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Gear / Technical Help => Microphones & Setup => Topic started by: voltronic on February 12, 2017, 06:03:43 PM

Title: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: voltronic on February 12, 2017, 06:03:43 PM
After purchasing a Rycote Duo-Lyre 68 to hold a stereo mounting bar, I was surprised to find how much stiffer / less compliant it is than the individual lyres even though the shore rating is rather close to the 62-shore single lyres I was using.  I reached out to Simon Davies at Rycote, and he gave me a detailed reply and also agreed to let me post his responses here.

Here is Simon's explanation for the difference between the single and duo lyres (emphasis mine):

Quote
The single Lyre & Duo-Lyres have many different parameters within their design that allow us to control the overall compliance of the suspension. Shore-hardness is one, and probably the easiest to measure given that it's the material used that sets the hardness. However the difference between the single Lyre & Duo-Lyre isn't just the shore hardness, it's the overall thickness of the Lyres used on the Duo version. As their primary role is for a cantilevered shock-mount, the Duo-Lyres are much thicker than the single Lyre at key points. This means the point at which the Lyre "swings" to allow the compliance up & down becomes much stiffer. This is needed if there is front loading (ie a foam or slip-on windshield). The front/back compliance of the 68-shore Duo-Lyre (the critical compliance for a shotgun or cardioid mic) is actually very close to that of the 72-shore single Lyre - so will indeed feel much stiffer than the softer 62-shore singles.

And from a later reply:

Quote
I'm glad that helped. I'm more than happy for you to share anything I've written. If anyone has any questions, on of my small team will be able to help (here's a link: http://rycote.com/support-form/)

Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: ArchivalAudio on February 13, 2017, 01:45:11 AM
Thanks that's interesting and goo d to know.
So far I really like my DIY Rycote lyre shock mount w/ rapid release
Some day I may try a duo lyre..
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: F.O.Bean on February 13, 2017, 11:12:59 PM
I IMMEDIATELY noticed the difference in stiffness between the single vs. Duo Lyre's, since I switched from the Grey 82 Shore Single Lyre's, to the Black & Grey Duo Lyre's!

After owning both the INV6 & INV6HG's [first], and now the INV-HG mkiii's & SRS Duo Lyre Bases with the Grey & Black Duo Lyre's, I MUCH prefer the stiffer Duo Lyre setups! BUT, I ONLY use my Duo Lyre's to mount 2 & 4 channel setups, and NOT individual mics. So it depends on what you're running to determine which setup you need IMO!

If you're running stereo & 4 channel setups like me, I would just get the INV-HG mkiii or SRS Duo Lyre Base from the get-go, and be 100% DONE with it :) However, if you're running individual mics, I'd definitely consider the 72 Shore Black or 82 Shore Grey SINGLE Lyre's for each mic. Or a single Black/Grey Duo Lyre setup for each individual mic, depending on it's weight capacity! Naks are heavy as shit with their internal batteries, so they might need a Duo Lyre for EACH mic FWIW ;)
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: voltronic on February 14, 2017, 07:50:10 AM
Taking Mr. Davies' explanation and looking at the range of Lyres, it would seem that they progress as follows from softest / most compliant > stiffest / least compliant:

Single Lyre 62 > Single Lyre 72 > Duo-Lyre 68 > Single Lyre 82 > Duo-Lyre 72

(http://mymic.rycote.com/uploadresources/images/Large_LyresTypes.jpg)


NOTE: The URL in the image no longer takes you to this info after the terrible website redesign.  You may find the Lyre info here (http://mymic.rycote.com/products/lyre/).
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: waltmon on February 14, 2017, 09:08:18 AM
Their LD shock mounts look pretty interesting as well.
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: F.O.Bean on February 14, 2017, 12:23:35 PM
Taking Mr. Davies' explanation and looking at the range of Lyres, it would seem that they progress as follows from softest / most compliant > stiffest / least compliant:

Single Lyre 62 > Single Lyre 72 > Duo-Lyre 68 > Single Lyre 82 > Duo-Lyre 72

(http://mymic.rycote.com/uploadresources/images/Large_LyresTypes.jpg)


NOTE: The URL in the image no longer takes you to this info after the terrible website redesign.  You may find the Lyre info here (http://mymic.rycote.com/products/lyre/).

