Rep Power: 346

Ok yall, I need some ideas...better yet, a solution. I have been having the worst hissing problem coming from my tweeters all summer. It started earlier this summer the day I got my highs amp and crossover installed. It has been obnoxiously loud. I had sent my crossover to get fixed by Audiocontrol so I asked if they can check out the hissing as well (and they said there was nothing wrong to cause hissing). So I connected some female-female RCAs to hook up my normal RCAs since I had no crossover to hook them up with...and I had a normal amount of hiss with my RCAs strait to my amps (very quite with just the amp hooked-up).

Since I got my x-over back I have tried EVERYTHING to get rid of hiss; I have spent 50 dollars to buy new RCAs, regrounded my head-unit and crossover, tried having my gains all the way down on both the x-over line drivers and amp gains, re-routed my RCAs, and got ground loop isolators (because when I moved my RCAs around I started picking up more noise )

What causes hiss and what are some good ways to get rid of it? Please do not tell me to turn down my gains beacause I have tried this many times (I get slighty less hiss, but still way louder then it should ever be). I currently have the gain on the x-over almost all the way up, and the amp gain almost all the way down to an 8 volt sensitivity. If I turn the gain down on the x-over (all the way down) and turn it slightly up on the amp (1/8-1/4 of a circle) I get even horrible hiss (even though I had it like this when I had no x-over).

Could it be where my x-over is located (under the seat)? Could it be because the only thing that seperates the RCAS to the x-over from the floor/chasis of the car is the floor carpet and maybe a lil white padding...or would that not be the cause of noise?

If it helps diagnose my problem, I also get a louder high pitched staticky noise after I drive my car for a long time with the radio up loud.

Please help with ideas.

thanks
fonto

 
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You have a large snake somewhere in your dashboard. It's hissing when you turn your car on.

 
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maybe the source unit is the source of your problems

 
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The hiss occurs both with the car on and off...slighty louder with car on.

I don't think it is the HU because it was never there before Installed the x-over, and it was gone when I bypassed the x-over when I sent it in for repairs.

It is something with the x-over for sure because I narrowed it down to the x-over by using muted RCAs starting at the amp all the way to the hu...the x-over is definently the culprit...I just can't figure out why? Is it mounted woung? Hooked up wrong? Is it worth trying to separate the x-over from the chasis with some MDF?

thanks


edit:
BTW, what is a snake??? I have one in my pants but I dunno about in my dash board imp:

Seriously though, I have a lot of my excess RCAs stuffed by my e-brake, not really in the dash.

 
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did you try the different jumpers inside the xo for ground?

call audiocontrol and ask them

 
Rep Power: 346

I have tried that a few times...but not since I re-grounded my x-over ( I have about an 8 inch ground to the bump in the chasis under the front of the seat. I will give it a shot.

I will maybe call audiocontrol tomorrow, but they were not able to help me to much in the past (Long story that my x-over was not working at all after I had sent it in the first time).

anywayz, any other ideas people?

 
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I would say try a different ground location, also try just running the RCA right from the head unit to the X-over ( like not routing the wires anywhere, just a direct line from the HU to the X-over ) I also have a Audiocontrol x-over and I was getting the same problem as you are, my ended up being a fan I had wired to my remote lead, it was causing some kinda feedback into the x-over, by pass the x-over and the hiss went away, put it back and the hiss returned, so if you have a fan on there check that too. If not just try a different ground spot, if its still there just take the HU out and run a rca cable right to the x-over. Hope this helps

 
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Thanks man....good ideas!!

 
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all audiocontrol pieces have built in line drivers, meaning any noise that's already there gets amplified.. a lot. The hiss was probably there before, just too quiet to hear. It sounds like your source unit's causing you problems. What kind is it, and who did the install?

 
Rep Power: 346

My HU is Kenwood Excelen kdc-x559 (I think). I did the install.

I have officially tried everything, unless the noise is coming from my turn-on-lead somehow??

This is what I noticed last night:

-I can turn my amp down to 6 volt input sensitivity and turn my line driver gain to about max, which is about 9 volts is I have aenough power coming from my HUs outputs...and I get a pretty good hiss.

-I can turn my line driver all the way to minimum and adjust the gain on the amp as I usually would I get a pretty bad hiss.

-What seem to work the best is to turn the gain on my amp slightly up from the minimum (1/8 of a circle), and turn the gain on my line driver to a lil over 75%...I get the least hiss with this set-up while still be able to hear my radio.





Maybe I am just overly concious of the hiss...but I can blantantly hear it with the volume down and I am sitting in the seat normally with the windows up and car running.

Another problem that seems to happen is that when I drive the car for a long time with the stereo blating I get a loud ringing, static hiss noise after awhile coming from my tweaters...I can't figure that one out, but I am assuming that it is heat induced since it only happens after I drive for awhile?


-Could hiss be caused by my x-overs being to close to my Power wires, the jumpers on my x-over not being connected right, speaker wires touching metal, My HU not being screwed down in the dash, RCAs that are too long?

