I would ask Icotec, but from my experience with it is that it will keep the volume roughly the same output, you just have another channel. Which will reduce the battery power some but from comparing it to a foxpro banshee and flx500. The Icotec battery life is WAY better (I'm aware its not quite as loud). When the sound is not playing (icotec) the amplifier is off where as the others or at least foxpro you are just muting the sound but still pulling the power from the amp.
If you are semi electronically savvy I would recommend replacing the speaker with more efficient and better frequency range one similar to the TOA 610 or Speco spc12 (or something comparable). At 1 meter I gained somewhere around 6dB I believe, and had better low and high range.
