REL Acoustics Strata 5 - Manual (Page 15)

REL Acoustics ST 5 User Manual
15
Trying to ignore all other music in the cut, listen for the bass drum and its effect on the
listening room.
1. Phase Orientation: Once in the corner we need to adjust for phase. This may be the
single most critical step, and because it really is quite simple, it is often over looked
by even the most experienced audiophiles. The right phase is whichever position is
the loudest or fullest. While playing music with true low bass, adjust the crossover to
a point where the sub and the speaker are sure to share frequencies (40Hz for big
speakers or 60Hz for smaller speakers). At this point turn the gain so that both sub
and speaker are roughly equal in volume and then, using the “Phase” button on the
remote control, change from 0 to 180 degrees (this shows as 0 and 18 in the display).
Select the option that sounds loudest or fullest from the listening position. At this
setting, the sub-bass system is working in harmony with your main speakers,
reinforcing bass, and not cancelling it. Don’t be surprised if the chosen position
shows as 180 degrees “out” of phase. Within your room/system it is IN phase.
Alternatively the phase can be changed using the control knob on the front of the
cabinet. Although perfectly feasible, the remote is the preferred method as the
assessment can be done from the usual listening position and is the more accurate
way of achieving the best result.
2. Room Orientation: Next, if space allows, try two different orientations of the woofer
relative to the wall. First, while playing the set-up cut, place the REL with the
connection panel parallel with the rear wall. Second, place the REL with the
connection panel parallel with the sidewall. As with phase, the orientation which
yields the most output is the best position for that room. This process simply positions
the driver to most efficiently drive the room. In some instances there may be little
difference, at which point aesthetic concerns may override performance concerns.
3. Placement: The next step is to determine precisely how far out from the corner of the
room the sub should be placed to achieve the most efficient output, as well as the
lowest frequency extension. With the sub fully into the corner and continuing to play
the music, slowly pull the sub from the corner on the diagonal, equidistant from both
side and rear walls. Do this a couple of centimetres (an inch) at a time. At a certain
point (sometimes a matter of only a few centimetres, in rare cases up to 25
centimetres or more) the sub will audibly go lower, play louder, and if it truly locks on
to the room and is fully pressurising it, the air around the sub will seem to be
energised, stop right there! This is the correct position for the sub.
Crossover and gain settings
The last stage of the set up is crossover and gain. You will require an acoustically recorded
track preferably with bass instruments and vocal. What we are looking for here is a seamless
crossover and integration between your main speakers and the sub-bass system. Firstly you
will need to set a rough volume level. To do this leave the crossover where it is and simply
play the system varying the volume until you have a happy medium between the speakers
and sub, the sub will sound obvious still but this is just the start.
Next reduce the frequency to minimum (16Hz). Using the same track, gently increase the
frequency 1 Hz at a time. What you are listening for is the point where the sub begins to
sound obvious within the system (usually somewhere between 20Hz and 33Hz with most
loudspeakers). Once you find the point where you can hear the sub over the response of the
speakers reduce the setting by 1 to 3 Hz This is not an exact science, but what we want is the
sub to be invisible within the system sonically. In short we increase the REL until you can
hear it and then reduce until you cannot.
Finally adjust the volume to taste. This generally will be by 1 or 2 positions. And that’s it. All
that’s left is to open a good bottle of wine, relax and enjoy.