I bought a new pioneer deh-p7400mp head unit and when i installed it the speakers sounded distorted. I also have aftermarket speakers. I figured the problem is that the speakers were getting over amplified because of the monsoon amp in the back. What i did was cut the harness that plugs into the amp and i was just gonna connect the wire colors to the appropriate color. I thought this would be easy until alot of the wires don't match up. can anyone tell me what wires connect where or a better solution to disable the amp? thanks

 

The problem you are experiencing is due to the Monsoon amplifier trying to deal with speakers it wasn't designed to operate with, and the signal output of the stock head unit is signal level (200-500mV) The speaker outputs of the Pioneer are of a much higher level (>2v) The "hotter" input signal you are feeding the stock amp is probably overdrivivg the input stages of the Monsoon. Also, I believe that the stock Monsoon speakers have higher impedance voice coils, probably 8 or 16 ohm, or both. By replacing these speakers with your aftermarket speakers which have 4 ohm voice coils, you are causing the stock amplifier to distort because the amp is trying to produce over it's rated power into a lower resistance, causing the signal output to clip. There are three solitions to remedy this problem:
1. Use a multimeter to determine the voice coil resistance of the stock speakers, and buy aftermarket speakers with same rating. (99.9 of your car audio designed full-range speakers are going to be 4 ohm)
2. Disconnect and remove the Monsoon amp, then run speaker wire under the carpet, and through the doors between the speaker outputs of your pioneer, and your aftermarket speakers, using the internal amp of your pioneer deck. It won't be as loud, because decks usually don't have large amplifiers in them (usually 15-22w x 4).
3. Purchase an aftermarket 4-channel amplifier. (something around 30-50w x 4) a good amplifier usually costs around $0.80 to $1.00 per watt) connect the RCA signal outputs of the pioneer to the amp, then the speaker outputs on the amp to your speakers. Others on this board will agree with me when I say that upgrading the Monsoon system is a bitch, because you have to replace everything, speakers, amp and deck.

 

here are the wire colors you need,
http://www.houston-f-body.org/tech/m...mpFirebird.htm

if you want to go that way.... however, i would not, and would buy a new amp, as the monsoon amp is the weak link in the system.

aftermarket head + Stock monsoon = good

Aftermarket speakers and monsoon amp = bad

Aftermarket head, wired direct to aftermarket speakers = good

Aftermarket head, aftermarket amp, and aftermarket speakers = BEST.

Some info on the monsoon listed here.

I ran a aftermarket head, with stock monsoon, and it was better than stock. But now have deck, 2 amps, 4 new speakers, 2 tweeters, and a JL sub.

http://www.houston-f-body.org/tech/monsoon/Firebird.htm

Question to Snootch? Why do you think the monsoon amp has low voltage inputs?

Ryan.

<small>[ April 23, 2003, 01:19 PM: Message edited by: slow ]</small>

 

Slow, I said that because most amplifier input stage only accept low-level inputs, and are most common, granted alot of amps these days have hi and low level inputs. I was assuming that GM/Delco/monsoon would go the cheapest route on designing the amplifier. I read another post that the amp normally recieves a speaker-level input, and you can swap head units using a simple Metra/AI wiring harness. If this is the case, I guess that I was wrong about that. However, what about the impedance mismatch between the stockers, and the aftermarket speakers?

 

ok, that makes sense, just wondering if you had some more info on the monsoon amp that i had not heard before.

The impediance mismatch is there, but it uses low impediance drivers, 2 ohm camaro , and dual 4 ohm for the pontiac "subs" , insteead of the high impediance drivers like most other "premium' systems use. from what i have read, the door speakers seem to be 4 ohm, so i don't see why you could not replace them <img border="0" title="" alt="[Frown]" src="gr_sad.gif" /> i never tried, i just gutted the amp, when i went to the comp's in the doors.

Ryan.

<small>[ April 24, 2003, 10:01 AM: Message edited by: slow ]</small>

 

Really? That's interesting. I just assumed that the Monsoon was just like most other "premium systems" that i've gutted over the years. I think I'll post a thread of every Monsoon speaker voice coil impedance when I gut my system here in a few months, and replace everything. <img src="https://ls1tech.com/threads/images/graemlins/cool.gif" alt="" />