Amplification and Audio
The user panel located on the rear of 2100-LFC loudspeakers includes audio input connectors, one for analog audio, the other for Milan AVB digital audio.
2100-LFC User Panel, Audio Inputs, Sealing Caps Not Depicted
Both audio inputs are always active. If signal is present at both inputs, both signals are reproduced. When using one input as a backup to the other, utilizing GALAXY processor input or output mutes is one strategy to switch between input types.
Note
Using Groups and Controls in Compass, a single control button can be assigned to toggle some or all the input or output mutes of a Galileo GALAXY processor or processors.
The analog and Milan inputs will arrive at the loudspeaker at different times due to transport time of the Milan signal through the network, usually less than 2 ms. The latency of the Milan signal is dependent on the number of network switch hops and the presentation time set in software. To synchronize the signals, determine the time offset and add that amount of delay to the signal reproduced earliest, usually the analog input signal.
If one input is used as a backup, time aligning it with the primary input provides a smoother transition when the signal to the primary input is muted and the backup is unmuted.
Synchronizing the inputs also preserves the time alignment with other system components regardless of which input is receiving signal.
Audio Connectors
The user panel includes two 3-pin Neutrik XLR True Outdoor Protection (TOP) connectors for analog audio input and audio loop output. The network connector is a Neutrik etherCON True Outdoor Protection (TOP).
Caution
The analog and network chassis connectors are certified for outdoor protection (IP65, UL50E) only when mated with the Neutrik TOP cable-mount connectors, or when the connector is not in use, when the sealing cap is fully inserted
Check the sealing caps for moisture before covering the connectors. If wet, dry the caps before covering the connectors to avoid introducing liquid into the connectors.
Always seal the connectors with the sealing caps when the connectors are not in use.
Calculating Analog Input Load Impedance
To avoid distortion when looping multiple loudspeakers, make sure the source device can drive the total load impedance of the looped loudspeakers. In addition, the source device must be capable of producing +24 dBU into 50 Ohms to produce the maximum peak SPL over the operating bandwidth of the loudspeaker.
To calculate the load impedance for the looped loudspeakers, divide 10 kOhms (the input impedance for a single loudspeaker) by the number of looped loudspeakers. For example, the load impedance for ten 2100-LFC loudspeakers is 1000 ohms (10 kOhms / 10). Most source devices are capable of driving loads no less than 10 times their output impedance. To drive this number of looped loudspeakers, the source device should have an output impedance of 100 ohms or less (1000 ohms / 10). Galileo GALAXY outputs have an output impedance of 50 ohms, capable of driving the load of up to 20 loudspeakers with 10 kOhm inputs without distortion.
Caution
Make sure all cabling for looped loudspeakers is wired correctly (Pin 1 to Pin 1, Pin 2 to Pin 2, and so forth) to prevent the polarity from being unintentionally reversed. If one or more loudspeakers in a system receive audio signals that are of the opposite polarity, frequency response and coverage will be significantly degraded.
Analog Audio Input (XLR 3-Pin Female)
The XLR 3-pin female connector labeled “Input” accepts balanced audio signals with an input impedance of 10 kOhm. The connector uses the following wiring scheme:
Pin 1 — 1 kOhm to chassis and earth ground (ESD clamped)
Pin 2 — Signal (+)
Pin 3 — Signal (–)
Case — Earth (AC) ground and chassis
Pins 2 and 3 carry the input as a differential signal. Pin 1 is connected to earth through a 1 kOhm, 1000 pF, 15 V clamped network. This circuitry provides virtual ground lift for audio frequencies while allowing unwanted signals to bleed to ground. Make sure to use balanced XLR audio cables with pins 1, 2, and 3 connected on both ends. Connecting the signal ground at only one end is not recommended. Shorting the signal ground conductor to the connector case may cause a ground loop, resulting in hum.
Note
If unwanted noise or hiss is produced by the loudspeaker, disconnect the audio signal cable from the loudspeaker input. If the noise stops, there is most likely nothing wrong with the loudspeaker. To locate the source of the noise, check the audio cable, source audio, AC power, and electrical ground.
Analog Audio Loop (XLR 3-Pin Male)
The XLR 3-pin male connector labeled “Loop” allows multiple loudspeakers to be looped from a single audio source.
This connector uses the same wiring scheme as the input connector. For applications that require one drive line to provide signal to multiple 2100-LFC loudspeakers, connect the output of the first loudspeaker to the input of the next loudspeaker, and so forth.
Note
The connector labeled “Loop” is wired in parallel to the input connector and transmits the unbuffered source signal whether the loudspeaker is powered on or off.
Milan Endpoint Module
The Milan Endpoint module (Type 3M Audio Input Module) shown in the figure below, includes a Neutrik etherCON TOP connector, an Ethernet connectivity LED, an On/Status LED, and a Wink button/LED.
2100-LFC User Panel, Milan Endpoint Module
Network Connector
The etherCON TOP connector provides the network connection for transmission of a digital audio signal to the loudspeaker and the transmission of telemetry data from the loudspeaker.
Tip
Use an Avnu-certified network switch when the Milan digital audio input is used. For a list of Avnu certified AVB switches please refer to the certification pages at avnu.org.
When the Milan input is not used, a standard Ethernet network (IEEE 802.3 compliant, supporting at least 100 MB/s, full-duplex) is capable of transmitting the telemetry data.
Digital Audio Input
The Milan Endpoint accepts a single channel of a Milan digital audio stream as specified by the Avnu Alliance. To utilize the Milan input, connect the loudspeaker to an Avnu-certified network switch.
