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Gear / Technical Help => Microphones & Setup => Topic started by: noahbickart on December 10, 2017, 01:43:56 AM

Title: Necessity for shock mounts for Omnis?
Post by: noahbickart on December 10, 2017, 01:43:56 AM
Like most "open" concert tapers these days, I'm accustomed to using shock-mounts. I run schoeps "active" cables; and 3d printed bars wich hold multiplr pairs of capsules in Rycote shocks.

I'm experimenting with spacing some omnis in addition to the near coincident pairs, and am wondering if my enormous and stiff rycotes are even worth their weight on the stand, given how much less susceptible omnis are to movement and wind.

Any thoughts on mounting omnis (in my case schoeps mk3 [now renamed to mk2xs]) without shock-mounts? The followingbob 24" bar and tiny clips would be so low pro.
Title: Re: Necessity for shock mounts for Omnis?
Post by: DSatz on December 10, 2017, 10:14:32 PM
As a rule of thumb, you could figure that a pressure transducer will be maybe 20 dB less sensitive both to wind/breath noise and to solid-borne sound than a comparable pressure-gradient transducer. This is largely because of the higher membrane tension.

Now, 20 dB of protection is definitely nice--enough, in many cases, to make the difference between a ruined recording and one that's merely impaired. But interfering noise (either from wind or from something bumping into your setup) can very well cause higher signal levels than the loudest program material that you're recording that night; it can cause preamp overload or even microphone overload, neither of which you can filter out later.

If any interfering noise is audible in a recording (even at only a moderate level), and you know that you could have prevented some of it, I think you're likely to wish that you had done so. And unfortunately, sometimes one doesn't realize the risk that something will occur until it has already occurred.

--best regards
Title: Re: Necessity for shock mounts for Omnis?
Post by: John Willett on December 11, 2017, 08:03:56 AM
I always use shock mounts - AND - I always also use the thin and flexible Rycote XLR tails to minimise and noise being transmitted up the cable.
Title: Re: Necessity for shock mounts for Omnis?
Post by: Gutbucket on December 11, 2017, 10:15:02 AM
Practicality dictates the answer for me.  I'll use shockmounts when I can and if they are easy to include, usually as a simple and practical way to mount the microphones.  If I can't then I'll retain the setup geometry I want, achieving it in the most practical way foregoing shocks.  Have had only a couple instances where I wish I'd used them yet didn't, but innumerable instances where I was glad I didn't compromise the microphone setup I wanted to use just because I couldn't run shocks.  Maybe I've been lucky, but I just don't worry much about structure-borne noise and shock mounting.  Wind-noise is an entirely different issue though and I am much more concerned about taking precautions to prevent that when necessary.  That's with directional mics.

I don't think I've ever used a proper shock-mount with the miniature DPA 4060/4061 omnis I use.  They don't have sufficient mass for a shock mount to work anyway, unless I was to mount them directly to a weight or something.  Recall that a shock-mount works as a mass/spring system tuned to an especially low fundamental resonance frequency - the compliance of the spring must increase (become more flexible) as the mass of the microphone decreases in order to keep the resonant frequency low enough to be effective, otherwise the shock mount isn't doing any significant vibration-relieving.
Title: Re: Necessity for shock mounts for Omnis?
Post by: Gutbucket on December 11, 2017, 10:46:10 AM
The one microphone I have for which I always try to use shock-mounting as well as sufficient wind protection is the TetraMic.  It uses EQ calibration corrections to provide flat bi-directional response down to very low frequencies, making it significantly more susceptible to both wind and structure-borne noise than any of my other mics.  Sort of the opposite of a straight pressure-omni in that way.