Pumping when converting 32 bit to 16

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killhead43

New member
I'm new to mastering and have been practicing on a few of my own songs. They were all recorded at 96khz and 32 bit floating-point. However, when I apply my mastering chain and export it, every time I try to convert it into 16 bit 41khz I get a significant amount of pumping every time an instrument with a lot of attack hits (snare, kick, etc.). I'm not too clear on how bit depth affects the audio and is there any way to prevent this and convert to CD format with no loss?
 
It's not bit depth that is doing this. Compressing the track too hard is doing it.

You will need to look at your compression settings in your mastering chain and pull them back a bit.
 
gecko zzed said:
It's not bit depth that is doing this. Compressing the track too hard is doing it.

You will need to look at your compression settings in your mastering chain and pull them back a bit.
Click to expand...

Would I still do this if there is no pumping when it is exported as 32 bit but only when it is in 16 bit?
 
I assume you are listening to this track -with these final effects/settings etc before exporting, and it's ok then?
 
mixsit said:
I assume you are listening to this track -with these final effects/settings etc before exporting, and it's ok then?
Click to expand...

Yes in the DAW it sounds perfectly fine but when it's exported there is pumping.

---------- Update ----------

mixsit said:
Not sure what you're saying here.
Click to expand...

I mean that I have it in the DAW processing at 32 bits but then when I export it at 16 bits there is pumping.
 
"when I apply my mastering chain" is still the clue for me.

First test would be to turn off everything in that chain, then export. My guess is that the pumping will stop. However, if it continues, then we have to look further afield
 
your routing scheme is wrong.


dither does not do this, only applying compression and limiting.

what you are monitoring while listening to the playback, is not what is being sent to the output, there is a missing piece of the puzzle.
 
Would you happen to be converting, then bringing the 16bit version back into the same project, with the mastering chain (limiter/compressor?) still on? In other words, it's going through your mastering chain twice and being limited and/or compressed again?
 
Btyre2013 said:
I hope you are using dithering when you convert to 16 bit, are you?
Click to expand...

Yes I am. I think I've gotten the problem under control now. I went back to the mix, exported it at 44.1khz with 16bit depth at a very low volume and no bus compression and then put it through my mastering chain. After readjusting everything to get the levels right there is no pumping.

Also I exported with and without bus compression and both times there was no pumping so I don't think it was the compression.
 
always do the 'dither' as the last step in the chain, when you output to 16 bit/44.1khz.
red book standard.
 
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