Limiter settings
The Rated Power specifications in
Section A1.2
show that the maximum allowable
power dissipation depends on the driver/s being driven. This is because big low and
low-mid drivers are capable of dissipating more heat than smaller high-mid and high
drivers.
Normal music and speech signals, however, are a combination of relatively low
general power levels with a multiplicity of short term transients. These short term
transients do not significantly heat the driver voice coils so it is quite permissible to
use the same 250-300W into 8
Ω
(500-600W into 4
Ω
) power amplifiers for all
sections of the W8
as long as they are sourced by a correctly set controller.
When choosing power amplifiers, do not be tempted to exceed the 250-300W into 8
Ω
(500-600W into 4
Ω
) power rating unless the amplifier's power rails are well
regulated (see
Section A1.6
) - even with properly set controllers in place.
Although Martin Audio drivers are mechanically designed to survive normal road use
and the occasional operator error, over-powered or bridged amplifiers can cause over-
excursions that stress and age drivers. The best way to get the clean, relaxed sound of
an overpowered amplifier is to choose an amplifier with plenty of current reserve - ie
an amplifier with good 2
Ω
specification - and avoid running more than two cabinets
in parallel.
To ensure transparent limiter operation without obvious distortion or pumping, the
DX1 limiter attack and release times are factory preset to be inversely proportional to
each band's high pass frequency as follows:
High pass filter range Attack time Release time
>31Hz 45mS 720mS
31Hz - 63Hz 16mS 256mS
63Hz - 125Hz 8mS 128mS
125Hz - 250Hz 4mS 64mS
250Hz - 500Hz 2mS 32mS
500Hz - 1KHz 1mS 16mS
1KHz - 2KHz 0.5mS 8mS
2KHz - 22KHz 0.3mS 4mS
These attack times will allow the power amplifiers to clip momentarily but not for
long enough to be obvious to listeners or cause driver overheating. It is quite normal
to see amplifier clip indicators on the odd programme peak but continuous clipping
would indicate a cable short circuit, wrong controller settings, excessive power
amplifier gain or low mains voltage.
All material © 2007. Martin Audio Ltd. Subject to change without notice.
Summary of Contents for Wavefront W8CT
Page 130: ...All material 2007 Martin Audio Ltd Subject to change without notice...
Page 138: ...W8LC outline dimensions All material 2007 Martin Audio Ltd Subject to change without notice...
Page 139: ...W8LM outline dimensions All material 2007 Martin Audio Ltd Subject to change without notice...
Page 140: ...W8LX outline dimensions All material 2007 Martin Audio Ltd Subject to change without notice...
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