mach 460 question maybe bad ground.

[notch351]

I have a 94 cobra my problem is i have been unhacking an aftermarket radio install. put the stock stuff back in everything is working good but i found that the front door speakers were removed. i installed new ones and there is a lot of engine noise coming from the lower door speakers only. the rest are fine. obviously a ground but not sure were to look or which amp controls those two speakers.any thoughts. thanks

 

[Chythar]

There are 3 amps in the Mach 460 system. If I remember correctly, the amp beneath the radio controls the 4 tweeters; the left amp in the rear tray controls the two left speakers (front and rear), and the right amp in the tray controls the two right speakers. If you're getting static from the two bottom door speakers only (no static from the speakers in the rear tray), then I doubt it's either amp. The Mach 460 wiring does not have a special ground screw just for the sound system, so I doubt that's the issue.

Did you replace the door speakers with OEM Mach 460 speakers, or with aftermarket? The large speakers in the Mach 460 double as woofers and can't be replace with aftermarket speakers without losing the low-end bass.

 

[notch351]

I tried putting in two way pioneer speakers in the doors. the sound is engine noise though not just static. but the back subs are ok. they were doing the same thing and it was the connection under the kick panel. thought there might be a seperate connection for the front doors. gotta love stupid problems like this

 

[Chythar]

The Mach 460 wiring is a bit weird, I know. I'm not sure what to tell you about engine noise only from the lower door speakers. Engine noise from all speakers is usually the small cylindrical capacitor attached to the coil, but just the replacement speakers? Maybe the OEM speakers have their own filter on them somehow. Sorry to say, but I don't have any ideas.

The dash grounds are in the center-right of the console. Basically, sit in the passenger seat and pull the top edge of the carpet back by your left foot. There will be two ground screws with a few ground wires connected there.