Filter
Top Products
LOWPASS CROSSOVER
Locate the rotary dial marked LPF. This is the LowPass Filter (crossover) for the amplifier. The lowpass crossover points are fully variable from 50Hz to 250Hz making
them ideal for subwoofers. Adjust this dial either to the recommended crossover frequency for the subwoofer or, more importantly, to a level where the subwoofer
blends well with the midrange.
*Note: Due to the limited frequency range of these Class D amplifiers, the crossover is always active.
LOW IN
R
L
LEVEL
HPF FULL LPF
OFF ON
MASTER
IN
OUT
INVERT
SUB
SONIC
50 250
LPF
LINE OUT
REMOTE
CROSS
OVER
SLAVE 0 180
Line
level
inputs
Lowpass
crossover
Subsonic
Filter
Remote
level
control
recepticle
Preamp
output
w/crossover
Bridging
circuit
Gain
control
PEAMP FEATURES
PEAMP FEATURES
The Crossfire BMF600D and BMF1000D have a tremendously powerful preamp section located on the panel opposite the power terminals. Included in this preamp
section are Lowpass Crossover for the amplifier, a switchable/variable Subsonic Filter, Preamp Output with Variable Crossover, a Digital Remote Level Control, and a built
in Bridging Module. These features can be used to improve your system quality an as well as make the amplifiers easier to use on a day to day basis. Please read the
following instructions carefully.
SUBSONIC FILTER
The subsonic filter is used to reduce the amount of low frequency harmonics and/or subsonic noise picked up in audio systems. Both of these can be damaging to
subwoofer and possibly the amplifier. As well, harmonics and subsonic noise can cause the amplifier to pull excess power from your electrical system.
The subsonic filter on the BMF600D/1000D is selectable, ON/OFF, and variable from 20Hz to 50Hz. We make this switchable ON/OFF, for every system is different. For
most people it is desirable to have the filter on. However, if you have an outright SPL system, it may be beneficial to remove the subsonic filter because harmonics can
actually increase the sound pressure in many cases.
So what frequency should you set the subsonic at? For most applications it is desirable to leave this between 20Hz and 30Hz. If you are using a ported enclosure
designed for SPL, yet you are using the system on a daily basis, a higher filter frequency may be desired. This will allow the enclosure to be tuned higher and reduce the
chance of the woofer to becoming non-linear and destroying itself.
REMOTE LEVEL CONTROL
Optional to the BMF600D/1000D is the digital remote level control. This level control can be mounted in an area within reach from the driver's seat and can be used to
raise and lower the output level of the amplifier to the desired level. To connect this, run the provided cable from the remote to the amplifier. Plug the cable into the
receptacle on the preamp section of the amplifier marked "REMOTE". The remote control receives power directly from the amplifier so no extra wires need to be
connected.
LINE LEVEL OUTPUTS
The line level output is to be used as an easy solution to link multiple amplifiers together without the use of problematic RCA y-cables. The signal is buffered so that
there is no loss. Please note that the signal passing through these outputs is not affected by the gain control of the amplifier.
Included in the circuit of the line level output is an electronic crossover variable from 50Hz to 250Hz. This crossover is switchable from highpass, lowpass, and full range.
This allows the stereo system to remain flexible enough to be arranged in a numerous amount of ways. Please refer to the diagrams at the end of this section for
suggestions.
5