Amplifier install problem

[truoss]

I just installed a 600watt 4 channel MTX MXA amplifier. I am running infinity perfect 6.1 in the front, and I plan on getting some 6x9's for the rear. I am also running one 10" woofer.

Now, my plan was to use the 4 channel amp to run the perfects and the 6x9's, and another bridged 2 channel amp to run the woofer.

I have two problems so far:

1.) When I hook my RCA cable to my front speaker output at my head unit, I get a strange buzzing noise in my speakers. When I hook my RCA cable to my rear speaker output at my head unit, there is no noise. What could this be caused by? Is it possible that the RCA output for my front speakers is bad?

2.) When I turn my volume up pretty high, my sound is played in jolts....like the power to the speakers is turning on and off every 1/2 a second. Does this mean my amplifier is not getting enough power? Bad wire? What could it be?

 

[vtecsir1]

first off are you running the wires all together? like the power line for the amp next to the the audio cables?

 

[truoss]

I am not running the wires together, but they are fairly close. But, I don't think that is what is causing the buzzing noise...because my rear speaker RCA cable is right next to my front speaker RCA cable, but it does not cause the buzzing noise.

 

[hcivic.com]

Bad rcas

 

[vtecsir1]

do not run them close at all, run the power wire on one side of the car and the rcas on the other. try new cables they dont cost to much,

 

[truoss]

I tried swapping RCA's. Didn't make any difference. RCA cables are good.

 

[truoss]

Okay, I will try that vtecsir1. But, I don't think that can be my only problem. The rear rca output doesn't cause the noise, but the front does. It's strange. I hope my headunit doesn't have a problem.

 

[TommyTheCat]

you did try hooking the rear-amp rca to the front-HU rca?

 

[truoss]

No, I didn't try that. --should I?

Anyone has any idea about my second problem?

 

[JDMH22Integra]

Ok, so as far as running the cables together...

Is your buzz a constant buzz, or a whine that changes with your RPMS... the whine would be a fault of running the cables together.

If its a constant buzz, then it sounds like your headunit has a problem, but you shouldn't be running subs to front RCA cables anyway, so no worries.

 

[truoss]

It is a constant buzz.

I didn't plan on running a sub off the front HU RCA output.

If I do have a problem with the HU, then I guess I can just run one RCA cable from the rear RCA output, and buy a Y-connector to connect it to my 4 channel amp. I wonder why my front RCA output would be bad though...I have never used it before. ??

My second problem is what's really worrying me though.

 

[JDMH22Integra]

Ok, I've delt with a LOT of different stereo system problems.

What is the difference between when you get the buzz and when you dont, is there anything you do different other than where you plug the RCA cables? If not, I would seriously doubt anything BUT your headunit. As for why is would be fucked you... you got me, make sure all your grounds are money, and beyond that I would take it to a shop who can tinker with it for a while.

Since its a constant buzz, it sounds more like a ground problem... definitely not alternator whine (thank your lucky stars, its a monster).


As for your second problem... what is the wattage of your head unit, etc... If its "jolting" as you put it, and what I think is probably a bouncing sound, it sounds like your overpowering something, whether it be your speakers, your head unit, what have you. Check the power ratings and make sure everything is kosher. If it is, I would definitely think your head unit may be at fault, the buzz may be related to the max power bounce.

 

[truoss]

okay, thanks for the info. I'll look into groundings etc tomorrow.

Okay, all my power ratings are kosher. My 4 channel puts out 75 watts RMS per channel, which should be great for my infinities. And I have a gain control on the amp, so that I can adjust depending on the power output of my head unit. I followed the directions for tuning, but I still have the problem. I know the problem is with the MTX amp, because I hooked my speakers up to my 2 channel amp, and the "jolting" did not happen.

 

[TurboMirage]

what size wiring are running to the amp? i use 4ga in most of my high end applications.

 

[CRX-YEM]

Originally posted by truoss@Feb 4 2005, 12:10 AM
I just installed a 600watt 4 channel MTX MXA amplifier. I am running infinity perfect 6.1 in the front, and I plan on getting some 6x9's for the rear. I am also running one 10" woofer.

Now, my plan was to use the 4 channel amp to run the perfects and the 6x9's, and another bridged 2 channel amp to run the woofer.

