January
2022

To couple or not

It's not about getting married or having sex. It's about spikes versus isolators, specifically under heavily heaving kit like subwoofers and full-range speakers. If you're of the view that our floor shouldn't amplify mechanical resonances to add those to our transducers' sound delayed in time, you need disruptive not coupling tech. I've practiced that credo for a while now with HifiStay's multi-level ball-bearing footers which isolate my upstairs rack, speakers and sub.

When Martin Gateley's dual 15-inch DSUB 15 hit our downstairs disco, I quickly replaced his stock couplers with HifiStay decouplers. Those went far in minimizing bass knots that were structural in nature. They just didn't go all the way. As synchronicity would have it, into the breach stepped Jeffrey Jenkins' enormous Carbide Footers from Texas. By combining ball bearings with viscoelastics, they added atop my existing horizontal displacement vertical energy dissipation. Since it's the vertical direction of a jackhammer which mimics how resonating objects on our floor transfer physical resonances into it, it's intuitive that an interruption of that pathway would reap benefits. I was surprised just how effective and audible this action was in cleaning up my low bass whilst stripping it of add-on mechanical micro echoes. It's why the four beneath our new big sub ain't going nowhere.

The footers beneath the 80Hz high-passed speakers turned out to be redundant. The ones beneath the subwoofer already did the job.

Upstairs my smaller 2 x 9½" Dynaudio sub already sat on HifiStay horizontal isolators. Yet replacing their equivalents beneath HifiStay's X-Frame equipment racks with two quads of Carbide footers still registered. It reconfirmed my downstairs experiment that roller bearings alone aren't 100% effective at disrupting the migration of physical pulses from a subwoofer into the floor then onward back up into a rack. Obviously playback SPL and floor construction details will have their say to make suspended wooden flooring more talkative than a concrete slab. Still, heavy industrial equipment like CNC routers and saws already on concrete slabs routinely bolt down through viscoelastics to minimize how much of their noisy operation amplifies in the flooring. We even see viscoelastics between hifi power transformers and their plinths. Our closest/grossest equivalents to industrial bad-vibe generators are subwoofers and full-range speakers. After all, during playback the loudest part of our room is inside the speaker or subwoofer boxes. That energy wants to go somewhere. If you don't think that turning our floors into minor soundboards and our transducers on them into exciters is a good idea… then not to couple is your answer.