When a Milan Endpoint loudspeaker and a computer are connected to the same network via an Avnu-certified network switch, the loudspeaker will be listed in Meyer Sound’s Nebra software or other AVB controller software. The Milan Endpoint loudspeaker (Listener) must be assigned to an available audio source channel (Talker) for the loudspeaker to reproduce the audio stream transmitted by the Talker.
For Milan audio transport, the network connection speed between the last network switch and a Milan Endpoint is 100 bT, 100 Mb/ second. The connection speed between network switches transporting Milan digital audio signals is 1000 bT, 1 G/second.
Telemetry
Loudspeakers with Milan Endpoints transmit telemetry data via the network connection. To view the telemetry data, connect the loudspeaker(s) and a computer to a network switch. The loudspeaker telemetry data is displayed in Meyer Sound’s Nebra software which displays extensive system status and performance data for each loudspeaker, including amplifier voltage, limiting activity, power output, fan speed and driver status. A mute function is available.
An Avnu-certified switch is not necessary when the network is only transporting telemetry data. When the network only transports telemetry data, the connection speed from end-to- end is 100 bT, 100 Mb/second.
Wink Function
The Wink function facilitates the identification of physical loudspeakers listed in Meyer Sound’s Nebra software. When making digital audio signal connections in software, it’s necessary to know which physical loudspeaker the signal is routed to. A network connection between the loudspeaker and a computer running Nebra software is required.
When active, the Wink function is indicated in four locations: Nebra software, the Wink push-button on the user panel of the loudspeaker, the LED bar on the amplifier cowl, and two LED strips on the front of the cabinet.
Once a Milan Endpoint has been detected and auto-discovered in Nebra software, the loudspeaker’s detail page includes a button with an icon of an eye. Clicking this button toggles the Wink function, which is indicated in the software. When the Wink function is active, the Wink push-button on the user panel of the loudspeaker, the LED bar on the amplifier cowl, and the two LED strips on the front of the loudspeaker illuminate. The wink function times out after 10 seconds.
Wink/Activity LED (Green)
To activate the Wink function from the loudspeaker, press and hold the Wink button down while observing the On/ Status LED, which turns red and then off. Release the Wink button when the On/Status LED turns off, activating the Wink function. The Wink LED turns green for 10 seconds. If the Wink button remains depressed, the On/Status LED will turn red again and the Wink function will remain off.
To turn off the Wink function, wait 10 seconds for it to time out or depress and hold the Wink button, the On/Status LED will turn red. Wait until the On/Safety LED turns off, then release the Wink button.
On/Status LED, Wink Button/LED, Network Connectivity LED, and Network Connector.
Ethernet/Network Connectivity LED
The Ethernet connectivity LED immediately to the left of the network connector) turns solid yellow when a 100 bT link is established; otherwise, it is off.
On/Status and Limiting Indication
During normal operation, when 2100-LFC is powered on, the On/Status LED on the user panel is solid green. Limiting activity is indicated by the On/Status LED illuminating yellow while limiting is active.
When limiting is engaged, the channel’s gain is reduced. The limiter protects the driver and prevents signal peaks from causing excessive distortion in the amplifier, thereby preserving headroom and maintaining a smooth frequency
response at high levels. When source levels return to normal, below the limiter’s threshold, the LED turns green and limiting ceases.
The loudspeaker performs within its acoustical specifications at normal temperatures when the On/Status LED is green, or when limiting is not continuous. During continuous limiting, the loudspeaker is nearing its operational limits, resulting in the following effects:
Increases to the input level have no effect.
Distortion increases due to clipping and nonlinear driver operation.
The drivers are subjected to excessive heat and excursion, which compromises their life span and may eventually damage them.
Caution
The On/Status LED indicates when a safe, optimum level is exceeded. If a 2100-LFC loudspeaker system begins to limit before reaching the desired acoustic output, consider adding more loudspeakers to the system.
2100-LFC Cooling System
The 2100-LFC employs forced-air cooling with variable-speed fans to prevent the amplifier or driver from overheating. The amplifier module fans draw air in through the inlet grille on the rear below the user panel and through the vent at the bottom of the amplifier cowl. The exhaust exits through the upper-left exhaust vent next to the user panel. The driver cooling system draws air into the lower-left inlet grille, which exits via the front-facing acoustic chamber ports, shown in the figure below.
The two vent grilles to the right of the user panel are provisional, not functional.
Caution
To keep 2100-LFC from overheating, allow at least six inches (15 cm) of space with unobstructed airflow behind the enclosure for proper ventilation.
Regularly inspect the foam and screen behind the air intake grilles located below the user panel, at the bottom of the amplifier cowl, and the lower-left intake next to the user panel. If a significant amount of particulate has accumulated on the screen or foam, power down the loudspeaker for at least one minute and remove the cover of the contaminated intake(s). Vacuum, then rinse the screen and foam with water until the particulate is removed. Allow the screen and foam to dry completely, then reassemble.
2100-LFC Amplifier Ventilation
Caution
If a system being operated in a hot environment includes 2100-LFC loudspeakers and the telemetry data (Nebra software) indicates very high thermal conditions, consider adding more loudspeakers to the system.
Tip
When 2100-LFC is connected to a network, Meyer Sound’s Nebra software displays telemetry metrics, including the fan status and operating temperature.
Cable Rings
Two cable rings are provided on the rear of the 2100-LFC cabinet. Power and audio cables should be tied off to these rings to reduce strain and prevent damage to them.
Caution
Cable rings should only be used to reduce strain on cables and not be used for any other purpose.
Cables Tied Off to Cable Ring