Hi out there

Yesterday night, I tried another rig configuration for my friday night residency at the local irish pub.

I usually play with a fishman soloamp and a DB-12 subwoofer. Stick and microphone go into a Mackie ProFX 8. Mains out go to the subwoofer, which handles the frequencies inferior to 100 Hz for all the channels (vocals, stick bass and melody side), then out of the subwoofer to the Fishman.

This time, I was playing with a drummer, and went for the so called «aux fed subwoofer» strategy.

Very simple. On the melody channel of the stick and on the vocal microphone, I engaged the low cut switch that eliminates almost everything under 100 Hz.

On the bass side channel of the stick, I turned the monitor send up, sending the bass side to the monitor output of the Mackie.

I did the same for the kick drum microphone, the rest of the drums didn’t need to be amplified as it was leaking through the vocal mike anyway.

I connected a main output of the mixer to the Fishman, sending it the whole mix as usual.

I connected the monitor output of the mixer to the subwoofer, sending it ONLY the low frequencies of the Stick's bass side and kick drum mike.

I then aligned the volume of the sub with the volume of the Fishman (no complex device required, two good ears are enough).

The result is VERY GOOD. With this approach, only the low frequencies of the bass side and the kick drum are handled by the subwoofer. All the other channels being low cut at 100 Hz, there is no stage noise, leakage, rumble or any other noise going through the subwoofer. The bass spectrum is punchier and clearer.

On stage, this system was behind the drummer and me (as with a Bose system). So we both heard ourselves very well.

The main output of the Mackie mixer was also fed into to 2 Mackie Thump TH12-A flown from the ceiling, functioning as FOH. On these 2 units, I turned the bass EQ a bit down, since the subwoofer was already providing enough bass.

After the gig, some people told us how good the sound was. The vocals came through loud and clear, as did the Stick and drums, with a very wide spectrum from very low bass to cristal high frequencies.

Here is also a short Wikipedia explanation and a link to what made me try this (highly recommendable) approach. For other infos, you may google « aux fed subwoofer ».

Aux-fed subwoofers

Instead of being incorporated into a full-range system, concert subwoofers can be supplied with their own signal from a separate mix bus on the mixing console; often one of the auxiliary sends ("aux" or "auxes") is used. This configuration is called "aux-fed subwoofers", and has been observed to significantly reduce low frequency "muddiness" that can build up in a concert sound system which has on stage a number of microphones each picking up low frequencies and each having different phase relationships of those low frequencies.[2] The aux-fed subs method greatly reduces the number of sources feeding the subwoofers to include only those instruments that have desired low frequency information; sources such as kick drum, bass guitar, samplers and keys. This simplifies the signal sent to the subwoofers and makes for greater clarity and low punch.[55] Aux-fed subs can even be stereo, if desired, using two auxiliary mix buses.

http://worldofste.co.uk/206/system-design/aux-fed-subs/