Audio issues

[cherrington17]

I was troubleshooting this with ryan, but i figure someone can benefit from reading this in thread form....


i got my new 6.5s in, and they sound great. but from day 1, there has been a loud "pop" everytime i turn the car off. Obviously, its the amp thats older and doesn't have a soft turn off feature. I could live with that.

Just yesterday, I drove to school with no problems at all (it was nice, windows down some, stereo up louder) but when i got back in, there was a loud hum, which turned to a whine when i was about half way home. I turned the radio up louder to overcome the hum, and it'd start popping intermittantly. So i just straight turned it off.

So the troubleshooting began. All my amp connections are solid (power grounds remotes) i moved my RCA lines as far away from the power lines as i could (still have a big of overlapping for a couple inches before they go to each amp) And ryan suggested to check all the grounding on my h.u, thinking maybe that was the issue. So i moved them to what i'm positive is a solid ground. and its still there.... just as loud.

so i turned the levels down on my amp (powering the 4 corner speakers) and the hum pretty much disappeared. So am i to beleive this is the amp's doing?? I'd much rather replace that then my headunit. (amps are much cheaper... :lol: ) The amp i'm using is about 10 years old, and has been in storage for about 8 of those... i'm guessing it probably needs a good internal cleaning and/or replacement of a couple vital parts. but it still won't make it new.

so.. questions, answers, suggestions?

[AGT]

The overlapping could cause it but I doubt it. How shielded are all of your wires, including the speaker wires to the new 6.5s

[cherrington17]

going TO the crossover then to speakers aren't shielded, other then the standard wire casing. (16ga i believe) and the rca's are your standard el-cheapos. :lol: but even those should have your basic shielding.

powers are on the driver side, rcas on the passanger, speaker wires under each seat...

[AGT]

You'd be surprised of the difference between el-cheapos and some Stinger Bullet Series.

[cherrington17]

yeah.. but i've never had an issue like this before... i really don't think its the cabling....

[AGT]

Okay. True it may not be wiring but you know how they say go with the cheapest fix first. I would say that amp could be a problem.

[cherrington17]

i just figured if it was audio cables, it would be there from the day i set it up... not just start spontaneously...

and if it IS the amp... who makes a good 4ch 400w small amp?

[jayson_waltz]

i'd say try better RCA cables and a ground loop isolator first. it sounds like your just getting interference in the signal
if you are looking for a decent cheap amp, try www.techronics.com. i've had good luck with them

[AGT]

i'd say try better RCA cables and a ground loop isolator first. it sounds like your just getting interference in the signal
if you are looking for a decent cheap amp, try www.techronics.com (http://www.techronics.com). i've had good luck with them

ground loop isolator!!! I couldn't think of the term to save my life. Thank you.

[jayson_waltz]

^lol no problem

[Ryan from Ohio]

Ok, maybe I didnt get it.

But I thought in pm you said it was coming from all speakers. Meaning your interiors run off one amp and your subs off the other amp.

If its just coming from one amp in particular:

Take the RCAs and swap them about to see if theres a difference.

If no difference wire a test speaker to the other amp, plug the rcas into that amp to see if the problems still there.

If not, then its your amp.

[cherrington17]

yeah, i'm gonna try that tomorrow... as well as a ground loop isolator (since we had one at work here for pretty cheap)

and yeah, i did miss out on that sale. :glare:

Ok, maybe I didnt get it.

But I thought in pm you said it was coming from all speakers. Meaning your interiors run off one amp and your subs off the other amp.

If its just coming from one amp in particular:

Take the RCAs and swap them about to see if theres a difference.

If no difference wire a test speaker to the other amp, plug the rcas into that amp to see if the problems still there.

If not, then its your amp.

i'll be checking this, too. my subs are on one, and all interior on the other. i can definitely check to see if one amp is bad w/ that method. not sure why i didn't think of that.

my friend who i got the amp from thinks it might be a RCA solder connection in the amp itself... so while i'm disconnecting to test, i'll open'er up and take a look.

[lonnie]

That ground loop isolator will remove alternator whine but it wont help with that hum at all.

