7
clipping? Volume knob placement does NOT indicate much. Some receivers reach full output well
before 12:00 on the dial. Use of the loudness button, bass boost and treble boost can all drive the
receiver and then the speaker into distortion at fairly low levels.
•
Many of today’s recordings including DVDs and CDs contain extremely powerful low bass. This low
bass can easily drive woofers into over-excursion or cause the amplifier to run out of power and clip,
potentially causing damage.
•
Our systems are designed for accurate sound. Our rate of damage or failure is extremely low. We could
make the systems even more rugged if we were to compromise sound quality. Moving the crossover
points upward would protect midrange and tweeters better while causing a loss of detail, clarity and
imaging. The cabinets and woofers could be designed to roll-off the low bass which would protect the
woofers but this would lessen the low bass response and clarity. Protection devices could be added in
the crossovers which would shut the system down when damaging power or distortion was present but
every one of these devices audibly degrades the sound!
You can protect your speakers by following a couple of very simple guidelines:
•
If it sounds distorted, turn it down. Distortion is a warning sign that should not be ignored.
•
Don’t use tone controls or equalizers if possible. IF you must use them, monitor the system carefully.
•
Beware the party damage epidemic. Speakers are more often damaged during parties. All those bodies
soak up sound, requiring more output to sound as loud, bass and treble controls are sometimes
cranked up and nobody is listening for distortion.
•
Watch out for energy put out by the amplifier in the range below 20Hz which is not music. Examples
include record warps, DC current and subsonic noise in the recording. These signals can take up a lot
of amplifier power which means the amplifier runs out of steam very early. These signals can also
overload a speaker even though you can’t hear them. If you have ever watched a cone “flap” you know
just what we mean.
•
Vented speakers are particularly sensitive to signals below their F
3
point. The average vented box that
can handle 100 watts at 50Hz may handle less than 5-10 watts below 25Hz! Sealed box speakers with
low Qts. numbers have a similar characteristic although not as severe. Low organ or synthesizer notes
may cause an otherwise excellent woofer to bottom out at relatively low input levels.
•
Keep an eye out for excessive cone movement that is not producing music. Find the source of the
problem and eliminate it, play at low levels, or use a subsonic filter (usually in your pre-amp) which will
filter out energy below 20Hz. However, use of a subsonic filter may take away from the naturalness of
bass sounds. We don’t recommend it for extremely critical listening.
In over thirty years of daily evaluation of all types of speakers on everything from 10 to 1000 watts
with all kinds of music, we have never damaged a driver without first hearing audible distortion. If it sounds
bad, turn it down and you will never damage a speaker. Refer to the break-in recommendations at the end
of this manual.
Hookup
Your Sapphire XLs are furnished with five-way type binding posts. You may choose to utilize spade
lugs, banana jacks, pins, or bare wire. It is important that the positive and negative leads do not touch. If
you use bare leads, be sure to twist them tightly and insert through holes in such a manner that they do not
fray or short out against each other. Good connections are important, so make sure any ends are tightly
crimped and preferably soldered to the wire ends. Speaker wires should be kept as short as possible,
(long wires add excessive resistance and color the sound.) The use of quality wire is recommended. ACI
stocks and recommends DH-Labs Silver Sonic T-14 and Q-10 cable.
Make sure you hookup the speakers in the correct polarity. The red (positive) terminal on your amp
should hook up to the red binding post, and the black terminal should be connected to the black binding
post. Keep this the same for both speakers in a stereo pair. A way to check the correct polarity is to play
music with a lot of bass. The correct hookup will yield the greatest amount of bass.
