Amplification of the Double Bass

Amplification of the Double Bass

 The double bass is an instrument that is often forgotten when amplification is discussed. Many bass players have their own system, largely because they are left to sort it out themselves.

The first thing to think about when amplifying any bass instrument is size. Bass notes have a low frequency and therefore have a long wavelength. The wavelength directly effects the size of the loudspeaker required to reliably amplify the sound. It is true that small speaks will reproduce low frequency signals but inevitably the sound gets distorted and quieter the smaller the loudspeaker. To faithfully reproduce low frequencies, you need to shift a lot of air, this requires a large loudspeaker.

Large is a relative term, anything smaller than 8” is small for bass notes and even this will struggle to get very low at any significant volume. 12”-15” is more realistic. This means that the Accusound AMA-1 amplifier/speaker will not work well on its own, however it does have the facility to add an external slave loudspeaker, active or passive. This means that by combining a sub-woofer to the Accusound speaker setup you can reliably amplify just about any instrument.

This is the delivery end of the amplification sorted, what about the input or microphone end. Unlike reproducing low frequencies, a microphone to pickup low frequencies does not need to be any larger than one that would be used for any other instrument, it does of course need to be capable of picking up low frequencies, something that is not always true.

The Accusound flexible neck microphone for bass uses the same capsule as our other instrument mics and can easily pickup the lowest of bass notes.

Just like the smaller violin version, the favourite positioning of the microphone picks up sound from the f hole. This gives a good true reproduction but is sometimes felt to be a little soft or mellow for perhaps jazz music. To help with this we suggest using the Accusound contact mic for bass. This is T shaped pickup that is fixed to the curved underside of the bridge, no need to move the bridge, just fix it to the underside. This is then combined with the flexible neck microphone to produce a faithful but punchy sound. The relative amounts of the 2 microphones can be adjusted to get just the sound you want.