Audio is actually still one of the sole remaining industries of which a significant portion is still made and/or assembled in America, especially the high end brands. The List – American Made Audio
In addition to alot of the good answers here about home and portable audio, I would also like to add that as a guitarist, a significant chunk of high end guitars and amps are still made in the USA as well. Fender’s American made guitars, Gibson’s guitars, Gretsch, Guild, G&L and boutique brands like PRS, Suhr are all made in USA. Fender, Mesa Boogie and some boutique brands like Two-Rock, Swart, Milkman (What I personally have), Tone King, Greer, Matchless etc are all made in the USA.
Guitar pickups especially the handmade guitar pickup industry (giants like Seymour Duncan, Dimarzio and smaller ones like Lindy Fralin, Lollar etc) are all made in the USA sometimes by just one guy in his home, somewhere.
Boutique guitar pedals are all made in the USA as well. Wampler, Keeley, JHS, Earthquaker, Xotic, etc
So I’d say if you really want to buy made in USA products, the high end or boutique audio/guitar industry is a good bet.