System issues........need help....

[valin 10+ year member]

Hey guys. I am having system issues. I've done quite a few systems in the past, and am having big problems with my latest system. Here's the gear:

HU: Pioneer AVH-P6800DVD

Comps: MB Quart Premum 6.5" comps, and 5.25" comps

Subs: 2 - Rockford Fosgate Power HX2 12's, dual 2's, wired to 2 ohms - 2.0 cubes after displacement, sealed.

FS Amp: Memphis MC-3004

Sub Amp: Memphis Mojo MC-2000d

Capacitor: 20 farad, also used as a distribution block

Wiring:

0 gauge power from battery to capacitor

0 gauge ground from chassis to capacitor, approx. 2 feet long.

4 gauge power and ground from capacitor to Mojo

8 gauge power and ground from capacitor to MC-3004

This system is 1/2 new, and 1/2 old. I have run everything but the subs and the comps before in my last system, wired with the same. The box is also new. (Last system consisted of two 18" Fi Audio BTL's, in 12.5 cubes at 32 Hz, and Memphis Power Reference comps).

The entire system sounds like crap. I find the mids will distort with moderate power (probably only 30-40 watts), which is quite a bit below the 60 watts RMS, the tweets do not sound clean (currently set to -1.5 db), and are not very bright at all, which I am very surprised at considering most people say the MB Quart tweeters are very harsh. Every channel sounds the same. The the subs have very poor output as well. The box is sealed. The inside is completely covered in resin, and all the internal seams were glassed. It is a downfiring enclosure, and has 2" of clearance from the drivers to the carpeted floor. I had to build the box like this in order to fit it underneath the seats of my Toyota Tundra. I tried raising this up an additional 1", with no change in output. The bottom of the enclosure (face) is open, as you can see in the pictures, so the output can basically go forward and back.

I am also getting a pop when I turn the system off in the components, not in the subs, so it seems the MC-3004 is not powering down softly. There is no engine noise in the system.

One thing I can note is that when I was installing the system, I got lazy and used the remote wires that are with the patch cords to run the remote. They are extremely small, but I wired all 3 together. I don't think this would be a problem, since the amps are powering up.

My lights are also dimming under power, which did not occur in the last system while running this 20 farad capacitor. The capacitor has a voltage readout on it when it gets a remote signal, and is reading proper voltage when under load.

It's driving me crazy. I was thinking about bypassing the capacitor with a distro block to see if there was any change, and also running a bigger remote wire, but I am sure this will not affect anything. What should I do?

You can see the "feet" on the enclosure on each side that keeps the face off the drivers off the floor 2" after full excursion.

Click to read more...

 

[maddskillzz 10+ year member]

If it werent for the lights dimming i would say you needed a new HU.. But it sounds like you are seriously underpowered...maybe a bad connection somewhere on the main power wire.

 

[valin 10+ year member]

That reminds me, I have not done the "big 3" yet, either. That will probably cure my voltage issues. However, I don't think this will fix the "sounding like crap" issue.

I will go through it and re-check all main power connections.

I was also running the system with only the front stage hooked up while I was building the sub enclosure, and the comps still sounded the same, so they do not only sound crappy under a bit load.

 

[forbidden 10+ year member]

Change the head unit to a eclipse, the system is going to come to life. Ensure all the mids are wired in phase both electrically and acoustically. No sense in having the front speakers in phase with each other and out of phase with the rears.

 

[valin 10+ year member]

I have already tried connecting the channels individually for the mids, and they all sound the same, so phasing isn't an issue. I did not have any issues with this HU in a previous install, but I do have a Sony HU laying around that I can hook up just to test.

 

[valin 10+ year member]

Just went out and did part of the big 3. I ran 0 gauge from the battery negative to the chassis. I was going to do it all, but Toyota put the alternator underneath the motor, so I'll need to hoist up the truck to do it. I am hoping to finish the rest of the big 3 tomorrow.