I have two problems so far:

1.) When I hook my RCA cable to my front speaker output at my head unit, I get a strange buzzing noise in my speakers. When I hook my RCA cable to my rear speaker output at my head unit, there is no noise. What could this be caused by? Is it possible that the RCA output for my front speakers is bad?

Usually a bad ground or ground loop, bad rca cables

2.) When I turn my volume up pretty high, my sound is played in jolts....like the power to the speakers is turning on and off every 1/2 a second. Does this mean my amplifier is not getting enough power? Bad wire? What could it be?

The amp is clipping, being driven beyound it's specs

[post=456177]Quoted post[/post]​

 

[truoss]

Okay, I tried lots of things today, and here are the problems:

The constant buzz I was talking about is not constant, it changes with the engines RPM's. The strange thing is that the noise only comes from the front speaker RCA output at the HU, not the rear. So, is there a way to fix this? It has something to do with the alternator? The noise disappears when the engine is off.

The clipping noise cannot be due to the amplifier being driven too hard. A 600 watt MTX amplifier should be able to make the infinities go way louder than it is without clipping. Really, it's not that loud when it starts clipping. I tried my Pyramid 2 channel amp that puts out 75 watts per channel RMS, and I could turn the volume up way higher without any clipping. So, is there any other cause for clipping?

I have tried all that you suggested....better quality wire, separating the wires from each other, etc.

I am thinking now that the MTX amplifier is faulty. I may have to send it back for a replacement. =(

 

[lowassaccord]

sounds like your front output is bad from your headunit if you have tried multiple rcas, the problem with the volume is probably a bad voice coil on one of the speakers you could of damaged part of the speaker and it is grounding out which some headunits will turn off for a few secs to save them from damage. Try unhooking each speaker and pluging one in at a time and see if this solves the problem, it should.

 

[lowassaccord]

Originally posted by lowassaccord@Feb 4 2005, 10:56 PM
sounds like your front output is bad from your headunit if you have tried multiple rcas, the problem with the volume is probably a bad voice coil on one of the speakers you could of damaged part of the speaker and it is grounding out which some headunits will turn off for a few secs to save them from damage. Try unhooking each speaker and pluging one in at a time and see if this solves the problem, it should.

[post=456726]Quoted post[/post]​

sorry forgot, how this solves the problem when it fails you will know which speaker (maybe more than one) is bad

 

[JDMH22Integra]

Well, if the amplifier is drivin fine on the rear RCA's, then its not a problem with your amplifier. The clipping could easily happen when your amplifier is overpowering your speakers. The speakers are set for a max wattage at a certain ohm, and if you exceed that, the circuit is basically screwed (AP Physics from high school, spent the whole first semester on circuits). If you circuit is being overpower, it would indeed cause a surge and kill (or jolting as you put it) in the power supply. To be honest, I would need to hear whats going on to fully put my input in, so all I can say is keep trying things until it works. But most of all it seems as if you have a problem with your front RCA hookups. If you have a friend with another head unit, see if he'll/she'll let you borrow it to install in your car and retest everything. If everything runs fine, then its got to be your headunit.

Just my 2 cents

edit: lowassaccord may be on to something... when my subs failed I thought it was the amp. But what had happened is a terminal had vibrated loose and all 800W of my amp went to 1 sub and blew it. Check connections and individual speakers.

 

[truoss]

Thanks for the input.

I do not think my speakers are bad, because I tried my 2 channel Pyramid amp to drive them, and everything worked as it should (no clipping). The clipping problem is with the MTX amp. I just don't know if I am doing something wrong in the installation, or if the amp is just infact bad.

As for the whinning noise coming from the front RCA output at my HU, I think that is just a problem with my HU. Must be...because I think I have tried everything there is to try! It is not a wiring issue, because I have tried different types of wires, and have separated them from each other...and it is not a power issue, because my infinity speakers are supposed to handle 100 watts RMS, and this amp is supposed to produce 75 watts RMS...so everything should be kosher. Any other ideas? Wiring is good, including the RCA cables....my head unit has a whinning problem, but that should not be producing the clipping....my only conclusion is that the MTX amp is bad. ??

JDMH22INTEGRA: The MTX amp is not driven fine with the rear RCA output. When I use the rear RCA output, that just solves my whinning problem. It does not solve the clipping problem.