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Placement and Operation

Generally speaking, the best location for your new subwoofer is the front

of the room, close to a corner (Figure 5). Every room has its own unique

sound characteristics, and flexibility in the exact placement of the sub-

woofer is always desirable. The closer the subwoofer is placed to a wall

and especially a corner, the more and deeper the bass response you will

hear. Because of an acoustic phenomenon known as "room gain," a well-

designed wubwoofer playing in an acoustically-favorable room may well

deliver low bass deeper than its rated response. However, in some rooms,

corner placement can produce a "one note" boomy effect. Under such

circumstances the subwoofer may work better away from the corner.

Experiment to find the best position in your room.

HELPFUL HINT: A particularly useful experiment is to place the

subwoofer right at the prime listening position (move your couch

or chair out of the way and put the sub in its place). Then play

something with good bass content (preferably music), and walk

around the room, listening to the subwoofer's response. When

you locate an area that has an ample amount of well defined bass,

you've found a good place to locate the sub.

Figure 5

Typical arrangement for a single subwoofer in a home theater.

1. Start here

System Set Up

When setting up a complete home theater we strongly recommend that

you use a Sound Pressure Level meter. Radio Shack® has a good one

that is very affordably priced (approximately $50). To use this meter,

turn on your system, put the Processor/Receiver in the Test Mode and

set its main volume control to 0dB. Sit in the prime listening position, set

the SPL meter to the 70dB scale, Slow Response, and C Weighting. Now,

holding the meter pointed up and in front of you, let the system cycle its

test tone from speaker to speaker and set every speaker to 75dB using

the individual level settings in the Processor/Receiver. As tempting as

it may be to set the subwoofer and/or surround speakers higher than

75dB, listen again after calibration and see if you can acclimate to these

levels. Try watching several different movies and keep in mind that the

goal is to have a system that sounds like you're actually "in the movie. "

When using the latest discrete digital electronics which include internal

level controls for all channels, we recommend setting the front mounted

Level Control to its Preset position and using the Processor/Receiver's

built-in subwoofer level control.

If you decide not to use an SPL meter try to set all the speaker levels the

same using the Test Tones. Of course, this will be much more difficult

without the meter, especially for the subwoofer.

Figure 6

Front Panel Variable Level Control located behind the removable grille

Subwoofer Tuning Without an SPL Meter

or Test Tones

Start your listening with the subwoofer Crossover control set at around

100Hz or in the Bypass position if you're using a THX Certified proces-

sor or one with a built-in crossover. Set the phase switch to Normal, and

2. Move to

the front panel variable level control (Figure 6) to the Preset position.

corner for

more bass

Play some music that you know has good bass content, and turn the

level control up until you just start to hear the subwoofer working. Now,

from your normal listening position, determine whether the subwoofer

is playing loudly enough and filling in the bass frequencies of the music

evenly. If adjustment is necessary, start by changing the setting in the

processor or with the sub's level control if your processor lacks a sub-

3. Move away

woofer level adjustment.

from wall for

less bass

If the bass seems too ponderous, boomy, or heavy, no matter how you

set the level, try moving the subwoofer away from the wall/corner. If

the bass seems too thin, try moving the subwoofer closer to the wall/

corner. Small differences in positioning can make big differences in bass

response. When you find a position that seems to work well, try switch-

ing the phase switch between its two settings, listening particularly to the

transition from the subwoofer to the satellites.

How Much is Enough?

Sometimes people prefer more bass impact for movies. Using the movie

setting for music can result in overpowering and unnatural bass repro-

duction. You may wish to determine both a video level and an audio level

if you find yourself falling into this camp. Remember however, the most

common error people make when setting up their system is to play the

subwoofer (and surrounds) too loudly. Of course, the Home Theater

Police will not arrest you for this act. But should you desire the most

accurate overall reproduction, a well balanced sound from deepest bass

to highest treble is the best way to get it. Have fun. Experiment. Enjoy.

Model 224, 334 and 444 SB Powered Subwoofer

Recess and indicator for

level adjustment

Preset Position

Indicator LED