Buying in Canada

Must declare purpose of visit; business or other. Upon return to US, must report to customs any items purchased (with receipts) and the value. Big ticket items will be inspected and possibly checked for current market value.

worst case scenario...returning from Canada with top of the line speakers and declaring their value too low to avoid paying customs charges. You will be interviewed.
I have first hand knowledge with undervaluing a Harley.

You should google US Customs fees. You are allowed up to a certain amount without charge. But I'll bet HiFi gear is over that limit. cheers.

take Elizabeth's advice. I got in trouble w/ customs cause I declared the value way too low, and they knew Harleys were much more expensive. My buddy and I were foolish, I think you'll be fine.