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Need Help with My Audio Setup....
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Posted by: KenA

Ok, so I was having problems with my Freaking car stereo...I have a Koss Head unit (Deatachable face, 35x4) a 80's Amp with no stickers or identification on it, and 4 new Kenwood 3 way 6.5's...I went to Circuit Shitty on Saturday to get my stereo fixed (due to my ignorance on consumer electronics)..

Here was the problem--It would work the two left side speakers (it sounded OK when it worked) but it would cut out all the time...

So I go in there and they tell me 69 Bux to fix it...I was like, ok....Paid them the money and waited...waited...waited...finally they call my cell phone and tell me that my cables going to my amp are bad and that will be an extra 45 bucks plus installation...I told them to wait..I ran over to Breast Buy and got some new cables for 20 bux (monster cable) and paid them 25 for the installation...

OK, now all for speakers work...But the problem is that they sound like complete shit...I have lost all the bass response that I had when only two of the speakers worked...The Amp is working (I think) because it is hotter than hell...

Here is my hypothesis...2 speakers sounded great because it took all the power from said Ghetto Amp and channeled it into two instead of four...

But honestly, I think the amp might actually be sucking power out of the head unit..I have heard less than 35x4 systems that sound better than mine now...

On top of that, my EGT, Boost, and Oil Temp guages dont light up now.. :mad:

Any Ideas?

And John, how much you want for that Amp??

Posted by: John

wow! whatta mess!

first off, i'd check the gain on the amplifier. it may have been turned down. that would decrease low end response because teh signal stregth would not be strong enough. there should be a set screw somewher on the amp that is labeled GAIN or has a + and a - on a rotary dial label.

to adjust your gain, turn on your radio and turn it up as loud as it will go without hearing distortion. usually about 75% total volume. then goto the amplifier. stick a screw driver in the slot for the gain dial. start turning the gain up slowly listening to the radio as you go. as soon has you hear distortion, stop and back it off just slightly so the distortion goes away. that is you maximum gain level. usually, the lower the voltage on the pre-amp outouts, the higher you have toturn up the gain on the amplifier. i'm betting your pre-amp outputs are running around a 1.7-2.0v signal strength. there may also be a setting on the radio that is limiting frequency response.

now, for your guage problem. check teh power wires to them. see if the monkey from Circuit Shitty dissconnected them. probably did. if not, they may have pinched a wire between a metal frame and a mounting bracket which is causing the power to the guages to ground out. also check the power source. they may have disconnected your guages and since none of them know anything useful about cars, they won't reconnect what they take apart because they don't know what it is, why its there of what it does.

no, about your hypothesis. its wrong unless the amp was wired that way. a 4 channel amp will not divert power away from channels that are not in operation unless you specifically wire it that way. the amp not have been getting as hot because the current draw was half that of what it is now.

now for the amp i have. its currently powering Emily's stereo in her car. but Zeus has arrived! i haven't had a chance to get it in her car yet though. but as soon as i get that done, i'll have the Pioneer 4 channel free. i don't know yet if the Kenwood 2 channel works. i haven't had it out to test yet. but as for the amp, i'm not sure what i want for it. probably $75 bucks. installation would be free of course.

but your experiences with Circuit Shitty is the reason that i learned to do my own stuff. my offer still stands. if you want it installed right and you can get your car up here, i will do it for ree. i'll install whatever you want me to install in the way of stereo equipment. all i ask is that i get a weekend of time to get done what needs to be done. if you do come up, you get to work the camera and take pictures so we can document a stereo installation for a tech article here too.

Posted by: electec_1

Sounds like you have a positive and a negitive from the speaks to the amp reversed.

Posted by: electec_1

ps do your own installs, really its not that hard, and everything is labeled for what wire goes where

Posted by: John

[quote:4e01686376="electec_1"]Sounds like you have a positive and a negitive from the speaks to the amp reversed.[/quote:4e01686376]

wiring an amplifier with speaker outputs out of phase would not cause a reduction in frequency response. a speaker does not need a polarity check. its just a simple resistor that flows power in either direction. wiring a speaker with the leads reversed will only server to muddle the stereo sound stage and play speakers out of phase. they wouldn't cancel each other out, they would sound more distant to the ear and the sound stage would be shifted away from the speaker that is out of phase. and i really doubt that the monkey at Circuit Shitty wired the car up out of phase. they are stupid but they aren't that stupid.

the only symptom that his stereo is exhibiting concerning reversed polarity on one speaker is the overheating amp condition. but so many variables can factor into that, that over-heating alone cannot point to a reversed polarity.

in addition, he said that the Circuit Shitty lacky replaced amplifier power wires. he did not replace speaker wire cables. if the amp had previously performed well with intermittant signal to one side of the car then there is no reason that the intermittant signal, when fixed, would cause such a noticable drop-off in performance. there is no reason that a repair of any kind should cause a drop-off in performance.

of course, this is all just speculation. its hard to tell without seeing the actual installation. while it could be possible, nothing is pointing to reversed polarity wiring and speakers being out of phase. i suppose its worth it to check though. couldn't hurt.

Posted by: electec_1

I understand where you are coming from, and from my own schooling I would agree, except for experence.

2 speakers on the same amp, one wired right,, the other wrong will cause both to sound as if they have lost the bass. I dont know why, but I have had it happen several times. Like I said tecnically it shouldnt, but it does.

