It’s very important that the amplifier system has an equalizer and a limiter or compressor in order to protect the
loudspeaker form excessive power.
In particular, all frequencies under 300Hz must be attenuated by at least 12 dB to reduce distortion and to prevent
the voice coil from overheating, and frequencies above 2000 Hz should be amplified by at least 10 dB.
It’s important to calibrate the limiter in order to prevent saturation of the amplifier and prevent the loudspeakers
from passing 60w RMS.
As you cannot listen to music outside water if you haven’t a limiter you cannot control the sound volume, so the
loudspeakers may be damaged.
Normative reference
EN 60529-97 Protection (IPX8) for continuos immersion
CEI 64-8/7 Sez. 702 (update.06/2003) - Electrical system for swimming pools and
water fountain
EN 60598 Parte 2 Sez.18 Lighting equipment for swimming pools
EN 61558 -1 Safety transformers
EN 60065 (Agg 01/2003) Safety requisition for audio-video equipment
EN 61000 - 6 - 1
Electromagnetic Immunity