[sandeepmohan]

Originally Posted by DerAlte

If it was HU end problem, it would give a whine even while playing without the sub. Make sure the amp ground is connected to ground (car body) at the nearest point - seat or seat-belt bolt.

A pair of rear speakers are powered by the same amplifier used for the sub woofer. The amplifier is 4 channel. I have bridged the 2nd pair of speaker outputs for a sub woofer.

As the sub woofer is placed in the boot, I have never checked if there is whine coming from the sub woofer, but the moment I plug the Sub Pre Out from the head unit to the cables that lead to the amplifier I get whine from the rear speakers. Not otherwise. That is how I narrowed down on the possibility of whine coming from the head unit. Besides; I have used the wiring harness provided in the car from drawing power for the head unit and its grounding.

The amplifier is grounded on a seat bolt.

As a test I tried grounding my head unit at the same point the amplifier is grounded (seat bolt), the whine reduced. This was not a good idea as I later noticed my head unit lights dimming with hard hitting bass at high volumes. I reverted back to grounding the head unit to the stock car stereo wiring harness & as of now am living with the horrible whine.

[DerAlte]

The amp is amplifying the hum caught by the cable from HU (Sub-out) to the amp. The problem is not with the HU side grounding.

1. Try changing the cable you use to connect the Sub-out to the amp. Disconnected shield in the cable can cause havoc

2. I would recommend that you get the amp ground re-done. Use a copper washer to get a better contact at the seat bolt

[sandeepmohan]

Originally Posted by DerAlte

1. Try changing the cable you use to connect the Sub-out to the amp. Disconnected shield in the cable can cause havoc

I know you mean well but please don't say this. I spent a huge (For me) Rs. 3700 on THE BEST audio inter connect cables for car audio from MDR Electronics (MX). This was used for linking up with HU to the amplifier. Going by the build quality of these cables I doubt if there could be an issue with them. I will still check.

I should be heading to TMC Electronics this weekend to have Mr. Venu look at the problem.

[drjanakpatel]

hi
the problem in my car has been solved. i visited another installer and he solved it in 10 min. i don't know the exact details but he changed the connections to the amplifier from the battery. he said that the connection was faulty.