Well, I went along with Northwards advice, to kill another one of those devilish details and stop any rocking from the cabinet backwards-forwards when music is playing. Not as elegant a solution as Northwards design where tensioned wires are compressing springs versus the cabinet, flush mounted in a glass wall (if I remember correctly). But, …, it seems to work quite well.

The first two pictures show a mock up of the idea and the 3rd when the device is in place between cabinet and the structure of my doghouse opening. It is a quite simple solution to install: An Allen screw of appropriate length goes through the doghouse structure and into a kind of hurricane nut which is forced into the wood from beneath when the Allen screw is tightened. There is about 10 mm / 3/8” of free screw length down towards the cabinet underneath after tensioning. On the free length, a washer and a nut is threaded on. The nut can then be tensioned versus a piece of rubber which is placed on top of the cabinet. To check for a correct compression of the vibration dampers under the cabinet and reach optimal lowest resonance, a calipers was used to measure the compressed height between cabinet and the structure (shelve / floor).

I didn’t have an accelerometer / contact microphone or stethoscope, so I used the old foreman trick. –A wooden dowel pressed to the ear, the other end of it first on the cabinet and then the doghouse structure. Not much noise from the cabinet itself really and substantially less, next to nothing, from the doghouse structure. So, the rubber shims between cabinet and tensioned nut seem to work well to prevent transmitting cabinet vibrations. There is one on each upper corner of the cabinet and the cabinet does only move ever so slightly if I push on it with substantial force with both hands now. The air gap between cabinet and the structure will be closed off with some cell foam later on.