I know that is the shore ratings, but IMO the Black Duo Lyre is stiffer than the 82 shore lyres ;) I just went from the 82 shore Grey Single Lyre's, to the Black & Grey Duo Lyres, and the Black Duo Lyre's are DEF stiffer than the 82 shore Grey single lyre's :) Also, the Black & Grey Duo Lyre's seem about the SAME stiffness to me and in my hands. I know the Grey Duo Lyre is supposed to be stiffer, but if it is, I sure don't notice it!

Their LD shock mounts look pretty interesting as well.

I wouldn't run ANYTHING but those for LD's if I owned them ;)
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: jmitchell on February 15, 2017, 10:43:43 AM
The light grey dual lyre seems to on backorder from a number of places.  I'm waiting on another for my SRS ORTF Nak mount
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: voltronic on February 15, 2017, 03:05:11 PM
The light grey dual lyre seems to on backorder from a number of places.  I'm waiting on another for my SRS ORTF Nak mount

The separate lyres are often a special order item.  The 62 Lyres were for me, and it looks like the 82 are most places.  72 is what comes standard with the INV-6 and INV-7.

Back before I ordered the 62 lyres, I contacted Redding Audio (http://www.reddingaudio.com/), who are the US distributor for Rycote.  They said that it is possible to purchase a set of INV series mounts with whatever Lyres you want; just contact them and let them know which retailer you'd like to purchase from and they would special order it.
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: dactylus on February 16, 2017, 08:57:39 AM
Their LD shock mounts look pretty interesting as well.

I have a pair of the LD shock mounts that I used for a pair of AKG 414's and l still use with my Gefell UM-70's...

Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: John Willett on February 18, 2017, 12:55:22 PM
Their LD shock mounts look pretty interesting as well.

I have a pair of the LD shock mounts that I used for a pair of AKG 414's and l still use with my Gefell UM-70's...

There is also a special Gefell version of the USM and USM-L available - thay have green Gefell buttons instead of the red Rycote ones and the L version has black lyres instead of red ones.  Price is about the same as the Rycote one and available from Gefell distributors.

This is the G-USM-L

(http://img.ymlp.com/9x38_GUSMforweb_2.jpg)

For the Gefell UM 70, UMT 70S etc., the Rycote INV-7HG III is an excellent option - Håkan now do a special Pop Killer for this combination:-

(https://sound-link.co.uk/images/P110%20INV-7HG-V.png)

This picture is the pre-production version of the Håkan P110 INV-7HG-V pop killer - the production version will be black.

Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: rocksuitcase on March 27, 2018, 01:38:18 PM
Thanks that's interesting and goo d to know.
So far I really like my DIY Rycote lyre shock mount w/ rapid release
Some day I may try a duo lyre..
Archival- do you have  a thread link or pictures of your single Lyre DIY? Thanks
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: rigpimp on March 27, 2018, 01:58:08 PM
This thread just reminded me that my dual lyres are too rigid.  Ugh, I still have to come up with a solution. 
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: voltronic on March 28, 2018, 07:50:01 PM
This thread just reminded me that my dual lyres are too rigid.  Ugh, I still have to come up with a solution.

What are you running?  I now have one pair of 72 lyres to run my stereo bar with the CM3s and it's the perfect amount of compliance.  This is replacing the Duo-Lyre which was much too stiff as I mentioned earlier.
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: voltronic on April 20, 2020, 08:38:22 PM
I know that is the shore ratings, but IMO the Black Duo Lyre is stiffer than the 82 shore lyres ;) I just went from the 82 shore Grey Single Lyre's, to the Black & Grey Duo Lyres, and the Black Duo Lyre's are DEF stiffer than the 82 shore Grey single lyre's :) Also, the Black & Grey Duo Lyre's seem about the SAME stiffness to me and in my hands. I know the Grey Duo Lyre is supposed to be stiffer, but if it is, I sure don't notice it!

Hey there Bean - coming back to this thread for my own reference after a long time and I am just seeing your comment here.  Are you saying that the progression of stiffness really is like this?
Single Lyre 62 > Single Lyre 72 > Single Lyre 82 > Duo-Lyre 68 > Duo-Lyre 72

...rather than what I previously reasoned?
Single Lyre 62 > Single Lyre 72 > Duo-Lyre 68 > Single Lyre 82 > Duo-Lyre 72
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: vanark on April 20, 2020, 08:45:19 PM
I'd be pretty surprised if he sees your response.
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: voltronic on April 20, 2020, 09:04:50 PM
I'd be pretty surprised if he sees your response.

