C A R A U D I O
B M W 3 2 0 i S E
CAR OF THE MONTH
L I N K S
The signal processing in the system consists of a
single electronic crossover
and a pair of passive crossovers that supply the three way front speaker sets. These are
described in more detail in the speakers section of the stereo system. A crossover
splits the sound signal by frequency to supply each particular speaker in the system the
most appropriate range of sounds. For example, tweeters receive the highest frequencies
as they are small and designed to just produce high frequencies. An electronic crossover
feeds the signal into amplifiers, whereas passive crossovers pass they're signals directly
into the speakers themselves. If you need / want a more detailed explanation of this process,
just fill in the form below and let me know.
Phoenix Gold MX2|
This unit was and is a nice crossover unit, except is variable bass crossover had only two markings
on the pentometer to judge the frequency. This meant you were never quite sure of the
frequency your sub's were set at. This makes' setting up a very slow and tedious procedure.
I ended up part exchanging the unit for the AX406A that currently does the job very well.
This is the second Phoenix Gold crossover that's been in my system,
the first being an MX2, a much
less sophisticated and less flexible piece of equipment [ see the MX2 box to the right for more
details ]. I upgraded to the AX406A as you can control the crossover points and the much more
capable unit can be used in a wider variety of ways. There are plugin crossover modules that
allow you to choose at what frequency you want to crossover, e.g. all sub bass to be 70hz and below,
everything else to play 120hz and above.
Phoenix Gold AX406A electronic crossover
Other advantages are the ability to plug in an LPL (low pass level) controller, which allows
you to adjust the level of bass +/- 18db from the front of the vehicle. The AX406A can work in a
two way / four channel [front left and right, rear left and right and sub bass] or in a three way /
two channel mode [high, mid and sub, in stereo]. This means greater flexibility should I ever change
around the setup I have, which is currently the latter [three way / two channel].
This means I use the higher frequency output to run the front speakers [120hz and above], and
the sub output to the rear, into the subwoofers. The subwoofers are set to mono, as the pair
of subwoofers are housed in the same cabinet. This is explained in more detail in the
subwoofers section. The technical specification of the AX406A is in the table below.
||0.02% THD at 1KHz 0.02% I.M. at 1KHz|
||10Hz - 30KHz +1/-3 db|
|S/N Ratio (A weighted)
||Plug-in resister module -any frequency|
|Crossover slope rate
||18db per Octave (3rd Order Mrs. Butterworth)|
|Output voltage level
||9 volts max.|
||13.8 volts DC negative ground|
||0.5 amp max.|
||9.75" W x 1.3" H x 5.75" D|
248mm x 35mm x 146mm