Project Unleashed

iTrader: (1)

Howdy Gang,
2001 Firebird with stock monsoon system. None of the speakers sound blown, no modifications to the sound system. A few months ago the stereo system developed a constant buzzing. The buzzing does not change with rpms and the buzzing occures whether or not the engine is running and it is also independant of the volume control. Its possible to turn the volume up high enough to cover up the buz but its very anoying at lower volume levels. I seem to have tracked problem down to the RF speakers. I took turns disconnecting the 6.5" mid and the tweeter and the buzzing only stops when BOTH are disconnected. This seems VERY strange as i thought the tweeters ran directly from the HU and that the mids came off the trunk mounted amp. I dont currently have a spare car speaker to hook up and test further but im going to dig around or pick up a POS speaker somewhere to test with.

Hoping not to upgrade HU or speakers at this time if possible. Any insight appreciated.

edit: I just clipped in one of the rear tweeters to the RF and buzzing persisted until i disconnected the quick clip. argh. so im doubting its the speakers and rather the wiring...or did i read the specs wrong and a shared ground between the RF'(s) and the amp could be problematic?

Edit: question, I think i want to try bypassing the forward speakers at the amp and go straight from the HU to the front speaker(s). Im concerned about the two component speakers that make up each of the L and R fronts. On the Right front It looks like the same colored medium dark green colored wire is used for each of the grounds (mid and tweeter). I have not disconnected the main harness at the amp yet and i have seen the write ups on here about bypassing the amp. dont think i quite understand relationship of the mids and tweeters vs. the HU and the amp. if anybody has time for a quick run down on this topic it be greatly appreciated.

WetChicken

iTrader: (1)

This sounds like a problem in the HU or the amp. Probably a cap went or something in the PA that is allowing an oscillation into the audio chain. It might also be a ground loop.
I think you will be ok to replace either component to test without damaging the other, but I can't guarantee that.
Double check your grounds, and common connections between the two for good measure. A connection may have become corroded, so be sure the key is off, and just yank the radio and amp connectors and check for that, and proper placement for all connections.

WhiteBird00

iTrader: (4)

The Firebird Monsoon system is different from the Camaro system mainly because of the number and types of speakers. Both have an 8-channel amp. In the Camaro, that's enough channels to power all of the speakers. The Firebird has dual voice coil subs in the sail panels as well as tweeters both front and rear. That totals 12 channels so GM wired the front and rear tweeters (4 channels) directly to the head unit and powered all the other speakers (8 channels) with the amp.

The Monsoon amp uses speaker-level input (rather than low-level input like most aftermarket amps) so it was easy to wire to the speaker output of a standard Delco head unit. There are four channels of output from the head unit - left front, right front, left rear, and right rear. These signals are fed to the Monsoon amp which filters the signals and outputs them to the eight channels.

Somewhere along the wiring harness between the head unit and the amp, there are extra wires spliced into the signal wires. Those extra wires go to the front and rear tweeters providing them with unamplified signal. They also have inline high pass filters that prevent low frequency signal from damaging the tweeters. So your door has a tweeter that gets its signal from a wire spliced into the output of the head unit and a mid that gets its signal after it has been passed through the amp.

Each speaker has its own signal and return (power and ground) wires. This is known as floating ground. The system will not work properly if the speakers share a ground wire (common ground). In fact, mixing a floating ground system with a common ground system (without the proper adapter) can cause serious damage to equipment.