MMC6500's with C400's

[CRTguys]

Just got done installing (4) MMC6500's into (2) C400's wired such that I am using the pre-eq button. (two speakers to one amp x 2)

When the volume is above say 20, the sound is excellent. If the volume is low (under 20), I can hear some distortion in the woofers (bass is muffled and distorted). Now what is weird is if I leave the volume such that I can hear distortion and ADJUST the fader to either full rear or full front, the distortion goes away. As soon as I bring the fader back to 0, the distortion reappears. Turn the volume up and it goes away. I can get good sound out of the system up to about 32 on my head unit.

Any suggestions?

BTW, my head unit is a clarion XMD1 (in my boat)

Thanks

[CRTguys]

more info......

right now I have the front and rear preamps from my HU split to both amps. Since all 4 speakers are in my boat cockpit, can I just use my REAR outputs from the HU and split those to both amps? (leave the front preamps unused)

If I can try that, do I still wire the speakers and tweeters like PA suggests using the pre eq button or do I need to re-wire the speakers?

[cam5860]

You either have a bad ground connection or a sorry pair of rca cables.

[CRTguys]

You either have a bad ground connection or a sorry pair of rca cables.

nope, tried multiple grounds...still there....running top of the line stinger RCA cables that are only 18" long

[cam5860]

It's hard to say man! Make sure your not running your RCA cables on the same side as your power wire. It's possible something could be wrong with the voltage signal coming from your headunit. I had a sony headunit one time and before it went bad. It would go out on me at low volume and come in at high volume. Preamp section of the unit finally went out on me which = No Sound.