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Mix Rescue: Phase Relationships | Media

Mixing & Recording Advice
By Mike Senior

Here is a selection of audio files to accompany this month's Mix Rescue show how manipulating the phase relationships of some tracks in your mix, plus a little disciplined pruning, can revitalise a flat‑sounding track. You can listen to these as MP3s in the media player in the main article (/sos/apr10/articles/mixrescue_0410.htm) or can download from this page as CD-quality WAVs for more critical auditioning in your DAW.

OH Raw Audio icon ohraw.mp3 File ohraw.wav

Here are the raw drum overhead tracks, simply panned hard left and right. Because one of the tracks has inverted polarity, the stereo image is unnaturally wide and unstable and in mono the sound thins out disastrously because of phase cancellation.

OH Polarity Fix Audio icon ohpolarityfix.mp3 File ohpolarityfix.wav

Inverting the polarity on one of the overhead mics immediately solidified the sound and dramatically reduced the destructive phase-cancellation effects when auditioning in mono. However, the timing of the snare drum transients is still slightly out of alignment, which positions it off-centre in the stereo, and reduces its impact.

OH Timing Fix Audio icon ohtimingfix.mp3 File ohtimingfix.wav

By shifting one of the overheads slightly to align the snare transients, the snare was shifted back into the centre of the stereo image, and the punchiness of the drum was also slightly improved, especially when listening in mono.

OH Ringing Fix Audio icon ohringingfix.mp3 File ohringingfix.wav

Now that the polarity and phase issues were dealt with, I next targeted some EQ issues that needed attention. First and foremost, there were a couple of undamped frequencies ringing in the snare sound which popped out unflatteringly. I tracked down the exact frequencies (354Hz and 797Hz) using Schwa's Schope frequency analyser and then loaded an instance of DDMF's LP10 equaliser and pulled these out of the way with a couple of high-Q peaking cuts. In addition, I added a little extra high end (just a couple of decibels of shelving boost about 5kHz) to brighten the overall picture.

OH Plus Kick Audio icon ohpluskick.mp3 File ohpluskick.wav

Here's the overheads now mixed with the first kick-drum close mic, which had received processing from SPL's Transient Designer plug-in, set to +4dB attack and -6dB Sustain. Notice how the low end of the overheads is clouding the kick-drum sound a bit, and while this is perfectly appropriate for some styles, I felt that here the overall effect of the drums would be more driving and rhythmic if the kick sound were drier than this.

OH Filter Plus Kick Audio icon ohfilterpluskick.mp3 File ohfilterpluskick.wav

Here's the same mix as in OHPlusKick, but demonstrating the effect on the mixed kick-drum sound of using a 24dB/octave high-pass filter on the overhead mics, turning over at 120Hz. (This filtering was again provided by DDMF's LP10 multi-mode equaliser plug-in.)

OH Kick Snare Audio icon ohkicksnare.mp3 File ohkicksnare.wav

For this file I've added in the second kick close mic, but with about 4dB of low-midrange cut using one of DDMF LP10's peaking filters at a medium Q of 1.2. I've also mixed in the over-snare close mic, which as you can hear has a number of unpleasantly undamped resonances which assert themselves rather too prominently.

OH Kick Snare Notches Audio icon ohkicksnarenotches.mp3 File ohkicksnarenotches.wav

A couple of narrow peaking filter cuts from a DDMF LP10 EQ plug-in on the snare channel helped scotch the worst of the resonances, giving a much more appealing snare sound. The offending frequencies here were 865Hz and 1037Hz.

Snare Linear Phase Audio icon snarelinearphase.mp3 File snarelinearphase.wav

This is the over-snare close mic that was added for the OHKickSnareNotches example file, but using 112dB's Redline Equaliser in its linear-phase mode for the narrow peaking-filter cuts. Notice the unnatural pre-ringing that this causes before each snare hit.

Snare Minimum Phase Audio icon snareminimumphase.mp3 File snareminimumphase.wav

This is the was the over-snare close mic was actually processed for the final remix, using DDMF's LP10 equaliser in minimum-phase mode rather than linear-phase. In this case it's a much more effective solution because it avoids the pre-ringing artefacts you can hear in the SnareLinearPhase file.

LV No Dist Audio icon lvnodist.mp3 File lvnodist.wav

Here's the lead vocal as it appears in the final remix, but without any send effects. Processing consists of a chain of plug-ins. First in line are two of IK Multimedia's T-Racks 3 plug-ins: Opto Compressor for general gain levelling, and Classic Equaliser for reducing proximity-effect bass boost below about 500Hz and adding a little presence around 3.7kHz. An instance of DDMF's new NYComp compressor then adds faster compression for more obvious attitude, while 112dB's Redline's Equaliser takes the same contour created by Classic Equaliser and pushes it a couple of decibels further. Finally Digital Fishphones' Spitfish de-esser takes the edge of some sibilance and a light sprinkling of Stillwell Audio's Exciter adds some extra air.

LV Dist Audio icon lvdist.mp3 File lvdist.wav

To reflect the aggression of the lead vocals, I decided to add in some distortion using a Fender Champion 600 amp emulation from IK Multimedia's Amplitube X-Gear. However, as you can hear in this audio example, the phase cancellation artefacts of this addition really hollowed out the sound when the distortion was mixed back in with the undistorted signal.

LV Dist IBP Fix Audio icon lvdistibpfix.mp3 File lvdistibpfix.wav

The solution to the horrible phase-cancellation you can hear in LVDist was supplied by an instance of Little Labs' new IBP plug-in (running on the Universal Audio UAD2 DSP platform), which I inserted on the distortion return channel. By using the phase adjust control, the phase relationship between the distorted and undistorted audio was altered, and hence the nature of the comb-filtering could be adjusted to end up with a much more appealing tone.

Bass Gated SFX Audio icon bassgatedsfx.mp3 File bassgatedsfx.wav

This section of the remix shows how I've used a fuzzy background drone to increase the thickness of the bass sound for the chorus sections. The drone was placed on a separate track and then gated with the trigger signal for the gate coming from the bass track. That meant that the drone only sounded when the bass did. Compare this to the BassNoGatedSFX example to hear the impact of this tactic.

Bass No Gated SFX Audio icon bassnogatedsfx.mp3 File bassnogatedsfx.wav

For comparison with the BassGatedSFX file. Notice how the chorus doesn't arrive quite as definitively in this version.

Original Mix Audio icon originalmix-0410.mp3 File originalmix-0410.wav

Here's The Black Bloc's original mix of their song 'If You Want Success', as submitted to Mix Rescue.

Remix Audio icon remix.mp3 File remix.wav

This is my remix based on the same multitrack files, but with a fair bit of copy/paste rearrangement of the guitar parts and a little help from some additional background ambience samples.

Published April 2010