Road vibration - shock absorbing mounts?

[dimitris]

I moved to Seattle 2 years ago, and brought my 98.5 Audi A4 with its platinum phatbox with me.  The roads around here are pretty rough from all the studded snow tires, and my car rides on tires with pretty firm sidewalls.  One has to do what one can about steering response :-)

The constant vibration from a typical ride on, say, I-5 consistently causes my phatbox to "give up" after a few minutes.  I think that the disk has some sort of error counter that gets tripped by the vibration.  I've checked the combo connection in the back and it's very tight, so I don't think it's the pins losing contact.  In fact, before I moved, I consistently saw the same behavior *only* on parts of I-80 (near Lake Tahoe) that are similarly worn by snow chains.

Does anyone here have any advice about shock-absorbing mounts I could use?  I really want to make my phatbox usable again!

D.

[Terry_Kennedy]

The constant vibration from a typical ride on, say, I-5 consistently causes my phatbox to "give up" after a few minutes.  I think that the disk has some sort of error counter that gets tripped by the vibration.  I've checked the combo connection in the back and it's very tight, so I don't think it's the pins losing contact.  In fact, before I moved, I consistently saw the same behavior *only* on parts of I-80 (near Lake Tahoe) that are similarly worn by snow chains.

Does anyone here have any advice about shock-absorbing mounts I could use?  I really want to make my phatbox usable again.

Well, I drove my BMW wagon (AWD, stiff suspension, 17" tires) down 20 Mule Team Canyon in Death Valley and didn't have any PhatBox skips or shutdowns:



This was with the stock 60GB Toshiba DMS from PhatNoise. A common problem is that the ribbon cable from the PhatBox to the DMS socket (or the switch in the same spot) is sensitive to vibration. This is covered in the Wiki here (or if it isn't, it should be). If you haven't already done the hack to support non-PhatNoise drives, you might want to do that and try a different brand of drive, if fiddling with the cables doesn't help.

[dimitris]

Thanks, I'll open up the box and check the ribbon cable - it's waaay out of warranty anyway.

BTW, is yours mounted vertically or horizontally?  With a wagon I suspect it's the former.  Mine is horizontally bolted directly (metal to metal) on the rear deck, so vertical vibration translates to up/down forces on the disk heads :-(

[Terry_Kennedy]

BTW, is yours mounted vertically or horizontally?  With a wagon I suspect it's the former.  Mine is horizontally bolted directly (metal to metal) on the rear deck, so vertical vibration translates to up/down forces on the disk heads :-(

Continuing my "pictures are worth 1000 words" theme, here's all you ever wanted to know about my mounting:

[A543]

If your box is mounted metal to metal maybe just some simple low-pass filtering using rubber grommets could help.

[dimitris]

Thanks!  Although it is metal-to-metal, the screws do not, as I previously thought, thread through the PB's aluminum so grommets are definitely worth a try.  I figure one on each side of the mounting hole, to minimise screw-to-PB contact.

I also checked the ribbon cable and it seems firm on both its ends.

By the way, how do you get the front plastic plate to unlatch in order to fully open the box?  Latch highlighted here:



In more detail:



I tried using a screwdriver, but I don't have enough leverage and it can easily slip and damage something in there.  Also tried using my pinky finger through the DMS door but couldn't get them to budge.

[judb]

i pried the bottom loose first and then worked a screw driver (small flat blade) around the edges and it popped loose without breaking.

[dimitris]

I'm working on building a custom bracket.  I need to select the right type of "miniature shock absorber" from here:

http://www.vibrationmounts.com/

Does anyone happen to know the platinum phatbox's weight?  I guesstimate it at around 4 pounds/2Kg, but I have no scale here :-(

Many thanks

D.

[freetorun]

Dimitris,

Did you ever have any luck reducing the vibration and resultant skipping?  I'm having a similar problem with the vertical hard-mounted Phatbox in my Audi TT coupe while driving at freeway speeds even on good roads.  All I have to do is rest my hand on the DMS cartidge to stabilize the playback but this is pretty impractical for long periods of time.

I'm going to tear into the mounting to try to reduce the vibration as soon as I have a moment.

Thanks,

FreeToRun

[LloydDobler]

I just used 2 layers of 3m double backed foam tape to mount mine to some brackets I made out of strip steel, and I have no problems at all on a lowered car with a 12" sub right above the Keg.  In other words, it doesn't take much to isolate it.  I did have skipping problems when I had it hard mounted.