9484 FAQ

FAQ's will be added as questions are submitted to


SEALING THE CONDUIT

Question:
  I am using Lubell swimming pool speaker (underwater). I am facing difficulty to water proof connection of cable through conduit hub. Is there any requirement of cable gland to fix in 1/2" conduit hub? --NM

Answer: Wet-niches designed for underwater luminaries / speakers have flooded conduit design by nature. It is for this reason that the opposite end of the conduit must be elevated above the pool's water line (as dictated by Local, National, and International Electrical Code -- 8" minimum typical) and terminated inside a junction box. If the pool is in a location not subject to freezing, then generally no additional precautions are required. If pool is in location subject to freezing, then conduit/hub area inside wet-niche is sealed with sealing compound (as prescribed by Local, National, International Electrical Code), and RV type anti-freeze is poured inside sealed conduit as secondary protection.

AMPLIFIER REQUIREMENTS


Question:
Can any amplifier be used to power the 9484 in wall pool speaker?

Answer: An amplifier rated up to 78 watts rms @ 8 ohms (25 Vrms) may be used to power one or two of the 9484-25V-*** speaker kits, providing amplifier has UL or ETL listing label, and has a three prong power cord connected to a grounded GFCI power outlet per National Electrical Code.  Each LL916 UW speaker / AC205B transformer box circuit presents a 16 ohm load; Multiple circuits must be wired in parallel only, observing minimum impedance rating of amplifier. Commercial sound amplifiers having 25V output (NOT 70V output) may be used -- allow 37.5 watts amplifier power times each Lubell speaker and transformer hung on the 25V line.  Again insure that amplifier has UL or ETL safety marking, and has a three prong power cord connected to a grounded GFCI power outlet per National Electrical Code.


REMOTE VOLUME CONTROL

Question:  Can an L-pad or autoformer volume control be installed between the speaker/transformer and the amplifier?

Answer:  No.  The Lubell underwater speaker is a reactive piezoelectric speaker providing a primarily capacitive load to the amplifier.  Inserting a variable resistor or autoformer between the capacitive speaker and the amplifier will result in an alteration of the frequency response as the volume is changed.  For this reason, use a remote volume control that changes line level signal to the amplifier.