[Wayner]

I'd say it doesn't make much difference at all (except for maybe a TT). Of course it should be sturdy and level, but to go way beyond is well.......pointless.

[mcgsxr]

25 years ago I built a flexi rack using 2x6 pine laminated to build the 17x26 shelves.  I now have that entire rack in a separate room so truly isolated.

[g3rain1]

High density materials can transfer vibrations well internally. They don't absorb or transmit vibrations well from lower density mediums, like air, unless they strongly coupled, like to the floor. Generally speaking pressure waves don't like changing mediums of differing density.

So a dense rack that is isolated from the floor will perform well. Isolating the equipment from the rack will improve things further.

[FullRangeMan]

For vibration isolation there should be several layers of different materials such as>
- Soft rubber 10mm
- Cork 5mm
- Felt 5mm or more
- Aluminum 3mm or other non-magnetic metal
This sandwich is suitable for isolation feets, but can be use in racks also.
Iam using aluminium 10mm.

[FullRangeMan]

[underdog64]

Google -Mana Acoustics (No longer made).Design completely opposed to just about everything before or since but mostly superior to everything before or since

[genjamon]

Anyone every try bubblewrap between wood platform and shelf - as an absorption/dampening layer of a sandwich?  Poor-man's "inflatable bladder" as JLM mentioned?  I tried it many years and four homes ago, when I had a not-so-robust suspended wood floor listening room over a crawl space that seemed to vibrate a fair bit.  Can't remember how that sounded, though.

[jpm]

But the rack should be  between the loudspeakers and kept as low as possible to avoid disrupting the sound stage and minimize speaker cable lengths.

I've seen manufacturers urge people never to site their equipment between speakers but instead to use longer speaker cables and locate equipment to one side. I don't take a position either way (my equipment is between my speakers) but food for thought.

[JakeJ]

My racks are long out of production AV123 short 3 shelf units that are very rigid and I glued Herbie's Giant Fat Gliders on each leg.  Each component is isolated by some form of Herbie's product.  Most are Tenderfeet, Fat Dots, or Baby Booties.  Although I have not used an accelerometer to measure the effectiveness of the devices, my ears do detect better clarity in the system.  I make sure the mechanical units (spinners, turntables, valve gear, etc) get the better ones and components with no moving parts (SS gear, DACs, tuners, etc) get less attention.

That's my general approach.  I think vibration isolation is dealt with in two disciplines of thought, mass and rigidity, or suspension and flexibilty.  To couple or to uncouple, that is the question.  Of course any combination of these two schools can produce better results.

[JLM]

Intuition doesn't work for vibrational analysis (racks and acoustical panels).

[FullRangeMan]

I've seen manufacturers urge people never to site their equipment between speakers but instead to use longer speaker cables and locate equipment to one side. I don't take a position either way (my equipment is between my speakers) but food for thought.

Any solid object between the speakers will block the soundstage forming.
Its an obvious fact but must people dont know this, so some manufacturers aware of their customers level make this warning or recommendation.

[Freo-1]

I solved my speaker vibration issue by having tempered 3/8 inch tempered glass panels made to set the speakers on. The speakers are ATC SCM 40 V2 with spikes, and the floor is oak hardwood.  This solution works very well.