Martin Audio W8L Longbow Application Manual page 129

Can I parallel drive W8LM cabinets?
Yes. In normal systems up to four W8LM cabinets are paralleled at the loudspeaker
column using short link cables. All W8LM sections are 12 ohms. Each cable drives
up to four speaker loads so cables must be rated for 3 ohms. See cable
recommendations later.
How many amplifiers do I need to drive a typical
W8LM system?
It depends whether you drive your W8LMs bi-amped or passive (determined by a
switch on the rear of the W8LM). Bi-amped mode provides a slightly smoother
mid- frequency response and greater mid-band headroom but uses more power
amplifiers.
Bi-amped
1 power amplifier for 4 bi-amped W8LM cabinets...
1 x 2ch MA2.8S power amplifiers drive 4 x bi-amped W8LM
2 x 2ch MA2.8S power amplifiers drive 8 x bi-amped W8LM
3 x 2ch MA2.8S power amplifiers drive 12 x bi-amped W8LM
4 x 2ch MA2.8S power amplifiers drive 16 x bi-amped W8LM
Passive
1 power amplifier for 8 passive W8LM cabinets...
1 x 2ch MA2.8S power amplifiers drive 8 x passive W8LM
2 x 2ch MA2.8S power amplifiers drive 16 x passive W8LM
3 x 2ch MA2.8S power amplifiers drive 24 x passive W8LM
4 x 2ch MA2.8S power amplifiers drive 32 x passive W8LM
Why do I need high power amplifiers for the high frequency
sections!?
There are several reasons for this:
1) Although vocal and percussive signals demand fairly low continuous power,
their peak power can be much higher. Many touring systems have less than adequate
peak power at mid and high frequencies and simply clip vocal fricatives and
percussion transients producing poor mid and high frequency definition.
2) Our mid and high frequency sections are designed to reproduce these peak
power transients faithfully without stress. We use carefully matched RC coupling
networks to compensate for high frequency driver voice coil inductance. These
coupling networks improve transient performance and present an easy load to the
power amplifier.
All material © 2007. Martin Audio Ltd. Subject to change without notice.