A couple of basic newbie questions for you: audio signals can get distorted
from either analog or digital recording levels being set too high.

1) Analog levels that are slightly too high can sound better than levels that
are just under "max" input. Can speakers be damaged by playing analog signals
that are more than slightly too high?

2) Digital signals that are too high at all instantly result in clipping and
its characteristic crackling noise. Is there any danger of damage to speakers
playing back recordings that were made with digital levels set too high? Or is
the only downside the crackling noise? If a digital signal that clipped during
recording is reduced in volume via software, will the crackling go away or must
it be removed with a filtering program?

3) Does removing unwanted noise with filtering/cleaning programs degrade
signal? Do they remove or alter anything other than the specific things that
they are designed to remove (e.g., tape/mic hiss, pops from vinyl lp's,
diginoise from DAE)? Do they resample or in any other way basically alter the
source material?

Thanks,

Barton

In article ,
btrthnk (Barton Bosch) wrote:

A couple of basic newbie questions for you: audio signals can get distorted
from either analog or digital recording levels being set too high.

1) Analog levels that are slightly too high can sound better than levels that
are just under "max" input. Can speakers be damaged by playing analog
signals
that are more than slightly too high?

Severe clipping can be a problem, especially if the speakers aren't
rated much higher than the amplifier.

Clipping distortion changes the natural distribution of frequencies in
music. It also raises the power output of the amplifier, up to 2x its
RMS rating. Those two factors together make it possible for one driver
in a multi-way speaker to receive an abnormal amount of power and
overheat.

2) Digital signals that are too high at all instantly result in clipping and
its characteristic crackling noise. Is there any danger of damage to
speakers
playing back recordings that were made with digital levels set too high? Or
is
the only downside the crackling noise? If a digital signal that clipped
during
recording is reduced in volume via software, will the crackling go away or
must
it be removed with a filtering program?

Same as above applies. Turning the volume up near the limits of the
speakers could roast a driver.

There's no good way to filter the clipping. Bits of the original signal
are lost.

3) Does removing unwanted noise with filtering/cleaning programs degrade
signal? Do they remove or alter anything other than the specific things that
they are designed to remove (e.g., tape/mic hiss, pops from vinyl lp's,
diginoise from DAE)? Do they resample or in any other way basically alter
the
source material?

Yes, it degrades. Software can only guess what is unintended noise and
what is music. You'll have to play with the adjustments to see if you
can get results that sound better than the original.


Thanks,

Barton

"Barton Bosch" wrote in message
...
A couple of basic newbie questions for you: audio signals can get
distorted
from either analog or digital recording levels being set too high.

1) Analog levels that are slightly too high can sound better than levels
that
are just under "max" input. Can speakers be damaged by playing analog
signals
that are more than slightly too high?

yes


2) Digital signals that are too high at all instantly result in clipping
and
its characteristic crackling noise. Is there any danger of damage to
speakers
playing back recordings that were made with digital levels set too high?

Yes

Or is
the only downside the crackling noise? If a digital signal that clipped
during
recording is reduced in volume via software, will the crackling go away or
must
it be removed with a filtering program?

You should *never* accept digital-clipped signals, or analogue ones, unless
a fuzz-box.

3) Does removing unwanted noise with filtering/cleaning programs degrade
signal?

Yes

Do they remove or alter anything other than the specific things that
they are designed to remove (e.g., tape/mic hiss, pops from vinyl lp's,
diginoise from DAE)? Do they resample or in any other way basically alter
the
source material?

Yes.

It is better not to have a problem in the first place, than to get a problem
then try to fix it.

geoff

"Barton Bosch" wrote in message

A couple of basic newbie questions for you: audio signals can get
distorted from either analog or digital recording levels being set
too high.

1) Analog levels that are slightly too high can sound better than
levels that are just under "max" input. Can speakers be damaged by
playing analog signals that are more than slightly too high?

Speakers can be damaged by any kind of signal that causes the voice coil
travel or voice coil heat dissipation limits of the speaker to be exceeded.

2) Digital signals that are too high at all instantly result in
clipping and its characteristic crackling noise.

There is no appreciably difference between good analog clipping and good
digital clipping. In both cases the signal is flat-topped, and that is that.
There have been digital converters in the past that did not clip cleanly,
but those can be viewed as analog domain problems.

Is there any danger
of damage to speakers playing back recordings that were made with
digital levels set too high? Or is the only downside the crackling
noise?

See comments about speaker damage, above.

If a digital signal that clipped during recording is reduced
in volume via software, will the crackling go away or must it be
removed with a filtering program?

The cracking won't go away, and filtering programs will adversely affect
sound quality. Whether in the analog domain or digital domain, the best rule
is to not clip.

3) Does removing unwanted noise with filtering/cleaning programs
degrade signal?

Yes.

Do they remove or alter anything other than the
specific things that they are designed to remove (e.g., tape/mic
hiss, pops from vinyl lp's, diginoise from DAE)?

Of course they remove more than just the basic damage, although some of the
better vinyl noise removal programs can have remarkably pleasing results.

Do they resample or in any other way basically alter the source
material?

They definitely basically alter the source material while they remove the
noise. As usual, there is no free lunch.

