User's Manual
QUADRA
LECTROSONICS, INC.
4
System Overview
The Quadra system provides an entirely new level 
of audio and RF performance in a wireless monitor 
system. The combination of analog or digital input 
capability, ultra-low latency 24 bit, 48 kHz audio, digital 
RF modulation and discrete four channel mixing capa-
bility make the Quadra a truly unique IEM product for 
mission-critical, professional applications. 
The system is designed for line level analog audio 
signalsandAES/EBUdigitalaudioinputsignals.
48kHz/24-bitaudio,ruler-at20Hzto20kHzfrequency
response, ultra-low distortion and high dynamic range 
assure excellent audio quality. Housings and panels 
are machined aluminum with electrostatic powder 
coated and anodized finishes and laser etched mark-
ing for durability. An intuitive mixing interface and 
comprehensive LCD on the belt pack receiver provides 
performing artists and monitor engineers alike with a 
comfortable and confident user experience.
M4 Transmitter
The half-rack transmitter can accept up to four inputs 
from digital or analog sources. The inputs can be con-
figured as follows:
• Fouranaloginputsusingallfourjacks
• Twodigitalinputsusingjack1andtwobalanced
analog inputs using jacks 3 and 4
• Fourdigitalchannelsusingjacks1and2
The input connectors are full-size balanced XLR types 
forAES/EBUandbalancedlinelevelanalogsignals.
Input preamp circuits use a special balanced amplifier 
with very high common mode rejection to minimize 
hum and noise.
EitheranalogorAES/EBUdigitalinputsignalsare
converted to an internal 24-bit digital format which is 
then encoded, organized into packets, and passed to 
an RF modulator using spread spectrum techniques 
and error correction for robust reception. The modu-
lated RF signal is filtered before and after amplification 
to suppress out-of-band noise and spurious signals, 
andacirculator/isolatorguardsagainstintermodulation
interference (IM).
The transmitter can be free-standing or rack-mounted 
in single units (via an optional rack mounting kit) or in 
a dual configuration using supplied hardware.
A USB port is provided for firmware updates.
M4 Receiver
The receiver employs advanced antenna switching 
diversity reception, switching between the antennas 
during packet headers in order to maintain a seamless 
audio signal. A configurable four-channel mixer on the 
top of the receiver housing allows the user to mix from 
four discrete audio channels according to the needs 
of the performance. The headphone jack is fed from a 
high-qualitystereoamplierwithgreaterthan100mW
available to drive headphones or earbuds to sufficient 
levels for stage performance or other environments 
with significant background noise. A high-density, 
backlit LCD allows the user to make setup changes via 
the available menu options.
A USB port is provided for firmware updates.
Frequency Range
Using the license free 902 - 928 MHz ISM band, this 
system is outside the normal broadcast frequencies 
thus providing both technical and operational advan-
tages over standard analog systems.
OR
Freq 1
Freq 2
Freq 3
Freq 4
4 CHANNEL MODE
2 CHANNEL MODE
Freq
1A
Freq
2A
Freq
2B
Freq
3A
Freq
3B
Freq
4A
Freq
4B
OR
OR
OR
Freq
1B
In four-channel mode, the system occupies 4 MHz and 
is selectable between four available center frequen-
cies: 907.776, 912.384, 916.992 and 923.904 MHz. 
In two-channel mode, Quadra occupies 2 MHz and 
is selectable between eight available center frequen-
cies: 906.624, 908.928, 911.232, 913.536, 915.840, 
918.144, 922.752 or 925.056 MHz.
Multi-Channel Capability
Quadra can be configured to provide either 2 or 4 
audio channels. In the 2-channel mode, eight different 
frequencies are available, each with two audio chan-
nels. In the 4-channel mode, four different frequency 
bands are available, each with four audio channels. 
Multiple Quadra systems can be operated in the same 
location to provide up to 16 audio channels.
The performer can then use the on-board mixer to tai-
lor the audio output to his or her tastes or the require-
ments of the performance at hand.










