G wrote in message
...
In article , Meat Plow
wrote:
On Tue, 18 Sep 2007 14:47:28 +0100, N Cook wrote:

Reported as fuzzy sound on the bass guitar E string even at relatively
low
levels
but otherwise fine sound rendition or backing off the bass control .
Feeding a signal generator in then indeed a distinctly fluttery
distortion
in the range 50 to 70 Hz on top of the wanted output, ok above or below
that
range.
No external speaker output on this cube and before getting inside to
scope
it or run an external speaker I took the front grille of in case of
parasitic rattling but no change. But putting a sock in the front/back
vent
tube in the speaker surround cured it.
Where to go from here ? sci.acoustics.repair ? charge for an old sock ?

Try a different speaker.

Well it seems like it could be electronic or mechanical. Putting a sock
around
a vent will usually make the cone move more and create more distortion, if
that is the problem. I can't believe there is a vent, and a 10 inch guitar
speaker can't reproduce 50 Hz unless its a HIFI driver. The description
about
speaker surround, baffles me.

greg

The vent is clearly seen at lower left on
http://media.zzounds.com/media/feed/...CUBE30BASS.jpg
looking like a tweeter but
the tweeter is mounted co-axially to the main cone.

Blocking up this vent means you can turn the bass control up and the volume
up without the fluttering noise in the 50 to 70 Hz range. Will take apart
tomorrow and scope, external speaker etc.
No problems with the reservoir cap solderings


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/