Owner's Manual

Setup and Adjustments:
Crossovers: The primary function of a
crossover is to keep small drivers safe. The
secondary function of a crossover is to
provide an appropriate division of low and
high frequencies to ensure an inaudble
transition from one speaker to another.
In order for a speaker to play high frequen-
cies well, it has to be small and the dia-
phragm along with the rest of the moving
parts must be lightweight. Small speakers,
tweeters especially, aren’t designed to
handle a lot of power. This is OK, because
most music doesn’t contain a lot of signal
at the highest frequencies.
For tweeters, choose a high pass lter
frequency that’s about twice the tweet-
er’s free air resonance (Fs). You can nd
that information in the owner’s manual, For
midrange and midbass speakers, choose
a high pass lter frequency equal to or
higher than the speaker’s free air reso-
nance. Speakers make the most distortion
at and around Fs, so avoiding that range
of frequencies is an easy way to make
your system sound better.
For subwoofers, we don’t have any choice
but to use them around their resonance,
Fortunately, our hearing is less sensitive to
distortion at really low frequencies.
Using a high pass lter on a subwoofer in
an innite bafe installation or in a vented
enclosure is very helpful in preventing over
excursion which sounds bad and will even-
tually destroy the speaker.
When using the crossovers in the A150.4D
and the A600.1D:
1. Be sure that the HIGH PASS lter frequen-
cy is set to a frequency lower than the
LOW PASS lter frequency.
2. Don’t set a bandpass lter less than an
octave wide. The low pass lter frequency
should be set to at least two times the high
pass lter frequency.
3. The ter slopes in these ampliers are
12dB/octave. 12dB/octave crossovers
change the phase of the signal by 180 de-
grees. Alternate the polarity of adjacent
crossover bands to x this condition. For
example, if you are driving tweeters with
one pair of channels, midrange with the
other pair of channels and a subwoofer
with an A600.1D, connect the tweeters in
the proper polarity. Reverse the polarity of
both midrange speakers and connect the
subwoofer in proper polarity. This ensures
proper crssover performance.
Phase Control (A600.1D) Use the phase
control on the A600.1D to align the phase
of the subwoofer with the phase of the
front speakers. You can do this with an RTA
or by ear, if you don’t have an RTA. The
setting that provides the most midbass
impact is correct.
Levels: The LEVEL controls for each
channel are intended to match the input
sensitivity of the amplier with the output
signal of a radio or signal processor. In car
audio systems, we also use these level set-
tings to set the balance between different
frequency bands, to ensure that ampliers
and speakers don’t produce excessive
amounts of distortion and to minimize the
amount of noise present in the system.
There are many ways to test signals and
set levels and the appropriate process
differs depending on whether you’re using
the speaker level outputs of a factory
head unit or amplier, an aftermarket
radio witih preamp outputs or a DSP.
Please see the Audiofrog Tech Blog at
www.audiofrog.com for process sugges-
tions for these varous circumstances and
for system conguraton suggestions.
Never, under any circumstances, should
you use sine wave tracks to set your sys-
tem levels with the tweeters or small mid-
range speakers connected to the ampli-
er. Doing so will burn the voice coils in an
instant. ALWAYS disconnect tweeters and
midrange speakers during this procedure if
you choose this method.