HRS M3 vs Symposium Ultra platform

Has any one had any experience with either of these platforms? I'm looking to place one under my CD player.
Seems to be a huge difference in price.
Hi, I've used the Symposion Ultra's before under a tube pre amp (bat vk51se), digital (esoteric dv50s), and a turntable (sme 20/2).

All benefited. Honesty I wish I never sold them.

I can say that better isolation is a good thing. I haven't heard the HRS, the Symposioum should be very noticable, it's not subtle and all good.
I use Ultra platforms under my amps and under my linestage, and Svelte Shelves under my speakers. Symposium products do a good job dissipating vibrations. A friend has a huge HRS rack and shelves which, at least in terms of construction, looks and finish, are in an enirely different class.

These are tuning devices, meaning that it is impossible to say whether their effect will be positive or even negative absent trial. It would be easier to tweak systems if "more" were always better, but that is NOT the case. In a friend's system, I heard the effect of using an Ultra shelf under an Aero Capitole CD player. The shelf had a dramatic effect, but, in this particular system, that effect was entirely negative (sound became way too lean and dry) to everyone who participated in the trial. I've heard this sort of thing with other CD players as well. My own CD player (Naim CD555) seemed relatively immune to the effects of such platforms or use of rollerball type couplers.

Isolation devices and devices that dissipate vibrations as heat, and all other similar tweaks, have to be tried in a system to determine if they will improve the sound. Yes, they "work" in terms of altering the sound, but, that could be either a good thing or a bad thing.
Are you saying that these tweaks have there own sonic signatures?
I've use the Symposium Svelte and Super shelves and find them very effective under speakers, amps, and CD/turntables.

However, most of my components rest on Symposium Rollerblocks because they're just as effective and more flexible. The double-stack configuration with tungsten (or Superball) is particularly good for CD players and turntables. The result is significantly more detail throughout and less background noise and hash.

Keep in mind that the Ultra shelf is 3.5" thick, and the stock sizes might not fit your rack or CD player. The other advantage is that the Rollerblocks can handle footfalls. My VPI turntable never skips when someone walks on my springy hardwood floor.

Symposium is widely available so you can try the shelves or Rollerblocks and recoup your cost if you don't like them.

BTW, I was quite surprised that my power conditioner really benefitted from good isolation. It seems that even a "passive" conditioner (eg. Nordost Thor) needs vibration dissipation.

Those tweaks that "work" (affect the sound) have a sonic signature. Most of the time, dampening vibration is desirable, particularly because it improves clarity and resolution. But, I am just warning that whether one likes the result is a matter of taste, system tuning and synergy. That is particularly the case with components like speakers and turntables. A turntable that effectively controls internally generated vibration and blocks external vibration may be described by some as quiet and well behaved, while others might characterize that same table as lifeless--it is a matter of taste and how each component interacts with or complements others.

Because CD players are mechanical devices, they generate a lot of vibration internally and are probably sensitive to external vibration so shelves or rollerblocks would normally be expected to have a substantial impact on the sound. More often than not, I would expect a positive effect, but, there is the possibility you won't like the effect.

I have also heard amps placed on Silent Running Audio (SRA)platforms. Those are quite effective too, but can be quite expensive. Like the HRS platforms, the SRA platforms are customized for each particular component (the weight and weight distribution of the component is factored into the design so that the dampening layers are optimally compressed).

Another caveat: It is easy to get caught up in certain obvious improvements, like greater clarity and resolution of detail, and end up losing something else that is harder to quantify or explicitly recognize ("musicality" or repose and grace). I've done this myself with certain tweaks. I wish it were the case that there is a defined formula or path for "improvement," but it really is not that simple.
Hi Larry
I agree with what your saying especially "It is easy to get caught up in certain obvious improvements, like greater clarity and resolution of detail, and end up losing something else that is harder to quantify or explicitly recognize ("musicality" or repose and grace)."
I would suggest that the HRS does not have a sonic signature. It does not tip the top end to create hyperdetail. It does not add warmth to the midrange. It does not lower the bass. It simply removes component generated vibrations so you hear your equipment. Whatever you put on it, you will get more.

Many products remove certain vibrations but not all. This results in a sonic coloration. Whether you talk about a shelf, footer, or rack, most will do some things. And many of those things are sonically fine. If you need to speed-up the sound, or slow-down the sound, then this can be accomplished at many price points. The HRS just results in a purity and clarity, IMO. It may not hit you over the head on a brief audition, but I think it is the foundation of a long-term satisfying system.

I would suggest you try an HRS platform when one comes-up used. If you don't hear a difference, you could probably sell for very little loss. Consider supplementing with the HRS nimbus footers as well and allow some time to allow your ears to adjust to what it does.
The HRS is far superior to the SU stuff. I had both. If you want one of best get the HRS.

RTN has it right.