Don Pearce wrote:
On Mon, 10 Jul 2006 11:10:55 GMT, "dadiOH"
wrote:

David Morgan (MAMS) wrote:

I had a look, and I can't see how the device works without modifying
dynamic range

Simply put...

1. Find max volume among all songs
2. "Turn up the volume" in all others so their max is the same as the
loudest.

Won't work - can't work. If you have a mixture of music, then peak
levels as related to average loudness will vary wildly. The loudest
sounding will have highly compressed dynamics, with most of the tune
crammed against the limit. If you try to increase the levels of all
the others until they sound as loud, they will all be clipped to hell.

No, not necessarily *sound* as loud just increase the values in the softer
songs until the greatest is equal to the greatest in the loudest song. For
example...

Loud song greatest value = 29000

Song to be changed, greatest value = 24,500

(29000)-(24500) = 4500. Therefore, all values in this song are to be
increased by 4500 when played.


--

dadiOH
____________________________

dadiOH's dandies v3.06...
....a help file of info about MP3s, recording from
LP/cassette and tips & tricks on this and that.
Get it at http://mysite.verizon.net/xico

On Mon, 10 Jul 2006 13:05:17 GMT, "dadiOH"
wrote:

Don Pearce wrote:
On Mon, 10 Jul 2006 11:10:55 GMT, "dadiOH"
wrote:

David Morgan (MAMS) wrote:

I had a look, and I can't see how the device works without modifying
dynamic range

Simply put...

1. Find max volume among all songs
2. "Turn up the volume" in all others so their max is the same as the
loudest.

Won't work - can't work. If you have a mixture of music, then peak
levels as related to average loudness will vary wildly. The loudest
sounding will have highly compressed dynamics, with most of the tune
crammed against the limit. If you try to increase the levels of all
the others until they sound as loud, they will all be clipped to hell.

No, not necessarily *sound* as loud just increase the values in the softer
songs until the greatest is equal to the greatest in the loudest song. For
example...

Loud song greatest value = 29000

Song to be changed, greatest value = 24,500

(29000)-(24500) = 4500. Therefore, all values in this song are to be
increased by 4500 when played.

But what does that do? They are just numbers, and they have only the
most tangential relationship to the perceived playing of the track -
which is what this is all about.

Incidentally the maths is all off too. You can't do this by adding
numbers, you have to multiply.

d

--
Pearce Consulting
http://www.pearce.uk.com

Don Pearce wrote:
On Mon, 10 Jul 2006 11:10:55 GMT, "dadiOH"
wrote:

David Morgan (MAMS) wrote:

I had a look, and I can't see how the device works without modifying
dynamic range

Simply put...

1. Find max volume among all songs
2. "Turn up the volume" in all others so their max is the same as the
loudest.

Won't work - can't work. If you have a mixture of music, then peak
levels as related to average loudness will vary wildly. The loudest
sounding will have highly compressed dynamics, with most of the tune
crammed against the limit. If you try to increase the levels of all
the others until they sound as loud, they will all be clipped to hell.

What you're forgetting here is that the MP3 is not just PCM data with
absolute scalar values for every sample. There is a "volume" field in
the header which tells the playback application how loud to play the
thing. By tweaking THAT, you can turn down the level of a track without
affecting the actual resolution (except of course the resolution is still
limited by the converters at the final playback, and if the gain is lowered
digitally, that will be reduced... still, that's a marginal problem at
best).

The thing is, that field is ALWAYS maxed out whenever anyone hands you
an MP3, because all the encoders want their products to play back as loudly
as possible. So you can usually turn it down, but seldom can you turn it
up.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

On 10 Jul 2006 10:56:07 -0400, (Scott Dorsey) wrote:

Don Pearce wrote:
On Mon, 10 Jul 2006 11:10:55 GMT, "dadiOH"
wrote:

David Morgan (MAMS) wrote:

I had a look, and I can't see how the device works without modifying
dynamic range

Simply put...

1. Find max volume among all songs
2. "Turn up the volume" in all others so their max is the same as the
loudest.

Won't work - can't work. If you have a mixture of music, then peak
levels as related to average loudness will vary wildly. The loudest
sounding will have highly compressed dynamics, with most of the tune
crammed against the limit. If you try to increase the levels of all
the others until they sound as loud, they will all be clipped to hell.

What you're forgetting here is that the MP3 is not just PCM data with
absolute scalar values for every sample. There is a "volume" field in
the header which tells the playback application how loud to play the
thing. By tweaking THAT, you can turn down the level of a track without
affecting the actual resolution (except of course the resolution is still
limited by the converters at the final playback, and if the gain is lowered
digitally, that will be reduced... still, that's a marginal problem at
best).

The thing is, that field is ALWAYS maxed out whenever anyone hands you
an MP3, because all the encoders want their products to play back as loudly
as possible. So you can usually turn it down, but seldom can you turn it
up.
--scott

So.........?

d

--
Pearce Consulting
http://www.pearce.uk.com

Scott Dorsey wrote:

Don Pearce wrote:
On Mon, 10 Jul 2006 11:10:55 GMT, "dadiOH"
wrote:

David Morgan (MAMS) wrote:

I had a look, and I can't see how the device works without modifying
dynamic range

Simply put...

1. Find max volume among all songs
2. "Turn up the volume" in all others so their max is the same as the
loudest.

Won't work - can't work. If you have a mixture of music, then peak
levels as related to average loudness will vary wildly. The loudest
sounding will have highly compressed dynamics, with most of the tune
crammed against the limit. If you try to increase the levels of all
the others until they sound as loud, they will all be clipped to hell.

