Hey, I got tired of trying of Hijacking other peoples threads for an answer and figured I'd post my own.

So I built myself up pretty reasonable system and I've run into some issues so I was wondering for those who already have or just have a great knowlege of 12v/car audio could lend a hand.

The problem:
Audio is slightly muted; bass doesn't hit as cleanly as it should and Highs sound held back. It has intermittently corrected itself over a rough patch of terrain or abrupt stop. but only temporarily. When it does come in right it's impressive. Otherwise it's just a slight improvment above running the speakers off the HU amp

The potential culprits:
I've pulled a few potential no-nos; I ran the speakerwire, power, RCAs down about a 2 ft channel together. I'm yet to run an additional Ground to the alternator (more for dimming than anything else). I do have the excess speaker wire and RCA coiled underneath the amp (under the drivers seat). I also used seat bolts for grounds (dremeled the contact points to ensure ground) and ohmed out the grounds from the amps to the HU mounting bracket (0.1ohm). Also in a bout of lazyness I spliced the speaker wire (monster twisted 16g) off the amp into the stock wiring (triple checked labled and color coded, the whole shebang). All no-nos depending on how anal you are about it.

What I installed:
Panasonic CQVD6503 /w Ipod cable
Pioneer GM-6300f (60w x 4@4ohm rms)
Boston Acoustic SL65 and SL95 (60w@4ohm RMS)
Alpine PLV-7 subwoofer (belive the hype, um when it's working right)
Power cable and ground Monster 4gauge (fuse 4g junction box at amp under drivers seat)
Grounds no longer than 14"

related question:
Of you who upgraded your stereos and ran amps, did anyone reground the firewall? I was thinking of running a 4 guage from the Neg term to the where the Alternator bolts on, and then one from the block to the firewall... necessary, over kill?

It sounds like your splice connection isn't mated well. Also are the signal wire going to the right posts. If they are backwards it will be out of phase and may sound a little funny. There may be a power issue with the amp in the sub. Also did you try a different rca cable, in case it's bad? It sounds like you have the grounds covered, which would cause you to have almost no output. Those are a few things to look for, good luck.

The speaker wires are spot on (I labeled each end with sharpie before I even began and the speaker wire is that twisted stuff with one blue and one clear) had the wiring diag on hand and an extra of eyes double check. I crimped/pull tested each lead. I tried pulling the RCAs one by one to ensure it was all in phase... I wouldn't expect the one or two bad sets of RCAs to effect all six, well 5 (have a 5.1 out setup 6 outs one for sub one for center (unused) and the front and rear channels are the other 4).

I was thinking it might be a grounding issue since this is a Body on Frame Truck perhaps the Body and Frame might be insufficiently grounded... It would explain why the the lights dim slightly if I just try to put two windows up at the same time let alone all 4... So them what throw an extra ground to the Engine and then ground the Engine to the firewall? Would I risk creating a ground loop? It goes without saying the light dim when the volume is up there...

There should be a ground strap between the body and the frame. Of course it's probably not the best contact, since manufacturers aren't into creating a perfect sound stage. I would add a ground and it might help. The engine is already grounded, otherwise it wouldn't start.

By the sound of your setup, you probably have a big mess of cables in back of the head unit. Maybe the connector on the radio is tweaked from the bundle of wires. That's why when you hit bumps it kicks in. Try and bundle the wires to create the most space behind the head unit. I'm thinking that is probably the main reason for the bad sound.

Actually it's quite neat back there, working slack only. I de and re-rack fiber and broadcast equipment every night, I'm quite fastidious when it comes to that sort of thing.
I do have a Monster XLN 4ch on the way I think that make me feel a little more comfortable with clearance (stupid tubular bar) and kill any chance of bad RCAs

As for the Grounding the Block,
I've been posting on Audio based sites and they keep refering to The Big Three:
1. Negative battery wire to ground - replace the negative battery terminal and wire with a bigger one and ground it to the factory location
2. Engine block to ground - replace the ground wire from the engine block to the chassis with a bigger wire (4 gauge or bigger)
3. Alternator to battery - add a fused wire from the positive post on you alternator (the one coming from the battery) to the positive terminal on your battery. Don't replace the factory wire, just add a extra one. Fuse it the same size as your factory fuse.

Supposedly if done right you wouldn't need a cap given you have a powerful enough alternator. basically Caps are usually not the solution.
I'm not going for loudness I just want to hear all my music at all volumes

Are you able to try the stereo with it pulled out, to see if the sounds improves? I'd wiggle the connectors on the head unit to see if that is the problem. It could just be a bad head. Do you have the head grounded with a separate wire also? I know some have a grounding post on the back. It sounds like everything else should be good to go. Since you are saying both the speaker and the sub are muted, that narrows it down to the head unit.

