8
OWNER’S MANUAL
P-1200
SETUP
Placement
There are a number of factors, both acoustic and aesthetic, that ultimately determine the best loudspeaker
placement. Subwoofers, by nature of the frequency range in which they operate, have their own challenges, which
have as much to do with the room acoustics and listening position as anything else. In many cases the designated
location may already be chosen and the only available adjustments may be the subwoofer’s controls. The P-1200
controls will allow you to make the best of virtually any installation. If you feel uncomfortable with setting up your
P-1200 after reading through this section 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 the placement and tuning of your P-1200 subwoofer. If
possible, experiment with the placement of your P-1200 to determine what works best in your listening room.
»■Most rooms have signicant 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 reected 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 eld of acoustics can be worthwhile if one nds that the low frequency
reproduction in their room is unsatisfactory or if one wants assistance in optimizing their installation.
»■Placing a subwoofer on the oor near a wall will increase its radiating power by as much as 2X. Placing a
subwoofer on the oor 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
signicant effect on how the bass is experienced. Sitting at a room’s boundary, such as near the back wall of a
room, will signicantly 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 difcult 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 nds 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, oors, 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.