Why is that?  He was here a few weeks ago.

Last Active: March 31, 2020, 02:51:17 AM
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: DSatz on June 06, 2020, 07:03:11 AM
Also coming back to this thread after a period of absence. I don't know, but it looks to me as if "shore hardness" might describe a material's properties, rather than those of any particular item made of that material--like density, which alone won't tell you how much a bar of iron will weigh, until you also know how much iron is in the bar.

--best regards
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: voltronic on June 06, 2020, 08:44:20 AM
Also coming back to this thread after a period of absence. I don't know, but it looks to me as if "shore hardness" might describe a material's properties, rather than those of any particular item made of that material--like density, which alone won't tell you how much a bar of iron will weigh, until you also know how much iron is in the bar.

I have to imagine that density of the material plays a role in shore rating, though I can't say for sure:
https://en.wikipedia.org/wiki/Shore_durometer (https://en.wikipedia.org/wiki/Shore_durometer)

From my correspondence with Simon Davies, he makes it clear that the big difference between the stiffness of single Lyres and the increased stiffness of Duo-Lyres of the same shore rating is the thickness of the material at certain points in the suspension.  What that means is that going by shore rating alone can get you to the wrong product for your application, as it did for me.

It's no secret that I am a big fan of Rycote suspensions, but I wish they would make this clear in their literature, instead of just saying that a particular suspension is for "this one particular mic, with a windscreen fitted".  If you own mics that are not in one of their application lists, you need to do some investigating and experimentation.  I arrived at the 62-shore single Lyres for Line Audio mics because their mass is similar to the MKH 8000 mics for which those Lyres are specified, but I feel I got lucky to find something that close.

What would be far more helpful is to list suspensions by a compliance rating for a certain mass and length range.  For example: "suitable for microphone systems with a total mass (including windscreen) of 300-600 g".
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: dactylus on March 30, 2021, 08:55:03 AM
Thanks again voltronic!
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: Gutbucket on March 30, 2021, 09:47:22 AM
[snip..] [the difference in stiffness between suspensions] of the same shore rating is the thickness of the material at certain points in the suspension.

This is correct.  Shore harness is a material property, compliance of a monolithic part is determined by its geometry in combination with its shore hardness, and effective vibration damping is the result of the interaction of that compliance with the mass it is suspending, working as a specifically tuned system.  Actual suspended mass includes the microphone itself, its windscreen, a portion of the attached cabling, and the suspension clamp which attaches the microphone to that compliant spring part.
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: voltronic on March 31, 2021, 02:18:34 PM
[snip..] [the difference in stiffness between suspensions] of the same shore rating is the thickness of the material at certain points in the suspension.

This is correct.  Shore harness is a material property, compliance of a monolithic part is determined by its geometry in combination with its shore hardness, and effective vibration damping is the result of the interaction of that compliance with the mass it is suspending, working as a specifically tuned system.  Actual suspended mass includes the microphone itself, its windscreen, a portion of the attached cabling, and the suspension clamp which attaches the microphone to that compliant spring part.

Regarding the bold portion above:

This is precisely why I wish Rycote (and all other shockmount manufacturers) would specify an operating range of total system mass where their models are effective. It's one thing to say a shock is designed for a particular microphone - you can then look up its mass to see if your mic is comparable. That's how I arrived at the 62-shore Lyres for my Line Audio mics, because those Lyres were designed for the Senn MKH 8000 series mics which are of similar mass.  What's particularly maddening is when a suspension is specified for a particular mic plus a windscreen... Well, which windscreens, exactly? Too many variables!

