The HEBs have a very flat and extended low frequency response. In some
cases, particularly where the hall or sound system has an emphasized
bass frequency response ("hall boom"), it is desirable to roll off the
low bass frequency response.
To address this we offer two battery boxes with bass roll-off filters.
One has a fixed-response bass roll-off filter. The other offers a
The switchable box has a very high quality, locking mini-toggle switch
mounted on the outside of the box under the mini-XLR jack. It is
switched between flat response and the bass filter response very easily,
but the locking toggle lever must be pulled outward to switch filter
positions, and so can't be accidentally switched.
When used with recorders like the Sony PCM-M10, the bass roll-off filter
rolls off frequencies below 120 Hertz at 6 dB/octave.
In general, we don't recommend that you have only the bass roll-off
filter unless you regularly note too much bass in your recordings. If
you want to be able to select between a flat and a rolled-off response,
we recommend having the switchable box, or two fixed-response battery
boxes on hand: one that's flat and one that has the roll-off filter.