Mastering engineer Graham Semark on some of the questions often asked when recording and preparing audio for mastering.

The following topic contains extracts from a discussion with mastering engineer Graham Semark on some of the questions often asked when recording and preparing audio for mastering.

How do I ensure that my recordings are best prepared for mastering?

“Take care not to record too loud – we all want to achieve the best possible signal to noise ratio, but allowing recordings to peak at 0VU on some equipment does risk digital distortion being a major problem in mastering. In my view, it is always best to allow 1 or 2 DB headroom to allow for any peaks that your meters aren’t able to show. Also, use dither when you can – this will aid audio quality across the spectrum, but is particularly beneficial to quieter signals.

Try to avoid unnecessary processing, copying etc. as even digital adjustments on high quality processors can still incur small errors that may effect the overall sound quality – the cleaner it is, the better the CD will sound.”

What is Dither?

“Dither is a process that adds low level high frequency signal to digital files during processing to combat the problems of truncation errors – benefits include a greater dynamic range and improved purity of sound in natural ambience and reverberation.”

What about compression and normalisation?

“As mentioned earlier, I always prefer to work from as cleaner source as possible and would recommend that these processes are left until the final mastering session were at all possible - even though modern equipment allows excellent results to be obtained in home studios any gain alterations even in digital workstations can cause some degree of audio deterioration.”

How should I supply my masters and do the songs need to be in the correct order?

“We can work from all of the common formats, including digital files and analogue tapes – CDR and DAT seem to be the most common, both of which work well.

When using DAT machines, always record 2 minutes of silence at the beginning of the tape and allow the machine to record for 4 – 5 seconds before the start and after the end of each track. Tidying starts/ fine-tuning fades and sorting the correct gaps between each song is best left to the final mastering session if at all possible and this procedure prevents any important bits being clipped!

You don’t have to worry about supplying your songs in the correct order, but always supply a track sheet specifying which mixes you wish to be used, where you want them on the CD and their running lengths.

A safety copy is also a very good idea, but always make sure this is done digitally as each time an analogue copy is made a degree of quality will be lost.”