Question 1

Examples of When to Dither in the Studio

James Hardiman · Accepted Answer

Bob,

Hope you are doing well. I have your Mastering Audio book that I reference quite often and have question that I hope will help me in reconfiguring some new gear.

In terms of bit depth and dither it is always best to dither at the very final stage. However, there are times where dither may come into play before that. I believe you mentioned that it is always best to dither when reducing bit depth or risk truncation distortion.

Audio is passes through the mix engine of the DAW at 32 bit float and then leaves the system at 24 bit at the converters. I have read where some people consider adding dither across the monitor outs. If that is the case would it matter that the dither used might not be the same dither type in the final master? In other words would it make a difference say in imaging, depth, etc. or anything else? Would adding dither here be worth considering, even if not the same type in mastering?

Hi Barry

In the case of monitoring you'd be using 24 bit dither. The audible impact of 24 bit dither is so low as not to change the tonality, sound or depth of the music, it just prevents low level distortion. So don't think of that 24 bit dither as impacting your workflow in any way. In fact, you could cumulate several stages of 24 bit dither (if necessary) without any affect on the sound. Regardless, dither at the 32 bit float to 24 bit fixed boundary will be very subtle. Some people claim they can hear an improvement, others do not.

My second question that goes along with this deals with digital outputs of the interface. Also I have heard people say I don’t want to give up an analog output on my interface and my monitor controller has “better” converters. They will send the audio to the monitor controller via digital outputs, being TOSLINK, SPDIF, or AES. Well isn’t the spec on those protocols only 24 bit? So wouldn’t that be subject to truncation distortion as well? Would this be a spot that dither might be used? I would assume it is still applicable with digital transfer as well, correct?

Any time you reduce wordlength, you should dither. Whenever I feed an SPDIF or AES/EBU output, I try to dither to 24 bits when it's possible. Truncation is truncation, wherever it occurs, and SPDIF and AES/EBU are included.

Hope this helps,

Bob

Question 2

Examples of When to Dither in the Studio

James Hardiman · Accepted Answer

Bob,

Hope you are doing well. I have your Mastering Audio book that I reference quite often and have question that I hope will help me in reconfiguring some new gear.

In terms of bit depth and dither it is always best to dither at the very final stage. However, there are times where dither may come into play before that. I believe you mentioned that it is always best to dither when reducing bit depth or risk truncation distortion.

Audio is passes through the mix engine of the DAW at 32 bit float and then leaves the system at 24 bit at the converters. I have read where some people consider adding dither across the monitor outs. If that is the case would it matter that the dither used might not be the same dither type in the final master? In other words would it make a difference say in imaging, depth, etc. or anything else? Would adding dither here be worth considering, even if not the same type in mastering?

Hi Barry

In the case of monitoring you'd be using 24 bit dither. The audible impact of 24 bit dither is so low as not to change the tonality, sound or depth of the music, it just prevents low level distortion. So don't think of that 24 bit dither as impacting your workflow in any way. In fact, you could cumulate several stages of 24 bit dither (if necessary) without any affect on the sound. Regardless, dither at the 32 bit float to 24 bit fixed boundary will be very subtle. Some people claim they can hear an improvement, others do not.

My second question that goes along with this deals with digital outputs of the interface. Also I have heard people say I don’t want to give up an analog output on my interface and my monitor controller has “better” converters. They will send the audio to the monitor controller via digital outputs, being TOSLINK, SPDIF, or AES. Well isn’t the spec on those protocols only 24 bit? So wouldn’t that be subject to truncation distortion as well? Would this be a spot that dither might be used? I would assume it is still applicable with digital transfer as well, correct?

Any time you reduce wordlength, you should dither. Whenever I feed an SPDIF or AES/EBU output, I try to dither to 24 bits when it's possible. Truncation is truncation, wherever it occurs, and SPDIF and AES/EBU are included.

Hope this helps,

Bob