REL Acoustics No. 25, Руководство по эксплуатации

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Parametric Equalizers
It is not recommended that average users attempt to use the parametric equalizers included in No.25 as
miss-application of these filters can produce results detrimental to the average room. No.25 provides for
2 parametric filters that may be used to cure certain room acoustics challenges. Use of these should very
much be seen as optional, and engaging either requires physically turning on the toggle switch on the rear
panel that supplies power to BOTH parametric EQ’s. These 2 filters provide for up to 6 db of boost or cut at
any frequency between 20 and 90Hz.
Attempting to use any filter to produce perfectly flat response is a fool’s errand. Best results will be achieved
by gentle application of gain or cut functions with +/- 3 dB or less to be considered a normal operating range.
Application: Most rooms produce room gain--higher output--in the upper bass region, typically in the 70-80Hz
region. Generally speaking, most rooms have reduced gain in the low bass regions, somewhere in the mid-20’s
to mid-30’s area. For this reason, we provide you the ability to produce noteworthy improvements in both
trouble regions by gently cutting the higher bass frequencies and gently boosting the lower region.
To share our own experiences; while developing this filter set in our own studios, we found +2 dB at 25Hz
and -2 dB at 43Hz (crossover frequency was set to 34Hz) produced evenness of output and the overall result
was found to be much more consistent across the entire bass range. More impressive in long term listening
were improvements in clarity extending all the way up into the upper midrange. This is clearly the result of
a slight reduction in mid bass overhang that the 43Hz cut function provided.
Resist the temptation to try to affect massive swings in output in certain very narrow frequency ranges
(+6 dB at 34Hz and -6 dB at 38Hz) as this will almost certainly prove to be counterproductive.
Stereo Set-Up of REL No.25
Stereo Sub-Bass is advised for the fastest, clearest, deep bass—not for more output. Conventional wisdom
has it that stereo subs results in b3 and +6 db additional output depending upon positioning. In and
of itself, this is of only passing interest in most instances since even a single No.25 is capable of profound
output. What then, is the point to adding a second stereo sub bass No.25?
In a word, clarity. Clarity that permits “seeing” back into the farthest reaches of the sound stage. Clarity that
illuminates all dimensions of the musicians and the space that they inhabit equally and enhances the natural
reality of a great full range system, as only RELs can. Stereo No.25s and vertical stacks, often referred to as
6-Packs, produce clarity, transparency, speed and low level detail NOT just in the bass but throughout the
entire spectrum of music.