For quality sound.....one word. ...Sub Woofer, Sub Woofer, Sub Woofer.
I won't disagree but have to point to the chuckle we shared with Donnybrook's post... He was upset about the current draw of a standard radio at 2.5 amps. Due to the fact that as frequencies get lower the energy required to reproduce them goes up logarithmically, true bass takes a lot more power.
I have a proprietary 5-channel amplifier in my sailboat that is über efficient but it has a potential max current draw of 30A. That's a commitment on a boat that uses wind as power.
The best retail subwoofer amp in the product line I sell in terms of efficiency s 92% efficient, as it is a very specialized amp designed to drive a super-low 1/2-ohm load, (dual 1-ohm voice coil woofer with the coils wired in parallel). It still has a max draw of 15 amps. For a sailboat where you aren't dealing with wind or engine noise you would probably use a fraction of its capability so maybe 5 amps.
I'm all for it and will help design systems with bass but it comes with real expectations regarding battery consumption... It's easy to stay under 30 amps but much tougher to stay under 10.
FYI