I am willing to bet that many people using mics that are not specified by the shockmount manufacturers are using shockmounts which are not effectively isolating their mic systems.
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: aaronji on March 31, 2021, 02:43:28 PM
^, ^^ Just to very slightly nitpick (as we scientists may be prone to do), I think you guys mean "weight" and not "mass". People tend to use them interchangeably, but weight (newtons or, um, maybe slugs?) is dependent on the local gravitational field while mass is not (W = m * g). So you would need different shore lyres on the moon...  ;)

More on topic, though, I think it might be difficult to specify an effective weight range for a shockmount due to differences in the susceptibility of mics to vibration noise?
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: aaronji on March 31, 2021, 03:15:28 PM
^ To nitpick my nitpick, I think the slug is unit of mass? I am bad at non-conventional Imperial measures; everything is basically SI these days...
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: Gutbucket on March 31, 2021, 05:05:35 PM
The key terms with regards to vibration isolation are mass and spring-rate.. equally applicable in zero G. The other factor we've not mentioned is damping, which effects how quickly the spring-suspended-mass system is brought to rest. In terms of vibration-isolation alone (considered in isolation ;) ), more compliant is always better.  Regardless of the mass being suspended, a more compliant suspension will isolate to a lower frequency.  If you want to know what effective frequency that is, you need to know the mass being suspended as well as the spring-rate.  In combination with that, a more compliant suspension isolating to lower frequencies needs to move/deflect a greater distance. 

In real-word situations one must find a reasonable compromise between the desired degree of isolation and an acceptable amount of deflection.  Deflection in reaction to vibration or other dynamic loads is how far the suspended microphone is allowed move or oscillate when subjected to those loads.  To isolate to very low frequencies the compliant suspension will need to be able to move a significant distance.

Weight is important in that it is a specific case of deflection.  It effects how much the suspended system will sag due to the force of gravity acting on the mass.  Deflection in reaction to weight is sag.  Sag eats up some of the available deflection which is available.  If we want to keep deflection reasonable, we can't make the suspension overly compliant, or the weight of the microphone and other suspended bits will bottom out the available deflection and then there is insufficient isolation. Directly related to this is that a more compliant suspension is more wiggly in general.  How wiggly is acceptable?  It's a trade-off.


It may help to relate all this to the suspension system of a car, which is designed to accommodate dynamic loads such as bumps, corners, braking, acceleration.  It also counters the force of gravity, holding the car up off its lower bump-stops.  When tweaking a suspension for racing, the most common things to do are to modify the spring rate and damping rate which work in relation to the mass of the vehicle.  Weight matters only in regards to the non-dynamic loading - how much the springs are compressed by the weight of the car (at rest and/or in motion) before the system reaches equilibrium, which affects ride height and suspension-travel.  An old Cadillac suspension is soft and plush which isolates road noise and vibration well but feels loose and wiggly.  A sports car of the same mass is typically provided with a higher spring-rate (and higher damping rate to match) which makes for a less plush ride but a less loose and wiggly "faster" reaction time.  In the words of Colin Chapman, race cars are made faster by "adding lightness" (reducing weight), but its actually mass reduction, not weight reduction that maters.  Weight actually helps! as it is a form of down-force that increases traction.  Imagine a drag-race on the moon.  One engineering trade off moon racers face would be finding the most optimal trade off between traction and inertia. Traction on the moon will be largely determined largely by the vehicle's weight (no aerodynamic down-force of any significance is available) and is necessary for transferring acceleration force to the lunar surface in order to overcome the vehicle's inertia, which is determined by its mass.  A heavier vehicle with sufficient power (to overcome its increased inertia) wins the race.

Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: Gutbucket on March 31, 2021, 05:09:07 PM
So you would need different shore lyres on the moon...  ;)

Same lyres with respect to isolating structure-born noise through the mic-stand (vibrations from lunar footsteps, meteor impacts, LEM landings and launches, and lunar drag-racers), however the mics will only sag 1/6th as much in the mounts!
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: Gutbucket on March 31, 2021, 05:58:39 PM
More on topic, though, I think it might be difficult to specify an effective weight range for a shockmount due to differences in the susceptibility of mics to vibration noise?

Rycote should be able to specify an applicable weight range for each suspension.  Different microphones of the same weight will have different susceptibilities to solid-born noise, but whatever that starting point, a suspension tuned for that weight ("weight" because they must accommodating sag as well as vibration isolation.. and because its an easy measure) should provide the same proportionate amount of reduction.  It just matters more for microphones that are more susceptible.  Its mostly a question of finding an acceptable balance between the desired degree if isolation and acceptable wigglyness for any particular weight range.

