Tips: Auxiliary Fed Subwoofers
This article doesn't directly relate to kick drum microphones, however, implementing this system is one of the single best ways of improving the sound and power of your drummer's kick drum.
Implementing an auxiliary fed subwoofer setup is the single largest improvement that an engineer can make for his or her sound system. By running your subwoofers off of an auxiliary send instead of your main output bus, you remove a large amount of "mucky-muck" from your low end. You only send the subwoofer inputs that have useful low end energy, and you don't send the sub un-useful inputs.
Traditional Two Way Setup
In a traditional two way sound system setup, the full-range main output from the sound console is split between the high/mid and subwoofer speakers by use of an active crossover. The crossover sends only higher frequency signals to the high/mid speakers, and only lower frequency signals to the subwoofer.
Aux Fed Subwoofer Setup
In an auxiliary fed subwoofer system, the high-mid speakers are fed signal from the main output, and the subwoofers are sent signals via an auxiliary send. Each type of speaker (high/mid and subwoofer) will still need to be crossed-over to eliminate frequencies that they are not designed to handle. In the above example, a mono system is used with a single stereo crossover. If you desire stereo, you will need an additional crossover.
With the aux-fed subwoofer setup, the engineer can choose which input channels are (and are not) sent to the subwoofer. For instance, inputs that would be sent to the subwoofer aux send would be:
- Kick drum
- Floor tom
- Bass guitar
Since you pick only the inputs that are needed in the subwoofer, the subs are not getting any low frequency garbage from microphone inputs, guitars, and other non-low end inputs. This allows for precise control over what is and is not going into the subwoofer.
Using this setup, you will see a marked increase in the efficiency of you subwoofer, and the performance of your kick drum mics.
The downside to this setup are mostly logistical:
- Requires the use of an AUX send that you may not be able to sacrifice (you may need it for monitors or effects)
- Generally requires another crossover, unless you run your system in mono
- Requires an additional one or two snake channels
Overall, implementing this system is one of the single best ways to improve the sound and power of your drummer's kick drum.