Worth a try. You could also try running the shielded cable and stick with the converter in the amp. Won't hurt to try.

My amp is in the trunk (above gas tank), and I ran shielded wire under the drivers side door sill, and have a passive high-low converter at the head unit (home-made). When first installed I had lots of noise, till I grounded my rig-job passive converter under the dash. Noise was reduced to a low enough level you can't hear it if the engine is running. I think my remaining noise is from two sources; the factory wiring running parallel to the shielded cables in the door sill, and a ground-loop between the amp ground in trunk and the converter ground under the dash. Not enough for me to worry about since I will be upgrading to a MP3 head unit or HD-based system in the next few months. Hopefully.

 

The problem is now solved. I have ZERO noise that I can hear.

The problem was the signal from the head to the amp. I tried twisted pair speaker level and it did nothing. I finally installed a low level converter to the head and ran monster cable (probably a waste of $$$) and the problem was solved.

System now sounds great and head unit never gets turned up past 1/3. Gives me sufficent resolution and good quality signal (relatively). I am using 100W @ 4 ohms, 200W @ 2 ohms amp.

Here are some comments and leasons learned.

1. Don't use speaker level inputs. I guess some people got this to work but it was a PITA for me.

2. Wire up the remote turn on. I was using a "smart" amp that turned on when speaker level signal was detected. The problem is the amp is slow to turn off. It causes a bunch of noise when you turn the car off. Using RCAs and remote turn on works great with no shutdown noise.

3. Buy the best converter / cable you can. It is a lot of work to get this stuff in and its better to waste a few $$$ then a second weekend.

The monster cable I bought had the shield connected only on one end and had one common shield for both signals. The signal cables were twisted as well. From what I have read this is the best way to do it. I conneced the grounded side of the cable to my amp since I was more sure of its ground. Didn't try turning the cable to see if it made a difference since the first test was so good. I am sure there are similar setups for less $$$.

4. Be careful removing the seats. The feet WILL scratch the plastic if it even barely touches it.

5. Buy some extra push thingies (used in carpet and body panels) from Honda before you start. You are bound to destroy a few.

6. Sand off the paint and use a star washer on your ground. I think my good ground is another reason I have zero noise.

7. Take your time. Solder all connections or terminate with a connector. Use shrink wire wrap over bare wire. Use wire ties and tape to keep your cable from moving.

Thanks for everyone's help. I hope I never have to take the interior apart again. Installers earn their money but I am glad I did it for peace of mind.

 

Nice to hear you got it resolved. And yes, I too have "saved" $3 on parts only to have to spend another 3 hours replacing with the better stuff.