One complication is that real world microphone suspensions are never isotropic - they have different degrees of compliance and deflection across different axes.  Rycote is well aware of this and designed the Lyre suspension to take advantage of this as feature rather than bug, by providing increased compliance along the axis normal (perpendicular) to the microphone diaphragm of a suspended end-address microphone.  That means the compliant Lyre part moves more easily front/back (and can move farther along this axis) than it can in the up/down or left/right axes.  I recall reading Rycote literature that claims this is appropriate because the primary vibration mode of the microphone diaphragm is along this axis.  I don't doubt that.  But it also make the system more practical by having the less compliant axes oriented up/down and left/right, reducing sag and wigglyness in those directions.  This is something to consider when using Lyres for suspending mic-bars and side-address microphones, although Lyres still probably work better than most other suspensions in such cases case, even though the axis of greatest compliance and free-movement is no longer normal to the plane of the microphone diaphragm.
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: aaronji on March 31, 2021, 06:35:57 PM
Because weight and mass are directly proportional for any given gravity, the natural frequency can be expressed in terms of either. That is fn = (1/(2*pi))*sqrt(K/m) = (1/(2*pi))*sqrt((K*g)/W) = 3.13*sqrt(K/W). That means that increasing stiffness or decreasing weight increases fn and vice versa. So, given a constant gravity, it doesn't matter. I retract my nitpick! Unless my math, or ancient recollection of physics, is incorrect, either weight or mass is appropriate assuming we are at the same spot...
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: Gutbucket on March 31, 2021, 06:51:47 PM
Easiest to keep things down to Earth!

Colin Chapman never raced on the moon.
(Aaron, that last quip is in reference to his "adding lightness" quote I added to my post above when editing it for clarity, made after you read it, presumably while you were posting your nitpick retraction)

Cheers!
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: aaronji on April 01, 2021, 03:21:13 PM
In the words of Colin Chapman, race cars are made faster by "adding lightness" (reducing weight), but its actually mass reduction, not weight reduction that maters.

Last off-topic post, I promise!

Maybe I am missing something, but this difference seems to be more semantic than anything else. Weight and mass have a linear relationship; even the formula is the basic formula for a line that everyone learned in high school algebra. That is, you can't reduce (or increase) one without reducing (or increasing) the other. I guess you can effectively increase weight in the case of a car, by adding a wing or something, but the true weight will always be m*g (or the mass will always be W/g, depending on how you want to look at it), right? 
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: Gutbucket on April 01, 2021, 04:15:21 PM
Right.  Yes semantics, but clear definitions are as important to engineers as nitpicking scientists.

Dominating inertia is the race car engineer's primary challenge, not overcoming gravity.  So it's mass rather than weight that is the appropriate measure to those for whom such differentiations carry meaning,
even though the two are essentially equivalent on all earthbound race-tracks.  Doesn't matter when talking in the everyday speak of folks who like to get laid (laypeople) - all credit to DSatz for that joke.  And without question, making a car lighter is less nerdy than reducing its mass. Everyone knows what is meant by it, even those who sweat proper definitions.

Interesting historical tidbit- Porsche pressurized the welded tube frame of the 917 with inert gas and I read somewhere that they used helium. The intent was not to lighten the weight of the vehicle but as an easy way to safely monitor for frame cracks during a race via a pressure gauge in the cockpit, deemed necessary because the frame was so optimized it was relatively fragile.  Obviously there was not enough volume within the frame to significantly lighten the car by replacing the entrapped air with helium, but with a fine-enough scale, the effect would be measurable.. and in that case doing so altered the weight of the vehicle more than its mass.  By an inconsequential amount, but still.

A helium balloon trapped against the ceiling has a positive mass value, but negative weight.
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: aaronji on April 01, 2021, 04:31:07 PM
I guess pretty much any equation with either mass or weight can be re-written in terms of the other, so, at least mathematically, they are interchangeable, if not in engineering terms. Here is an example (https://www.engineeringtoolbox.com/tractive-effort-d_1783.html) I saw (for tractive force), where they provide the formula in terms of both weight and mass. Of course, nothing is so simple, as they note about the moment created by the engine during acceleration. I was kind of gratified to see "slugs" in there; I am not sure why that term still occupies some sliver of memory more than 30 years after my last physics class...
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: Gutbucket on April 01, 2021, 08:10:36 PM
I guess pretty much any equation with either mass or weight can be re-written in terms of the other, so, at least mathematically, they are interchangeable, if not in engineering terms.
 
