Raven said "egg-crate style packing *foam*......it's the closest thing you can get to floating your gear on air - and if isolation is the best solution for you, this will let you know on the cheap."I really wish my explorations here could support this Raven.
Roughly speaking, and aside from foot design/shape attributes, I have noticed that feet of a given material tend to sound sort of like itself ...metal sounds hard and brighter, hardwood sounds a little softer, soft wood is softer yet, but still articulate....and at the other end, sorbithane sounds mushy and uneven in its peculiar way.
With egg crate, there are variables of shape, thickness, petro formula and density---the proportion material-to-air. And how much material we hear relative to air is again effected by the weight of what we put on it. I retested it to check my memory, and maybe its the remaining air after compression from the amp that gives it a sense of neutrality, but compared to isocups, I hear reductions in extension on both ends, detail (especially micro and inner detail) and dynamics, macro and micro...The MKIV is heavy, but this test reminds me of when I have tried it before, and for me, foam is not the ideal reference for whether or not good feet would help my music.
Isocups seem to drain amp vibrations while also keeping shelf vibrations from getting to the amp. I think the Herbie's explanation sounds pretty right from my experience if you are interested:
http://herbiesaudiolab.net/compfeet.htmWith Decware feet, we are deciding to use hard rubber with the particular sound it allows/imparts.
I have never had any two foot types sound the same, and all I have tried do effect the sound. And I have not by any means heard it all, gravitating to DIY, and the less costly ones others have found effective, and that can be returned. It is all choices, and like everything else, how it works here or there depends on where we start. Maybe Decware feet will sound better to some, but this is not the case for me.
But the reason I decided to play around with feet was not this. My sound, always tuned into a pretty specific balance, I found the RAMdisk had cleaned it over the top. I had been tuning to musically balanced detail and clarity, in part compensating for unknown distortions introduced by my hard drive running my player software. My Mini is tweaked and damped pretty heavy, and Pure Music plays files entirely from memory, and the app and I have cut a lot of system stuff off (I even went into terminal so I could quit the Finder, and yes you can hear it). So it is amazing to me that by putting Pure Music into RAM (no music files), the sound changes as much as it does. It was enough to blow my carefully found balance of clarity with musicality...at least with lesser quality recordings.
In this balance, the minor distortion I was getting from my drive was actually pleasant, giving a slight softening sense of musical blending and texture. This is part of why it was hard to decide which I liked better at first. But compared with the RAMdisk, it is clearly noise induced.
Looking at the whole, there is the thing that tubes can introduce various levels of "inaccuracies" in compression, distortions, harmonics, frequency balance, and so on, but we tube heads really like them for giving a sense of beauty and realness to music! And where is the limit of cleanliness? I seriously doubt if any of my gear was voiced with Ramdisk clarity, nor Pure Music. But it is seductive...so I of course dig in.
With new sound changes, if I play with feet, or cables, or both, I can often find balance again. In this case I needed to take the edge off of a too-clean sound, to keep the clarity but more musically.
Before, trying for a smooth but still open sound, and more bass definition, I had put Jasper gemstones in the back amp isocups, between the transformer outer corners and speaker terminals. By putting back supersonic hardballs, and moving all four around a bit, the overly clarified qualities the Ramdisk exposed softened, the sound still open, dynamic and detailed, but friendlier.
On Vyokyong's advice, I bought some Soundcoat damping sheet from partconnexion. I decided to try it in the place of Herbie's grungebuster, grungebuster being a soft, rubbery material and wondering what the harder soundcoat would sound like under a shelf, the feet of the Mini, and under my Firewire drive that has the music. The grungebuster helped when I first put it in, cutting vibration. But I recalled I generally don't like Herbies Tenderfeet and they are sort of rubbery. The grungebuster is even more soft. Is it softening the sound too much?
I agree with Vyokyong on first impressions. The soundcoat sounds good, with the soundstage seeming a touch more clear, and with a tighter, but musical sound. I think it increased dynamics a bit too, but I need to play around more.... I may play with a combination of grungebusters and it next.
Anyway, I think we can safely say the RAMdisk has proven (once again) that noise from electronics, vibration induced and/or otherwise, effects the sound.