REL Acoustics Storm - Manual (Page 8)

8
POSITIONING STORM WITHIN YOUR ROOM
Ideally, STORM should be positioned mid-way between your main
speakers but pushed back as far against the wall as possible. This will
help with sound integration between the two different sources. It seems
that we humans prefer to listen to plane waves rather than spherical.
Waves become planar as they travel away from the source, just like waves
expanding from a stone dropped in a pond. The further the waves travel,
the more planer they become. Perhaps it is because we tend to hear plane
waves at a concert or in a Cathedral or any large building, but whatever the
reason a more distant source, particularly of low frequencies, appears
more interesting. It follows that the very worst place to position a sub-
woofer would be just behind the listening chair. Because of the Haas effect
(precedence effect of two similar frequencies) we would find such a position
very fatiguing if not downright offensive. Fortunately, in the preferred choice
of position even with surround sound, very acceptable results can be
obtained with a single very low frequency source. Note that these
comments apply here because all REL sub-woofers are integrated into the
main system by means of the ABC. Thus only very low bass is being
generated by the sub-woofer. Such very low frequencies are truly omni-
directional. Unfortunately, with many sub-woofers which cross-over up
around 100 Hz, there will be problems because the crossover has a roll-off,
it is not a brick wall! Therefore there will be some radiation from such sub-
woofers even at 200 to 300 Hz. At these frequencies we can detect their
source.
If the preferred position is not possible, try moving the sub-woofer to one
side or the other. Possibly for a Classical music lover the right hand side
may be preferred because the double basses are generally on that side.
(This is being very purist of course).
Note that a subtle effect is far more effective at improving imaging and
depth than an up front, overblown bass. Tests appear to show that when
the bass is made too prominent, the subtle effect of stage depth
improvements are completely masked. This may mean a much lower
setting of both the filter controls and the gain than might at first have been
thought necessary. It is necessary to emphasise that manufacturer's
claims for their speaker’s in-room low frequency responses should be
treated with care. It is far better to trust the results you are getting in the
room with your own ears rather than someone else's in their room.
When the final position has been settled, it is better to shorten the signal
lead to the ideal length, rather than coiling it up. Although most modern
amplifiers are usually exceptionally load tolerant, it is foolish to tempt fate
by inviting trouble with a coiled up speaker lead (which is what it is in
effect). A shorter lead also minimises the risk of RFI (Radio Frequency
Interference). This is more likely than instability today with so many CB
enthusiasts around. STORM has internal circuitry designed to reduce the
possibility of RFI to almost zero. Unfortunately, many power amps do not.
The pick up on the speaker leads (any speaker leads, not just STORM's )
can be fed back on the amplifier's internal negative feedback circuit to