..as long as the inertial axis in question is aligned with the vector of gravity. When cornering, the inertial forces acting on the mass of the vehicle are no longer aligned with the gravity vector.  Going up a hill the gravity vector is no longer normal to the contact patch between tire and road surface.  How well does that tractive force equation apply to a near vertical surface?  It then only works if we substitute force normal to the surface for weight.  We need to be very careful of the unstated simplifications in the mathmatical and engineering models, which sometimes become more apparent when the mathematical truths are applied to concrete engineering examples.  Same math though. 

Fun puzzlers, thanks.
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: voltronic on April 02, 2021, 07:27:59 AM
I just checked in on this thread expecting some questions about shock mounts. I wasn't prepared to learn science-y things!
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: capnhook on April 02, 2021, 08:46:40 AM
Better get the lyres that won't freeze or melt.  Crazy temps on the Moon.

 :bigsmile:
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: Gutbucket on April 05, 2021, 08:46:58 PM
I'm double posting the message below from a mic bar question thread over in Ask The Tapers- https://taperssection.com/index.php?topic=196577.0 because it falls right in line with the discussion we've been having above, and were I'm headed myself-


The key to effective shock-mounting is achieving a reasonable match between the springiness/compliance of the suspension and the weight/mass of whatever is being suspended.  For very light microphones that are shock-mounted individually, one can add weight which is suspended along with the microphone to load the suspension so that the decoupling becomes is effective.  That helps in a pinch, but is unwieldy so it generally works better to shift to suspending the entire mic-bar along with a pair of lightweight mics.

With a large bar such as that nice looking t.bone StereoBar 1 Pro Voltronic linked [in the other thread], supporting micrphones of typical weight (not super small and lightweight), typical individual suspensions along the bar for each microphone will be the most straight forward and easiest approach.  If trying to suspend and shock mount a large and relatively heavy mic bar along with microphones rigidly attached to it, a larger and relatively more stiff suspension would need to be used.  This is the opposite problem of trying to individually shock-mount tiny lightweight microphones that don't have enough mass to effectively load the suspension on their own.

AEA used to make a big heavy-duty stand decoupler for use with large arrays like a Decca tree that they referred to as a "floater".  I searched for but can no longer find it nor a photo of one.  I'm in search of something like that myself for use between my multichannel microphone array contraption and its mounting stud that fits into the top of a mic-stand, clamp or support arm.  I don't need something as heavy duty as the big HD AEA Floater, so I'm thinking something like this: The Hook Studios Large Size MD-175-70 Mechanical Decoupler - https://thehookstudios.com/filters.html, or this Neumann decoupler -https://en-de.neumann.com/z-26-mt (https://en-de.neumann.com/z-26-mt) might work effectively while being sufficiently compact and streamlined aloft for me.  Otherwise I might build something myself using some Sorbathane samples I have on hand.  Of the 8 microphones I have in the array, 6 will benefit from improved decoupling, but 5 of those are tiny and weigh almost nothing, and I'd much rather achieve it using a single compliant element at the common support point. 

Rycote Lyres are great but not really the most appropriate geometry for something like this.  Annoyingly, none of the decouplers I've found including the one's linked above indicate a target weight range.

(https://thehookstudios.com/images/md-175-70-f_300px.jpg) (https://thehookstudios.com/images/th-md-175-70_300px.jpg) (https://thehookstudios.com/images/md-side_2_300px.jpg)

(https://thehookstudios.com/images/decplr_akg_c12_300px_sq.jpg)

(https://www.fullcompass.com/common/products/original/348745.jpg)


Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: Gutbucket on April 06, 2021, 10:34:31 AM
The first two photos on the linked page show the two different sized decouplers.

The first shows the bigger one, Large Size MD-175-70 Mechanical Decoupler (diameter: 1.75") supporting an AKG C12.
The second shows the smaller one, Standard Size MD-150-70 Mechanical Decoupler (diameter: 1.50"), supporting an AKG 460 (held via another shockmount clip)

In both cases the Spin Grip mount (I've never seen one before) is on the support side, not the suspended side the decoupler.

