T
echnical
The Serie R models use an unusual method of bass loading. It is designed to operate below normal system resonance.
This has been achieved without the normal form of bass boost or electronic equalization. Instead of a constantly
i
ncreasing bass equalization response, we simply ensure there is sufficient amplifier gain to drive the speaker unit
to its maximum excursion level at whatever the designated lowest operating frequency is, and then cut the bass at
a controlled rate of 12 dB per octave above this frequency. Although this may at first seem identical to boosting the
bass, it is actually quite different and ensures that the timing of transients is far improved compared to the usual bass
equalization used. Bass will sound cleaner and faster.
The amplifier is fully DC coupled to avoid phase shifts and compromises in its low-end performance. It is inherently
stable and will retain its characteristics over very long periods of time – important in a unit designed for an exceptionally
long working life. These amplifiers are designed to withstand reasonable abuse and overloads. If in doubt, please
contact your dealer.
We believe that the importance of the electronics, cabinet and drivers being designed to work in harmony is paramount.
This belief allows the Serie R to achieve the highest possible level of fidelity.
Overload Protection
All REL Sub-Bass Systems are designed as true sub bass speakers. They are designed to reproduce those exceptionally
deep notes that are felt rather than heard. This it will attempt to do at whatever volume level you set. If set too high no damage
should result because the built-in electronics will limit the cone movement. This electronic control is called Set-Safe™.
It constantly and instantaneously monitors the output from the power amplifier and is totally transparent in operation
until required. This means it has absolutely no effect on the sound quality of your REL until an overload is detected.
Ordinarily an overload would cause the power amplifier to go into clipping with resultant loss of control over the drive
unit. This can cause drive unit damage, and always sounds nasty. Set-Safe™ detects the point of incipient clipping
and gently soft clips the waveform of the signal to ensure actual clipping does not occur.
This is a necessarily simplified description of what actually happens, but in effect, Set-Safe controls the amplifier and
ensures there is minimum risk of amplifier and driver damage caused by over-driving.
A thermal overload device is fitted to all R-Series Sub-Bass Systems. If the unit is deliberately overdriven this device
will sense the temperature rise and cut the output; recovery time is approximately five minutes. If this happens, it is
a warning that the unit is being overdriven and the volume level control should be reduced to a safe level.
Although everything possible has been done to minimize risk of thermal overload failure, there can be no defense
against those individuals who deliberately abuse the device. Such damage is NOT covered by warranty. Please
remember your REL is there to supplement your main system, not overwhelm it!
Power Saving Efficiency
All REL Sub-Bass Systems are designed for maximum power efficiency, both when passing a signal through to its
resultant output sound into the room and also when silent.
REL circuitry is designed for “power starvation” operation under no signal conditions. This means that immediately
when there is a gap in the signal the REL is instantly at maximum power saving efficiency, yet remains at maximum
readiness to respond immediately to a sudden transient signal, such as an explosion in a movie, even after a long
quiet period and regardless of level.
This compares to some “auto power on/off systems” which remain powered up for a set period of no-signal condition
(up to 10-15 minutes) and which need to power-up on receipt of a sudden transient, thus failing to catch the start of
that transient. There is also the possibility of the unit remaining inoperative during listening sessions where the overall
volume is low.
It is not necessary to switch off between listening sessions – it will not significantly shorten its life by leaving it
switched on. On the other hand, it will not harm sound quality if it is always switched off. The power consumption in
the quiescent (no signal) state is negligible.
It is perfectly safe under all normal domestic circumstances as it is fully protected by internal fuses and an external
mains fuse in the fuse holder of the mains input socket, with a spare inside this holder.
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