[cherrington17]

ground loop isolator got rid of both. :huh: what does that mean? need shielded rca cables? (i know, i know... i should have had those from the start)

new oddity showed up. I tested like ryan suggested, and connected one amp in place of the other. The noise was still there, but the 1400W 4 channel (was using for my subs) is ALOT quieter on the 4 channels, then the 400W 4 channel. what?? how is that possible? i know it doesn't quite put out the 1400 (its way overrated) but it shouldn't be that quiet (had to have my h.u up to about half to be able to hear it)

so i guess my shopping list, so far, is a new 4 channel amp (for subs) and 3x20ft shielded rca cable and 2 more ground loop isolators

http://cgi.ebay.com/Triple-Shielded-4-Channel-RCA-Cable-20-20-Feet_W0QQitemZ190215455436QQcmdZViewItem
These good enough quality?

and if this is the subs i have...
http://www.sonicelectronix.com/item_1504_Rockford+Fosgate+FF1024+10-+HE2+Fast+and+Furious+FFS1024.html
they can handle 400W per channel? they ARE dvc (just so i'm reading that right) so the amp i'm looking for can do up to 400W per single channel?


lastly... to make sure i have these settings correct. on my headunit, i have preout:S/W (subwoofer) and rear sp: FULL ? from what i understand on pg 43.
http://akamaipix.crutchfield.com/Manuals/130/130DEHP760.PDF

[Ryan from Ohio]

Take some good advice and buy the decent stuff this time around.

http://www.knukonceptz.com/productDetail.cfm?prodID=KRY-1M2F

Thats a solid set of quality cable and the price is reasonable. Im running cables 3x's that price for the looks... Only reason.

Actually if you ask very nicely, I could probably just sell mine to ya- if you want uber high quality and sexy looks.

Outside that, the amps open for debate.

Someone here (YALLER?) bought some amps off my recommendation on E Bay.

If your on a budget I might be able to get something from one of my dealers new. Also note the Cadence Summer sale items of www.caraudioforum.com in the for sale section. Search summer sale

[cherrington17]

meh, sexiness of the cable doesn't matter to me at all. it gets buried and never seen. good quality is a concern though. so the knukonceptz 6m cable is a decent price, if its good stuff.

and for the amp, i really don't know whats going on, but i'd need something that can power 2x10" dvc 400rms subs @ 4ohm. am i better off doing it with 2 separate amps, or just one big 4 chan? and what kinda deals do you think you can get? (i glanced at the cadence stuff, and i don't see anything that'd really fit my power need, but i might have missed something)

[cherrington17]

i'm gonna hold off on the amp... just for the fact that i just tried it w/o the isolator, and it was much louder, with very little noise on all 4 channels... so as a sub amp, i think it'll do. i'll start with getting some high quality cables and go from there.

i'm guessing i'll be tweaking and upgrading this slowly over time, as my budget allows.

so i guess my next question (besides the ones above) with high quality, shielded cable, should i still need those ground isolators??


so i'd be able to get away with:
Krystal Kable 4 Channel 6M Twisted Pair RCA Cable
NEW Karma SS 2 Channel 6 Meter RCA Cable

or would the karma ss be good enough for all 4? (don't necessarily need somethings thats going to be WAY overkill)

[Ryan from Ohio]

I would get the Krystals.

What your seeing is 2 different shielding technologies.

The Karma is the twisted type, which uses thin shielding and relies on the twisted nature to protect them from RFI.

The Krystal is more standard and provides multiple shields. In my eyes more practical.

Ive used both. The karma is cheap and smaller.. Mine were the older version an the RCA ends that screw on would work loose...lol A little super glue fixed that though. New ones seem to be improved.

But Knu is time tested and proven value.

[jayson_waltz]

no you shouldn't NEED the isolator with high quality cables, but since you already have it try with it and without it when you get the new cables and see if there is any difference.

[cherrington17]

i got the isolator from where i work. so i returned that for the time being (can reget it later if i NEED it) but i just ordered the krystals, and i'll put them in later this week... see how it works.