I'll probably order the larger one, its probably about right and not too pricey.  I'll weigh my rig to see how close it is to a C12, and contact them to inquire about weight ranges.  Guessing the weight is pretty close, although I will be supporting long leverage arms extending outward.  I'll need to use 3/8" adapters on either side of it, maybe turning down and re-threading the stud side on the lathe in the shop.  If I end up making my own, it will likely be of similar construction using a larger diameter Sorbathane "puck".  The Sorbathane pieces I have are quite compliant and I think I'll need a somewhat larger plate on either side to limit sag. May incorporate a locking ball mount between the decoupler and mounting stud for tilt and swivel.. or maybe just a simple locking hinge, which should be sufficient.
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: voltronic on April 06, 2021, 07:05:12 PM
The first two photos show the two different sized decouplers.

The first shows the bigger one, Large Size MD-175-70 Mechanical Decoupler (diameter: 1.75") supporting an AKG C12.
The second shows the smaller one, Standard Size MD-150-70 Mechanical Decoupler (diameter: 1.50"), supporting an AKG 460 (held via another shockmount clip)

In both cases the Spin Grip mount (I've never seen one before) is on the support side, not the suspended side the decoupler.

I'll probably order the larger one, its probably about right and not too pricey.  I'll weigh my rig to see how close it is to a C12, and contact them to inquire about weight ranges.  Guessing the weight is pretty close, although I will be supporting long leverage arms extending outward.  I'll need to use 3/8" adapters on either side of it, maybe turning down and re-threading the stud side on the lathe in the shop.  If I end up making my own, it will likely be of similar construction using a larger diameter Sorbathane "puck".  The Sorbathane pieces I have are quite compliant and I think I'll need a somewhat larger plate on either side to limit sag. May incorporate a locking ball mount between the decoupler and mounting stud for tilt and swivel.. or maybe just a simple locking hinge, which should be sufficient.

Well, that was piss poor reading comprehension on my part! I completely missed the part about two different sizes. I'm deleting my earlier reply for being completely off base.

For either this commercial version or what you are envisioning for your DIY version, are the threaded fittings with their flanges simply epoxied to the Sorbothane?
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: Gutbucket on April 06, 2021, 07:41:48 PM
I assume the flanges are flat surfaced and adhered to the Sorbothane using some kind of adhesive effective enough to resist edge pealing away from the flanges when a side-load is applied.

Making the flanges of sufficient diameter to counter excessive "floppiness", in combination with sufficient thickness to effectively isolate, while keeping the thing relatively compact will be key if I end up building something. We have some funky industrial two part fusion adhesive we used to join rubber pads to stainless or aluminum which may work.  We also just had a sample of super sticky backing tape adhesive stuff dropped off which might work.  Its the adhesive with a release paper backing found on the backside of the lighytweight foam footing surface material originally used on surfboards, then jet-skis and wave runners, and now as decking surface pads on small fishing skiffs and ski boats.  We had some custom panels of that foam decking cut for a job and after I applied one of them I realized how tenacious its adhesion is.

I've considered worst case failure modes if the decoupler were to disassemble itself while aloft and I was recording. In that case the microphone cable bundle in its techflex sheath is secured both above and below the coupler and would keep the assembly from completely falling to the floor from atop the stand.  Obviously I'll test it extensively first and check for wear to prevent that, and could design in some sort of restraint which allows free movement but not complete disassembly, but I don't expect I'll need that complication.  Hopefully the off the shelf Hook Studios decoupler works as is or with slight modification.  Stay tuned.
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: DSatz on April 07, 2021, 12:23:35 AM
I've had Neumann Z 26 decouplers for many years and have used them in the occasional, odd situation. With their stiffness, to me they seem designed for heavy microphones. I often stack a pair of them for use with smaller, lighter microphones.

I don't feel as if they do me much good, frankly--but in some situations it's a choice between some good and none.

--best regards
Title: Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
Post by: Gutbucket on April 07, 2021, 11:40:48 AM
Thanks for that input.  Is the compliant part made of rubber or some sort of squishy urethane (which is what Sorbathane is)?  I included the Neumann Z 26 because it was the only other one that came up in my web-search, even though it didn't seem ideal for this application.  It looks rather stiff to me in the photo, but I have to question my own perception on that - what does stiff look like in still photo such a part?  I guess its the length x width ratio of the rubber part.  If it were compliant enough along its primary axis, it would flop over easily under a bending load.  It actually resembles the small motor mounts we use at work on electric motor hydraulic power units, which are relatively hard rubber and not nearly complaint enough for an application such as this.