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VSeries_Sub_Manual
5/12/04
6:12 PM
Section 8 — Bass Management Theory
Bass Management
Bass management is a method for extending the bass response of small, near-field
speakers used in 5.1 surrounds sound systems (familiarly called Home Theatre sys-
tems). This is done by routing frequencies below a cutoff point to a separate sub-
woofer (Sometimes called "bass redirection" in home-theater receivers, the process
can usually be enabled by selecting "Small Speakers" from a speaker-setup menu.).
This process places a group of two-way filters in the speaker output path, typically at
80 Hz. (See Figure 1.) These filters route all sonic energy above this given frequen-
cy (e.g., 80 Hz) to the Left, Center, Right, Left Surround and Right Surround speak-
ers. In turn, the process redirects the low-frequency energy from the five full-range
channels to a single subwoofer, which also reproduces the separate LFE channel.
Bass management is used in practically every consumer home-theater system.
Therefore, audio engineers mixing for modern listeners should realize that their stu-
dio monitoring systems must be able to reproduce sufficient low frequencies so they
can avoid recording undesirable subsonic information. Without such studio monitor-
ing, it is possible to release a mix with infrasonic problems, such as plosive pops, air
conditioner rumble, traffic noise, footsteps, etc. These subsonic noises will be elimi-
nated (masked) by the natural high-pass filter effect of using near-field monitors with
a response that goes down only as low as 40 or 50 Hz. Thus, infrasonic problems
may not be recognized (heard) in the studio. Since, however, virtually all home-the-
atre systems use subwoofers with bass management; consumers will hear these
infrasonic problems at high volume levels in their home.
Bass management effectively extends the low-frequency response of near-field mon-
itors down into the 20-30 Hz range (depending on the subwoofer used). This allows
the engineer to take evasive action in the studio, such as engaging high-pass filters
on input channels and microphones, adding pop filters and suspension mounts to
microphones and correcting HVAC and other rumble problems.
Section 11— System Troubleshooting
Problem: If there is no power, check to see if...
• The power cord is plugged into both the IEC socket on the rear panel of the unit
and into the AC mains
• The AC mains voltage is matched to the operating voltage requirements (See
Changing Voltage in the Connecting the System section on page 3). If the AC
mains voltage is higher than the selected voltage it is possible that the fuse
needs to be replaced.
• The power light is illuminated on the front panel of the V8. If not, turn the power
switch OFF and check the A/C mains fuse(s). NEVER USE A LARGER AMPER
AGE FUSE THAN IS SPECIFIED! Turn the power switch back on. The power
light should illuminate.
• If the fuse blows on power-up after a fuse change, the monitor needs to be
returned to the dealer you purchased it from or to KRK for servicing.
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Problem: If you can't hear any sound...
• Repeat steps in the previous troubleshooting section above before continuing to
the next steps.
• Check to see if other audio devices using the same AC outlet are still operating.
• Make sure that:
• The audio source cable is plugged into both the source output and
the monitor input.
• The System Gain pot is turned up fully clockwise (+ 6 dB).
• The signal source (E.g. mixing console, work station, CD player, etc.) is
turned up to a level that can properly send a signal to the monitors.
• If one of the monitors is working. Exchange the audio input cable from the non-
working monitor to the working unit. This will determine whether it's really the
monitor, a faulty cable, or some other glitch in the audio chain.
• If the monitor is still not responding, it should be returned to the dealer that you
purchased it from or to KRK for servicing.
Problem: If the monitor suddenly stops working...
• Turn the monitor send down or off.
• Repeat steps in the troubleshooting sections above before continuing to the next
steps.
• Carefully check to see if the amplifier's back plate is hot! If the monitor has been
running at highest power output for an extended period of time, it could be that
the unit has become overheated and the protection circuitry has shut the system
down momentarily. The V-Series 2 subwoofers provide maximum circuitry
protection against AC power surges, amplifier overdrive, and overheating of the
amplifiers. Turn the monitor off then wait 30 minutes to allow the back plate to
cool down. Turn the power switch back on.
• Increase the volume to check for normal operation.
• If the monitor is still not responding, it should be returned to the dealer that you
purchased it from or to KRK for servicing.
Problem: The sound quality changes...
• Repeat steps in the previous troubleshooting section above before continuing to
the next steps.
• Disconnect the signal cable at the input of the monitor. With the power on, place
your ear close to each driver (tweeter/woofer) and listen for noise (i.e., a slight hiss
or hum). If there's absolutely no sound whatsoever, it could be that one or more of
the drivers (woofer or tweeter or both) is at fault. It's also possible that the
problem lies some where in the electronics.
• Play some non-distorted source material at a low volume. Carefully cover the
tweeter (to block the sound) without touching the diaphragm. Is the woofer
producing a clean sound? If there is not a clear tonal quality or any sound at all
then the woofer probably needs to be replaced.
• Cover the woofer so you can hear mostly the tweeter. Is the tweeter producing a
clear sound? If there is not a clear tonal quality or any sound at all then the
tweeter probably needs to be replaced.
• Once you have a better idea of what may be at fault then call us and speak with
someone in the service department. They will help you determine the best
solution to correct your monitors. The service department can be reached at
(805)584-5224,
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