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Topic: Feeding an EQ to a Replaygain scanner (Read 1811 times) previous topic - next topic

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  • skamp
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Feeding an EQ to a Replaygain scanner
Like others, I have noticed that Replaygain sometimes "fails" on certain albums, i.e. I sometimes have to increase or decrease volume from one album to another.
Case remarked that some heavy EQing could invalidate Replaygain's analysis, which kinda makes sense to me.

I think it would be cool if one could feed a list of EQ parameters to a Replaygain scanner, and have it compute values that would better match such setups. Off the top of my head, the scanner could either store the altered values in the usual metadata fields (e.g. REPLAYGAIN_TRACK_GAIN and REPLAYGAIN_ALBUM_GAIN), or (a little hackish) store the normal album gain in REPLAYGAIN_ALBUM_GAIN and the altered album gain in REPLAYGAIN_TRACK_GAIN, so that one could switch between album gains with the EQ on and off.

Edit: obviously that would only make sense to people who always use the same EQ parameters, like me.
  • Last Edit: 26 January, 2013, 02:23:10 PM by skamp
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  • darkbyte
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Feeding an EQ to a Replaygain scanner
Reply #1
I've had a similar idea once when i tried to minimalize the processing power required to achieve radio like sound for the things i'm listening to. (i'm currently using Stereo Tool for that which is a very good tool but it requires a lot of CPU power). I've looked for something simpler that can adjust the bass, the mids and highs relatively to the track so tracks doesn't just have similar loudness but similar sounding (i don't know what's the correct word for that but i think you know what i mean). I though about applying Replaygain analyzis on to a set of bandpass filtered signals so you'll end up with not just one but as many replaygain values as many bands you've created for a track. You can do this in very high resolution once and store it in the meta. Then if you have a favourite EQ preset, the player can calculate the relative EQ values required to achieve this from track to track. This would probably solve ReplayGains failure on eg. The Fugees's Ready or Not where the bass is so loud and deep compared to the music that it doesn't really achieve anything useful (at least for me).

But i haven't ever done it actually, because i don't know if it's actually doable. I thought that RMS will not really produce different values when i just simply apply it to separate bandpassed signals (because RMS is weightened around the the spectrum). But i still have a lot to learn about these things so maybe i'm wrong.
  • Last Edit: 26 January, 2013, 03:53:03 PM by darkbyte
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  • saratoga
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Feeding an EQ to a Replaygain scanner
Reply #2
If you're just using EQ to flatten out the response of your headphones or room, then RG will give you the most accurate result if you don't feed it the EQ curve (since in theory at least the eq is just balancing out the equipment).

If you're not concerned with the equipment and just want to 'remaster' everything with more bass, perhaps it would make more sense to just EQ before encoding?  That way replaygain will have the access to the actual audio.  Or is the point that you want to be able to dynamically change how files sound while having the replaygain values update?

  • skamp
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Feeding an EQ to a Replaygain scanner
Reply #3
I'd rather not alter the source files (or create duplicates), if I can help it. Also, I was thinking that maybe a fb2k component could automatically detect foobar's EQ settings, thereby making the process fairly straight forward, from the user's point of view. And I say fb2k because that's the prevalent player around here, but the same goes for any other player with an EQ and a plugin system.
  • Last Edit: 28 January, 2013, 07:16:19 AM by skamp
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  • DVDdoug
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Feeding an EQ to a Replaygain scanner
Reply #4
Quote
I've looked for something simpler that can adjust the bass, the mids and highs relatively to the track so tracks doesn't just have similar loudness but similar sounding (i don't know what's the correct word for that but i think you know what i mean).
Ozone Izotope has a "Matching EQ" option. 

But, my guess is that using something like that blindly is just going to muck-up the sound.  It might make a good starting-point for EQ adjustment by ear.    Something like that might be helpful (as a starting-point) if you are recording half the songs for a CD in one studio and half in another, or if you are compliling "Greatest Hits" CD and you want the songs to sound more-alike.