 
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idea.... try hooking your rca's up to like a walkman or something and put it up by your radio, if you get the hiss, move the walkman to right by your audiocontrol, if you get the hiss, bypass hte audiocontrol and hook the walkman straight to the amps

 
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maybe you could stop stopp worrying about you ice and focus somewhere else give your brain a rest and it will come to you bro!
i know that i could go all day finding rattles and hisses in my system.
the answer doesnt come to me until i walk away and give it a rest.

 
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LOL, best advice I have ever seen on this forum!

 
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good idea!

 
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THE FACTORY SYSTEM DOES NOT ACTUALLY RUN A COMPONENT SYSTEM IT HAS THE FACTORY 61\2 AND THE TWEETER. THE TWEETER
IS STILL A FACTORY TWEETER REGARDLESS OF THE DIFFERENT THINGS YOU DO TO IT. IT PROBABLY IS NOT BUILT TO HANDLE THE POWER YOU ARE PUTTING THROUGH IT.
MAYBE YOU JUST NEED TO UPGRADE

 
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He's running a $500 2-way component set.

 
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oooooooooooooooh there is nothing in your profile. sorry

 
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LOL

 
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Dude, I have ****in tried everything...it has been all summer trying to figure this ish out and it is a good thing that I don't live or work in a high rise!!!!

Man, everything is Perfect...except for this hiss...and the noisy ringing hiss that I get after bumping my system for awhile.

sorry, had to vent.

So if there are no objections, I will use this thread to keep track of the ish I have tried so far...

tonight I went from component to component testing each with a MD player...and I got a lot of noise pluged into the crossover, and I got some noise when plugged dirrectly into the amp. I also moved every jumper that is possible to move around in my car, and I tried different x-over modules.


I tugged on the ground of the amp, and it seems solid...the area that it is connected to (bump behind the seat and sanded) is starting to get a copper tone to it (almost borderline rusty looking).


Could my amp being poorly grounded be the cause of my annoying hiss???????????????

Man, I have tried so much ish and spent weeks trying to figure this ish out...I don't want to have to move all the boards from and box to get to the ground...but I have to try it I guess (since I can't reach the screw without moving everything).

Once again, I will ask...Could my amp being poorly grounded be the cause of my annoying hiss...please let me know so if it won't make a difference I won't bother wasting anymore time.

 
Rep Power: 329

yes it could. when i had my amp poorly grounded, i would get almost a warning before the music stopped... i would hear a popping and hissing with a high pitched whine until finally the stuff in my trunk completely disconnected the ground wire. the hiss could be caused by electric and/or magnetic fields (you seem to have tried everything here), could be a poor ground (your next step it appears), or by the grounding location itself (if you grounded somewhere other that directly to the chassis). you might try ground everything to the exact same location and see what happens. put the audiocontrol ground on top of the the amp ground. this at least would eliminate any eddy currents giving you feedback (worth a shot if you're doing the ground over anyways).

rust occurs faster at higher temperatures. could mean a significant voltage drop at that spot is heating it up when it is on, thus creating heat. this would accelerate the rate at which the rust would form, and could explain why the noise gets worse after you've had it playing awhile (best i can come up with).

 
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Thanks man! A very well thought out answer

 
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ok, I tried regrouding and I tried shorter RCAs....uhhh, no luck

 
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So if it doesnt happen when you take out the audiocontrol piece, then take it out. Do any of your friends have another crossover that you can try? I had to send an amp back to PPI 3 times before they actually fixed it. So it is possible that they were backed up on repairs and just sent it back to you without fixing it.

 
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ummm, do I need a relay for all my stuff? Could 4 things running of the turn on lead be causing the problem?

 
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the turn on lead won't be it. the problem has got to be internal to the crossover. speaking from experience in electronics, anytime i had a f'd up signal on an ocilloscope, the first thing i would check would be the capacitors. 9 times out of 10 if it wasn't my wiring, it was a blown cap.

since a crossover contains a bunch of variable resistors and capacitors, it's quite likely that one of these simply went to ish. i would hope audio control would have determined that upon testing it, but maybe they didn't have it up loud enough to hear or something. a blown cap will have one of the ends blown off, if you open it up to look at it. but sometimes it will simply lose it's capacitance be being pushed beyond it's limits (possible since you have had the gains at extreme highs and lows). it might even look fine but not be functioning anymore though. i'd send the x-over back and have them look at it again, if they hook it up to an occilloscope it should be pretty obvious...

 
Rep Power: 346

You know what I noticed on my sub channel output of my x-over...that the RCAs slighty touch the chasis (the right does for sure and the left maybe does) of the xover, which in turn is screwed onto the chasis. I dunno if this causes the hiss, but it may cause the ringing hiss that I get after driving my car for awhile???

Thanks DD for the info

 
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Well, I am still getting that same ringing hiss after I drive my car for awhile listening to the radio. I have no idea what it is since I have moved every thing.

I did notice that the noise will go away for a few seconds if I roll the window down a lil (either window) or roll 'em up. Hmmmmmmmm! I dunno?

Maybe speaker wire is touching? That is the only thing I haven't checked because I am putting in new speakers in soon.

or maybe it is the alternator??

 
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Is your car red and named Christine ????

 
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Huh