Operation Manual

REL Acoustics ‘ST III’ User Manual
18
REL Set-Up Made Simple
RELs are not traditional subwoofers, but true sub-bass systems. A REL is designed to
augment the performance of “full range” speaker systems, to provide linear response down to
below 12 Hz (Studio III, -6 dB down at 9 Hz). Therefore, for the moment, set aside everything
you’ve been taught about subwoofers and how they are integrated into a stereo or theatre
system. RELs set-up and positioning differs from other subwoofers. A REL will take
advantage of physics and room acoustics to provide deep pressurisation as no other sub-
woofer can. It’s important that you bring to the set-up process a willingness to do things a little
differently in order to obtain these superior results. The end result of your labours will be an
utterly seamless integration of true deep bass to a sound system, regardless of the main
speaker’s low bass capability.
Two Things Before You Begin
A. It is helpful to know that you will almost always connect the REL to the input on the
rear panel labelled “Hi Level.” This connection is made using the supplied 34’ 10” (10
meters) cable, the bare leads of which connect to the speaker output terminals of the
power amplifier. The easy and foolproof connection at the REL is done with a Neutrik
Speakon connector. The purpose of connecting to the speaker output terminals is
one of the unique secrets of REL’s success. By connecting to the high level input on
the REL from the amplifier, you build forward the sonic signature of your main
system, including the tonal balance and timing cues of the entire electronics chain. In
this way, the REL is fed the exact signal that is fed to the main speakers.
B. When possible, the REL should be placed in one of the corners behind the speakers.
Remember, we are dealing with true LOW bass pressurisation with RELs, not the
mid-bass that most competitors settle for. Low bass pressurisation below 40Hz is
best derived from corner placement, where the most linear and efficient low bass can
be produced.
Basic set-up should take no more than ten to fifteen minutes to accomplish once connected.
Connecting
High-level connection, using the enclosed cable with the Neutrik Speakon connector,
is always the first choice. By connecting to the amplifier’s speaker outputs the sonic
signature of the entire amplification chain is folded into the signal for the sub, thereby
keeping timing and timbre cues consistent. In other words, the signal sent to the REL
is exactly the same signal sent to the speakers, allowing for seamless integration. This
connection can be made without affecting the performance of the amplifier because
the sub’s amplifier input impedance is 100,000 ohms. This scheme also avoids adding
any detrimental effects by not interposing any additional electronics into the
amplification chain.
• The standard high level hook up procedure is: attach the red wire to the amplifier’s
right positive speaker output terminal; attach the yellow wire to the amplifier’s left
positive speaker output terminal; attach the black wire to which ever of the amplifier’s
ground output terminals is convenient; plug the Speakon connector into the sub’s
high level input.
• For differential amplifiers using one sub, simply use the standard connecting scheme
with the exception of connecting ground to chassis ground, not to speaker output
ground, and then connecting into the high level input (Hi Input or Unbal Hi Input on
Stentor III and Studio III).
• For differential amplifiers using two subs, one for each channel: connect red to
positive; yellow to negative; and black to chassis ground; plug the Speakon into the
balanced high level input (Bal Hi Input).
Low-level connection, RCA inputs (or XLR on some models), is always an option, should
high-level connection not be possible, or in a theatre system where both high-level and low-
level connection should be used. When connecting to the low level inputs, connect a single
RCA cable to the 0dB RCA jack. Additional gain can be achieved by connecting to the +12dB
input. If you are connecting two channels of stereo output from a pre-amplifier, simply use a
high-quality y-adapter to sum the two signals together.