Buying speaker and amps from Canada to the US.Tax?

I have both sent items from Canada to the USA, and received items from USA. I have been charged UPS brokerage fees even on items that were produced in Canada. I know that some items have had brokerage fees added on after I have sent them to people in the US. I think UPS is a bit of a rip-off. I have enquired about their brokerage charges, and they say if you use an expedited service such as "2-day", the brokerage charges are included. I have never had any brokerage charges with Canada Post or the US Postal Service.
Duties should only be charged on items originating in non-NAFTA countries.

Thanks a lot everyone... Now I should think if it is really worthwhile to buy gears in Canada... The gears I am interested are heavy ~150lbs (PASS amp and B&W N802) and may require freight service...

I am going through the same consideration. I would get good discount across the border in Canada but I am not sure what to expect on the hassle of duty and paperwork. The speakers are british-made and the components are china-made. Based on my research (checking the tariff schedule downloaded from the US Custom website, chapter 85), I should expect a 4.9% duty of the merchandise. To avoid the shipping cost and the risk of shipping damage, I will probably plan a short vacation there and transport the items back in my van on my return.

Would anyone please share their actual experiences about the duty and the paperworks and the practicality of transporting the merchandise across the border themselve?

Thanks all in advance.

AS with Sc53, I ignored the bill UPS sent me when I bought a used amp and speakers from Canada. Never heard from them again.

Update on my earlier response about ignoring a customs brokerage bill from UPS: Though I have never heard again from UPS, and it's been 18 mos at least, I am currently being dunned by FedEx for an $80 customs brokerage fee on a speaker shipment that FedEx damaged and thus I returned to them for inspection. In other words, I did not keep the speakers. I was going to, but instead of returning them to me, after their inspection, FedEx GROUND returned them to the shipper in Canada! In their broken down abused boxes! Needless to say, they arrived in even worse shape after their second cross-country trip. Now he too has received a bill from the FedEx Customs Brokerage agency for the "service" they delivered in processing the speakers back into Canada to him. Neither he nor I want to pay these bills, but FedEx Ground will not cover customs brokerage fees as part of a claims settlement for damaged goods, and the brokerage company insists they did provide a service when they processed the speakers across the border twice. I tried my old tactic of just ignoring the bill, but this brokerage company is adamant and sends collection notices every month, so I guess I'll have to pay it. The brokerage company did tell me that the fee would not have been charged had my shipper applied for a "NAFTA license," which involved some filling out of forms. So in the future, if you deal with a Canadian seller, ask him up front about the NAFTA license and whether he has it or will apply for it, because if he does the customs fees are waived.