If you have a good floor the last thing you want to do is decouple the speaker from the floor. Ideally you would bolt it down to the floor. Spikes are the usual option. Why? Newton's 3rd law. You need a very massive, fixed mass (the floor) to control the reactive forces or the speaker shakes. Play a 20 Hz test tone and put your hand on the speaker. What you feel = distortion. Now spike the speaker to the floor and you will feel less shaking. You might also notice more aggressive bass. I'm afraid this whole speaker decoupling gig is an example of lay intuition. If a floor is so bad that it resonates in the audio band then fix the floor. Most floors dampened by carpet might only resonate in the 5 to 10 Hz range, great for causing footfall problems with turntables but not a problem for loudspeakers.
You might want to consider a MiniDSP SHD Studio. This assumes you have your own DACs. It uses Dirac Live which is similar to ARC. This unit is $1,300 and includes streaming. Benchmark Media Systems uses a Studio with their own DACs and is super pleased with the results. It also includes subwoofer crossovers and bass management.
