OK I have finally done it. replaced the entire Bose system with much better speakers.
I replaced the front with Infinity Kappa Perfect 6.5" components and the rear with Infinity Reference 6x9's, all powered by the Infinity 7541a 111 W RMS x 4.
I also added two Kappa Perfect 10" subs powered by the Infinity 1211a 854 W RMS mono amp.

I am running the Rockford Fosgate 3Sixty.1 signal processor tapped right after the radio.

now the problem:
I get GREAT sound from the fronts and subs, but my rear speakers have a slight hissing sound (regardless of whether or not the car is running or just on ACC power) and also have an annoying alternator whine coming only from the rear speakers.

I am completely clueless as to where to even start. I am not sure it is the ground because then i would expect there to be noise and whine from the fronts as well. Does anyone have any idea what could be causing this problem? Any help is appreciated.

I tried searching but couldn't really find too much information about my particular situation here.

I grounded the amps in the trunk through a self-made hole (nothing underneath it) and get a constant reading of 13V or higher while the car is running.

Thanks!

 

how did you tap the signal? you should solder them if you haven't.. and if that doesn't work then turn the RF level up and the amp level down.. and as a last resort go to radio shack and get some ground loop isolators

and as for the ground -- if you read the sticky at the top of the forum you'll see its not the number of volts you get but the amount of resistance. read the sticky and do the test to see how good your ground really is

 

i tested some stuff out and when i unplugged my RCA's for the rear and just the right front speaker, i get no more hissing or whine. I know that i have a ground wire very close to one of the ground wires running to my amps. I read on the12volt.com that if the signal wires are close to power wires, that hissing can occur. but besides that, what would be the best recommended ground spot? i will check my ground connection tomorrow.

 

the BEST ground, for our car, is running a line back to the battery. but other people have had various sucesses testing different spots in the trunk. There are spots on either side of the trunk where stuff is already grounded, or they use the bolts under the rear seats or something similar.. each car is a little bit different.

what did you use for the actual connection to the factory lines? did you use crimp connectors or t splice connectors or did you solder? because those connectors allow noise to get in very easily.

 

I would really like to avoid running a wire all the way back to the front, but if that is what it takes, then so be it. but my connections to the factory lines are not soldered, they are crimped using little white crimp caps (looks like little street cones). But i just find it strange that I have slight alternator whine in the subs, real bad in the rears, and slightly in the right front, and have hissing only in the rear speakers. The left front has no static or whine. when the music is turned up though, it sounds really good and clear, but if i turn it down, well you know it just gets annoying.

 

Under normal circumstances, running the power & signal next to each other won't cause an issue. You more than likely have several problems. I don't know much about the 3sixty, but it sounds like you may have crossed or pinched a wire somewhere on the input.

As for the hissing, it does sound like your rear gain is too high on the amp.

 

the gains on the amps are set to about a quarter of the way. I can actually hear a slight hiss even when the RCAs are not connected, so i will toy around with the amp gain some more. Also, i was putting my head inside the trunk and could hear a very slight, but continuous "thmp.....thmp.....thmp......thmp" from the subs. the gain on that amp is barely a quarter of the way up, if even that high. I am going to run a ground wire from to the battery tomorrow and see if that helps any, especially with the engine whine.

Also, i will definately try and test my connections to make sure they are correct and not crossed. now what i definately need to know for this, i need a reliable and accurate diagram of the harness coming out of the radio for speaker wire info and also a reliable daigram of the Bose amp output harness regarding speaker wire info (which color is right front + and right front -, etc.) I know there are a few out there but they each vary. I will do a search on my own right now for that, but if someone has them handy right now, it would be greatly appreciated.

For those familiar with the 3Sixty, would it make a difference if i calibrated the system with the volume at max? rastaman suggested i set it up at volume 28, but at that volume, the red clip LED never began flashing, even when the input **** was at max on the 3sixty. if i re-calibrate it at 28, would that make any difference? thanks.

sorry for the extremely long post.

 

I did mine on 30 (max is 34 i think)-- but i don't have the bose... i don't think it makes a WHOLE lot of difference though... because it doesn't auto adjust the main output levels.. just the EQ levels.. so maybe level 10 on your HU will be slightly louder than mine would be -- as long as you don't turn it up past whatever you tune it at should be no problem at all..