[cherrington17]

got my cables.... just a matter of needing time off to get them in and try it. hmm... i'll update this post when i have more info.

[Ryan from Ohio]

Looks good eh?

[cherrington17]

yeah, very slick looking wires. most of the wire ends where loose, but luckily they are just screw on.

got any recommendations for how/where to hide these? considering ONE pair of these rcas is the size of all 3 pairs of my olds ones. :lol:

[Ryan from Ohio]

take the trim up around the doors, pulle the carpet all the way back and toss it in there.

I have a few sets running front to back, but mine go down the middle ;)

[cherrington17]

i'm thinking i'll have to go down the center next to the passanger seat. looping it under all those cables for the various "power" features that run down under the trim makes it too much hassel.

how did you manage to fish it under the center carpet?

[Ryan from Ohio]

Seats and center console out of the car. lift the carpet up.


http://caraudiocentral.net/ryan/images/alero/instl1.jpg
http://caraudiocentral.net/ryan/images/alero/instl2.jpg
http://caraudiocentral.net/ryan/images/alero/instl5.jpg
http://caraudiocentral.net/ryan/images/alero/instl6.jpg

[cherrington17]

yyyyeeeaaahh... doubt i'll be able to do that. this is my daily driver and i only have like 3/4 of a day off to get the job done.

guh. i'll figure something out.

[cherrington17]

alright, got the wires in and the hum is virtually gone. (little hiss coming through the speakers, but they have about 100W going to them so i'm going to assume thats normal. (can be heard with the radio volume at 0 )


now the problem is, the alt whine is still there(and with some authority). so does this mean its a headunit issue, or should i upgrade all my grounding wires?? it did it before with both amps, so (as much as i'd love to get a new 400W amp with soft turn off) that one is eliminated.

also, i read on a different site, that if you move your grounds closer together, it might cut down on it...? so should i run a wire from where my main ground is upfront, to the back?

[Ryan from Ohio]

www.bcae1.com

#95

Your best bet is to try regrounding the head unit. If the problem spans all amps, its the source.

[cherrington17]

so move the ground for the headunit back to where the amps are grounded?

[Ryan from Ohio]

No.

You probably have it run right into the wiring harness ground? If so unhook that and find you own ground.

[cherrington17]

i have the wire harness (for the chimes and whatnot) grounded in one place and the h.u grounded in the same block, but separately.

i can just move the main wire that grounds that whole block, back to where the amps are....

[cherrington17]

update #...whatever

i temp moved the ground to the back of the car, and the whine is still there.

also added one extra wire from chassis to battery (-). i'll be doing the tranny one tomorrow... and any others i might find.

and other things i need to check, should be...?

rca shield to metal ground around the headunit, to see if thats actually grounded. (if not, i suppose i can open it up and see if i can fix it)

if not.. whats a good headunit that can control an ipod? i have pioneer right now, but i can't say i like the looks of any of their current models...

[Ryan from Ohio]

Heya boss, you should of tried grounding the headunit up front, to a different location. Thats what Ive been telling you.

Running a line all the way to the back is silly. Whoever suggested that is giving you bad advice. You probably used small gage wire and it probably hurt you more than anything. Since power flows from the body to the unit and returns through the + side...

[cherrington17]

it wasn't a permanent job, and i used some scrap 8ga i had laying around, as a test. (and i know enough about wiring to know not to use a small gauge over a long distance. sheesh, gimme some credit. :lol: )

i get to tear things apart and play around more tomorrow, so i'll try another solid location. (just gotta find a decent one) the thing i don't really understand is, after i set it up, it worked fine for about 2 weeks, then outta the blue i get a ground loop problem. wtf is with that? if it was a ground problem, shouldn't i have had it from the start??

[Ryan from Ohio]

ya, thats why Im figuring its the head.

[cherrington17]

F* F* F*. the rca's on my head, aren't grounded to the shield around the radio. somehow 3 of them are grounded w/ the inside pin, but not their shield.

so i guess that explains it. :mad2:

Thanks for all the help ryan. you've been pretty tolerant to deal with my 8000 questions. :lol: