white noise sound behind your center dash console?

[LancePearson]

Sounds behind the center of the dash when driving? It’s probably the ZF six speed gear noise which I believe sets up a resonance inside on the plastic housing stack which holds the DIC, HVAC controls and the Bose Gold radio head which actually sits over what becomes a cave when installed and the plastic center console trim is back in place. I bought mine in Dec. in Atlanta and drove it 515 miles home on the interstate wondering the whole way what that background “whooshing” sound as I characterized it was. I knew the tranny was working perfectly and subsequently got the fluids checked and changed to be sure that was all okay. I later found that when I folded and laid a microfiber towel on top of the cigarette lighter area and across the bottom face plate below the radio on the center console trim it went completely away which isolated it.

I needed to remove the tunnel trim to check the shift boots and fish out someone else’s dropped screws with a magnetic probe, etc., remove the radio to put a new face on it and see if I could not do some sound proofing incidentally. There is plenty of thickish, basic sound proofing between the exterior and the interior but this vertical utility stack of digital electronic controls sits both attached to and in a relatively thin plastic material with the cave below. I’m no sound engineer but it seems to me like it was a perfect place to take what sound seeps upward and, you pick the word, either magnify it or resonate it as the thin plastic vibrates a little and that cave works it too, perhaps even a miniature echo chamber.

I bought .080 and .050 sound deadening material on ebay, you need less than a foot and a half square feet in there. It is just foil faced sound deadener of some type of urethane or rubber material which has adhesive coating on the back and comes with peel off paper which allows you to cut to fit and then peel the paper, attaché it, then use a small roller to press it on.

It is not a huge task. It is not thick. It is not smooth by design.

It does seem to have completely stopped that sound for me. How? I’d argue it stopped the thin plastic from resonating and magnifying the sound which previously you might hear as a kind of annoying white noise behind the radio, dic, hvac stack as you drive with windows up and top on.

Not anymore. It worked. I believe it both absorbs some sound/energy in the plastic material and stabilizes the plastic structural frame that holds these devices by killing vibrations to a great enough degree to matter.

I actually put a piece on about half of the metal top of the radio head case and the bottom and 2” strips on the side just to be safe though I believe the metal did not hear enough sound to resonate.

I wouldn’t do this just for itself but as part of opening the center console up, I’d consider it as it takes less then fifteen minutes to do once open. I was careful not to cover any openings so that air will continue to flow nor any screws or bolts for obvious reasons. This is not the greatest thing since sliced bread but it did quiet that irritating noise down for me as I was doing other things that needed doing in the stack. I also put a piece on the bottom inside part of the center console stack finish trim plastic piece just in case since it forms the “front” of the cave below the radio head as well when it’s reinstalled. This sound deadener is thin enough that it does not stop anything from fitting.

I’m sure some sound engineer might know more about this but what I know is it worked rather well in a test drive today. We’ll see how it works out over the next few months but it should stay put and I have no plans to go back into that stack again….all other punchlist things done.

I share this as a possibility for you if you have ever wondered. Not something you have to live with it seems to me. Will post photos here and in the subsequent panel so you can see what I'm talking about if you haven't opened your console up.

Lance Pearson

[LancePearson]

a few more photos of my 1991 efforts...all done.

[vilant]

Nice job. I don't have to worry about that, though. My car is so loud because I have the power effects exhaust dial, wide open. I hear nothing besides the roar of the car, lol. I have to turn the radio up fairly loud to hear the words. With the dial closed, it's quieter, but then I hear all the other creaks and rattles.

[Kevin]

You have my favorite exhaust joe. The only buzzing I have is when the shifter lock out ring gets loose

[LancePearson]

Follow up. With the bronze targa top in place and windows up I'd have to review and reflect that the addition of the thin soundproofing did not materially change the "white noise" working its way into the cockpit seeming to come from behind the center console under the dash....Not opening it up further as it's not something I'm not used to but I have to say it really didn't make a difference when I get further from it and across a wider set of configurations and uses.

Lance

[Schrade]

YikES! You went DEEP there Mr. P !

I did that in the '94, and took 4 days to re-assemble ( I put every screw back in the empty hole as I dis-assemble). And shoot snappics GALORE.

