JBL MS-8 - Output Setup and Crossover Configuration

www.jbl.com
OUTPUT SETUP
Next, the MS-8 will display Xover Setup. During Xover Setup, you must tell
the MS-8 which speakers are connected to the system, and you must select
the crossover characteristics for all of the system’s speakers. Referring to the
Conguration Chart that you lled out when you connected the MS-8 will make
this process easy. During Xover Setup and Channel Selection, you must enter the
information according to the specic sequence that the MS-8’s display presents.
A note about crossovers
In general, your car stereo’s small speakers are designed to reproduce high frequencies,
while its large speakers are designed to reproduce low frequencies. Larger speakers do a
poor job of reproducing high frequencies, and smaller speakers are not able to reproduce
low frequencies and may even be damaged by them.
A crossover is a lter or combination of lters that limit the sounds that are sent to a
particular speaker so that it receives only the frequencies that it can safely reproduce.
The MS-8 features a sophisticated crossover system that you can set to get the best
performance from whatever type of speaker system is installed in your vehicle.
In the MS-8, a crossover (or lter, abbreviated “Xover” on the MS-8 display) frequency
refers to the frequency at which the sounds sent to that speaker will begin to be
attenuated. The crossover lter slope refers to the rate at which the sounds will be
attenuated. The MS-8’s crossover contains two types of lters:
• High-pass lters, which send the frequencies above the crossover frequency to a
speaker while attenuating the frequencies below the crossover frequency. This type of
lter is used to prevent lower frequencies from reaching smaller speakers.
• Low-pass lters, which send the frequencies below the crossover frequency to a speaker
while attenuating the frequencies above the crossover frequency. This type of lter is
used to prevent higher frequencies from reaching larger speakers.
A high-pass lter can be combined with a low-pass lter to create a third type of lter,
called a band-pass lter. A band-pass lter sends the band of frequencies between
the high-pass and low-pass crossover frequencies to a speaker while attenuating the
frequencies below the high-pass crossover frequency and above the low-pass crossover
frequency. This type of lter is used to prevent lower and higher frequencies from reaching
midrange speakers in three-way speaker systems.
The most important thing that determines your selection of an MS-8 crossover
lter’sfrequencyandslopeismakingsurethatyoursystem’ssmallspeakers
don'treceivetoomuchbass,whichcancausethesoundtheyreproducetobe
distorted and can even damage them.
For example, an 80Hz high-pass lter will remove frequencies below 80Hz from the signal
that the MS-8 sends to a smaller speaker. However, it may not completely remove those
frequencies; a 6dB per octave lter slope will still allow the speaker to receive 1/4 of the
signal’s power at 40Hz, while a 24dB/octave lter slope will allow the speaker to receive
almost no power at 40Hz and will keep the speaker from receiving too much bass. We
recommend using 24dB/octave slopes between subwoofers and midrange
speakers and between midrange speakers and tweeters.
CALIBRATION/SETUP
26