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S E T U P
Tips, Hints, & Suggestions
The MODEL 500 controls will allow you to make the best of virtually any installation. If you feel
uncomfortable with setting up your MODEL 500 after reading through this manual then you should
consider enlisting the help of an experienced person or contacting your dealer.
Below are some generalized rules for understanding the acoustic nature of low frequency sound
reproduction in an average residential listening room. These rules will aid in establishing the best
placement of your subwoofer and the tuning of your MODEL 500 amplifier. Experiment with the
adjustments of your MODEL 500 to determine what works best in your listening room.
Most rooms have significant resonant modes at low frequencies. The listener will experience these
resonant modes as a variation in the intensity of certain frequencies at different locations within
the room. Resonant modes are the result of reflected acoustic energy interacting within a room's
boundaries. The resonant modes can produce large errors in the frequency response and reduce
the overall enjoyment of the audio reproduction. Equalization cannot simultaneously compensate
for all locations within a room. However, physical elements within or at the room's boundaries can
effectively improve the room's behavior. Subwoofer placement also has an effect on the excitation
of the resonant modes and the way they are experienced. Contacting an expert in the field of
acoustics can be worthwhile if one finds that the low frequency reproduction in their room is
unsatisfactory or if one wants assistance in optimizing their installation.
Placing a subwoofer on the floor near a wall will increase its radiating power by as much as 2X.
Placing a subwoofer on the floor near the intersection of two walls (a corner) will increase its
radiating power by as much as 4X. Corner loading, as it is sometimes called, is an excellent way to
get bass extension and greater acoustic output from a subwoofer especially at very low frequencies.
In the same way that the subwoofer's output is augmented by a corner, the listening position can
also have a significant effect on how the bass is experienced. Sitting at a room's boundary, such
as near the back wall of a room, will significantly increase the bass level across much of the low
frequency spectrum.
Placing a subwoofer close to the listening position (less than 5ft (1.5m)) can increase the intensity
of the transients and reduce the acoustic power demands from the subwoofer in some installations.
In others, it can increase the power demands if the woofer is placed at a primary node. Placing a
subwoofer(s) close to the listening position can also create more tactile sensation.
Bass frequencies below about 80Hz are considered to be omnidirectional and tend to have no
localization. That is to say that it is difficult to determine their place of origin. For this reason,
placement of most subwoofers is not limited to the front of the room. However, in practice this
is not always the case. There are cues such as tactile and audible vibration and higher frequency
signal content that can suggest the direction of the source. For this reason it may be desirable to
locate the subwoofer(s) at the front of the room. It may also be necessary to reduce the crossover
frequency below 80Hz if one finds that the bass sounds too detached from the other sound sources.
Placing a subwoofer(s) at the back of the room is also a consideration especially if placement of
a subwoofer at the front of the room is not suitable or produces poor results. Placement directly
behind or beside the listening position can produce very good results as well as corner loading in
the back of the room. Other options include placing the subwoofer(s) on the side(s) of the room
especially when multiple woofers are used. If possible experiment with different positions. Don't
exclude the possibilities of locating your subwoofer in walls, ceilings, floors, or underneath, beside,
and behind furniture.
Symmetrically or asymmetrically locating two or more woofers in the room can be done to reduce
room mode effects and to balance the localization of the sound.
It is not necessary to direct the front of a subwoofer at the listening position.
MODEL 500 AMPLIFIER
O W N E R ' S M A N U A L
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