is D class that much better than a/b?

[helotaxi 5,000+ posts]

They are much more prevelant in home audio than car audio at the moment (which seems backwards, given car audio's demand for lower current draw & smaller chassis size)....but Xtant, Alpine, Altomobile and Eclipse have full range class D amplifiers as does Lanzar. There are more, but they aren't coming to me at the moment.

Add in the amps in many small radios currently made.

JL has a line of full range Class D coming out soon, too.

Tripath amps are a different topology. Theyare a switchmode design but are not a Class D amp. They vary the switching freq with the freq being produced and with it vary the efficiency of the amp. More efficient at lower freqs, but that's where you get the most benefit anyway.