If you dont belive me, go try it.

BTW I wouldnt trust a bona fide stereo shop not to rehookup everything, and just tell you a story to get you to spend money. Thats the disadvantage to getting someoneelse to do it. It coulda been nothing but a grounded wire etc, but they say you need this and that just to get you to spend more

Posted by: KenA

Thanks Guys..I'll check for the gain adjuster when I head out to the car after work.....And Yes, Speakers wired backwards sound like shit..I have done that before too...But if that was the case, I think at least one of the speakers would give me the response I wanted..They all wouln't sound as Ghetto as they do...Pisses me off...

Thanks for you help guys...I'll keep you updated...

Posted by: KenA

There are a couple things I dont do when it comes to cars....Wiring (other than basica guages/tach install/Foglights) and Transmission work...

Put it this way, one of the reason that Buss fuses is still in business is because my attempts at installing stereos...

Posted by: electec_1

Bah! Just make sure you do one thing, every time:

Turn off the ignition. I failed to follow that simple step about 3 times back in Highschool, and it resulted in 3 clarion headunits saying goodnight.

Posted by: John

[quote:024577d3c0="electec_1"]Bah! Just make sure you do one thing, every time:

Turn off the ignition. I failed to follow that simple step about 3 times back in Highschool, and it resulted in 3 clarion headunits saying goodnight.[/quote:024577d3c0]

that doesn't quite cut it there bro'. you need to disconnect the battery while doing an install. there are circuits in cars that are live all the time and you have to connect to one. also, inwiring an amp, you shouldn't be running trhough teh fuse box. yuou should be running directly to the battery and the positive power connection is the very last connection you should make.

turning off the ignition is not enough. maybe for installing speakers, it is good enough but when installing amplifiers, crossovers or head units and thier accessories, all power should be disconnected. more for your safety than the electronics. you can always buy new gear, you can't buy a new you.

Posted by: KenA

This thing must be OLDer than Penske..It doesn't even have a gain Adjustment on it...

*sigh*

Posted by: electec_1

More for your saftety than the equipment????

Nothing in car audio could hurt you, even if your standing barefoot in a pool of water. (Unless there are gas vapors or something.

its 12 volts. you cannot even feel 12V. Even the outputs of the amp you cant feel. I have a 2000 Watt Rockford in the trunk and you dont feel a thing when its running if you grab the wires.

What I am refering to on the ignition is damage to the one thing that takes damage easy: The headunit. An amp can take just about anything (except a B+ and neg reveresed

Posted by: John

[quote:dcc213fe38="electec_1"]More for your saftety than the equipment????

Nothing in car audio could hurt you, even if your standing barefoot in a pool of water. (Unless there are gas vapors or something.

its 12 volts. you cannot even feel 12V. Even the outputs of the amp you cant feel. I have a 2000 Watt Rockford in the trunk and you dont feel a thing when its running if you grab the wires.

What I am refering to on the ignition is damage to the one thing that takes damage easy: The headunit. An amp can take just about anything (except a B+ and neg reveresed

but a headunit can fry for almost any reason.

Not saying you shouldnt pull the power when installing, its the troubleshooting that gets you. You see a RCA off when the Headunits on, and think no big deal plug it in. Then everything goes bye bye[/quote:dcc213fe38]

really?

ok then, take teh positive and negative leads connected to your battery and stick your tongue on them.

let me know how works out.

Posted by: Chris Kelly

I've run into the Bass Loss problem before, too. Finally someone explained it to me.

It turns out, the problem is sonic, not electrical... Bass speakers create large, slowly changing sound waves. If you put two in close proximity with opposite polarity, the compression waves will be close enough to opposite polarity that they will actually cancel each other out!

The problem actually happens at all frequencies, but only at locations equidistant from the speakers, at an effect area which depends on the wavelength. In essence, you'll have a few large dead-bass areas, and lots of little dead-treble areas.

Weird, eh?

Posted by: John

[quote:e539707e2d="Chris Kelly"]I've run into the Bass Loss problem before, too. Finally someone explained it to me.

It turns out, the problem is sonic, not electrical... Bass speakers create large, slowly changing sound waves. If you put two in close proximity with opposite polarity, the compression waves will be close enough to opposite polarity that they will actually cancel each other out!

The problem actually happens at all frequencies, but only at locations equidistant from the speakers, at an effect area which depends on the wavelength. In essence, you'll have a few large dead-bass areas, and lots of little dead-treble areas.

Weird, eh?[/quote:e539707e2d]

that can only be true provided one speaker is wiried out of phase from the other and that has not yet been determined.

on the same note, like you said, the cancellation occurs at a point equidistant from both speakers. if the driver is sitting off-set to the equidistant point, he would not experience the cancellation to the level that he has it. it would manifest itself to him as a lopsided sound stage with noise levels skewed to one side. the side with the correct polarity.

Posted by: KenA

OK,

So here's what I'm gonna do...I am going to swap wires to my speakers (reverse +- ) and if that doesn't do anything, I am going to ditch my amp for a 50 Buck special from Wal Mex and finally be able to enjoy my audio experience...

My amp gets so hot that I cant touch it...I could use it as a grill...

Posted by: John

let us know how it works out. i'm pretty interested to know.

just remember, if you tear teh old amp out and stuff a new one in its place, mark the wires so you can hook them back up the way they were. that way you won't switch polarities yourself if that is what is wrong!

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