Running stereo buses or full mixes through analogue devices like compressors, equalizers, summing boxes etc. is fun. They can add that magical touch to your track – a bit of stardust, the so-called 3D effect, punch, fullness and all sorts of adorable favours. But many times you face a problem even with high-end devices: the stereo image shifts…
I was mastering a track recently which has been run through a very expensive channel strip unit to add some shine to the mix. Sounded gorgeous except for that the mix – most noticeably the bass and the vocals – slightly shifted to the left, which was kind of annoying.
I asked my client to send me the mix without the channel strip processor applied on it. Then I measured the RMS levels for the left and right channels on both versions of the song (you can use Voxengo SPAN for such tasks). It looked like this:
Original (in the box) mix: Left: -18.2 dB, Right: -18.3 dB
Mix run through the channel strip: Left: -19.4 dB, Right: -20.4
You can see that the right channel has become 0.9 dB quieter compared to the relative levels of the original mix. To compensate for this I used the free Stereo Tool VST plugin from Flux where you can adjust the levels of the left and right channels independently (besides many other options). I increased the level of the right channel by 0.9 dB: now the vocals and the bass came back to the center. Problem solved!
Just a final note. Always check the mix with your ears too because RMS values are sometimes misleading. So don’t compensate for the stereo image shift in the mix blindly.
Here are some tips for mixing your songs which will help you to achieve more clarity and definition. None of this is craved into stone but can help you out in many situations.
- When using equalizers it’s usually better to cut than boost
- You can achieve more clarity if you high-pass every track around 80 Hz, except bass instruments
- Use a wide Q setting for equalizers unless you need surgical adjustments
- If you need more punch for your bassdrums boost high frequencies instead of lows which will “sharpen” the attack
- Use small amounts of reverb – it’s better to feel it instead of hearing obviously
- Shorter reverb settings contribute to more clarity in the mix
- Add both reverb and delay to pads to make them sound bigger
- Add a little ambience reverb to dry sounding drums and bass tracks
- Filter the delay effects with high- and low-pass filters to avoid your mix sounding busy
- It’s generally better to use a low compression ratio for buses
- Applying parallel compression on drums and vocals will result in a more powerful sound
- Watch drum transients – make them sound snappy instead of smeared
- Organize instruments into groups and apply bus compression instead of compressing every single track
- Don’t mix too hot, apply proper gain staging by setting your channels to 0 VU using an analog style VU meter (prior to mixing)
- Use an autopanner on some of the tracks to make them sound more alive
- Pan backing vocals to sides
- Avoid hard panning of single instruments
- Spread instruments in the stereo space
- Place lead vocals, kick, snare and bass instruments in the center
- If an instrument sounds too narrow apply a 10-20 ms channel delay between the left and right channels
- Avoid the “big mono” effect when every sound comes from two sides
- Don’t invert the phase for only the left or right channel of a track – this will lead to mono compatibility issues
- Fix smaller noise issues with a noise gate instead of a denoiser plugin
- Keep your hihats lower in level, too loud is ear fatiguing
- A little chorus on the bassline can make it sound fuller
- Check your mixes on multiple systems: e.g. on headphones, in the car, on laptop speakers etc. to make sure they translate well
- If you don’t have a decent monitoring system use a spectrum analyzer to spot errors in the frequency balance
- Build up the mix: start with the drums, then the bass, the vocals, lead instruments and finally the background elements such as pads, strings. This will result in better balancing.
- Always compare your finished mix to commercial releases
I recently worked with a DJ who remixed an early 80′s song. There were two transitions from the remix to the original song which was a low quality, mono mp3 file. So when the song played the original parts, the previously wide and dynamic sound collapsed, it sounded thin and grainy.
First I tried to revitalize dynamics and match the frequency curve of the different parts. Then I split the original parts to 3 frequency bands and applied a short 10-12 ms left-right channel delay on the highs. And so it sounded awful… Although this technique often works fine with individual tracks this time it did not. The original parts did not have enough clean air to work with and even worse, the instruments and the vocals just did not come apart.
I thought it once again and found a very simple yet wonderfully working solution. I routed the original parts to two different busses. On the first buss I made the required dynamics and EQ adjustments so the samples sounded bigger and cleaner. On the second buss I set up a tempo synced stereo delay 100% wet, and processed the echos to sound smooth and clean with a weak low end. I turned the volume fader all the way down and then started to slide it upwards very slowly. At a very low setting the mix started to sound quite fine. The original samples had the same punch as the newly produced tracks and a nice stereo width without hearing any echos distinctively. Job done!
Well, not a mixing technique this time but a very useful entry for many of you I’m sure!
I’ve always been very critical about selecting the best tools for my studio which ensure a seamless mixing and mastering workflow. Through the years I’ve came across several freeware VST plugins and other free audio software too. Here’s a list of the free software I use regularly and which are on par with the most expensive ones:
A very musical sounding HP/LP filter, great for mastering as well:
One of the best software audio analyzers:
A general purpose mid-side plugin:
My go-to stereo tool and analyzer:
A great tool for widening the stereo image:
A utility for delaying left/right or mid/side channels:
A neat autopanner:
Delay effect with a very good sound:
And finally one of the best sample rate converters available (not a plugin and runs from command line; a short tutorial will follow this entry soon):
Although mixing with headphones is something I wouldn’t recommend to do there are situations when you’ve got to go for it. So let’s see what’s wrong with it and how you can compensate for the disadvantages.
When you listen to music through headphones you experience a quite unnatural ‘in your head’ sound. First, room acoustics is totally excluded which results in a dull and fully dry sound. Second, the sound doesn’t come from the front but goes directly into your ears which causes total stereo separation. Also, your ears respond to sound pressure coming from speakers differently then when coming from headphones. That’s quite bad so far… But here comes the good news!
To compensate for the undesired side effects of listening to music through headphones you can use virtual speaker simulation tools. Most of them operate with head-related transfer functions (HRTF) under the hood to simulate acoustical transfer from loudspeakers to ears and reflections from the human body, and binaural room transfer functions (BRTF) to simulate room reflections. For me the most convincing results were produced by the now discontinued Focusrite VRM box. My second choice would be TB Isone by Toneboosters which is a binaural room simulator in VST plugin format. Other options cover (not exclusively) 112 dB’s Redline Monitor, G-Sonique’s Monitor MSX5 or Beyerdynamic’s Virtual Studio. For best results you should use high quality headphones with a full band flat frequency response especially designed for pro audio applications.
Still, I wouldn’t solely rely on such a tool during a mixing session. However, I would recommend using it to double check your mixes to hear how they would sound in various listening environments. Also, if you don’t have a decent loudspeaker based monitoring environment you’ll most probably produce better-translating mixes by using a speaker simulator when monitoring through headphones.