Avalon Acoustics AVALON SYMBOL Subwoofer And Center Channel - Manual (Page 8)

8
4 Low Frequency Fine Tuning
The Symbol Subwoofer will produce prodigious quantities of low frequency energy with
accurate phase and transient response. Any thickness or overhang in the low frequency
presentation will be easily discernable and is the direct result of improper setup. The
following guidelines should be regarded as a sound starting point; those who have
extensive experience in sophisticated low frequency tuning may improvise beyond these
rules of thumb.
Placement
For best phase alignment the Center/Subwoofer combination should be at the same
plane as the Symbol Satellites. Since this is the case, the Subwoofer will optimally be
placed a few feet from the wall on which the video will be displayed, centered from left
to right between the Symbol Satellites. Any deviation from this configuration should be
re-aligned through compensation within your surround sound processor. Most processors
will have easily adjustable “distance to listener” parameters. Once a final position has
been determined, the included spikes should be installed, leveled and locked in place
with the supplied spike nut.
Any low frequency acoustic transducer will produce non-uniform loading when in close
proximity to a boundary layer, such as a wall. Full output at low frequencies and
accurate transient response will exacerbate this effect. For this reason it is strongly
recommended that a DAAD4 acoustic device (more information is available at
www.acusticaapplicata.com ), be placed between the Subwoofer and wall horizontally
on the floor. Absorption of this energy buildup will reveal much of the true transient
characteristics of the system.
Surround Sound Processor Tuning
Most sophisticated SSP chipsets allow flexible bass management. Usually flexible
crossover points between sub and satellites are matched with second order filter slopes.
In such cases the crossover point should be set at approximately 60 Hz (+/- 5 Hz), with
both the Subwoofer and Symbol satellites being actively crossed. The Symbol Subwoofer
should ALWAYS be set to the HIFI MODE under these circumstances. Overall satellite to
Subwoofer volume balance should then be adjusted for optimal results. Usually the
appropriate Subwoofer gain setting will fall between 65 and 70 on the digital display.
Matching the “speed” between satellites and Subwoofer is critical. Miniscule changes in
Subwoofer gain will result in significant differences in overall presentation, and should be
fine tuned through SSP subwoofer gain settings.
Only when any thickness or overhang has been eliminated in the 60 Hz-120 Hz region by
careful gain adjustment, will the system perform as designed.