Mixing Tip #5: Frequency Masking

Seeing as we've used the term masking a few times, I thought we'd better add a few words to describe what it is and how to handle it.

Frequency Masking

Frequency masking is where the frequencies of two (or more) instruments are battling it out for space - ie... they share the same frequencies - and is probably one of the most common problems encountered when mixing.

Basically, a sound may have (in addition to its root sound) other harmonic sounds that contribute to its overall timbre.  If two sounds (timbres) share similar frequencies you could easily find yourself in the position where some of these harmonics are being masked in the mix; meaning that the instruments sound different than they do in isolation.

Testing for Frequency Masking

Apart from relying upon your own ears, here's a couple of tips if you're unsure as to whether you have any frequency masking going on:

• As touched upon in mixing tip 1 try listening to your mix in mono
• Level all your tracks to unity gain (0 dB) and then pan each track to the left, then right. You're listening to see if each sound sweeps audibly from the left, through the centre, and off to the right - If you can hear it crossing over, then you're more than likely in the clear, bo!

Fixing it

Compromise!

Yes, a term most muso's hate - particularly after having spent hours crafting the part. But them's the choices I'm afraid... too many cooks in the kitchen 'n' all that innit!

Here's a few options to consider:

• First of all, try using mono sounds and the panning trick.
• What's the most important sound? Make it the priority over the other offending part - In other words: Filter the secondary sound with EQ.
• Use the part elsewhere in the song.
• Worst case: Dump the sound all together if it just refuses to sit nicely.

Tough choices I know, but sometimes you just have to kill your children for the survival of the family.