Perhaps get a phase inversion amplifier. Real-time processing would do it, but integrating the stereo INTO it would be necessary, to not cancel the tunes too.

Someone else might know more-so how to do this...

edit:
and then, maybe not...
Good explanation here, although ambient (non-music signal) noise, is not addressed

[LancePearson]

Shrade,
I've decided to embrace the white noise since I rarely put the Targa top on anyway and can't hear it when the top is out due to wind noise! When in I have a microfiber towel folded which is long enough that it lays on the ashtray cover with four thicknesses of black towel and curls up the radio and eliminates about 50% of it and that's more than enough. I even put cotton round gauze in the cup holders to dampen the sound. None of it materially changed the sound so embracing it is much simpler! Mine is getting the serpentine belt changed, oil and greased and due back today so that when I drive it the 350 miles to Carlisle to the Wazoo deal April 5 for the April 6 day there with the group then home and then May 15 the drive of 646 miles on I 64 to the Gathering in Bowling Green I have a "known" belt. When I got the car there were no maintenance records and the car had very few miles put on it between 2003 and 2012 late when I bought it so despite low miles on the belt, I think its rubber is not the greatest like old tires so am doing pre emptive strike on it. It was squeaking a little anyway which is a sign of belts wearing in my experience. Should get the car back today. They started working on it late yesterday and just have the belt to do this morning. I asked them to save the old belt as I visually inspected it when I got it and it was fine but as I drove it squeaked a bit and maybe can track it back and see what it's vintage was. Which reminds me, did I put a set of jumper cables in the well boxes in the back? Will check. Are you going to the Gathering in May? Be fun to say hello if you are. Looks like a drive to one of the whiskey distilleries is shaping up on one of the less busy afternoons...80 miles each way from the museum. I leave the 15th and return the 19th. Will try my radar detector out on the I 64 Interstate drive in WV and Ky...might even see if it works for a short stretch at 150 mph. Have briefly had it about 140 mph but that's the fastest so far. Car had tons more but I just ran it up then ran it back down quickly ever mindful of John Law here in Va. where tickets are hugely expensive...like that one would be $3400 plus loss of license.

[Schrade]

Hey there Lance; will be doing lots of travel near future here.

Really would like to put some blacktop under the Z here, but ...

Just had the small claims on the auto swap, and the judge needed to go over particulars before disposition. No 'Completion' date hurt me, but they did acknowledge that all the shortcomings were their own work.

Fingers crossed here (and eyes, hair, teeth - got 'em all crossed). Will probably have to get PETE's wrench on it to get it RIGHT here.

Someone else said about sheet rubber to kill the acoustics chamber resonance. Ask at Home Depot about EPDM (or a roofing contractor, with leftover sheeting from a new job). Or maybe the hobby shop for cork sheeting - cork can be 'floating', but the rubber would need affixing between components...

[LancePearson]

Good luck geting it all put together. I got mine back late this afternoon with the pre emptive stuff done and need to call and see what they did to turn my underhood lights off. Worked fine before the shop had it. Will go out and reverse the fuse in case it's a polarity issue. You just pull the fuse down by the driver's side head light area to turn them off for long periods when the hoods up for hours and since I have leds now it is possible even the fuse has to be one way though that seems strange. the leds only work one way with polarity. Will check before bed than call tomorrow if that isn't it. Need to wash some fingerprints off as well. They do a good job but they are human. Did the work fine. The belt was new enough even though I had them replace it since it was a min. of 8-10 years old but the pulley that is in the tensioner had a small vibration at high speed which was what was probably making the sound and that was replaced and all is well with the engine now. I just want no problems on the two upcoming drives that I could have avoided and I now know the provenance of all the major systems and maintenance items because I've been through most once with me and mine here now.

I should have just stuffed a rag into the chamber area below the radio when I had it opened up but it's not worth messing further with. next time open, maybe so.

[LancePearson]

Before I even got out to double check this morning the shop and I talked and they had unplugged the lights where the wires connect at the base of the hood to avoid draining the battery and forgotten to replug them so in a few minutes I'll go out and reconnect then my entire short term punch list and preparation for the Wazoo Carlisle drive and then the drive to Bowling Green will be done. Engine runs sweetly.