I was worried we could never resolve the subsonic response but these did the trick. After setting these up and leveling the turn table we can crank it up as loud as we want without distortion! Just what we were looking for.

Got these for a new NAS with super noisy spinning hard disks, it didn't work by itself very well as most of the noise was still transferring to the wooden bookshelf and making noises. I add some rubber isolating half domes on top of these and they killed a whole lot of the noise, then these are good enough to kill the remainder of the vibrations so only around 5-10% of the original noise can be heard at the worst of times - amazing.

I have a 15 inch powered subwoofer in my house I used these to decouple it from the floor. In my opinion the bass hits harder and doesn’t make so much resonance throughout the house

The Nobsound Spring footers work very well to both isolate your equipment from external vibration and draw any vibrations generated by your devices out and away. The most notable benefits to audio equipment include improved center fill and depth of the sound stage as well as improved imaging. These spring units outperform Vibrapods, Cardas myrtlewood blocks, Sorbathane pucks, spiked feet, and thick maple platforms (and, for the most part, cost less). All of my equipment, including turntable, phono preamp, line stage, CD transport, DAC, amplifiers, tube headphone amp, and streamer are supported by these footers. Yes, even the electronics without moving parts (such as DAC, streamer, solid state and tubed devices) benefit, though to different degrees, as very low level vibrations generated by power supplies and such are carried any from the devices. The more resolving the equipment, the more apparent the benefit. These spring footers can also counter problems such as turntables disturbed by footfalls, but only to a mild-to-moderate degree. Further overall benefit is derived when used in combination with a quality equipment stand. As for UHD disk player, audio performance is again improved but for video the benefit appears minimal. Highly recommended, but YMMV.

I use 4 of these (4 springs each) [8 total] under pair of Elac Debut 6.2 speakers. Honestly, I can't tell a real difference, but it keeps the person on the other side of a party wall from complaining. Good enough reason for me.