Perreaux SM6/P - Manual (Page 20)

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Maximising System Potential
Interconnects
and Speaker
Cables
An often-ignored area in high fidelity systems is the cabling connecting the
various components. Interconnect leads should be high quality cable with
substantial terminations. Gold plate is inherently resistant to corrosion, and an
excellent conductor. The presence of corrosion induces distortion and poor
conductivity will seriously interfere with sound quality. Terminations must plug
snugly into sockets to maintain maximum conductivity and to avoid annoying
earthing problems.
Speaker cabling is equally critical. Use only solidly constructed cable of high
purity copper or silver content. Again, gold plated terminations are
recommended, of the spade or banana plug type. Use cables of equal length and
as short as possible to maintain uniform electrical resistance at the lowest
possible level. If your amplifier is closer to one of your speakers than the other,
avoid coiling the longer lead as this can create inductance, with the potential of
reduced high frequency performance. Keep all connections clean, firm and tight.
The traditional adage that a chain is only as strong as its weakest link most
certainly applies to audio systems.
Bi-amping Bi-amping uses two similarly powered amplifiers, with exactly the same input
sensitivity so that, when the same input signal is provided to each of them, the
output level will be exactly the same. This can often be done with one power
amplifier connected to the tweeters and another to the woofers, as it spreads the
power requirement between the two amplifiers. Bi-amping can achieve greater
control, dynamics and resolution than if you try to run everything from a single
stereo amplifier.
Balanced
Interconnects
The use of the balanced signal inputs and outputs can have the effect of cleaning
up hums, buzzes, radio frequency interference (RFI) and general extraneous
rubbish that can enter an audio system. A balanced signal input system operates
on the principle of differential amplification. The positive and negative inputs
are contrasted against one another and the difference between them is amplified.
Noise entering the system is imposed equally on the positive and negative
signals and therefore will not be amplified, as no differential voltage exists.
The term used to describe the quality of the effect is called Common Mode
Rejection Ratio (CMRR). CMRR is an equipment and system specification,
which describes how well unwanted common mode signals are counteracted
when used in conjunction with balanced connections. CMRR action prevents
the egress and build up of extraneous hum; buzzes and RFI when analogue
signals are conveyed down cables and between equipment powered from
different locations and is widely used in professional audio applications.