$275.36
By Lubell Labs Inc.
Model # AC211
Lubell 40 Vrms 10.6 ohm 200W Transformer Box
The Lubell Labs 20 volt LL9816 and LL916 underwater speakers must be connected to a Lubell Labs transformer box, which in turn connects to a Lubell Labs approved UL listed amplifier of the correct power and impedance rating. The transformer box and amplifier must be kept in a dry air conditioned area, and AC operated amplifiers must be connected to a GFCI protected AC outlet.
Lubell Labs die-cast transformer boxes provide electrical isolation of the underwater speaker from the amplifier for safety, impedance matching for proper amplifier operation, and a circuit that both limits current and flattens the frequency response during broadband operation (music, pink noise, etc.). When connected to amplifier of designated wattage and impedance, the output of the transformer boxes will not exceed 20 Vrms @ 3.0A at full drive, and each underwater speaker will produce maximum sound pressure level of 180dB/uPa/m @ 1kHz. A variety of transformer boxes are made to provide compatibilty with existing or custom sound systems. Splitting transformer boxes are offered to allow connection of an air and underwater speaker to an amplifier or sound system.
The AC211 Circuit Master Transformer Box allows connection of one Lubell LL9816 or LL916 underwater speaker AND one 8 ohm PA speaker (Quadra 10 or 12 recommended) to one or both channels of a portable mono or stereo PA system rated between 150 - 200 watts rms @ 8 ohms per channel. Operation: First sound level of underwater speaker is set using master volume control on amplifier. Then sound level of air speaker is set using volume control on the AC203E Circuit Master. Once this perfect balance between air and underwater sound levels is set, then the amplifier master volume control alone is used to control overall sound levels.