No Amp + Aftermarket Speakers=Crap

[traben27]

Title kind of explains it. When I bought the truck I had an aftermarket head unit, panasonic something (it folds down and stuff) and some infinity reference speakers. It all sounds okay, but it's very empty sounding because there is almost no bass and it gets distorted very easily. It looks like it had an amp, but they took it out before they sold the truck. It's got all of the wiring, including a red and white( maybe its black?) ended cable hanging out under the dash which also has two ends in the back, along with a large wire (for power i'm assuming) in the back under the carpet. I hate electrical stuff of any kind although I did help my friend put 4 new speakers+headunit+amp in his 94 pickup. Does it sound like this is just sub wiring or if i bought a 4-channel amp would it in anyway help out the other 4 speakers?

[Good Times]

I wouldn't try to use existing wiring that the previous owner left behind. You just never know where it goes and what's connected in the middle (i.e. heck maybe it's two diff lines that's cross tied?).

I'd start from scratch to ensure that everything works properly the first time around.

good luck

[traben27]

I wouldn't try to use existing wiring that the previous owner left behind. You just never know where it goes and what's connected in the middle (i.e. heck maybe it's two diff lines that's cross tied?).

I'd start from scratch to ensure that everything works properly the first time around.

good luck


Good point, I didn't really think of that. Plus I was thinking, shouldn't there be 4 more cables somewhere coming from each of the speakers or is that only the case with some amps/hu combinations. I know on my friends pickup we had to connect each speaker directly to the amp.

[Good Times]

each speaker should have 2 cables coming out of it. the amp should have 3 lines (power, ground, trigger to turn on from the radio) and 2 rca cables (or some other audio cables) from the radio to the amp. Not sure what other cables you'd have.

[Bob98SR5]

traben,

look on my website 4runners.org and there's a writeup on setting up a complete stereo system + amp + component speakers. it should give you an idea how these things are pieced together by the wires.

bob

[traben27]

Thanks guys, I'll look at it later this week. I hate how exams come in waves...one week everythings going great the next you're pulling your hair out from the stress. :chair:

[traben27]

Not yet, haven't had the time. Been super busy with midterms for school plus work. I had to squeeze a trip out to do some wheeling to relieve some stress but I have two more on monday, so looks like tuesday will be the day. I'll update then.

[traben27]

Well I ended up buying an amp today from someone on YT. It's a Clarion APX4240. I wasn't quite sure on the quality of the brand, but it got some pretty good reviews. I don't care all that much since I'll be putting the truck up for sale next August/September, I just can't deal with the speaker output anymore.

I'm just going to end up rewiring the complete stereo set up with the help of my friend (we did it in his pickup a few months ago). I'll let you know how it all goes.

[traben27]

I got the amp today, I'll probably be doing the install Friday morning until class, then after class until work. Hopefully that's all it will take.

http://img.photobucket.com/albums/v190/onlyindreams0871/IMG_0409.jpg

I'll update once it's in and tell you how it sounds.

[traben27]

Got everything in today, it sounds much better than before, a lot fuller and doesn't get distorted at such low volumes. Only problem is i'm getting a high pitched interference noise when it's on. My friend that helped me on it couldn't quite remember what causes it..something with the power wire and another wire crossing?

[Seanz0rz]

all power wires should be PERPENDICULAR to any signal wires from the head unit to the amp, now this is impossible. somethings you can do is wrap the signal wire with aluminum foil, and separate the signal wires from the power wire where ever possible.

for example, on mine, i ran power down the left side and signal down the right, and where they meet up i tried to cross them perpendicularly,

also, does the whine change with increased throttle? if so thats alternator whine, you may also have a ground loop problem. are all the grounds going to the same spot, and are they well grounded?

have a looksee here:
http://www.mp3car.com/vbulletin/car-audio-faq/79248-induced-noise-ground-loop-trouble-shooting-guide.html

[traben27]

all power wires should be PERPENDICULAR to any signal wires from the head unit to the amp, now this is impossible. somethings you can do is wrap the signal wire with aluminum foil, and separate the signal wires from the power wire where ever possible.

for example, on mine, i ran power down the left side and signal down the right, and where they meet up i tried to cross them perpendicularly,

also, does the whine change with increased throttle? if so thats alternator whine, you may also have a ground loop problem. are all the grounds going to the same spot, and are they well grounded?

have a looksee here:
http://www.mp3car.com/vbulletin/car-audio-faq/79248-induced-noise-ground-loop-trouble-shooting-guide.html


Thanks...that's my problem right there. I'll have to fix it tomorrow or something. It does also do the alternator whine, so I just need to check the ground on the amp, or is there anything else that would be wrong?

[Seanz0rz]

check the grounds, and see if moving the wiring around changes the noise.

[traben27]

Well, I looked at the amp ground and it wasn't the best so I fixed that and that cured the noise that was affected by the engine. But I still have the high pitched humming noise through the speakers only when the car is running. If i unplug the front speakers (via the rca cables at the amp) the noise goes away but of course so does the sound from the front. It does the same for the other way around as well...any ideas?

[Seanz0rz]

does the sound change (pitch or volume) as RPMs change? if they do then that is alternator noise, you need to separate the signal cables(rca cables, not speaker cables, speaker cables are not harmed by power signals) from power cables. ill try to snap some pics of my mess of wires.

ok here are pics, they are dark, sorry

http://i103.photobucket.com/albums/m141/hamiltoncomputers/DSC02161.jpg
http://i103.photobucket.com/albums/m141/hamiltoncomputers/DSC02162.jpg

you can see everywhere the foil crosses the power cables (gigantic red wire), they are perpendicular. the small red and black wires are speaker wire, and those are unaffected. i wrapped the signal wire (the RCA from the deck to the amps) with foil. doing both those things solved my problem.

[Seanz0rz]

yea when i did the install, i actually only had about a dollar in my pocket, and was borrowing gas money from friends for a while there, so it was a free fix.

[traben27]

I'll try to do that but I actually rerouted the power cable to go between the center console and the seat, while everything else is along the trim at the edge of the carpet by the door. The closest it ever comes to the RCA cables is right under the steering wheel and it's probably 3 or 4 inches away (I think?) Could this possibly be a grounding issue? It doesn't change with the rev of the engine, just the fact that the engine is on is what makes it come on.

[Seanz0rz]

if it does not change with the engine revs, then it is not alternator whine. it is most likely a grounding issue.

[traben27]

I'm slightly confused by your response, previous posts seem to say that alternator whine is caused by bad grounds, if I don't have alternator whine, then how is it most likely a bad ground? Maybe I'm just misreading previous posts...

[Seanz0rz]

ive always understood alternator whine as just interference with the signal wires coming from the alternator(through the power wire), while a grounding problem or ground loop being different potentials (voltages) in the grounding plane that harm the signal.

im not great at explaining this, basically all your grounds should be at one spot, the grounding point should be well sanded to expose bare metal. use appropriately sized conductors.

[traben27]

That was a clear explanation, thanks. I'm going to take a good look at it tomorrow, sand the ground down again and get it the best I can, I'll let you know the result.

[traben27]

After talking to a few guys at some audio shops, I ended up just paying 15 bucks and getting a ground loop isolator. Went out and plugged it in and BAM the noise is gone. Messed around with the gain a little and everything's just about perfect. The alternator whine can be heard slightly, but really only if the music is almost off or not on at all. Thanks for the help everyone.