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ETS SMA1-LP 2 Watt Speaker Driver and an SM Series Microphone Interface For Audio Surveillance
The ETS SMA1-LP is a line level, 2 Watt, selectable 70V or 8 Ohm speaker driver (power amplifier) and an SM series microphone interface typically for use in 2 way audio surveillance systems. This device directly connects to DVRs and remote monitoring equipment, and it can also be used in any single zone public address application requiring 2 way communication.
You can easily use one of the ETS speakers (with a built in 70V transformer) and an SM1 microphone with this device for cable runs up to 1000 feet. So if you're looking for a speaker driver with a built in microphone interface, then you've found what you need in the SMA1-LP from ETS.