Better Mixes

My 3 recordings were Forgot about Dre, Brothers, and We Can Work It Out.

Static Mix

A static mix is a mix that requires no automation. This can be accomplished by setting your faders to appropriate levels before the recording has begun, good musicianship and appropriate microphone selection and placement is also essential. EQing, Compression and plug-ins can be applied at a later time. We can work it out and Forgot about Dre are static mixes. Brothers was not as their was a problem with the signal to noise ratio which required automation in order to fix it, on a few channels the drums bled through so heavily that the sections where the desired instrument wasn't playing had to be automated out. As seen in the screenshot below, there is no automation on my Forgot about Dre track, making it a static mix. It is a static mix thanks for the mixing done after the recording.

Signal to Noise Ratio

The signal to noise ratio of a track refers to the amount of signal you want on the track as opposed to the unwanted noise also present on it. Unwanted noise could be bleed from other instruments or background noise like an AC. Background noise is irrelevant if you were to DI an instrument such was the case on my 'Brothers' recording where the Bass Guitar was DIed through the bass amp and then through to the stage box via XLR cable. However, if DIing isn't an option SNR can be countered in a few ways:

Microphone Selection: Decide what is the best microphone for the instrument you're attempting to record. For example, if you were to record an Acoustic Guitar then you could maybe use an SM-57 pointed directly towards the sound hole. The SM-57 has a cardioid pick up pattern so it is unlikely to pick up much else aside from the Guitar signal. In my recording of Brothers I used various microphones including the SM-57, SM-58 and the AKG-451s.

Microphone Placement: While this is important for every situation, it is especially important when miking a drum kit. Generally, an audio engineer will use overhead mics to pick up the overall sound of the kit. The AKG-451s are a common microphone pair to use for this job, they can be arranged in a number of ways ranging from spaced pair to the XY method, both of which are designed to pick up the sound you want and to reduce the unwanted noise you're receiving from other sources.

Environment: A proper live room will have been acoustically treated and built specifically to cater to musicians wanting to record instruments properly. They are best when they are virtually sound proof. However, if you were recording in a space with unique acoustic qualities (such as a church) you may want to capture a lot of noise.

All of my recordings were done in an acoustically treated live room. The sound team miked up each individual instrument using the appropriate microphone or DI. The biggest problem with the set up was that the drums were also recorded with the rest of the band in the same room, as the drums create a massive sound they bled through almost every other mic and in some cases completely drowned out the signal we wanted to hear. We remedied this by automating out sections where only the drums could be heard on the channel, some channels however were beyond repair so were muted completely. If I were to re record the piece I would record the drums in a live room on their own beforehand and then play them through the headphones of the rest of the band.

dBFS (Decibels Relative to Full Scale)

0 dBFS is the point where a signal is peaking. Peaking will lead to a distorted signal. This is very harmful to a digital recording and so it is avoided by audio engineers. It is recommended that a signal peaks at -3dB, -6dB or -12dB.Whilst recording and whilst mixing we were very careful to not let any of our tracks hit 0 dBFS. We did this by attenuating via the faders.

Dynamic Range

The dynamic range of a track refers to the difference between the loudest and quietest point of the signal. For example, if a signal's loudest point is 12dB and the quietest is 3dB then it has a dynamic range of 9dB. Below is the sound wave of my second Guitar on my Forgot about Dre track as it is displayed on Logic. Too much dynamic range can compromise the quality of audio. From the early 90s engineers and producers have been accused of unnecessarily increasing the dynamic range of their music in order for it to be louder than everyone else. This created problems with clipping and distortion and even when mixed properly would still sound badly put together.

Headroom

Headroom is how close the peak of a signal gets to hitting 0 dBFS. If a signal reaches -3dB then the headroom is 3dB. I made sure that my signals peaked at -3dB, -6dB or -12dB. If I were to mix my tracks again I would begin by firstly bringing down my faders by a few dB to instantly and easily create more headroom. It is better to start your mixing process with quieter tracks so that the more important tracks can be given precedence throughout the mixing process, this way you won't have to worry about clipping or distorting the signal.

EQing can be a useful tool in creating headroom. So many tracks have huge areas on the frequency spectrum that are totally useless and are creating unneeded noise. Simply use high or low pass filters on the appropriate tracks to free up space for the tracks that need those frequencies. This in turn will generate headroom.

EQ (Equalisation)

EQ is one of the most useful tools an audio engineer can use. EQ allows you to see what frequencies on the frequency spectrum a specific track is occupying. The range of the frequency spectrum is 20Hz to 20kHz, the range of Human hearing. Using EQ you can raise or attenuate a certain frequency, this is useful because it's very common to find that multiple instruments in any given piece of music will be fighting over the same frequencies creating a messy sounding mix. Giving certain tracks precedence over others at certain frequencies will create spacing and authenticity in your mixes. For example, a bass guitar and a kick drum reside in the lower end of the frequency spectrum at around 100Hz. EQ can be parametric or semi parametric (semi parametric being an EQ with one of more features missing.) You can easily raise the dB of the kick and attenuate the bass guitar or vice versa. This is the EQ on my lead vocal from We Can Work It Out. I did this because there isn't much happening below 100Hz anyway so it is an unneeded frequency. This helped to create vocal clarity and leads to an altogether less cluttered track. If I were to improve the mix I'd probably attenuate the frequencies between 200Hz and 500Hz on this track and many others as these region is where there is a lot of cluttered signals.

Compression Threshold

A compressor is designed to reduce the loud points of an audio signal. The threshold of a compressor determines at what dB the compressor begins to take effect. If you were to set the compression threshold at -5 dB then any signal that is above -5dB will be brought down in volume. In this example my snare is moderately compressed. The compressor threshold has been reduced to -33.5dB meaning that a lot of the signal is compressed but the low ratio means that it is compressed softly. The snare was very overbearing in the mix before it was compressed.

Compression Ratio

Indicates how much the audio is compressed by. A low ratio means less compression, for example a ratio of 2:1 means that for every 2dB that goes through the compressor only one is allowed to pass. Conversely, a signal with a compression ratio of 20:1 is heavily compressed as for every 20dB that goes through the compressor only one is allowed to pass.

Compression Output / Make up Gain

Make up gain is applied via the compressor after the signal has reached the point where the threshold has taken effect. The peaks in the audio signal are then reduced by the threshold, however you will then have an altogether quieter signal which is compensated for by applying some make up gain. This brings the overall level of the signal up. Output gain affects the signal regardless of whether the threshold is taking effect. It boosts the peaks in the signal also. If you were to boost the output signal without changing much else on the compressor you'd hear a lot of the unwanted background noise explained earlier in SNR. There is an auto gain option on the Logic compressor that will raise the make up gain as the threshold is lowered.

Analogue and Digital Distortion

An analogue signal does not contain any breaks so is a continuous noise whereas a digital signal has breaks and is sent in a series of pulses. When a digital signal exceeds 0 dBFS it peaks causing distortion, this effect isn't desirable in a digital format as it can warp the signal. Analogue distortion can be desirable in certain music as it doesn't pose a problem to the actual signal and essentially acts as an effect usually applied to electric guitars. In my mixes nothing was distorted.