Mastering to MP3 - PSP Xenon - Fraunhofer Codec Toolbox
Posted: Fri Aug 31, 2018 5:04 am
I am in 24-bit DP 9.52 and exploring mastering down to mp3, using a PSP Xenon mastering limiter and a Fraunhofer Codec Toolbox. My question is about dithering to 16-bit pre- and post-fader.
In his review of the Fraunhofer Codec Toolbox plug-in, Sam Inglis, SOS Jan ’14, it says :
“…you place Codec Toolbox in the last insert on your master bus…”
And in the Codec manual it says, section 6.1.4 :
“The encoders in the plug-in will accept an input signal with greater than 16-bit precision, but in such cases the signal will be dithered and truncated to 16-bits prior to the encoding process. The plug-in will not introduce dither at the 16-bit level if the input to the plug-in has been already dithered and truncated to 16-bits”
In his ‘Digital Performer Tips & Techniques - All in a Dither’, SOS Feb ’15, Robin Bigwood says :
“Simply put, the DP master fader is the ideal place to instantiate your preferred bit–reduction and dither processor, because it’s conceptually at the end of the mixing signal chain. However, some care is required to do things right, because it’s all too easy to immediately increase the digital resolution again and undo the plug–in’s good work.
It’s worth looking at this in some more detail, but first I’m just going to give you the two–part solution. First, put your bit–reduction and dither plug–in in a lower slot than any others, so it’s the last plug–in in the signal chain. Then, either keep your master fader exactly on a 0dB ‘unity gain’ position or, if it’s at any other position, or you’ve got it automated for a fade–out, make sure that the insert slot occupied by your mastering plug–in is in a post–fader position. How do you do this? Take a close look at your master fader’s (or indeed any channel’s) plug–in slots. Just to the bottom left of them is a tiny, inconspicuous grey ‘notch’. Hover your mouse pointer over it and the pointer turns into a hand — the notch is draggable! Drag it up to just above the last empty plug–in slot and it should change into a blue divider line. Then drag and drop your mastering plug–in into that empty slot, so that it’s now beneath the blue line. That’s all there is to it.
Now for the explanation, if you’re game. DP carries out all mixing tasks with 32–bit floating–point resolution, regardless of whether your actual audio files are 16– or 24–bit, and even for something as apparently simple as a level cut or boost dialled in with a channel fader. Meanwhile, by default, all DP’s plug–in slots lie in a pre–fader position, which is to say that audio flows into the mixer channel, first through the plug–ins, then through the fader, and on to the output.
Back in our mastering scenario, the dither plug–in is carrying out some really clever maths, effectively distilling (or ‘quantising’) the signal chain down to 16–bit, which is what we need for a CD master. If we place another plug–in in a lower slot fail! Its processing will have caused the digital signal to revert to 32–bit format. Similarly, if the master fader is set to somewhere other than at the 0dB position, and therefore applying some level cut or boost it’s more 32–bit processing and another fail! What we need to do is put the fader before the plug–in, so that the plug–in really is the last thing in the signal chain — and that’s what dragging the plug–in slot divider is for. Plug–ins above the divider are pre–fader, while plug–ins below it are post–fader. So by placing the mastering plug–in post–fader, we make it absolutely the last thing in the signal chain.”
So my question are:
Presumably I should insert my PSP xenon post main fader, followed by the Fraunhofer Codec ?
But if I do, will this cause the signal to revert to 32-bit ?
Would this cause an avoidable un-necessary dithering process ?
In his review of the Fraunhofer Codec Toolbox plug-in, Sam Inglis, SOS Jan ’14, it says :
“…you place Codec Toolbox in the last insert on your master bus…”
And in the Codec manual it says, section 6.1.4 :
“The encoders in the plug-in will accept an input signal with greater than 16-bit precision, but in such cases the signal will be dithered and truncated to 16-bits prior to the encoding process. The plug-in will not introduce dither at the 16-bit level if the input to the plug-in has been already dithered and truncated to 16-bits”
In his ‘Digital Performer Tips & Techniques - All in a Dither’, SOS Feb ’15, Robin Bigwood says :
“Simply put, the DP master fader is the ideal place to instantiate your preferred bit–reduction and dither processor, because it’s conceptually at the end of the mixing signal chain. However, some care is required to do things right, because it’s all too easy to immediately increase the digital resolution again and undo the plug–in’s good work.
It’s worth looking at this in some more detail, but first I’m just going to give you the two–part solution. First, put your bit–reduction and dither plug–in in a lower slot than any others, so it’s the last plug–in in the signal chain. Then, either keep your master fader exactly on a 0dB ‘unity gain’ position or, if it’s at any other position, or you’ve got it automated for a fade–out, make sure that the insert slot occupied by your mastering plug–in is in a post–fader position. How do you do this? Take a close look at your master fader’s (or indeed any channel’s) plug–in slots. Just to the bottom left of them is a tiny, inconspicuous grey ‘notch’. Hover your mouse pointer over it and the pointer turns into a hand — the notch is draggable! Drag it up to just above the last empty plug–in slot and it should change into a blue divider line. Then drag and drop your mastering plug–in into that empty slot, so that it’s now beneath the blue line. That’s all there is to it.
Now for the explanation, if you’re game. DP carries out all mixing tasks with 32–bit floating–point resolution, regardless of whether your actual audio files are 16– or 24–bit, and even for something as apparently simple as a level cut or boost dialled in with a channel fader. Meanwhile, by default, all DP’s plug–in slots lie in a pre–fader position, which is to say that audio flows into the mixer channel, first through the plug–ins, then through the fader, and on to the output.
Back in our mastering scenario, the dither plug–in is carrying out some really clever maths, effectively distilling (or ‘quantising’) the signal chain down to 16–bit, which is what we need for a CD master. If we place another plug–in in a lower slot fail! Its processing will have caused the digital signal to revert to 32–bit format. Similarly, if the master fader is set to somewhere other than at the 0dB position, and therefore applying some level cut or boost it’s more 32–bit processing and another fail! What we need to do is put the fader before the plug–in, so that the plug–in really is the last thing in the signal chain — and that’s what dragging the plug–in slot divider is for. Plug–ins above the divider are pre–fader, while plug–ins below it are post–fader. So by placing the mastering plug–in post–fader, we make it absolutely the last thing in the signal chain.”
So my question are:
Presumably I should insert my PSP xenon post main fader, followed by the Fraunhofer Codec ?
But if I do, will this cause the signal to revert to 32-bit ?
Would this cause an avoidable un-necessary dithering process ?