Rane ECS v2 Hardware (ECB 6 and ECM 8) - Manual (Page 7)

HW Manual-7
PHANTOM POWER
The ECM 82 Mixers are shipped with internal Phantom
Power switches in the “on” position. To change, remove the
top cover and look for the switches in the middle left of the
circuit board, as shown on page HW Manual-10.
REDUCING NOISE AND ACOUSTIC GAIN
Three methods are available to reduce noise and acoustic
gain due to the mixing of multiple microphones and multiple
Echo Cancellers.
The first method is a special NOMM Mode (Number of
Mics & Mixers open). This function maintains full level at the
Master Mic Input that has detected audio, while reducing
Gains of the other Mics in order to maintain unity gain.
The second method is a Mixer Gate. This function reduces
the Output Level of the Mixers that are not detecting audio
and do not have a current Master Mic. When using the ECM
82 Expansion Input, deselect
Mixer Gate.
The third method, Mixer Suppression, utilizes a one shot
suppression technique. This is only active when a new Mic is
Gated and audio is no longer detected at the previous Mic.
The added Suppression is 12 dB. Activating
Suppression
removes echo caused by the Echo Canceller re-adapting to a
new Gated Mic.
An example of Mixer Suppression:
1. Someone talks at local Mic 1. (New Input = false)
2. The person at local Mic 1 stops talking and someone at the
remote location talks. (No Mixer Suppression is added.)
3. Someone at local Mic 2 starts to talk. (New Input = true)
4. The person at local Mic 2 stops talking and someone at the
remote location talks. (Mixer Suppression is added.)
5. Someone at local Mic 2 starts to talk again. (New Input =
false) (No Mixer Suppression is added.)
DEVICE ADDRESS
The Mixer’s rear panel ECS INTERFACE DEVICE
ADDRESS determines its Mixer number and Mic Input
numbers. For example, Device Address 1 is Mixer 1 includ-
ing Mics 1-8, and Device Address 2 is Mixer 2 including
Mics 9-16. Only Device Addresses 1 through 6 are allowed,
since this is the maximum Mixers per Base. When a Mixer is
first powered up and has not received data from the Base, the
Mic Status LEDs display the Mixer Device Address.
An invalid Device Address set on the Mixer causes its
COM LED to continually flash. The ECM 82’s power must
be cycled after changing the Device Address. Unplug from
the wall, not the unit!
TERMINATION
ECS termination is optional and may only be needed if
there are more than four ECM 82s. To set ECS termination,
remove the top cover of the last ECM 82 and move the ECS
TERM jumper to its left position on the ECS data interface.
ECM 82 MIXER
The ECM 82 Mixer is a digitally-controlled-analog eight
channel Mic/Line auto-mixer. An optional internal DSP Echo
Canceller module is available either separately (model ECA
1) or included (model ECM 82A). Each Base supports up to 6
Mixers, allowing 48 Inputs. All system parameters of the
Base and Mixers are stored within the Base using non-volatile
memory (no batteries). The ECM 82 Mixer is not a stand-
alone device and will not operate without a Base connected.
All functionality is controlled through RaneWare. Soft-
ware controls are printed in san-serif type like this. See the
RaneWare Operators Manual for complete details.
LAST-ON or GATED MODES
Unique among automatic mic mixers, each Mic can be
independently set to Last On or Gated. A Mic assigned as
Gated simply opens the mic when the input signal is above
the
Threshold Level, and returns to its Gate Depth when the
signal drops below the Threshold Level and the Release
Timer has expired. A Mic assigned as Last On remains on
once it becomes the
Master Mic.
This is useful in boardrooms where the head table would
require last-on mics and the audience area requires gated
mics. This way, the board members (and their background
noise) are always heard, while the less-often used audience
(i.e., questions) mics, gate off when not in use. Rane has
patented this concept – the marketing buzz word being Smart
Last On™. Having an open mic also maintains the full duplex
awareness of the conference.
MIC THRESHOLD
Each Mic can operate in either Automatic or Manual
Threshold mode. With Automatic Threshold checked, each
Input determines its own background room noise level. This
calculated level is added to the set
Threshold Level for this Mic.
MZEC™ (em-zeck)
Using large auto mixers with an echo canceller can cause
echo problems when several microphones gate-on at the same
time. If a single Echo Canceller is adapting to all Mic signals,
and more than three Mics are on at the same time, the
acoustic model for the room may become too complex. This
causes Echo Canceller divergence, resulting in more suppres-
sion or return echo. To eliminate this problem, each ECM 82
Mixer allows the addition of an internal Acoustic Echo
Canceller. Placing an Echo Canceller in each mixer reduces
the number of acoustical echo paths for a multi-microphone
system, improving the system audio quality. (See the ECA 1
Acoustic Echo Canceller module on page HW Manual-10.)
This method is called MultiZone Echo Cancelling (MZEC™).
Important: When using an Echo Canceller in each Mixer,
at least one Mic must be open on each Mixer to allow the
Echo Canceller(s) to adapt. ECS maintains an open Mic for
each Mixer when
Mixer Gate is checked and each Mixer has
at least one Last On Mic. Setting the Gate Depth of a gated
Mic to 0 dB is another way to maintain Echo Canceller
adaption. The ECB 62 PORT 1 MONO OUTPUT must be
connected to all the E/C REF Inputs of the ECM 82 Mixers.