"Glenn Richards" wrote in
message
Don Pearce wrote:

Glen,, please give it a rest. You aren't funny any more
and this is all becoming just a little boring.

And herein lies the problem with this group.

I ask a serious question, expecting some sensible
responses, and instead all I get are sarcastic comments.

The theory is sound anyway,

No its not. Contrary to some naive beliefs, there is not a direct connection
from your power line to your speaker cable.

Here's a news flash: there is a fair amount of active and passive circuitry
between your power line and your speaker cable.

if sticking an LCR filter
across the mains input does indeed reduce the noise
floor.

It doesn't. For one thing there already is a massive LCR filter accross the
mains input in just about every piece of gear. It's called the power supply.

As reducing the noise floor (by whatever means)
improves dynamics.

If you want to reduce the noise floor - then why not address the cause of
the noise in the first place? Hint: the source of noise in properly-designed
audio equipment *isn't* leakage from the power line.

And this I have tested, I've recently
been involved in cleaning up some recordings made about
25 years ago on analogue equipment. This process involves
re-EQ followed by digital noise reduction, and the
results before and after applying the noise reduction are
nothing short of dramatic.

Hint: the source of the noise in those old recordings wouldn't have been
helped by power line filters.

This is using Nero Wave Editor (that comes with Nero
Burning ROM), so no fancy expensive software.

You're taking a good idea and running off to China with it.

My question was a serious one, as it's obvious to anyone
with any knowledge of audio that lowering the noise floor
will improve the sound.

Not if the noise floor is already below audibility. And reducing the noise
floor in your stereo will do no good if it is already lower than the noise
floor in the recordings you play.

So, I repeat. If you've got a lot of electrically noisy
equipment on the same ring main as the hi-fi (eg
switching power supplies in PCs etc) that's kicking out a
lot of RF interference on the ring main, would it not
follow that eliminating (or at least greatly reducing)
this noise, and therefore providing a clean power feed to
the amplifier and other equipment, would lower the noise
floor?

Flawed premise. Switching power supplies in PCs don't kick a lot of RF
interference into the mains. They have built in line filters that prevent
that from happening. PC's are widely used for audio production and testing.
They generally don't compromise those environments.

Once again, I'm not for a moment advocating spending £250
on something from Russ Andrews. What I'm actually talking
about is getting a standard IEC lead for a couple of
quid, then fitting a filtered 13A plug to it, also for a
couple of quid. At trade prices in single quantities this
will cost less than a fiver (which is actually less than
you pay for a standard IEC cable at places like PC
World).

Do a sighted evaluation of this idea. I'm sure you'll get positive results.

So, would someone like to provide a serious answer now?

Trust me, if improving sound quality was this easy, it would have been done
all over the place. And in some sense it has - by the plain ordinary power
supplies in regular audio gear.