The Lubell Labs LL1424HP is a high-power piezoelectric Underwater Acoustic Transducer (UAT) designed for use in Underwater Acoustic Deterrent Systems (uADS), Diver Deterrent Systems (DDS), Acoustic Sub-Bottom Profiling (SBP) systems, and general military and scientific applications. The LL-1424HP may also be used as an underwater speaker when high power is required.
The Lubell Labs LL1424HP has a useful frequency range of 200 Hz - 9 kHz, a maximum SPL of 197dB/uPa/m @ 600Hz, and a nominal impedance of 4 ohms (varies with frequency - see US Navy Z plot or tabular data). The LL-1424HP is intended for use in rivers, lake, and ocean by virtue of it's rugged MIL-A-8625 Type III hard coat anodize, and 8 mil PPG Amerlock II epoxy finish. The LL1424HP comes mounted in a heavy duty 316 stainless steel cage with an isolation mounting system.
The Lubell Labs LL1424HP is fitted with a Subconn MCBH3MAS underwater mateable bulkhead connector, and includes a mating 50 foot 16/3 Subconn SOOW cable fitted with Speakon NL4FC connector for connection to Lubell LL1424HP transformer box. Custom SOOW cable assemblies of varying lengths and gauges may be special ordered -- please allow 8 - 12 week lead time for delivery.
Included with the Lubell LL1424HP is a Lubell Labs AC1424HP transformer box, which connects between the LL1424HP transducer and the Crown CDi2000 amplifier (not included). The AC1424HP transformer box is a key element in the overall system design, providing tuned RCL circuitry for proper impedance and response of the connected LL1424HP transducer, as well as electrical isolation of the LL1424HP transducer housing.
Lubell Labs recommends the Crown CDi2000 amplifier, which uses Class AB topology to remain stable when driving reactive loads such as the Lubell Labs LL1424HP. Here are three possible connection schemes:
We can easily determine the SPL of the LL1424HP at a given frequency and drive voltage. For example (referring to the LL1424HP TVR column in the tabular data), we see that at 600 Hz, the output of the LL1424HP is 158.07dB/uPa/volt. To derive SPL, calculate the voltage gain and add to TVR value. Voltage gain (dB) = 20 x log (ending voltage / beginning voltage). For 80 Vrms drive, we calculate a gain of 38.06dB which is added to the 158.07dB TVR value resulting in an SPL of 196dB/uPa/m.
Our maximum voltage and current rating for the AC1424HP / LL1424HP across the frequency band of 200Hz - 9000Hz is 80 Vrms or 10 Amperes, whichever comes first. Monitoring the amplifier's drive voltage (with a True RMS DVOM) and current (with ammeter) is of utmost importance when setting up and monitoring the system. Our tabular data (from NUWC-Dodge Pond) may be referred to as well, but values will vary from published values depending on the water depth and conditions.