The Music Espionage

Bass Guitar

The Bass Guitar along with the Kick Drum often considered the power-house of any modern track. It is at these low frequencies where the principal drive, muscle and dominance of a recording can be found. Therefore it is really important to get everything as clear as possible and make sure nothing is masked. The major problem is that all instruments have bass frequencies, but not so heavy as bass guitar and a kick drum. In a mix, all instruments are played together and the primary problem lies in the bass frequencies, it is why every time you heard tracks that are not mixed, it sounds muddy or dull.

Dynamic Range Shaping:
The most likely effect that will need to be added to the majority of bass guitar recordings is some form of dynamics. Why? This to provide a steady beat backbone to the song, this will smooth out any performance fluctuations and keep the level balanced throughout the whole song. From a more technical stance it reduces the dynamic range of the signal fed into the unit. So it reduces the difference in level between the loudest and quietest parts.

The first effect that may be beneficial is the Limiter. This is really useful if you have a fairly steady track, but with the odd moment where is peaks. The limiter will reduce loud sounds over a certain threshold while quiet sounds remain unaffected. Listen through the affected areas and tweak the threshold level until you prevent the signal from going over certain amplitude.

Listen to this example of a bass guitar track with and without the limiter.
– With no effects: [audio:|titles=1 – Bass Guitar – No Limiter]
– With Limiter:[audio:|titles=2 – Bass Guitar -With Limiter]

In this recording the Bass guitar is at a controllable level until a slight moment when the level jumps. In this case we can use the Limiter to set the Threshold so that when the level suddenly jumps it will catch this abrupt transient and bring it back under control.

The second most common dynamic affect is the Compressor. Compression to a bass will help to ensure that the level stays constant throughout the mix, providing a more polished and professional sound. A compressor can also be used during the recording process to manage the dynamic range of the part, allowing it to be captured without clipping or excessive noise. The main concept of creating a big bass sound is slow attack and fast release. This is because the bass does not have very fast transients, so needs to develop the level first; then set compressor to attack the signal and release it immediately, the effect is a loud sounding bass. Using a fairly light compression will mean you will retain some of the dynamics so as to keep the sound ‘live’. If you wanted the more processed sound then crank up the ratio to about 4:1 but remember too much compression can make the sound thin. Not good for bass.

Listen to this example of a bass guitar track with and without the compression.
– With no effects: [audio:|titles=3 – Bass Guitar -No Compression]
– With Compression: [audio:|titles=4 – Bass Guitar – With Compression]

In the first recording you can hear the bass level jump as the performer naturally dose not play every note with the same energy. Inherently every recording will have some notes that are louder than others and some softer, and compression will smooth this out. The second example shows how the level can be controlled so that the signal is uniformed throughout the mix.

Here are good starter settings for compression parameters on bass guitar, nevertheless it is all about using your ears and listening to what works.

Attack: 2 – 10ms Release: 0.5 – Auto Ratio: 4 – 12:1 Knee: Hard Gain: 5 – 15dB

EQ and Frequencies:
Bass guitars put out all the frequencies that you really do not want on every other instrument. The clarity of bass is defined a lot at 800Hz. However, too much low end can mask the clarity of a bass line, making it sound muddy and dull. You may want to roll off everything between 20Hz and 40/50 Hz. There are no real fundamental in this range and often nothing but low-level rumble, again affecting the intelligibility and transparency of the sound. The modern rock track, Green Day, Muse, Killers, The Strokes etc. all have really strong bass that cut through the mix. This is achieved by carefully mapping the bass frequencies and all other instruments that also share this audio region (kick, the low area of the guitar, toms).

Using Logic Pro’s ‘Analyzer’ in the channel EQ illustrates just how much of the same audio region is shared by both the Kick and Bass guitar.

– Kick frequencies

– Bass guitar frequencies

If you designate 45Hz to 250Hz as the bass frequencies where kick drums and bass guitar mainly reside. The problem is how to blend the two. Since the bass guitar needs to sound heavy and dominant, it should dominate mainly the bottom 45 Hz to 250 Hz. But dip 100 Hz for the kick drum spikes to shine through. Often worth boosting the kick drum slightly at around 100Hz, just to allow it to punch through.

Listen to the first example; the Kick has a great deal of spill, also the main punchy sound, on the beat, is covered by the bass guitar. Moreover, both have a rumbly boom noise that distracts from the clarity.
– Kick and Bass with no EQ: [audio:|titles=7 – Kick and Bass – No EQ]

In the next example, the Low-Mids are boosted faintly on the bass guitar to make the slapping sound of the strings ring out. Both tracks have a high-frequency cutoff to completely remove anything in this area, mainly spill/bleeding on the Kick track and random high harmonics from the bass guitar.
– EQ on the Kick drum:

– EQ on the Bass Guitar:

– Bass Guitar and Kick with EQ adjustments: [audio:|titles=10 – Kick and Bass – With EQ]

If you boost a small area of the frequency range, with a mid size ‘Q’, then sweep this across to find where the different dominant frequencies live you will get a better idea of the whole sound recorded. Naturally this will work with any instrument recorded, and it good practice before you start to EQ. Alternatively, use a sharp cutoff and slowly move this to allow the frequencies through, listening to the different elements as they come in.

– EQ for Bass Guitar:

Anything Else?
As a rule, you will not normally need reverb on bass, mainly because it can easily destroy the mix due to the undesirable audio characteristics of applying longer reverb tail on very low frequencies. In addition the bass guitar in the stereo-field will typically dead centre, ‘0’, this is mainly owning to better representation of these low frequencies, but does not mean that you should not experiment with your mixers.