Become a Site Supporter and Never see Ads again!

Author Topic: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance  (Read 20892 times)

0 Members and 1 Guest are viewing this topic.

Offline voltronic

  • Trade Count: (40)
  • Needs to get out more...
  • *****
  • Posts: 4095
Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
« Reply #15 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
I am hitting my head against the walls, but the walls are giving way.
- Gustav Mahler

Acoustic Recording Techniques
Team Classical
Team Line Audio
Team DPA

Offline DSatz

  • Site Supporter
  • Trade Count: (35)
  • Needs to get out more...
  • *
  • Posts: 3347
  • Gender: Male
Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
« Reply #16 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
music > microphones > a recorder of some sort

Offline voltronic

  • Trade Count: (40)
  • Needs to get out more...
  • *****
  • Posts: 4095
Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
« Reply #17 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

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".
I am hitting my head against the walls, but the walls are giving way.
- Gustav Mahler

Acoustic Recording Techniques
Team Classical
Team Line Audio
Team DPA

Offline dactylus

  • Site Supporter
  • Trade Count: (62)
  • Needs to get out more...
  • *
  • Posts: 5992
  • Gender: Male
  • Maplewood, MN
Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
« Reply #18 on: March 30, 2021, 08:55:03 AM »
Thanks again voltronic!
hot licks > microphones > recorder



...ball of confusion, that's what the world is today, hey hey...

Offline Gutbucket

  • record > listen > revise technique
  • Trade Count: (15)
  • Needs to get out more...
  • *****
  • Posts: 15683
  • Gender: Male
  • "Better to love music than respect it" ~Stravinsky
Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
« Reply #19 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.
musical volition > vibrations > voltages > numeric values > voltages > vibrations> virtual teleportation time-machine experience
Better recording made easy - >>Improved PAS table<< | Made excellent- >>click here to download the Oddball Microphone Technique illustrated PDF booklet<< (note: This is a 1st draft, now several years old and in need of revision!  Stay tuned)

Offline voltronic

  • Trade Count: (40)
  • Needs to get out more...
  • *****
  • Posts: 4095
Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
« Reply #20 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.
I am hitting my head against the walls, but the walls are giving way.
- Gustav Mahler

Acoustic Recording Techniques
Team Classical
Team Line Audio
Team DPA

Offline aaronji

  • Site Supporter
  • Trade Count: (9)
  • Needs to get out more...
  • *
  • Posts: 3853
Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
« Reply #21 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?

Offline aaronji

  • Site Supporter
  • Trade Count: (9)
  • Needs to get out more...
  • *
  • Posts: 3853
Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
« Reply #22 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...

Offline Gutbucket

  • record > listen > revise technique
  • Trade Count: (15)
  • Needs to get out more...
  • *****
  • Posts: 15683
  • Gender: Male
  • "Better to love music than respect it" ~Stravinsky
Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
« Reply #23 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.

« Last Edit: March 31, 2021, 06:41:09 PM by Gutbucket »
musical volition > vibrations > voltages > numeric values > voltages > vibrations> virtual teleportation time-machine experience
Better recording made easy - >>Improved PAS table<< | Made excellent- >>click here to download the Oddball Microphone Technique illustrated PDF booklet<< (note: This is a 1st draft, now several years old and in need of revision!  Stay tuned)

Offline Gutbucket

  • record > listen > revise technique
  • Trade Count: (15)
  • Needs to get out more...
  • *****
  • Posts: 15683
  • Gender: Male
  • "Better to love music than respect it" ~Stravinsky
Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
« Reply #24 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!
« Last Edit: March 31, 2021, 06:42:38 PM by Gutbucket »
musical volition > vibrations > voltages > numeric values > voltages > vibrations> virtual teleportation time-machine experience
Better recording made easy - >>Improved PAS table<< | Made excellent- >>click here to download the Oddball Microphone Technique illustrated PDF booklet<< (note: This is a 1st draft, now several years old and in need of revision!  Stay tuned)

Offline Gutbucket

  • record > listen > revise technique
  • Trade Count: (15)
  • Needs to get out more...
  • *****
  • Posts: 15683
  • Gender: Male
  • "Better to love music than respect it" ~Stravinsky
Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
« Reply #25 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.
« Last Edit: April 02, 2021, 08:59:03 AM by Gutbucket »
musical volition > vibrations > voltages > numeric values > voltages > vibrations> virtual teleportation time-machine experience
Better recording made easy - >>Improved PAS table<< | Made excellent- >>click here to download the Oddball Microphone Technique illustrated PDF booklet<< (note: This is a 1st draft, now several years old and in need of revision!  Stay tuned)

Offline aaronji

  • Site Supporter
  • Trade Count: (9)
  • Needs to get out more...
  • *
  • Posts: 3853
Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
« Reply #26 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...

Offline Gutbucket

  • record > listen > revise technique
  • Trade Count: (15)
  • Needs to get out more...
  • *****
  • Posts: 15683
  • Gender: Male
  • "Better to love music than respect it" ~Stravinsky
Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
« Reply #27 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!
musical volition > vibrations > voltages > numeric values > voltages > vibrations> virtual teleportation time-machine experience
Better recording made easy - >>Improved PAS table<< | Made excellent- >>click here to download the Oddball Microphone Technique illustrated PDF booklet<< (note: This is a 1st draft, now several years old and in need of revision!  Stay tuned)

Offline aaronji

  • Site Supporter
  • Trade Count: (9)
  • Needs to get out more...
  • *
  • Posts: 3853
Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
« Reply #28 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? 

Offline Gutbucket

  • record > listen > revise technique
  • Trade Count: (15)
  • Needs to get out more...
  • *****
  • Posts: 15683
  • Gender: Male
  • "Better to love music than respect it" ~Stravinsky
Re: Rycote Single Lyres vs. Duo-Lyre Stiffness / Compliance
« Reply #29 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.
« Last Edit: April 01, 2021, 04:20:01 PM by Gutbucket »
musical volition > vibrations > voltages > numeric values > voltages > vibrations> virtual teleportation time-machine experience
Better recording made easy - >>Improved PAS table<< | Made excellent- >>click here to download the Oddball Microphone Technique illustrated PDF booklet<< (note: This is a 1st draft, now several years old and in need of revision!  Stay tuned)

 

RSS | Mobile
Page created in 0.088 seconds with 39 queries.
© 2002-2024 Taperssection.com
Powered by SMF