Lubell Audio Isolation Transformer Boxes

Lubell Labs LL916 series underwater speakers operate at 20 Vrms, and are designed for use with (and sold with) the Lubell Labs Audio Isolation & Matching Transformer Boxes listed below, which in turn connect to an UL or ETL approved 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 AC Series transformer boxes provide: 1) Transformer isolation of the underwater speaker from the amplifier for safety; 2) Impedance matching for proper amplifier loading; 3) A tuned RLC circuit that both limits current and flattens the frequency response during broadband operation (music, pink noise); 4) Volume matching of air and underwater zones (AC203E & AC211 "Circuit Master" models). When connected to amplifier of designated wattage and impedance, the underwater speaker output of the transformer box will not exceed 20 Vrms @ 3.0A at full drive, and each underwater speaker will produce maximum sound pressure level of 179 dB/uPa/m @ 1kHz. A variety of transformer boxes are made to provide compatibility with existing or custom sound systems. Splitting transformer boxes (AC203E & AC211) are offered to allow connection / sound balancing of both air and underwater speakers to an mono or stereo amplifier or sound system.

xfmr_AC102

Model AC102C (connectors for portable use only). Use with amplifier rated between 150 - 200 watts @ 8 ohms (40 Vrms)
5.5 inch x 3.75 inch x 2.5 inch, 2.25 pounds

Useful for connecting up to four Lubell LL916C or LL916H portable underwater speakers to a 150 - 200 watt mono amp (40 Vrms), or up to eight LL916C or LL916H portable underwater speakers to a 150 - 200 watt stereo amp (4 parallel units per channel). Load rating of 32 ohms at 40 Vrms maximum. Connect AC102 inputs in parallel and in phase only. Connect one LL916C or LL916H underwater speaker per AC102. Connect amplifier to GFCI only! Also useful for piggybacking an underwater speaker on to one or both channels of a 150 - 200 watt stereo PA system that has one 8 ohm air speaker connected to each channel.

Input of box is fitted with Switchcraft 1/4 inch (6.35 mm) mono phone jack, and output is fitted with Conxall 4182-3SG-300 (pin 3 hot). Supplied with 2 foot speaker cord with 1/4 IN TS connectors.

xfmr_AC202B

Model AC202B (Screw terminal I/O for permanent installation by contractor) - use with amplifiers up to 50 watts @ 8 ohms, or 100 watts @ 4 ohms (20 Vrms)
6.1 inch x 3.75 inch x 2.5 inch, 2.25 pounds

Used for connecting one in-wall LL916 U/W speaker (part of 9484 kit) to the 8 ohm tap of PA amplifiers not exceeding 50 watts @ 8 ohms or 100 watts @ 4 ohms (20 Vrms).

xfmr_AC202C

Model AC202C (connectors for portable use only). Use with amplifiers up to 50 watts @ 8 ohms (20 Vrms), or 100 watts @ 4 ohms (still 20 Vrms)
5.5 inch x 3.75 inch x 2.5 inch, 2.25 pounds

Included with the Lubell CAWSS System. Used for connecting one Lubell 
LL916C or LL916H portable underwater speaker to the speaker output connector of the Chiayo StageMan or APEX Pro amplifier.

Input of box is fitted with Switchcraft 1/4 inch (6.35 mm) mono phone jack, and output is fitted with Conxall 4182-3SG-300 (socket 3 hot). Supplied with 2 foot speaker cord with 1/4 IN TS connectors.

xfmr_AC205B

Model AC205B (Screw terminal I/O for permanent installation by contractor). Use with 25V constant-voltage (CV) amplifiers below or Russound A2100
6.1 inch x 3.75 inch x 2.375 inch, 2.25 lbs

Connects to 25V speaker output of following commercial sound amplifiers (allow 37.5 watts consumption per LL916 / AC205B connected):

One to three Lubell LL916 (part of 9484 kit) - Bosch PLE-1P120-US power amplifier, or InterM A-120 powered mixer (USA sales only)
Four to six Lubell LL916 (part of 9484 kit) - Bosch PLE-1P240-US power-amplifier (only USA model has 25V tap - order from Lubell Labs for export)

xfmr_AC205C

Model AC205C (connectors for portable use only). Use with amplifiers up to 78 watts @ 8 ohms (25 Vrms). 5.5 inch x 3.75 inch x 2.5 inch, 2.25 pounds

Also connects to 25V screw-terminal speaker output of following commercial sound amplifiers (allow 37.5 watts consumption @ 25 Vrms for each connected LL916/AC205C):
One to three 
LL916C or LL916H - Bosch PLE-1P120-US power amplifier, or InterM A-120 powered mixer
Four to six Lubell 
LL916C or LL916H - Bosch PLE-1P240-US power-amplifier

Input of box is fitted with Switchcraft 1/4 inch (6.35 mm) mono phone jack, and output is fitted with Conxall 4182-3SG-300 (pin 3 hot). Supplied with 2 foot speaker cord with 1/4 IN TS connectors.

xfmr_AC203E
Model AC203E Circuit Master (connectors for portable use only). Use with amplifiers up to 78 watts @ 8 ohms (25 Vrms). 5.75 inch x 4.625 inch x 2.5 inch, 2.75 pounds.
  • Allows connection of one Lubell LL916C or LL916H underwater speaker AND one EV ZX1-90 eight ohm air speaker to a mono PA amplifier not exceeding 78 watts rms @ 8 ohms (or the 25V tap of the InterM A-120 offered by Lubell Labs).
  • Operation: First, set the sound level of the underwater speaker using the master volume control on the amplifier. Then set the sound level of the air speaker using the volume control (autoformer) 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 air & underwater sound levels as different songs of varying levels are played.
xfmr_AC211
Model AC211 Circuit Master (connectors for portable use only). Use with amplifiers up to 200 watts @ 8 ohms (40 Vrms). 5.75 inch x 4.625 inch x 2.5 inch @ 2.75 pounds.
  • Allows connection of one Lubell LL916C or LL916H underwater speaker AND one EV ZX1-90 eight ohm air speaker to a mono or stereo PA system rated between 150 - 200 watts rms @ 8 ohms per channel (40 Vrms 10.6 ohm min).
  • Operation: First, set the sound level of the underwater speaker using the master volume control on the amplifier. Then set the sound level of the air speaker using the volume control on the AC211 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 air & underwater sound levels as different songs are played.
Transformer box AC1424HP-01-products-lubell
Model AC1424HP Bridging Transformer Box, included with LL1424HP underwater acoustic transducer. For use with bridged Crown CDi2000. 12.5 inch x 7.125 inch x 7.250 inch @ 15 pounds. Government sales only.

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