"Woody" wrote in message

"David Looser" wrote in
message ...
wrote in message
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In any speaker, when you put the volume up high, there
is more electric buzzing.

1) What is this buzzing called?

If it's a "buzzing" sound, it's usually called "buzz".
If it's more of a "humming" sound then it's called "hum".

2) What specifications in a speaker reduce the amount
of buzzing as volume is turned up? e.g. low/high
impedance, sensitivity, etc.

None at all, because it's not caused by the speaker.
It's caused by pick-up of mains-borne interference
earlier in the system, i.e.. the amplifier, it's wiring,
or the source components, CD player, tuner etc.

... or more often than not poor design and/or cost
cutting/inadequacy in the power supplies. Much of it is
due to poor mechanical layout within the amp case.

I've bench tested 100s of components and find that most amps, tuners,
optical disc players, etc, are usually audibly and measurably relatively hum
free.

I'm talking about equipment that is mid-fi or better.

Most of the hums and buzzing is due to:

(1) Cheap equipment, such as boom boxes and rack systems that are little
better.

(2) Broken equipment - some of which is decades-old.

(3) System problems, such as corroded connections, equipment located above
the power transformer of another piece, etc. In some systems there are
problems with gain-staging due to multiple pieces with volume controls, and
incorrect setting of those controls.

I had a power MOSFET amp that I built myself - actually
as dual mono - with fully regulated power supplies
capable of 110Wpc into transmission line loudspeakers
that could rattle windows with ease so good was their low
frequency response. Put you ear right up to the speaker
and all you could hear was a little hiss but no hum.

That's all fine and good. IME, most commercial equipment of even modest
quality is just about as good. It's not unusual for amplifier input stages
to have regulated power supplies. A properly-designed output stage will have
low hum if provided with a reasonably well-filtered unregulated power
supply.