Spikes/isolation

[realysm42]

Okay, what do you use, if anything?

Has anyone tried anything more that vanilla spikes (for example polycrystal spikes) and could you hear much of a difference?

[YNWaN]

Spikes couple rather than isolate. How a spike is made and what it is made of will alter the way that it couples the two surfaces it is between.

[bobbasrah]

Spikes couple rather than isolate. How a spike is made and what it is made of will alter the way that it couples the two surfaces it is between.

The coupling interface on the spike will only allow transference of certain frequency ranges and depends heavily on the structure above and below that interface. HORIZONAL movement is restricted or coupled however which is important with speakers, but again the frequencies passing through are limited.
eg My speaker stands are hardwood trays infilled with sand. The speaker sit on hard rubber washers onto the stand frame, the frame is then set on threaded hardened steel spikes to the laminate floor over concrete. The behaviour of this combination is quite surprising in that little if any sound passes into the structure. The same findings were made with harwood parquet directly laid on concrete. It is only fair to note that these are incredibly heavy speakers.

[YNWaN]

Well, I would say that the structure is more effectively coupled at some frequencies than it is at others; and that the structure is also coupled in terms of physical displacement. Adding a compliant element obviously reduces the level of coupling, but this will also be frequency and amplitude dependant.

But, in general, I agree.

[realysm42]

Thanks for the information guys; can you help me understand the difference between coupling and isolation?

[YNWaN]

Well the concepts are polar opposites, at one end of the scale the component is entirely isolated from its surroundings, at the other end it is entirely coupled. However, in reality, an element of both exists.

[bobbasrah]

And just to muddy the waters a little, most isolators decouple or isolate the device only over some frequencies, some passes through, and some is reflected back into the device. So they are not broadband isolators.....
Vibration in the end is energy, and absorbing the energy is like your vehicle dampers in that this is converted into heat.

One odd example of this is the experiments many of the Technics lads here try with various turntable feet with differing results. Some feet work better than others, but as it is a solid plinth, I suspect they are alter dampening of the plinth and interaction with whatever they are parked on, in short tuning the plinth.

Cheap trials to see any effects are easy enough with cork, insoles, squash balls, sorbothane, cellular foam, beer mats, ceramic or glass coasters, etc.......
Insoles should be new, or at least removed from the boots......

[realysm42]

That's what I like to hear, nice and simple :)