Harman REVEL CONCERTA B10, Service Manual

SUB B10 Service Manual     

6 OF 32 

SUBWOOFER PLACEMENT

Below 300Hz, loudspeaker and listener locations have 
a profound impact on the way sound is reproduced. 
All rooms have “standing waves,” by which certain 
frequencies are emphasized or diminished. Their 
complex patterns can combine to introduce 
tremendous sound coloration at low frequencies.  

The Concerta2 B10's Equalization controls can help 
to compensate for these effects, but no electronic 
system alone can fully compensate for the dramatic 
effects of room acoustics. Every room has locations 
where “nulls” at specific frequencies occur. These 
cancellations of the sound are like “black holes,” 
which no amount of equalization can fill. The best 
results are always achieved through careful 
placement of both the loudspeakers and the listening 
position. Preferable placement can be determined 
through the use of computer modeling programs, or 
by trial-and-error measurements. For optimal results, 
find the best loudspeaker and listener locations first, 
then use the B10 Equalization controls for fine-tune 
adjustments.  

To help determine good locations for the subwoofer(s) 
and the listener(s), it is recommended that you make 
high-resolution in-room response measurements. 
Your authorized Revel dealer can make the 
appropriate measurements, using suitable equipment 
to ensure optimal results.  

Note: Many sound-measurement devices are not 
accurate enough to properly measure low-frequency 
performance in a listening room, since room 
boundaries can often cause modes (standing waves) 
with very narrow-band peaks and dips. Check with 
your authorized Revel dealer to confirm that your 
measurement equipment is suitable for accurate, 
high-resolution measurements

.

SUBWOOFER PLACEMENT CONSIDERATIONS 

When using subwoofers within the limited confines of a 
typical home theater room, the reflections, standing 
waves and absorptions generated within the room will 
create peaks and dips in the bass response that can vary 
greatly depending on where the listeners are located in 
the room 

– a listener seated in one location may hear an 

overabundance of bass created by a response peak at 
that location, while another listener only a few feet away 
may hear a considerable lack of bass created by a 
response dip at that location.  

The subwoofers' locations within the room (along with the 
room's dimensions) also have a profound effect on the 
creation of these bass response peaks and dips. Careful 
subwoofer placement alone cannot compensate for all 
bass response peaks and dips throughout a room, but 
careful subwoofer placement can eliminate or 
significantly reduce the largest response dips.  

It is important to reduce response dips throughout the 
room as much as possible via proper subwoofer 
placement because equalization cannot be used to 
compensate for large response dips. For example, using 
equalization in an attempt to restore a 13dB response dip 
requires that the subwoofer amplifier delivers twenty 
times the power at that frequency. This can quickly 
overdrive the subwoofer amplifier into clipping, which will 
significantly degrade audio quality.  

In almost any room, placing the subwoofers in corners 
will produce the fewest large bass response dips and will 
also produce the most large bass response peaks.  

We strongly recommend that you install multiple 
subwoofers regardless of the room's size. Installing a 
single subwoofer will result in the least consistent bass 
performance throughout the room. Using multiple 
subwoofers can cancel some room modes at the various 
listening locations, resulting in much more consistent low 
frequency sound quality throughout the listening area. 
Additionally, it is often impossible to locate a single 
subwoofer such that large response dips, which cannot 
usually be corrected via equalization, are not present.  

The use of two or more properly placed subwoofers can 
almost always eliminate such dips in response.