Tannoy Proto-J Reference Manual page 5

2.3 Connecting your speakers
The types of cable used to connect the speakers to the power amplifier will marginally affect the
sound. The cross-sectional area of the cable should be large enough so as not to affect the damping
factor, generally a cable with a cross-sectional area of 2.5 mm_, or greater is recommended.
The lower the resistance of the cable between the amplifier and the speakers, the better the damp-
ing factor acting on the speaker. This has been covered in every audio magazine that has ever been
written about speakers, so we won't beat it to death here. You don't need to buy speaker wire that
costs as much as your speakers to get some benefit from wire size, select a finely stranded speaker
cable, and dress the cable ends to prevent "hairs" or stray conductors from shorting across the ter-
minals. If your amplifier will not directly accept that size of cable, you can trim down the cable size at
the amplifier end. Ensure that the binding post retaining nuts are screwed down firmly without strip-
ping or over tightening them.
2.4 Observing polarity
You already know about connecting the positive terminal on the amplifier to the positive terminal on
the speakers, and ensuring that both channels are "in phase" by checking to ensure that there's
more bass with both speakers on and not less bass. Absolute polarity is a bit trickier to confirm.
Absolute polarity is the maintenance of a positive pressure wave from the microphone capsule to the
listening room. A kick drum, for instance, has the drum skin whacked by the foot pedal, and it push-
es the air, which pushes the microphone diaphragm, which goes through the electronics and should
eventually come out of the speakers as a positive pressure wave, which should have the speaker
cones moving towards you, just like the drum skin. It turns out that you can't trust a conventional
recorded source to test this because there is no way to confirm that absolute polarity was main-
tained, it can even change from track to track. This isn't a trivial thing, especially when you're using
a true stereo microphone setup, or trying to accurately place things in your mix. This is something
that should be rigorously checked with every microphone and every signal line in a studio, but the
first step would be to use the kickdrum test described above with a few microphones. If you don't
believe it can make a difference, set up a little test using a mix you know and flip the polarity of both
channels at the same time, while listening to the same program...imaging, vague imaging, imaging,
vague imaging. Believe it.
2.5 Power Amplifiers
The power amplifier should be reasonably well matched in power to the power rating of the speak-
ers (see specifications). The use of a powerful amplifier (i.e. in excess of the recommended figure)
provides headroom, which is useful especially for highly dynamic programme materials.
Due of the high peak power handling of Tannoy monitors, responsible use of even more powerful
amplifiers should not represent a danger to the speakers if the amplifiers are not overdriven. Now,
just because you have a Ferrari, it doesn't mean to say you can drive it at the red line all of the time,
it will eventually blow up. Same thing goes here, just because the speakers will handle a large
amplifier, it doesn't mean that you can run them flat out constantly without eventually blowing some-
thing up.