 

I personally set my Bose HU @ 26 when calibrating my JL CleanSweep. I figured this this to be a definite "no clipping" volume. I would not calibrate yours @ max, it will clip. Don't be too concerned if your clip indicator does not flash on the 3sixty, it just means there is a lower voltage input signal. I'm not too familiar w/ infinity amps, but if you can't get a clipping indicator at your amps, you may want to add a line driver to maximize the signal.

Look here & here for the 100% correct Bose diagrams.

Also check the12volt.com and read about muting plugs to totally isolate each component. My old Fosgate sub amp had no noise in it, but would cause noise in my other amp when it was connected. Talking about a trick to find.

 

I'm not trying to get the clip indicator at the amp to flash, just the 3sixty manual states to turn the input of the 3sixty up until the red LED just begins to flash (which this is all done at the 3sixty processor and not at the amps). i think i may try and recalibrate it at a lesser volume, around 3/4 or so. When i go into work today, i will get my ground wire run to the battery, test a few connections, and toy with the gain to see if that is what is causing my hiss.

I am seriously a perfectionist and anything that sounds SLIGHTLY off, i can't rest until it is corrected. maybe i have a mild case of OCD....I just want my system to be perfect. i have been building this thing for over a year, and now will top it off with an alarm install today.

 

OK i have been playing around with some settings. when i push the 3Sixty bass control **** in to switch it over to the aux input, the engine whine and most of the hiss goes away. Now, to me that makes me think that the problem is not the amp grounds making the noise, because that annoying whine would still be there regardless of whether the aux input was engaged or not. could the problem lie in the radio and 3Sixty grounds? i have the 3Sixty tied into the ground of the factory radio. so i was thinking of regrounding the radio and the 3Sixty to another location. Do i stand a chance of eliminating the noise doing this or would i be wasting my time? thanks

 

I have had great success at removing engine whine by re-grounding the headunit directly to chassis. Haven't tried it on an 8 yet, but it's the same idea.

 

i figured i would bring this thread back to life.

Since i don't have a ton of time on my hands right now, I talked to one installer at the Best Buy here in Houston and he seems VERY competent in his work, and he said he would be able to look at my setup and probably fix my awful engine whine.

But, one of the other installers, whom i feel is less competent, said that you can't reground the factory radio because it would mess up since it is tied into the computer system. is that true?

 

Not true - I regrounded mine back to my capacitor (i also regrounded both of the CIG lighters on the way - it didn't mess up the radio, but it didn't help either. The only thing I've found to work is to turn down your amps (and up on the LOC or whatever to compensate) or if that doesn't work then to add some ground loop isolators (cost about 5 bucks from radio shack)

 

gonna try to reground the radio with the rest of the equipment, and if that doesn help, try some ground-loop isolators. but the amps are already almost at zero. i think the rears may be turned up about 1/8 of the way.

 

Cool. Let us know how it turns out!

 

OK tried out a Ground Loop Isolator, and, just as i thought, it didn't work. Whine is still coming through the rear speakers. It has got to be the radio or the 3Sixty.1 may have a bad channel or three. maybe I will be able to find time to just run a ground wire to the trunk from my radio. maybe that will help, but until then, i guess i am SOL for the time being.

 

You could always jumper a wire outside your vehicle from the 3sixty back to the battery. Just to test it out. If it doesn't solve your problem... well... not much time wasted.

 

i was thinking of just sending a ground wire from the 3Sixty and the Radio directly to the battery to see if that would work. maybe one of the audio gurus here could tell me if it would be worth my time and not damaging to my equipment

 

if its only coming from the rear speakers, it seems as if there is a bad connection somewhere between the radio and the amp. check your your connections for the 360, as well as the rca's themselves

 

i will try that. i think it has to be at the radio or 3Sixty since there is no whine when in AUX mode. but also, there is a VERY slight whine in the right front speaker and none at all in the left front, which maybe the cross-overs are filtering some of the noise out?

ugh, if i just had the money, i'd have the Corksport kit with a new radio altogether and bypass all this crap.

thanks for the replies. i will see what i can do

 

time to beat the dead horse some more here. got a REAL wierd situation now. Well, i still haven't had time to do any rearranging of my audio components to try and get rid of the whine, BUT, today i was messing around with the settings on the PDA and set my remote **** to be the Master Volume control instead of bass control, set my stereo at 27, and BAM, no more whine at all, just nice, clear music. but if i switch it back to Sub Control the whine comes back. so what in the world could cause this? it makes me more than happy about the situation as i can finally drive down the street, listen to some classical to calm my nerves, and not have to put up with the obnoxious whining.

anyone have any ideas about what could have happened?