When the Problem is Staring You in the Face

I had an interesting experience over the last couple of weeks, with a mixing problem that should have have been obvious and easy to fix, but because I was too focused on details, I missed the bigger picture and let the problem persist for way longer than it should have.

I’m still in the finishing off stage of a track which has ended up becoming the most drawn out and time consuming piece I’ve worked on so far. I just looked back to previous posts and realised I said I was on the ‘home straight’ with it more than 2 months ago.

Part of the reason this track took longer than others was that it was the first where I’d used an acoustic instrument for one of the main themes… an acoustic piano riff (from NI’s ‘New York Grand’). As with acoustic percussion samples I’ve discussed in a previous post, any recorded acoustic instrument is inherently going to have a much greater dynamic range than synthetic sound. And to fit this into the generally very narrow dynamic of club music, considerable but careful application of compression is required.

The piano riff I came up with, I thought, had a nice dynamic… getting thicker in texture and a bit louder/stronger towards the end of the riff… I felt this gave it a bit greater feeling of tension. Although a fair amount of compression would be required to make the riff fit well in the mix, I was keen to try and preserve as much of that dynamic as possible. Hence when mixing I was too focused on trying to preserve dynamic of the riff that I’d liked in the soloed part. This unfortunately led me to being too cautious in applying compression, and ended up pushing the piano part way too high in the mix (in order to get it to stand out properly). Added to this was the mistake of not following my own advice and regularly checking back against reference tracks, so when I finally did do a side-by-side comparison with my usual reference material I’d created a kind of ‘inverted smile’ in terms of frequency spread… with piano and mid-range way too dominant, and not nearly enough bassline nor cymbals.

Once I figured out my mistake, it was pretty easily corrected with a simple application of Waves’ Renaissance Axx compressor (after having spent at least a week going in the wrong direction)… sure I had to sacrifice some of the nice dynamic I had originally wanted to highlight, but looking back, I think that original desire was misguided. The track I’m writing is in a minimal-techno style… where narrow dynamic and very loud overall track levels are commonplace… the expectation to keep a main acoustic instrument part fairly dynamic, and achieve a competitive level in the overall track was a bit unrealistic.

So 3 important lessons I learned for going forward…

  1. Audition parts in the context of a mix. Things that sound good on a soloed part may no longer sound so good, or even be completely lost in the context of a whole mix. I was too swayed by trying to work towards a soloed piano sound which I thought sounded good… it would have been better to have always auditioned it in the context of the mix right from the start.
  2. Be realistic about how much dynamic range you can achieve in styles which are innately highly compressed.
  3. Listen to and compare to your reference tracks regularly!

Noise Reducing Percussion Samples

A quick tech ‘how to’ post today… around noise reduction in live-recorded samples.  As I’ve mentioned previously, I use a lot of live recorded sounds in my tracks, especially live recorded percussive sounds.  Sometimes these sounds can be recorded quietly in the studio, but other times I capture them ‘on location’, and hence have to work with background noise.  On other occasions the background noise is unavoidably entwined with the sound source.  This was the case today when I recorded some tom sounds from the Volca Beats speaker.  The direct sound from this Volca is fairly useable , but the speaker is really hissy, and hence I ended up with a lot of hiss in the sample…

The raw sample

In the past I used to try and remove this in one of two ways…

  1. Use a high shelf filter to reduce the hiss
  2. Use a gate to fade out the tail of the sample

…but neither of these were ideal… the filter option would remove high frequency content from the whole sample including the attack part (which can significantly alter the sound).  The gate avoids that problem, but requires that you find a trade off between cutting the low frequency content of the tail (using a short release time), and ending up with audible hiss remaining in the tail (using a longer release time).

But, using automation you can combine the above approaches and get a much better result than either in isolation.  The trick is to use a high shelf filter, but automate the gain/level control, so that it’s very quickly attenuated just after the attack of the sound is finished.  The screens below demonstrate the setup in Reaper.  First you import the sample into an empty track.  Then add a high shelf filter into the FX chain (I’m using Reaper’s built-in ‘ReaEQ’ below to keep things simple).  Then automate the gain/level control of the filter (using the ‘Track Envelopes/Automation’ button on the track control)…

noise-reducing-percussion-samples-1
Reaper track ‘Envelopes/Automation’ window

Then draw an automation curve as shown in the below screen…

noise-reducing-percussion-samples-2
Automation curve
noise-reducing-percussion-samples-3
ReaEQ settings (‘Gain’ is controlled by the automation)

Depending on the nature of the sample, you’ll want to try adjusting the 4 highlighted parameters above to get the noise-reduced version sounding right…

  • The point where the filter starts to drop
  • The time the filter takes to get to minimum gain, and the shape of the curve (above option is using the Reaper ‘fast start’ point shape)
  • The frequency and bandwidth/Q of the filter

If it’s an excessively noisy sample, a low pass filter might also work better than high shelf.

In this case, the same sample with the above settings turned out like this…

The ‘noise-reduced’ sample

… that’s a considerable amount of noise reduction, but has maintained all the attack and general timbre of the sound.