Introduction; The Transducers; Power Amplifiers; The Crossover - Mackie SRM350v2 User Manual

INTRODUCTION

Thank you for choosing LOUD Technologies' Mackie ac-
tive sound reinforcement speakers.
The SRM50v is a redesigned version of our popular
SRM50 active loudspeaker. With its newly designed Class-D
Fast-Recovery amplifiers, high-output compression driver
and new 10" neodymium woofer, it produces an even
smoother sound than the original. SRM means Sound Re-
inforcement Monitor, and the SRM50v truly produces a
studio quality sound in a sound reinforcement speaker.
Our design goal was to build a sound reinforcement
speaker with:
1. High precision, high output, and accurate playback.
. Very wide, smooth dispersion of mid and high frequencies.
. Ergonomically correct physical design for easy transport
and set up.
Through the combined resources of our top-notch
mechanical and analog engineers, and our experienced
transducer engineers at EAW, we were able to achieve our
design goals in every aspect. The result is a sound rein-
forcement system equally at home in a concert setting, in the
studio, impromptu concerts on the studio roof, in the cinema,
or in a home theater.
The Transducers
The SRM50v active speakers feature a 10-inch high-
power low-frequency woofer with a neodymium magnet,
and a 1.-inch titanium diaphragm high-output ceramic
compression driver. This high-frequency driver is mounted
on an acoustically non-resonant exponential waveguide,
providing a wide, controlled dispersion and precise
reproduction of the critical upper mid-range and high
frequencies. The result is an unbelievably smooth off-axis
response that allows everyone in the audience to experi-
ence the same high-resolution audio no matter where they
are seated.
Power Amplifiers
To power these beauties, each SRM50v includes two of
our acclaimed FR Series "Fast Recovery" power amplifiers.
In addition, the low-frequency amplifier uses a Class-D
design for improved efficiency and cleaner power. Our
exclusive designs use low negative feedback, yet allow the
amplifiers to maintain low distortion and stability and to
quickly recover when driven into clipping.
The amplifiers include the following features:
• The low-frequency amplifier produces 165 continuous
watts before clipping.
• The high-frequency amplifier produces 0 continuous
watts before clipping.
• When the output from either amplifier begins to clip,
a limiter gently reduces the input signal level until the
output is no longer clipping.

• The low-frequency amplifier also has a Dynamic Bass
Boost circuit. Our ears are more sensitive to bass fre-
quencies at high volume levels than at softer volumes.
This unique circuit automatically reduces the low
frequencies below 70 Hz as the volume of the speak-
ers goes up. This results in improved efficiency for the
low-frequency amplifier because it is not wasting power
trying to reproduce frequencies we hear better at loud
volumes. Instead, the power is used for the frequencies
where it is needed, resulting in a louder sound.
Warning: Although the amplifiers have
these protection circuits, you must
still make sure the LIMIT light is not
blinking continuously. If it is, turn
down your mixer faders, or preampli-
fier gain, or turn down the SRM50v
LEVEL control.
The Crossover
The built-in electronic crossover is a  dB/octave
Linkwitz-Riley design. Although more expensive than other
crossover designs, the benefits provided by the Linkwitz-
Riley design have been well documented. These benefits
include:
• Absolutely flat frequency response throughout the
bandpass, without the characteristic ripple near the
crossover point exhibited by other designs.
• The sharp  dB per octave roll-off of the filters ensures
that the transducers aren't reproducing frequencies
outside of their capabilities.
• The acoustic sum of the two driver responses is unity
at the crossover frequency, resulting in perfect power
response.
• Our heroic engineers have worked carefully to en-
sure that the SRM50v also provides perfect phase
response. This diligence has yielded phenomenal ac-
curacy, even if you are standing 0 feet away.
The Cabinet
The SRM50v cabinet was designed to be the strongest
molded composite cabinet on the planet (Earth). This ma-
terial is as strong as concrete, and rigid enough to prevent
unwanted vibrations in the cabinet. An optional bracket
kit is available for the top and bottom of the cabinet to be
used for flying, and a socket is provided in the bottom of the
cabinet for mounting on a tripod stand. Although it is an
exceptional choice for installed sound situations, its light
weight and durable finish also make it ideal for portable
sound system use. The asymmetrical trapezoidal design of
the cabinet makes it easy to use as a floor wedge for stage
monitor applications.