Your lights dimming when you use the windows could be from a motor going bad pulling extra amperage. I think you would blow a fuse if it was really bad. Check the resistance between the battery and body. You can always add an extra cable, which will help. Since you are grounding to the body on the inside, the battery is the next connection.

Sorry if this sounds a little scattered, I've been buried in cable myself at work.

I ran the speakerwire, power, RCAs down about a 2 ft channel together.

I assume that you ran them down under the center console?
I did about the same except the RCA's. I have speaker wires, a power cable, and an amp turn on wire running thru there.

Fofiddy,
Btw, I fianlly saw your response on my amp install topic. I responded there wtih a pic showing where I grounded the amp. That is the only additional ground I have though.

I think I may have figured it out... My grounds are fine although I may do the "Big 3" for posterity. I noticed when I got back from vacation the Sub would have a problem with output in the mornings. Where we just went from having temps fall form being lows in the 40's to highs in the 30s. It seemed anytime the Interior was warmed up the sub would hit like a champ. I metered out the outputs and even tan a temporary patch form the Pioneer output to the PLV-7 so make sure it wasn't a funky cable issue.

That morning I was waiting for the tow truck the amp had more than enough time to get to a nice warm temp thus the incredible full range of sound (stereo was muted long enough for the girl to calm down... Timing belt on a VW, you would need some silence too).

So I'm 100% it's the sub, possibly a cold solder point or a bad component in the path of the input...

The sub was a warrenty replacment (long cheap story) so being that Alpine's repair center is in So Cal the sub wouldn't ever have reached an the ambient temp the issue appears to occur at.
I think that about covers it. I'll call Alpine and see if they can send another one out... or pick mine up and send the replacment once recieved...

To answer your question BMX I ran it along the channel located in the driver's side door kickpanel. I'll also be fixing my door speaker shortcut and run the wires all the way to the doors instead of just the harness. Wehrn I put the better 4ch RCA's I just got

Glad you figured it out. Sorry about the girl's car though.

Cause I have something against sleeping (3rd shift) I waited for Alpine cust support to open and spoke to the Tech support guy who hooked me up the first time. He yet again hooked me up, UPS will be by to pick up my defective PLV-7. So I have about 45 min to disconect, unmount and pack the unit till my girl speeds off to work. I just feel bad for the UPS guy, this will be the 3'rd time he's had to lug that 75lb SOB up and down the stairs. He may drop it out of spite when they ship the replacment/repaired unit I should give him some cookies or horseshizz like that.

OK so I'm going to end up wiring the doors properly. Anyone done it? PIA? how long does it take to snake the wires anything to look out for (hangups)?

Thanks for your sympathy Boogeyman. Sharing the car this last 3 weeks (long story, incompitant mechanics, vacation, research) have been trying (trying to get better than 13mpg with Miss leadfoot sharing the helm). It's in the hands of a good mechanic now an I'll prob have them replace her clutch too. For those who don't know the VW 2.0 is an interferance engine: Broken timing belt=bent vlalves... hopefull the cylinder walls and piston are OK. I don't know how she does it, I hear a click, rattle, or a tire is down 4psi and I go Ape. The car could be falling apart on her and it's no big deal. I'll be waiting till she gets her car back before I even order the OME setup.

If there are bent valves, then the pistons should be replaced, since that is what bent them in the first place.

You should definitely give the UPS guy a little something. It will help you get the repaired unit back in one piece.

I would download the manual before you run the wires for the speakers so you have something to look at. There are directions for pulling the door panels off and that's probably the worst part. Just use the old wires to pull the new ones through instead of threading the needle. I would buy some extra panel clips, since they tend to break when you pull the door panels. Good luck.

Carl's PDF Sticky rules
I used it to put in the new door speakers. Been pretty good with the clips haven't lost one yet.

I just hope the guy fixing the jetta hurrys up and calls. Can't get anything done when she's at work.

Update:
Jetta is fixed, Path is all mine again, and subwoofer should be back from Alpine in Feb just in time for my Return from Winter X. Seems the PLV-7 and PLT-5s have been discontinued for 08. Shame, LAT technology shows a lot of promise.

F Alpine the amp is going out again today. What a bunch of hacks their service and repair department are.

Damn, is there a lemon law for amp's also?

Have you ever used the Orion HCCA series?

I wish... 3rd time this thing has been sent directly to Alpine. I was so sick of having my UPS guy give me the stink eye for lugging the 80lb SOB up and down the stairs that I name dropped my occupation and employer so they would just allow me to send the defective Amp. The PLV-7s were slick little units designed by Alpine, Bang Olufson, and Tymphany, won a CES innovation of the year award in 06. Sadly you get that many chefs, well the soup is only hot in certain situations... and it's 100% proprietary.

haven't looked into building another box/amp combo... I used to be a Phoenix Gold guy back when I did that sort of thing, never had an Orion.