I know this has been talked about before, but the forum search isn't giving me the answers i want!

I have an '04 TSX w/Navi
My audio setup: Blitzsafe AUX Input --> Harman/Kardon Drive + Play --> iPod

I'm having 2 alternator whine and ground loop inducing issues..

#1) I don't like what the Ground Loops Isolator does to the bass response of my music. It makes the bass sound compressed, shifted, and cutoff. By that i mean .. the bass below like 50-60hz, sounds like it's been shifted up in the frequency range, and compressed (no dynamic range). So when there is low bass in a song, it instead sounds not so deep, and very loud, muddy, and boomy. If I take the GLI out, the bass sounds like I'd expect, with good smooth and low bass extension. So i want to take the GLI out, and i started experimenting last night. I took the GLI out, and went to go make a cleaner ground cable going to the Drive+Play. But then I noticed that my Drive+Play (which also powers the iPod) was still functional with its power cable's ground wire disconnected, instead the unit was getting power from the positive power cable input, and grounding out through the negative cable of the RCA patch chord, arg! If I disconnect audio cable going into the Drive+Play, then the unit powers off. I guess that's what the ground loop isolator was isolating! So how do I get the unit to ground through the unit's power cable, and not through the rca patch cable?

#2) I also disconnected any rca patch cables from the Blitzsafe AUX Input's input, and I still get massive alternator whine. Is it picking up noise from the airbag ecu? (it's not that close to it). Or is it just grounding poorly through the radio?

so those are the 2 sources of noise I'm getting. Staticy/tingy/buzzy noise from ground loop and my aux device grounding through its patch chord, and alternator whine coming in from the Blitzsafe aux input

I've got 2 things coming in that I'll be throwing in, in hopes of cleaning things up... 1) a 12volt DC Filter for the + input .. and 2) the Navone Engineering Isolatoed Power Supply (http://www.davidnavone.com/filters.html)

any other ideas? I feel like the first thing I should do is clean up the Blitzsafe and make it not be a ground for the aux device? How do I even go about that?

-vasu

 

Hi, vasu, how ya doing? Long time!

1) Which GLI are you running? I've tested some lately with the audio analyzer and the cheaper ones roll off at 1090 Hz, no fooling. The radshack piece was like a crossover!

The best I've found that isn't $200 is the Soundgate Iso2Lite. If you want to try one I will send you one. They cost like $28 though. I'll send you one for free as a trial if you want.

As far as the grounding thing, whenever you pull a ground wire for the device the device will always try to ground through the audio shield ground. Nothing to worry about. Theoretically if your ground wire potential is the same as the HU's ground potential, that connection will not be a ground loop. Theoretically.



2) IF the GLI takes care of the noise (ignoring the SQ issues for a moment) then the power filter is not needed. You only need the power filter IF the GLI doesn't solve the noise problem.

Shoot me an email with your address and I'll mail you a Soundgate ISo2Lite for testing.

 

That should have read, 100 Hz.

 

Hey Ken! great to hear from ya! Last we spoke you were suggesting me get the MB RCE-269 for my rear bass speakers since I didn't want a seperate sub, and I've been very very happy with those speakers .. until I use the aux input and the bass cuts off! I didn't really notice the cutoff until I got those speakers, haha

I'm using the Radioshack GLI right now, and yeah it's definatley actng as a crossover, arg!

the GLI fixes the fussy, staticy, buzzy sound i was getting, but I still get an alternator (gas pedel) dependent whine. The higher the engine revs, the more whine I get.

What I'm looking to get rid of is a) the bass cutoff and b) the whine.

What's the Soundgate Iso2Lite cut off at?

-vasu

 

Well, the old Iso2Lite was fairly flat to 20 hz, maybe 3dB down at 25 Hz or so on my RTA. They have a new one I haven't compared yet.

If you connect a GLI and you still have RPM-related whine, you either have a ground loop on the other set of RCAs (if you have 2 pair), you have an inline power problem, or you have your gain up too high.

 

as far as those 3 things go...

1) There's only one pair of cables going from the Blitzsafe AUX input to the Drive+Play (which connects via dock cable to the ipod)

2) perhaps this is it?

3) The gains on my amps in the trunk are all the way down, I also experience no noise whatsoever (no hiss, whine, snap, crackle, pop, etc) when I listen to CD, even with volume at 40 and the rpm's revving high


Also eldude, I just tried something else..not sure how pertinent it is.... I connected my iPod straight to the Blitzsafe (and nO GLI either) via the its headphone jack and using the iPod's built in battery and not car provided power, and there was no noise whatsoever (no hiss or whine).. it sounded just like I was listening to CD.

I'm going to try the experiemnet from David Navone where you power a device with an external 12v battery and see if the noise goes away .. i'll report any findings .. please feel free to chime in with any other thoughts or suggestions .. i'm trying to get rid of this problem by Friday morning before I do 24 hours of driving

-vasu

 

well i tried hooking up the drive+play to a 12v battery (a 12v cordless drill battery) and the unit powered on, went off .. and now it wont come back on

-vasu

 

I have an older RS GLI, and I don't recall it being that bad, but then again, it's been a while since I used it. Anyway, I also had an alternator whine problem when I tried to add a PIE line driver (amp) inline with my Blitzsafe. The GLI didn't affect this. I was getting alternator whine PLUS engine (spark plug?) noise! It was bad. SO I took the PIE out, but I'd still like to get it to work. Any suggestions? I tried looking for a power line filter, but the local RS doesn't seem to carry that anymore.....

Like with vasu, without the PIE, it's perfect (just low in volume). I've been tempted to rig up a 12 v battery pack except that it's just going to annoy me to have to keep changing them out....

What is the best 12v power source? I tried running power from the fusebox (on one of the unused plugs), but maybe I should use something else. I also need to know what to ground to. I worry that it might be a lost cause, but maybe if I can find the right connections it would be OK. I guess I'd have more confidence if others got a clean install (and could share what they tapped into).

 

^^ I might have an old RS inline filter that I can sell you. I'll have to look around.

 

so yeah .. i blew up my Drive+Play .. really good timing since i'm going to be doing 24 hours+ of driving this weekend

They'll send me a new one, but not in time... maybe i'll just suck it up and buy a 2nd unit

 

that sucks.

 

I'm really hoping that when i wake up and go out to my car that magic will have fixed it.

I'm gunna buy a 2nd unit tomorrow from bestbuy and then either be a lowlife and return it after the weekend, or ebay it

-vasu

 

the Navone 12v isolated power supply was delivered today, so i went out and bit the bullet and got a new drive and play

conntected the drive and play's power to the power supply, and then connected that to car power, and powered it up and drove off and... NO NOISE!!! even with the volume up at 40, the engine at red line, and no audio playing through (ipod on pause), there is no whine, static, etc coming out!

no ground loop ioslators either

i just wired the power supply into the drive and play's cigratette ligher power adapter.. i took the chord, cut it in half, connected the power supply in the middle, and just plugged it in.

wooo!

-vasu

 

I looked up the Navone power supply, and that looks like just the thing to clean up the noise.. but at $100, yikes! It makes this MP3 adapter project pretty pricey.