[QUOTE]Originally posted by PJK3 ...

 

weirder and weirder...

ok -- went by the local shop and tried a load of stuff...
and i'm infinitely more confused than ever...

ok -- this is what i've done:

reset the head unit. same problem.
tested my head unit at the shop on their board using their amps
--sounded good.
tested one of their head units in my car w/ my amp
-- same issues.

i start to notice that the left channel is not only quieter, but that mids are 'reverbish' in the right channel (when the left is connected) and that there's no bass from the mids... start to think something's out of phase? i didn't notice this before -- could this be new?

tried 2 different sets of interconnects. swaped sub RCA's for high RCA's.
--same problem.
ran interconnects over the top of the car.
--same problem.

checked deck and amp grounds.
--both seem good.

at this point, i'm back to thinking the Adcom might be bad. i get pricing on some 2 channel JL and Audison amps. *sigh* good pricing, but money i'd rather not spend. i go home.

at home:

so, swapped my Adcom for the Kicker on highs, and ran the Kicker in stereo.
--SAME PROBLEM!?
slightly different but way too similar to be coincidence.
i can't believe both amps would piss out on me at the same time.

so, i get my discman again and play music to test both amps. in two separate efforts, i hook things up to run on both the Adcom and the Kicker (both pushing highs). i check sound directly into the amps, with the over the car RCA's and w/ the RCA's at the head.
--ALL sound fine.

(here comes the real ringer...)
i reconnect up the system as normal, and the problem is clearly still present.

i swap the left and right RCA leads at the amp...
--the problem STAYS in the left speaker.

pulling the amp's input right lead (doesn't matter which lead from the head unit) gives me crappy sound on the left speaker.
pulling the amp's input left lead fixes all issues w/ echo sounds in the right channel.

(i'm thinking a major WTF at this point... )

alright -- just got back from outside. swapped speaker wires at the amp.
-LEFT still the problem.

(always staying left it seems - what's left to check?)

i meter both speakers from the trunk...
--4.5 ohms from trunk for both speakers
checking resitance to ground:
right speaker + = infinite, - = infinite
left speaker + = 5 ohms, - = .4 ohms !?!

so, as of 9:10pm CST, i'm thinking that i'm shorting to ground on the left speaker's negative lead.

anyone care to argue or suggest otherwise?

i guess a 100' spool of 14 ga speaker wire will be my next investment... that and time to run it.


here's the ringer question though....
why does it sound fine when i use the Discman if i'm shorting to ground on a speaker wire?

 

Useless post exhibit A:

I'm totally stumped.

 

We have concluded that it is a shorted ground on the left front speaker line.

True?

However, it is bizarre that a Discman can magically "fix" a shorted speaker.

My theory: The reason for a consistent sound while the discman is playing through your amps may be due to a garbage in/ garbage out factor. That is, the speakers might not sound "good" but instead equal. It is hard to say without actually hearing the speakers.

Have you metered the speaker while running the Discman?
If the resistance is correct than it might not be a short.

 

FYI

You can't do resistance readings on a live circuit.

[QUOTE]Originally posted by Willie Gee
We have concluded that it is a shorted ground on the left front speaker line.

 

See useless post exhibit A

 

Did you ever rerun the new speaker wire or are you using stock cabling you cut into?

 

Bill, i suspect the reason the discman sounds ok is because the Adcom is a balanced amplifier and isolates the negatives from the ground. so when running the discman via batteries, i have no ground from the source, whereas the Alpine does run from the common ground, and thus provides a shorting path.

and John, yup still running through the OEM speaker wiring after the harness... i'm seriously considering replacing it, and probably will....

i just did some further checking, and the short is on the OEM wiring side of things.

i went back to my installer (i had the speakers installed b/c i didn't want to take a hole saw to my baby), and he's going to pull the door and make sure his install isn't bad.
-if his install is good, i'm running new wiring.
-if his install has a short (ie crossover has moved and is shorting), i'll let him fix it and have to decide on rewiring...

 

OEM= Just rewire those babies

 

I didn't read anywhere that you checked the x-over (Focals, right?), unless I was reading too fast. That's what I'm betting on...