RE: E36 M3 rear suspension noise

[Skip Bogard <skip.bogard@xxxxxxxxxxxxxxx>]

> Skip! Had a really good belly laugh visualizing your E-R contraption!
>
??? It's a bunch of cables, a tiny switch box, and a headphone.  No entertaining blinking lights,but
there is one power-on LED.   Not my invention, made by a company called Steelman.

>Question: If one of the bugs is attached near significant air flow don't you
>get mostly wind rumble (like one of those reporters in a hurricane)?

No.  However, It will pick up fast moving air, examples:
         a. you can blow on it and it will pick it up the noise
         b. you can clamp the jaws to a solid metal surface and it will still pick up wind noise

but these are high frequencies....they definitely sound different than low frequency thunks.  And
the high frequencies seem somewhat attenuated over low frequencies (thunks seem louder
than wind noise), but I haven't got a spectrum analysis plot for you.   For $40, I'll get out
my signal generator, a pink noise generator, my spectrum analyzer and I'll make you two plots:
one free-field space and one clamped on a 6 1/2" anvil.

Question for you: Wasn't the original problem discernable over speedbumps or other low speed
bumps anyway?  Maybe I misunderstood.

>the bugs attached metal to metal?

ceramic mike at the base of a 4 1/4" handled metal spring clamp, handles/mike protected by rubber
covering.   Jaws
open to a 1" opening.    Clamping surfaces are 1/2" wide.    Safety tied with velcro and or cable
ties (provided).

ChassisEAR cables BTW are 16 ft. long...six provided...whole thing costs $109...pretty good price
for 96 ft of wire,
six mikes, an amp, and full headsets IMHO.    I own one....it works...beats holding my ear at the
end of a long screwdriver
pressed against my engine.

- - Skip

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