"Engineer" wrote in message

Barton Bosch wrote:

A couple of basic newbie questions for you: audio signals can get
distorted from either analog or digital recording levels being set
too high.

1) Analog levels that are slightly too high can sound better than
levels that are just under "max" input.

Not in my opinion. Any clipping, hard or soft, introduces
odd harmonics and they sound very bad.

Asymmetrical clipping generates zero odd harmonics. I

f you clip a sine wave perfectly asymetrically, you get a DC offset and only
even harmonics.

If you want odd harmonics you must clip the waveform at least a little
symmetrically.

"Barton Bosch" wrote in message
...

Speakers can be damaged by any kind of signal that causes the voice coil
travel or voice coil heat dissipation limits of the speaker to be
exceeded.

Could someone expand on what "any kind of signal" might include, other
than the
analog or digital distortion discussed in the first message.

Would garden variety distorted rock guitar or thrash punk -- recorded with
levels set properly and playback volume within reason for the given
speaker/amp
combination -- cause the voice coil to travel beyond its limit, or the
speaker
to heat up and burn out? Is there any technical difference in listening
to
Hendrix in comparison to, say, chamber music, where potential speaker
damage is
concerned?

Moer possible than with the other, but only if you havew it ridiculously
loud.

What about the case where a digital signal is recorded (improperly,
obviously)
resulting in clipping and the characteristic crackling noise. That signal
is
then transferred to hard disk, reduced in volume, and then reburned to CD.
The
new disk no longer has levels which cause clipping distortion, but the
crackling noise artifacts are still present (they weren't filtered out
with a
cleaning program, etc.). Am I correct in assuming that playing this new
(signal lowered) recording of the original distorted source at a
reasonable
volume for the given stereo setup does not pose any particular danger to
the
speakers?

Possibly not, but still will sound like ****.

I understand that levels, particularly digital levels, should be set below
saturation. I am not trying to start a feud about people's subjective
preferences in setting analog recording levels a bit too high for extra
presence. In the real world of live recording, things happen and you only
have
one chance to get things right. Or you can try to clean up someone's
mistakes
afterwards. I just want to base my actions on accurate information rather
than
my collected assumptions from a decade of messing around with consumer
recording equipment.

There is no rocket science in it - just don't get clipped in the first
place. Then you needn't worry about it.

geoff

Barton Bosch wrote:

Speakers can be damaged by any kind of signal that causes the voice coil
travel or voice coil heat dissipation limits of the speaker to be exceeded.


Could someone expand on what "any kind of signal" might include, other than the
analog or digital distortion discussed in the first message.

I personally have destroyed a set of speakers by playing the Saint Saens
"Organ" Symphony at high volume. g


Would garden variety distorted rock guitar or thrash punk -- recorded with
levels set properly and playback volume within reason for the given speaker/amp
combination -- cause the voice coil to travel beyond its limit, or the speaker
to heat up and burn out? Is there any technical difference in listening to
Hendrix in comparison to, say, chamber music, where potential speaker damage is
concerned?

What about the case where a digital signal is recorded (improperly, obviously)
resulting in clipping and the characteristic crackling noise. That signal is
then transferred to hard disk, reduced in volume, and then reburned to CD. The
new disk no longer has levels which cause clipping distortion, but the
crackling noise artifacts are still present (they weren't filtered out with a
cleaning program, etc.). Am I correct in assuming that playing this new
(signal lowered) recording of the original distorted source at a reasonable
volume for the given stereo setup does not pose any particular danger to the
speakers?

I understand that levels, particularly digital levels, should be set below
saturation. I am not trying to start a feud about people's subjective
preferences in setting analog recording levels a bit too high for extra
presence. In the real world of live recording, things happen and you only have
one chance to get things right. Or you can try to clean up someone's mistakes
afterwards. I just want to base my actions on accurate information rather than
my collected assumptions from a decade of messing around with consumer
recording equipment.

Barton

I don't know if your reply was intended as a troll or if you just missed the
"assuming a resonable playback volume for a given speaker/amp combination"
statement in my message.

Your advice to "keep the volume turned down for 'any signal' and your speakers
will be fine holds for the general case," but in the case of a clipped signal
the volume/output spikes, and what was an acceptable volume for the non-clipped
portion of the signal quickly becomes hazardous to the speakers... A signal is
not just a signal when it is clipped.

Barton

"Barton Bosch" wrote in message


I don't know if your reply was intended as a troll or if you just
missed the "assuming a reasonable playback volume for a given
speaker/amp combination" statement in my message.

By definition, a "...reasonable playback volume for a given speaker/amp
combination..." will never damage it.

Your advice to "keep the volume turned down for 'any signal' and your
speakers will be fine holds for the general case," but in the case of
a clipped signal the volume/output spikes, and what was an acceptable
volume for the non-clipped portion of the signal quickly becomes
hazardous to the speakers...

Clipping a signal heavily is obviously not a really *nice* thing to do to
it, but just clipping a signal doesn't make it an instant destroyer of
speakers.

A signal is not just a signal when it is clipped.

But in reality, it is. There's a lot of lore about clipped signals, like the
idea that clipped signals always have more high frequency content, that just
isn't true.

The key consideration in any speaker damage situation is the nut holding the
knob on the volume control. Saying "the clipped signal made me do it" is IME
a cop-out.