FedEx Tracking showing a very low weight for my order?

So I ordered a home theater system (htib) and it was supposed to weigh about 70lbs, but on the tracking form online the weight came up as 15 lbs....is is possible that there was an error? I see no possible way that the package weighs 15lbs other than if it was tampered with. Btw, the system is the Onkyo HT-S5400, look it up on amazon the weight is supposed to be around 70lbs. Thanks, and help is greatly appreciated!