Genelec 1237A and 1238A Operating Manual
Introduction
Congratulations and a thank-you for the pur-
chase of this Genelec Smart Active Monitor-
ing (SAM) Series DSP monitor loudspeaker.
This product should be set up using the
fully automatic process in the Genelec Loud-
speaker Manager GLM™ software. There are
no setup controls on the amplifier panel.
This manual describes the basic setup of
the monitor for use with the GLM software, as
well as use in the Stand-alone mode without
the GLM software in use or permanently con-
nected for computer control.
Each monitor is supplied with a mains
cable, one GLM control network cable, and
an operating manual.
System
The Genelec 1237A and 1238A are three-way
monitoring systems for medium sized control
rooms. They perform well as free-standing
monitors as well as flush-mounted in control
room walls. They are suited for recording, film
and video post-production, broadcast moni-
toring as well as for mastering.
The unique Directivity Control Waveguide™
(DCW™) technology by Genelec provides
excellent stereo imaging and neutral fre-
quency response even in difficult acoustics.
With program material at a 2 meter listen-
ing distance, the fast low distortion amplifiers
drive a stereo system to peak sound levels
in excess of 122 dB SPL (1237A) or 124 dB
SPL (1238A).
The 1237A and 1238A are fully compatible
with Genelec Loudspeaker Manager GLM™
and proprietary Genelec control network.
They can be used with 8200-series SAM
monitors and 7200-series SAM subwoofers
in the same network.
Drivers and Cabinet
Construction
The 1238A reproduces low frequencies with
a 385 mm (15 in) woofer in a 110 litre bass
reflex enclosure. The 1237A features a 305
mm (12 in) woofer in a 65 litre bass reflex
enclosure. Both monitors use the same pro-
prietary 130 mm (5 in) direct radiating mid-
range driver, and a 25 mm (1 in) metal dome
tweeter, both acoustically loaded by the pro-
prietary Directivity Control Waveguide. All
drivers are magnetically shielded.
Amplifiers and Signal
Processing
The 1237A and 1238A use the RAM-L ampli-
fier unit. The RAM-L is mounted with vibration
absorbers in the rear of the monitor enclo-
sure, and can also be detached and mounted
to a 19 inch rack. Digital signal processing
in the RAM-L amplifier unit is done with high
precision algorithms, and includes driver
and amplifier overload protection. The room
response compensations include highly flex-
ible parametric filters, level alignment, and
acoustic delay compensation. These allow
accurate matching to all console output sec-
tions and room acoustics.
Mounting Considerations
Place monitors so that their acoustic axes are
aimed towards the listening position (see Fig-
ures 1 and 2). Place monitors with left-right
symmetry and at an equal distance from the
listening position. Acoustic reflections from
objects close to monitors and the listening
position can cause colouration and blurring
of the sound image. Symmetrical positioning
of reflective objects maintains good stereo
imaging. When soffit (flush) mounting, the
wall surface should extend to the monitor,
forming a continuous surface.
Minimum Clearances
The minimum clearance is 5 cm (2 in) behind,
above and on both sides of the monitor, when
the RAM-L amplifier is mounted on the enclo-
sure. The ambient temperature around the
amplifier must not exceed 35 degrees Cel-
sius (95°F). When soffit mounting, sufficient
ventilation should be a arranged behind the
monitor. This may require forced ventilation
around the RAM-L amplifier.
When the RAM-L amplifier is mounted
in a 19 in rack, the minimum free space
is 1U both above and below the amplifier
and both sides of the amplifier fully open
to enable free movement of air. Use the
included rack mount front plate to ensure
sufficient space above and below the
amplifier.
When the RAM-L is mounted on a table,
shelf or similar solid surface, there must be a
free space of at least 250 mm (10 in) above
and 10 cm (4 in) on both sides of the ampli-
fier. Free air flow must be possible in the front
side of the amplifier.
Set-up and Use
Monitor calibration and setup
The 1237A and 1238A are set up using the
GLM software. The setup is fast and consists
of the following steps:
1. Run a CAT5 (RJ45) cable from the mon-
itor control network to the next monitor.
2. Run the final cable to control network
input of the GLM Adapter device.
3. Connect the GLM Adapter device to
your computer USB connector. The
cable is a part of the GLM User Kit.
4.
Place the Genelec measurement micro-
phone at the listening location of the engi-
neer, on a stand, with the microphone
pointing upwards and the microphone
top at the height of the engineers ear in
normal working position. The microphone
is a part of the GLM User Kit.
5. Run the microphone cable to the micro-
phone input in the GLM Adapter device.
6. Download GLM software at the Genelec
web site (www.genelec.com). Install the
GLM software.
7. Follow the GLM software instructions to
measure and set up your monitors.
8. If you plan to not use a computer for
controlling the monitors, use the GLM
software to write the setting into the
monitors ("Store the Settings").
Recommendations for
AES/EBU Audio
For a digital input signal of –30 dB FS, the
1237A and 1238A monitors will produce a
100 dB sound level (SPL) at 1 meter distance,
in free space. The sensitivity of the monitor
system is set using the GLM software.
It is advantageous to keep the maximum
incoming digital audio signal level high, near
to 0 dBFS. It may be useful to lower the inter-
nal GLM level control. This enables maintain-
ing high digital resolution in the digital source.
Single-wire mode of AES/EBU is the
default and the older dual-wire mode is auto-
matically detected if used at the source.
The standard AES/EBU cable carries two
channels of audio, called A and B. As a default,
