[Amps] Acoustic Noise Comparison

[Jim Barber]

Good results.
Assuming the blower is running in balance, freshening the rubber baby 
buggy bumpers it mounts on might help some more with the vibration.

Turbulence is tougher. Apple has been working on that one for their new 
MacBook Pro, which uses a new fan design where the blades are different 
lengths. (doesn't decrease noise per se, but spreads it out across a 
wider range of frequencies making it appear quieter)  It works pretty 
well, but unfortunately I don't know how to copy the idea with a 
centrifugal blower yet.

It sounds like you've made significant progress. Quiet is good. :-)

73,
Jim N7CXI

On 6/22/2012 9:36 PM, Jerry Kaidor wrote:
> Hi,
>
>     I found a spare moment today and couldn't resist.  I popped open the
> hood of the Alpha and cut three squares of the "Dynamat Extreme" that I had
> left over from my car soundproofing project.  I stuck one square on the L/H
> side of the cover, next to ( but not over ) the RF deck.  The second square
> went above the power transformer.  The third square on the R/H side of the
> cover.
>
>     I also cut up a soft rubber mouse pad and put pieces under the amp,
> where the (missing) rear feet were supposed to be, and also under the
> (stiff, plastic ) front feet.
>
>     Buttoned it back up, plugged it in, powered it up.  The amp was MUCH
> QUIETER.  According to the sound meter, about 8 or 9 db quieter.  Just
> as quiet as the 30L-1 in fact.
>
>                                - Jerry Kaidor
>
>
> _______________________________________________
> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>