Advanced Operations - VocoPro SUB-1500 Owner's Manual

Advanced Operations

Adjusting the Crossover Setting
The SUB-1500's built-in crossover creates an allowable frequency band available to subwoofer output. The
available range is from 40Hz to 120Hz. If you would like the subwoofer to only output extremely low frequencies,
you would want to select a lower frequency setting i.e. 40Hz. If you would like the subwoofer to output to include
some higher frequencies as well as low frequencies, you would want to select a higher frequency setting i.e.
80Hz or 120Hz.
NOTE: The crossover setting does not affect the any speakers that may be connected to the HI-
LEVEL IN/OUT speaker jacks.
Crossover and Phase
Using the Phase Switch
Depending on the 'absolute' phase of your primary speakers, and relative distance of the subwoofer and primary
speakers to the listening position, the bass in the crossover region may be smoother if you reverse the phase of
the subwoofer relative to the main speakers. Try flipping the phase switch to determine which way sounds more
bass heavy. The more bass-heavy position is the setting where the output of the subwoofer and the main
speakers are most in phase. Play program materials with bass in the crossover region such as music containing
bass drums, double basses, bass guitar, etc. to determine the correct setting.
Regarding Phase
The easiest way to understand what speaker phase listening to how they sound different. The difference is
essentially this: a subwoofer in phase produces a rich and full-toned sound, opposed to the hollow and thin sound
produced from a subwoofer out of phase. The best test signal is octave-band filtered pink noise, preferably
centered to 80 Hz. If not available, use source audio of your choice. You will want to have a person with you to
help with testing as it makes things much easier.
First, have one person sitting close to the SUB-1500 making the adjustments/connections and the other person
in the target listening area. Have the person making the adjustments play the audio, while moving the PHASE
switch from 0 to 180. The listener should be listening for the most full-toned and rich sound. When that is
achieved, correct phase has been attained. You may need to adjust the volume level of the SUB-1500 compared
to the main system when correct phase has been attained. This is only done once as the relative phase between
them is not affected when the relative level is changed, so there is no need to go back and check phasing again.
So, again, when the phasing is right, all you need to do is to adjust the SUB-1500 volume level for adjustments.
One thing to remember is, if you move the main speakers considerable farther, in relation to the SUB-1500, the
phasing may need to be rechecked.
Movies Vs. Audio Music
If you listen to movies with your new set-up, you may find that the bass is a little "light" and doesn't deliver the
impact you expect. No problem-just turn up the subwoofer volume until you are happy. Mark the volume settings
that are best for music and movies and readjust as you switch sources. If that's too inconvenient, choose a mid-
point level that gives you the best balance of music and movie performance. But keep in mind that filmmakers use
bass effects as "punctuation." Bass shouldn't be a continuous drone.
16
CROSSOVER
Lower
Higher/Tighter
Bass Mid-Bass
40 Hz 160
0° PHASE 180°
In Phase
Out of
Phase