How Many Subwoofers?
For most applications a single PSW800’s is appropriate. However, in large rooms, high performance listening rooms or in home theaters, an array of two or more PSW800 will deliver astounding results. Unlike other subwoofer systems, a Niles Subwoofer Array is concealed. Consider the distance between the subwoofer(s) and the listener, the size of the amplifier, and the desired quality and volume of sound when deciding how many PSW800s to install in your home.
| Decibels and Power |
65dB | Conversation at three feet. |
75dB | Sewing Machine at three feet. |
85dB | Vacuum Cleaner at 10 feet. |
95dB | Subway Train entering a station |
| at 20 feet. |
3dB | The smallest difference in volume |
| the human ear can easily detect. |
10dB | Perceived as twice as much loud- |
| ness if it is an increase (half as |
| much if it is a decrease). |
Any speaker requires twice as much amplifier power to increase 3dB and ten times as much power to increase 10dB.
Comparison of 1, 2 or 4 Subwoofers
16’ x 18’ x 8’ Room @ 12’
| 25 Watts | 100 Watts |
1 Sub | 95dB | 101dB |
2 Subs | 100dB | 106dB |
VLSA of 4 Subs | 103dB | 109dB |
2 x Watts = 3dB Increase in Volume.
2 x Subs = 3dB Increase in Volume.
2 x Subs = 1/2 the subwoofer excursion for the same volume.
If you double the distance from the sub- woofer to the primary listening position you decrease the volume by 4 to 6dB.
Single Stereo Subwoofer
One PSW800 can produce the bass sound from both the left and the right channels because of its unique dual voice coil design. One voice coil powers the left chan- nel and the other powers the right channel. A stereo crossover divides the signal and fil- ters it according to the settings of the switch- es on the front panel. A single stereo sub- woofer is compatible with any 4 ohm stable amplifier. Eight ohm stable amplifiers may be used with a Niles IM volume control (see Impedance section on Page 7)
Dual Subwoofer Systems
Using two PSW800 subwoofers in a sys- tem raises the maximum attainable volume of the system by 3dB. Additionally, at lower volumes, excursion — and therefore distortion levels — are reduced. In a large room, or a home theater system, the effect on bass quality is extremely desirable. Another 2dB increase is possible if the voice coils of each are PSW800 paralleled. This requires a
VLSA Installations
A Very Large Subwoofer Array (VLSA) installation lowers the amount of excur- sion required to achieve a high sound pressure level. Lowering excursion dra- matically improves the quality of the sound. VLSA installations are most appro- priate when the listener appreciates detail and bass extension, but must have a con- cealed installation. A VLSA of four sub- woofers must have a
How Many Subwoofers?
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