[Powell]

"Jim Lesurf" wrote

My speakers have four spikes beneath them which makes it a pain to
move the speakers even slightly as the length of at least one spike
has to be adjusted to make all four rest on/in the floor. (The floor
is solid - maybe concrete - and not wood.)

"concrete"... is a very good vibration sink compared to wood, for
example.

What size/shape/structure/type of "concrete" do you have in mind, and what
do you mean by "sink"? Can you point pun me at measurements to support
what you say?

In theory, all things being equal (concrete's mass will convert
more sound energy to heat more efficiently as compared to wood
which tends to resonate. Many high end speaker manufactures
like Wilson Audio, B&W, Egglestonworks and others
construct speaker cabinets out of synthetic compounds,
stone, or aluminum for this reason., for example. Of course
in practice it is more a complicated subject because of Q
value effects.

Meausrements... yes, I have data. What is your specific
question?


If this is a carpet and pad installation over concrete it is unlikely
that spikes will work anyway, IME.

"Work" means?...

For maximum effectiveness spikes should not be run
through any type of carpet interface (carpet/foam).
If you have high quality carpet, spikes just won't
penetrate the carpet/pad substrate. The tightly
woven jute backing and under pad is the problem.
The conical shape of spikes simply will not couple
to the sub-floor... and I mean tightly. While it might
appear (feel) to you that your spikes are firmly in
they are still supported by the carper/pad. Sound
pressure measurements and auditioning indicate
only a poor improvement in fidelity if used in this way.


Quality casters make a good alternative (measured
reduction in cabinet vibration) to speaker spikes, IME.

Ah. Thanks, can you give a URL for the measurements
you are referring to here?

I've not placed this data on the web.