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more interesting. It follows that the very worst place to position a sub-woofer
would be 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 omnidirectional.
Unfortunately, with many sub-woofers which cross-over up around 100Hz, 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). STENTOR 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 STENTOR’S)
can be fed back on the amplifier’s internal negative feedback circuit to provoke
trouble through the main speakers. Where this occurs, shortening the signal leads
will usually effect the cure.
RUNNING-IN
Care taken over running- in will be rewarded by many years of pleasurable use.
Both the electronics and the drive units will benefit from an initial period of carefully
controlled use. During this period, permanent damage can be sustained by
running the unit at too high a volume setting. On the other hand, by taking a little
care over this initial period, about 24 hours of actual use, a longer life with a higher
potential eventual performance is assured.