What you're forgetting here is that the MP3 is not just PCM data with
absolute scalar values for every sample. There is a "volume" field in
the header which tells the playback application how loud to play the
thing. By tweaking THAT, you can turn down the level of a track without
affecting the actual resolution (except of course the resolution is still
limited by the converters at the final playback, and if the gain is lowered
digitally, that will be reduced... still, that's a marginal problem at
best).

The thing is, that field is ALWAYS maxed out whenever anyone hands you
an MP3, because all the encoders want their products to play back as loudly
as possible. So you can usually turn it down, but seldom can you turn it
up.

That's interesting Scott.

Is there a handy application to edit the header ?

Graham

David Morgan (MAMS) wrote:
"Laurence Payne" lpayne1NOSPAM@dslDOTpipexDOTcom wrote in message ...
On Sun, 09 Jul 2006 13:42:20 -0700, Julian
wrote:

Like ANY other sound editor. Unfortunately, it will re-encode your
MP3's, which is a BAD THING.
That's why to use MP3 Gain. It does NOT re-encode your MP3's. It
only writes a volume play back level to the header which can be
removed at any time.
Unfortunately that volume reduction is probably achieved digitally by
just throwing away bits, which is a bad thing.

It doesn't throw away bits. What it does is it changes "global gain"
values. Doing so is totally lossless and reversible.

Anyway do you WANT
everything reduced to the level of the quietest? You then have to
apply more amplification, bringing noise levels up.

So?

And you don't have to reduce them to the level of the quietest. What you
can do is apply "track gain" so that all the songs are a certain volume,
for example 89dB, and then use "constant gain" to bring the volume of
every song up or down by the same amount.

I had a look, and I can't see how the device works without modifying
dynamic range - but even if it works by lowering... you have another
valid 'yuk' point.

MP3Gain doesn't touch dynamic range.

--
http://pcguyelevated.ytmnd.com/

Scott Dorsey wrote:
The thing is, that field is ALWAYS maxed out whenever anyone hands you
an MP3, because all the encoders want their products to play back as loudly
as possible. So you can usually turn it down, but seldom can you turn it
up.

No.

It's the music industry that wants their *songs* to play as loudly as
possible, so they use dynamic compression to be able to make them as
loud as possible on CD.

You would never *want* to turn *up* the gain on these files, since it
will make the already-existing clipping even worse, but you can do it.

--
http://pcguyelevated.ytmnd.com/

"NRen2k5" wrote in message ...
David Morgan (MAMS) wrote:
"Laurence Payne" lpayne1NOSPAM@dslDOTpipexDOTcom wrote in message ...
On Sun, 09 Jul 2006 13:42:20 -0700, Julian
wrote:

Like ANY other sound editor. Unfortunately, it will re-encode your
MP3's, which is a BAD THING.
That's why to use MP3 Gain. It does NOT re-encode your MP3's. It
only writes a volume play back level to the header which can be
removed at any time.
Unfortunately that volume reduction is probably achieved digitally by
just throwing away bits, which is a bad thing.

It doesn't throw away bits. What it does is it changes "global gain"
values. Doing so is totally lossless and reversible.

Anyway do you WANT
everything reduced to the level of the quietest? You then have to
apply more amplification, bringing noise levels up.

So?

And you don't have to reduce them to the level of the quietest. What you
can do is apply "track gain" so that all the songs are a certain volume,
for example 89dB, and then use "constant gain" to bring the volume of
every song up or down by the same amount.

I had a look, and I can't see how the device works without modifying
dynamic range - but even if it works by lowering... you have another
valid 'yuk' point.

MP3Gain doesn't touch dynamic range.

If everything works downward in comparison to the reference... but if
gain is increased (especially on material where peaks are likely already
near FS) limiting will have to come into play, altering dynamics.

--
David Morgan (MAMS)
http://www.m-a-m-s DOT com
Morgan Audio Media Service
Dallas, Texas (214) 662-9901
_______________________________________
http://www.artisan-recordingstudio.com

"NRen2k5" wrote in message ...
Scott Dorsey wrote:
The thing is, that field is ALWAYS maxed out whenever anyone hands you
an MP3, because all the encoders want their products to play back as loudly
as possible. So you can usually turn it down, but seldom can you turn it
up.

No.

It's the music industry that wants their *songs* to play as loudly as
possible, so they use dynamic compression to be able to make them as
loud as possible on CD.

You would never *want* to turn *up* the gain on these files, since it
will make the already-existing clipping even worse, but you can do it.

Thus altering dynamic range even further, or living with massive distortion,
the latter of which I'd hope most products would not consider as an option.

In article ,
NRen2k5 wrote:
Scott Dorsey wrote:
The thing is, that field is ALWAYS maxed out whenever anyone hands you
an MP3, because all the encoders want their products to play back as loudly
as possible. So you can usually turn it down, but seldom can you turn it
up.

No.

It's the music industry that wants their *songs* to play as loudly as
possible, so they use dynamic compression to be able to make them as
loud as possible on CD.

That's a different issue altogether. That's not an encoding issue.

With CD, where you have no encoding, the only way to make playback louder
is with abusive compression.

With MP3, you have the field available to you when you encode it.

Back in the LP days, it was all manual, and you had to put "PLAY THIS
RECORD AS LOUD AS POSSIBLE" in the liner notes.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."