West, the modern inverters are actually rather efficient, over 90% when loaded near capacity. However, they may be electrically noisy depending on quality and intended use.

Some inverters output a genuine sinewave, and have been used extensively for mobile audio/video equipment. The more popular (cheaper) inverters output what's called a modified sinewave (although modified squarewave would be a little more accurate).

What might be a compromise is a mix: for the visible (and low-current) components, use typical 120-v equipment, powered by a genuine-sinewave inverter, and for (the high-current) amplification, use hidden automotive amps, run directly from a battery.

Of course, it's no secret that high-power automotive amps use built-in inverters, so don't assume that an all-12v audio or AV system is inverter-free. The main difference is that amps use ultrasonic frequencies, which allow smaller (and lighter) transformers.

Even planes use 400 Hz for the same reason. Anyway, you should make sure the RV has separate engine-starting and use-while-parked batteries, so they won't find the RV's battery too dead to start.

Larry
www.fineelectricco.com