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Online Guide Bass Effect Pedals
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Here you will find an overview of all the bass effects:
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Equalisation |
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Equalisation or ’EQing’ is the process of boosting or cutting a particular frequency range of a sound in order to subtly alter its sonic properties. For instance, it may be desirable to boost the low end, or remove some of the mid range ‘clank’ of the bass. Equalisation can be used in many ways to create different kinds of bass sound. There are several kinds of equaliser, the simplest consisting of just a bass and treble control. ‘Graphic’ equalisers, as found on some pedals, have fixed frequency bands which can be cut or boosted, and ‘parametric’ equalisers have more sophisticated controls for frequency, ‘Q’ which refers to the bandwidth of the frequency range to be adjusted, and cut/boost. Many equalisers also have low pass and high pass filters. A low pass filter cuts all frequencies above a certain point, effectively letting the low frequencies pass, and a high pass filter cuts all frequencies below a point, letting the high frequencies pass unchanged. It’s worth bearing in mind that the lowest frequency produced by a bass guitar is around 40Hz, so a high pass filter can be very useful for reducing any subsonic rumblings.
Boss GEB-7 Most bass amplifiers have equalisation built in, but it can be useful to have an external device for more detailed control and ease of bypassing. There are many pedals available featuring either graphic or parametric controls, and some combine EQ with distortion, which allows you to shape your sound more radically. |
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Compression |
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Compression circuits alter the dynamic range of an audio signal. Most often, a bass compressor is used to lower the peaks created when you play. This is very useful for ‘smoothing out’ the sound of your bass and giving you more sustain, and can also help your amplifier to perform more effectively. Typically, a simple compressor will have controls for ‘threshold’ (the point above which the signal is attenuated), ‘ratio’ (the amount the signal is actually lowered by), and also settings for ‘attack’ and ‘release’ which control the behaviour of the compressor. ‘Limiters’ provide more extreme compression, actually completely preventing peaks in your playing from exceeding a specified threshold.
Digitech Bass Squeeze Mutli-band compression is the term for a device that splits an audio signal into separate frequency bands and compresses them individually, before combining them back together at the output stage. |
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Distortion |
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Distortion is the process of changing the sound by allowing the signal to overload or ‘clip’. This creates varying degrees of a more crunchy and aggressive sound, depending on the settings employed. Used widely in rock music, the effect can be achieved by turning up an amplifier too loud, or by using a distortion pedal or ‘fuzz box’, for more controlled results.
EBS valve drive There are now many kinds of distortion pedals designed specifically for bass guitar, from simple distortion, fuzz and overdrive boxes, to much more complex digital modeling pedals, which digitally recreate the sounds of classic amplifiers and speakers. These can be very useful for recording, when it’s not always convenient to mic up a bass amp due to noise and space considerations. |
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Filters |
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Audio filtering devices cut or boost specific frequency ranges in a sound, but in a much more extreme fashion than EQ. As described previously, the most common types are low pass and high pass, which are sometimes used for removing sub-sonic and ultra-sonic frequencies. However there are many other ways to use filters - ‘resonant’ filters produce some very interesting results by adding a resonant peak at the filter cut-off point. Classic examples of this are found in ‘wah wah’ pedals and envelope filters such as the Mooger Fooger Low Pass Filter.
Electro Harmonix Nano Bassballs Envelope filters respond to the intensity of the note played. Playing harder opens the filter wider, allowing more of the original sound through and producing a squelchy, funky sound, often associated with 70s cop shows.
Morley Bass Wah Wah wah pedals use a continuously variable pedal to control a resonant band-pass filter. While you can use a regular guitar wah wah pedal such as the Jim Dunlop CryBaby with a bass guitar, it’s often more effective to use one that has been specifically designed for bass guitar, as regular guitar wah pedals do not allow any low frequencies through their filters. |
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Pitch Shifting |
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The most common implementation of pitch shifting for bass guitar is the ‘octave divider’ pedal. This doubles the pitch of the bass guitar at one and sometimes two octaves down, giving you a very weighty bass sound, and providing extended low range to a standard 4-string bass. If you’re using an analog pedal such as the famous Boss OC2, remember that it will only respond to one note at a time - playing two notes together (even if by accident) will confuse the unit and make the sound very unpredictable as it tries to work out which note to process! Some more advanced units do now work polyphonically.
Boss Octaver OC-3 Digital pitch shifters may allow you to shift the pitch a fifth, octave, or even more, transposing the bass line into a different key altogether. Adding feedback to this can also be interesting, creating extremely unusual effects as the pitch shifter feeds back into itself. Bear in mind that there will always be some small delay or ‘latency’ to the shifted signal, as the processing circuitry performs its maths on your playing. Some digital pitch shifters can be used with an expression pedal to give a portamento or fretless effect as the pedal is moved. |
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