I bought 2 used pieces of equipment from Canada several years ago, a phono pre-amp and a CD player. In both cases the seller lived near the border and drove the items into the US and shipped them. They said the border guards never checked. Of course that depends on theĀ check point. One seller said the US site was the nearest FedEx site and people did this all the time, especially for eBay sales. Might be harder with speakers.