I’ve done a bit of research on five audio production techniques. My group and I have applied four of them to our final studio project and the fifth we used in the editing stages of the Monty Python clip we worked on towards the middle of the trimester. First up is a little bit about compression!
So what I’ve learned from my research on this technique is that the goal of parallel compression is to reduce the dynamic range of a signal from the low level upwards, leaving the louder transients in place rather than pushing them downwards (as is normally the case when compressing a signal). We used this technique effectively in our studio project, more specifically on the vocal tracks of each of our studio recordings. The first step on your way to setting up parallel compression is to split your audio signal into two different channels, leaving one clean and applying a compressor (of the normal ‘downward’ variety) to the other. You set the attack and release as you normally would for the sound you’re working with accompanied by a high ratio and adjusted threshold so when the signal hits those high levels it’s reduced quite drastically. Once you’ve set this up you’re ready to go. The next step in the process is done by combining the signals. The downward compressor won’t be in action during quieter points in the audio signal, however, the combined signal results in a lift in the RMS level. This is how parallel compression works, from the bottom upwards. To get a greater reduction you can just apply more compressed paths of the same signal! I think this is a very clever technique. At this stage, my hearing isn’t so acute as to pick up on the use of compression every time it’s in use but I’ve read that parallel compression is a much more subtle way to compress a signal than the usual method of downward compression.
This is another cool technique. Multiband compression works by being able to divide a signal into different frequency bands, then having the ability to compress each frequency band individually and with different compression settings. So, essentially, a multiband compressor is a combination of a few smaller compressors that each work on a particular range of frequencies. This is a very effective tool to use when mixing a drum kit. A typical drum kit produces sounds of varying positions on the frequency spectrum e.g. a kick drum is quite low while a cymbal is very high. The process starts with feeding a signal into the multiband compressor. That signal is then filtered into however many smaller frequency bands (usually around four). They are then fed into individual compressors which have the usual compression settings i.e. threshold, ratio, attack, release. After the desired compression is completed they are reunited back into the one signal. This effect is most commonly associated with mastering but can be used during the mixing stage on anything from simple, small range signals right up to the wide range of a drum kit. A more notable occasion where we used multiband compression in our project was on the double bass in Dead Man’s Bones. Due to a less than satisfactory recording, we were hearing too much slap and not enough actual bass coming through. We compressed the higher end where the slap was coming through and accentuated the low end so we heard more of the bass cutting through.
Mixing at Low Level
This is a simple and effective technique that makes complete sense. I wish I’d used it when mixing in the past! The idea is that if a mix sounds good at low level then it’s going to sound fantastic when turned up to a louder level. I’m not certain of the science behind it but when listening and trying to mix at a higher volume, your ear can be tricked into thinking it sounds good when it actually doesn’t. At higher level, some frequencies can sound more prominent than they actually are. This is one of the reasons why your mix can suddenly sound super shitty when you turn it down or listen to it on a different system. Those frequencies you were hearing so prominently suddenly disappear and can’t be heard at all. Of course you’ll need to turn it up occasionally especially to check that any bass frequencies are sitting at a desirable level and position (they’re harder to hear at low levels). Other than that, to quote Kevin Ward of mixcoach.com: “If you can make your mix sound good, punchy and balanced at a low volume, chances are it’s going to sound GREAT when you turn it up.” We implemented this technique throughout the mixing process of Cattleprod’s EP, never having the monitors up too loud. You’ll see that our mixes sound amazing and mixing at low level may well be a contributing factor to this 😉
Izotope RX4 Advanced Denoiser
Advanced Denoiser is a part of the iZotope RX 4: Complete Audio Enhancement & Repair Toolkit. It’s an amazing tool that, essentially, gets rid of unwanted background noise. According to the product description, it can be used on pretty much any variety of audio recording like “music, old recordings, home movies, production recordings and more”. We implemented it during the editing stages of our sound replacement for Monty Python and The Holy Grail: Black Knight Scene. We needed some forest/bird sounds for ambience. Our best option to capture this type of sound was a park near campus. We recorded some birds chirping in some big, old trees and upon listening back to our recording in the C24 studio we found that the Zoom mic we’d used had picked up A LOT of wind and traffic noise from the main road across the river. Denoiser worked like magic on our recording, ridding it of all of that noise while maintaining the forest kind of sound we needed. I would recommend it to everyone!
Izotope RX4 Declicker
Another tool in the iZotope RX 4: Complete Audio Enhancement & Repair Toolkit is the Declicker. As its name would suggest, the Declicker rids audio recordings of “clicks, crackles, pops ad digital impulse noises”. According to the user manual, it’s most useful on recordings “suffering from quality degradation, digital errors, mouth noises, and interference from cell phones”. One of its features is called Decrackle. We implemented this tool while mixing one of our songs for our studio project. We’d used a Royer R-121 as a room mic and upon listening back to what it had captured we found there to be a lot of noise cutting through due the fact that we were recording electric guitar coming through an amp. We rid the recording of most of this unwanted noise so it was usable in the mixing process.
Aisher, B. (2012). Parallel Compression. Retrieved from http://www.attackmagazine.com/technique/walkthroughs/parallel-compression/
Albano, J. (2014). Mixing Tips: Understanding Multiband Compression. Retrieved from http://www.askaudiomag.com/articles/mixing-tips-understanding-multiband-compression
IZOTOPE RX4 FOR EDITORS. (2014). Retrieved from http://www.fcpworks.com/izotope-rx4-editors/
izotope rx. (2013). What is the difference between Declick and Decrackle? Retrieved from http://izotope-rx.livejournal.com/2599.html
Mixing At Lower Volumes. (2010). Retrieved from http://therecordingrevolution.com/2010/10/07/mixing-at-lower-volumes/
Multiband Compression Basics: iZotope Mastering Tips. (2014). Retrieved from https://www.izotope.com/en/community/blog/tips-tutorials/2014/06/multiband-compression-basics-izotope-mastering-tips/
Robjohns, H. (2013). Parallel Compression: The Real Benefits. Retrieved from http://www.soundonsound.com/sos/feb13/articles/latest-squeeze.htm
RX 4 Features. (n. d.). Retrieved from https://www.izotope.com/en/products/audio-repair/rx/features/
Simpson, R., Lawrence, J., Beentjes, R., Fischer, E, R., Raphael, M. (n. d.). RX 4 Testimonials. Retrieved from https://www.izotope.com/en/products/audio-repair/rx/testimonials/
Ward, K. (2011). 3 reasons to mix at lower levels. Retrieved from http://mixcoach.com/3-reasons-to-mix-at-lower-levels/
White, P. & Robjohns, H. (2002). MULTI-BAND WORKSHOP: Practical Multi-band Compression. Retrieved from https://www.soundonsound.com/sos/aug02/articles/multiband.asp
3 Mixing Tips To Be Thankful For. (2013). Retrieved from http://therecordingrevolution.com/2013/11/29/3-mixing-techniques-to-be-thankful-for/