Before you buy anything, gather enough heavy books to lay a stack of 6 on each of the feet (eight total) of your pair of 1.7s.
Leave them on for a few days and play music. See if the sound is cleaner, better focused, and at least as musically involving as before, if not better.
If this proof of concept works, you might try getting two sets of these sandbags made for holding camera, microphone, and light stand tripods stable.http://www.amazon.com/gp/product/B00CXUT5ZG/ref=pe_851860_152867710_em_1p_0_ti
I did this and bought the sandbags, filled quart Zip-Loc bags with sand and stuffed one inside each sandbag. It was a very nice improvement with no downside for a total of $33.00. Also, if you aren’t using the nylon washer spacers to tilt your 1.7s back a little, do it.