SOUND DESIGN - A MASTERING ENGINEER'S PERSPECTIVE
A little bit of a background story to how this content came about. I am an admin of an online community (DIY Sound Design) which as you may have guessed revolves around those interested in sound design practices. As sound design is an audio related practice, it's inevitable that many of the members were engaging in other audio related practices, recording, producing, mixing, mastering of which some topics get brought up in a discussion.
So I thought as a professional Mastering Engineer, "I could make a contribution based on observations I've made from people's sound designs when mastering records". While for most of you these pointers might seem BASIC; for me their core elements which help translate well down the line and affect the mastering process to some degree.
Phase Coherency; This is NUMBER one, I'm sure many of you are aware of. But phase coherency plays a big part in the impact of your transients, mono translation on live and broadcast systems on the final master.
Transient to signal ratio; Another sound design setback I've found are one shots/particular melodic phrases in a mix which just POKE straight through the mix. While this can be dealt with compression during mixing, it's much more tasteful to not have any imprint from a compressors GR on your sounds.
Resonances in mids to high-mids; Wavetable synthesisers are a great tool (I'm a big massive fan), but they work off displacements in phase-correlation between multiple waveshape oscilators. Those movements in phase correlation can sometimes produce pokey resonances/ringing on particular notes. When multiples of this resonance or even one are printed into a mix, it's a small nightmare to attend to in mastering. Unlike room resonances which are linear in recorded material, because this is synthesised they can move around a bit as well.
Resonances in bass leads/kicks; Ever been writing/playing in a bass phrase in a soft-synth and one note just sticks out louder than the rest? Because the waveforms of low frequencies are longer than higher frequencies, the shifts in phase between oscillators when moving up and down, a scale is much more prominent. Just be conscious of which notes are a bit more pokey and which ones are fading away and try to tune fine the wavetables/parameters in the synthesiser to help combat that.
Kick resonances/tone which are out of key; This is a big one I hear often, and usually has me using things like bx_dynEQ to help tame the out of tune resonances and another EQ to help boost a freq of the kick in key with the track. Make sure the body/tail of the kicks are harmonious with the composition, it is pretty easy. Follow this table to help you equalise frequencies that are complimentary into your kick, and attenuate ones that are dissonant: http://www.phy.mtu.edu/~suits/notefreqs.html