Schoeps UMS20 Isolation question

[MPemulis]

Hoping someone can help me out. 

Picked up a UMS20 bar to use with my schoeps MK4 and CMC1s, and am having a hard time figuring out how to use this combination with some vibration isolation.

• I saw in the UMS20 manual that the A20S suspensions could be used in lieu of the SG20 clips, and thought that would be a solid approach, and that I could just pop the clips off and replace them with the suspensions. So I picked up two of the A20s to use, and it's like the orientation of the mic holder is wrong, I can't figure out how to make them work. (Pic for clarity of what I am saying, it's like the mic goes across the wrong axis). Am I missing something? Did schoeps change the orientation of the A20S or something? 
• I tried using an A20S on the top end of the mic stand, but it feels like the suspension is not really strong enough for all the weight of the Cables and mics, everything kind of wants to tilt around and it doesn't feel ship shape to me. 

Anyone have a UMS20 who can shed some light on how I might solve this problem? 

[DSatz]

I've never owned or used one of these, but it's my understanding that you leave the clips on the bar alone, and suspend the entire thing by its handle in the A 20 S.

[edited later to add:] yes, according to the old, original flyer (see below) that's how they intended it to be done.

[goodcooker]

The stiffer A20S mount should do a fine job of isolating the entire bar if you add an extension to the bar's mounting screw. This is the same arrangement that I used with my Vark bar and MK41 active mics - clips for the mics and a single shock mount for the bar. The short CMC1 amplifiers shouldn't need to be "crossed over" to get ORTF or other closely spaced arrangements like DINa.

[MPemulis]

ok, helpful experience/thinking here, thank you. 

I am finding when I try the single A20 mounting the clip/bar, it just initially feels like the mics/bar are too heavy for the suspension, but I will play around with it and if I can get it more dialed in. still think it's weird you can't just add the suspensions where you mount the mics, but just because it's weird doesn't mean it isn't so. 

[DSatz]

I think that's a basic misunderstanding about the design of the product. You only needed to buy one A 20 S, not a pair of them. The two microphone holders that are part of the UMS 20 aren't the normal (SG 20) stand adapters; they pivot differently, and their exact heights are chosen so that the indicated stereo arrangements can be set up using the full-length amplifiers that existed back when the UMS 20 was invented.

The two microphones don't require isolation from each other; they need isolation from the mike stand or whatever else (railing, etc.) is supporting the entire fixture. To whatever degree mechanical disturbances can be filtered out before entering the stereo bar itself, they won't reach either microphone.

(Attached: The other side of the original product flyer)

[MPemulis]

To be clear, the second pic I posted originally is an A20S used the way that you both are suggesting, but the weight of the mics and cables causes it to feel overloaded and tilt too far forward, and it just doesn't quite feel or look quite right. 

[DSatz]

Hmmm, so it is.

Just in general, a lot depends on what kind of worst-case disturbance you're trying to protect against. A relatively loose (easily movable) suspension is a good thing up to a point--but if someone really whacks your stand, you don't want the range of motion to reach its limit and have any hard mechanical parts pushed into hitting one another, or the whole setup not restoring itself correctly to center. A stiffer suspension will prevent the suspended part from crashing into the edge of the suspension and will recenter itself more quickly after any disturbance--but at the very real cost of passing more noise along to the microphone. No one arrangement can be ideal for all possible mishap scenarios.  If some damn fool walks right into your mike stand there will be noise, no way around it.

You're already reducing the risk by using microphones with lower mass. A remote capsule setup, or one with CMC 1L amplifiers, would be even better, but of course that would require a different holder.

-- I see that Schoeps has released the AC 20 shock mounts that I saw in development the last time I was over there. ( https://schoeps.de/en/products/accessories/clamps-suspensions/ac-20.html ) They come with two strengths of elastic for either end, which are much more easily interchangeable than the elastics are on the A 20 or A 20 S. There are also new entries from Radius and Cinela (I happen to be especially impressed with Radius). Schoeps works closely with both of those companies, and distributes their products even though they compete with Schoeps' own. All these products benefit from materials and manufacturing processes that weren't an option in 1974.

-- This won't help you in your current situation but again, in general, pressure transducers (single-diaphragm omnis) are less sensitive to solid-borne noise than pressure-gradient transducers are, just as they are less sensitive to wind and breath noise, by maybe 20 dB--which surely helps, but won't make you completely invulnerable. (The in-between steps are in-between, e.g. an MK 21 is distinctly less sensitive to shock and wind noise than an MK 4 or MK 41 but more sensitive than an MK 2S, while the MK 8 is the most shock- and wind-sensitive of all.)