IPB

Welcome Guest ( Log In | Register )

> foobar2000 General Forum Rules

This is NOT a tech support forum.
Tech support questions go to foobar2000 Tech Support forum instead.

See also: Hydrogenaudio Terms of Service.

 
Reply to this topicStart new topic
Does ReplayGain degrade sound quality?
bombo
post Aug 27 2007, 12:21
Post #1





Group: Members
Posts: 10
Joined: 27-August 07
From: Finland
Member No.: 46542



So, I'm not using ReplayGain because I have heard rumours that it would cause degradation in sound quality. Perhaps this is just another urban legend but I'd like to know for sure rolleyes.gif
Go to the top of the page
+Quote Post
sld
post Aug 27 2007, 12:27
Post #2





Group: Members
Posts: 1016
Joined: 4-March 03
From: Singapore
Member No.: 5312



It IS an urban legend. Go in peace. smile.gif
Go to the top of the page
+Quote Post
VeaaC
post Aug 27 2007, 12:30
Post #3





Group: Members
Posts: 52
Joined: 10-December 06
Member No.: 38550



Not more than the Volume Control.
The problem with digital volume control is, that it reduces the amount of information in the audio data.
Go to the top of the page
+Quote Post
skamp
post Aug 27 2007, 12:37
Post #4





Group: Developer
Posts: 1430
Joined: 4-May 04
From: France
Member No.: 13875



That's what I've meant to ask for a while: how bad is software volume management?


--------------------
See my profile for measurements, tools and recommendations.
Go to the top of the page
+Quote Post
VeaaC
post Aug 27 2007, 12:40
Post #5





Group: Members
Posts: 52
Joined: 10-December 06
Member No.: 38550



Without top notch equipment you won't ever hear a thing.

Try it yourself. Adjust the software volume to 10% and your amplifier to match the old sound volume.
Go to the top of the page
+Quote Post
HiFiRE
post Aug 30 2007, 00:45
Post #6





Group: Members
Posts: 62
Joined: 4-July 04
Member No.: 15052



Are all these statements true?

-Replaygain scanning does not affect the mp3 audio data, just the meta data.
-Applying replaygain to mp3 data changes to the mp3 audio data.
-The former and the latter result in the same data being sent to the DAC.
-Using replaygain reduces the dynamic range of the audio (in cases where the gain is reduced).
-Other statements I can't make without an ABX test.
Go to the top of the page
+Quote Post
saratoga
post Aug 30 2007, 05:19
Post #7





Group: Members
Posts: 4925
Joined: 2-September 02
Member No.: 3264



3) is off, since you can't adjust mp3s as finely as you can adjust via metadata.

4) Depends on the system. Use 24 bit output, and you're not losing anything (for CD audio anyway).

This post has been edited by Mike Giacomelli: Aug 30 2007, 05:19
Go to the top of the page
+Quote Post
2Bdecided
post Aug 30 2007, 11:46
Post #8


ReplayGain developer


Group: Developer
Posts: 5108
Joined: 5-November 01
From: Yorkshire, UK
Member No.: 409



4 is dubious anyway. If ReplayGain is dramatically reducing the volume, the chances are that the recording didn't have much real dynamic range to start with!

Not always true, but often.

Cheers,
David.
Go to the top of the page
+Quote Post
Bodhi
post Aug 31 2007, 18:01
Post #9





Group: Members
Posts: 261
Joined: 10-June 06
Member No.: 31712



What about MP3Gain?
Go to the top of the page
+Quote Post
Dynamic
post Aug 31 2007, 20:22
Post #10





Group: Members
Posts: 810
Joined: 17-September 06
Member No.: 35307



MP3Gain has two modes, as does Foobar 2000.

Mode 1 is via tags. On a non-supporting player, the MP3 playback is at the original loudness. On a supporting player it's adjusted accurately.

Mode 2 is by modifying the global gain factor in each frame of the MP3 file (which changes volume in 1.505 dB steps, giving 0.7503 dB accuracy). Mode 2 also adds a tag that corresponds to the modified file, so players that support Replay Gain can:
a) still choose either Track or Album Gain mode
b) make the fine adjustment to the accurate Gain value, even though 0.75 dB is hardly perceptible. (In this way identical output to Mode 1 can be achieved, because no data was discarded from the MP3 file)
c) apply clipping prevention if desired

Non Replay Gain aware players will just output at the volume chosen when the adjustment was applied (i.e. Track or Album was chosen when it was applied, possibly with clipping prevention enabled also).

In practice, any quality reduction is almost certainly inaudible. 16-bit CD audio with flat dither and no fancy tricks has about -120 dB noise floor per frequency bin, giving roughly 120 dB of audible dynamic range. Often 96 dB is quoted for dynamic range, but this is actually the Signal to Noise Ratio, which is different because it applies to the whole bandwidth, not to each frequency bin. The ear effectively divides sound up into frequency bins and is comparable to a 1024-point FFT Power Spectrum (512 bins).

A professional 18 inch chainsaw is about 113 dB above the threshold of hearing at full revs without ear defenders. You'd have to play your music roughly that loud to notice the increased noise floor of applying about 7 dB replaygain on a 16-bit playback system.

That's why even 14-bit would have been quite adequate for CD digital audio.

In short, while it's obvious that some elements of the electrical signal will sink into the noise floor if you have 16-bit playback, and that freaks people out, none of the audible sound will suffer this fate and it's no worse than turning down the volume to get the track to a comfortable level.

It may actually improve the sound for anyone whose amplifier or DAC is non-linear or otherwise misbehaves at close-to-full-scale, though such problems are rare these days.


--------------------
Dynamic the artist formerly known as DickD
Go to the top of the page
+Quote Post
Bodhi
post Sep 1 2007, 13:16
Post #11





Group: Members
Posts: 261
Joined: 10-June 06
Member No.: 31712



Well, no question left after that answer... Thank YOU!
Go to the top of the page
+Quote Post

Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 



RSS Lo-Fi Version Time is now: 2nd September 2014 - 02:59