using adapters to try to improve a poor signal to begin with seems like a terrible waste of time and money to me.