Become a Site Supporter and Never see Ads again!

Author Topic: Schoeps mk41? Doubting to take the plunge...  (Read 9252 times)

0 Members and 1 Guest are viewing this topic.

Offline jerryfreak

  • (30)
  • Needs to get out more...
  • *****
  • Posts: 5059
  • The plural of anecdote is not data
Re: Schoeps mk41? Doubting to take the plunge...
« Reply #30 on: July 06, 2020, 01:00:36 PM »
forOTS arena taping where many people are simply using PAS, is there a large difference in imaging between supers and cards? seems the supers win every time for rejection of reverberant mud
People whose posts I wont see:
capnhook, daspyknows, Melanie, morst, Rob D., Scooter123, Sloan Simpson, Walstib62

Offline heathen

  • (23)
  • Needs to get out more...
  • *****
  • Posts: 3155
Re: Schoeps mk41? Doubting to take the plunge...
« Reply #31 on: July 06, 2020, 03:45:38 PM »
forOTS arena taping where many people are simply using PAS, is there a large difference in imaging between supers and cards? seems the supers win every time for rejection of reverberant mud

I'm highly suspicious of the conventional wisdom around here that hypers/supers avoid significantly more reverberant sound than cards from an OTS distance.  I don't have enough knowledge to state this definitively or with any authority, so I'll just leave it at "I'm highly suspicious."
Mics: AT4050ST | AT4031 | AT853 (C/SC) | Line Audio CM3 | Sennheiser e614 | Sennheiser MKE2 | DPA 4061 | CA-14 omni Pres: CA9200 | DPA d:vice Decks: Zoom F8 | Roland R-05

Offline audBall

  • (36)
  • Needs to get out more...
  • Posts: 6138
  • Gender: Male
  • Keep Stella (World Rally) Blue
Re: Schoeps mk41? Doubting to take the plunge...
« Reply #32 on: July 06, 2020, 04:19:02 PM »
I'm highly suspicious of the conventional wisdom around here that hypers/supers avoid significantly more reverberant sound than cards from an OTS distance.  I don't have enough knowledge to state this definitively or with any authority, so I'll just leave it at "I'm highly suspicious."

My understanding is that, fundamentally, higher frequencies attenuate more readily than lower frequencies.  In a reverberant scenario (i.e., OTS, distance recording, etc.) where higher frequencies have begun to attenuate, the primary frequencies providing detectable pressure levels are less head-on from the source and such (reverberant) frequencies tend to be mid- or lower-frequency (speaking generally here).  The frequency response charts for super-/hyper-cardioids show a reduction in dB amplitude response to those lower frequencies at respective lateral angles of incidence to the microphone compared to more open patterns (i.e., cardiod, subcardioid, etc.).  With a more open pattern, those lateral angles of incidence could likely be impacted more so (have a greater dB amplitude) by reverberant sounds reflecting all over the room/space.  Therefore, the conclusion is reached that hypers/supers tend to reduce pickup of highly reverberant sound [again, at those lateral angles] that could otherwise produce an undesirable recording from a distance.   

Obviously, there will be recordings that are outliers in our recording 'universe'.  We have heard recordings where hypers and cards were run from the same location with little-to-no difference in overall sound.  However, the fundamentals still apply and have contributed to such 'conventional wisdom'.
« Last Edit: July 06, 2020, 04:21:03 PM by audBall »

Offline Gutbucket

  • record > listen > revise technique
  • (15)
  • Needs to get out more...
  • *****
  • Posts: 13812
  • Gender: Male
  • Gunther Theile nailed it!
Re: Schoeps mk41? Doubting to take the plunge...
« Reply #33 on: July 06, 2020, 04:48:53 PM »
I think the biggest factor in that regard is the general difference in low frequency roll-off which is associated with the change of pattern.  Plenty of tapers choose between pickup patterns as a form of surrogate EQ in this regard.
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<<

Offline aaronji

  • Site Supporter
  • (8)
  • Needs to get out more...
  • *
  • Posts: 3033
Re: Schoeps mk41? Doubting to take the plunge...
« Reply #34 on: July 06, 2020, 05:47:12 PM »
With respect to direct/reverberant ratio and distance for different polar patterns, I find "distance factor" to be a useful way to think about this. See the attached tables, one from Shure and one from AT. The reason I attached both is that AT provides a figure for sub-cardioid but not super-cardioid, while Shure includes super-card but not sub-card.

Obviously, there are a bunch of assumptions baked into this; see the text from AT, which describes some of them.

Quote from: AT
A directional microphone’s ability to reject much of the sound that arrives from off-axis provides a greater working distance or “distance factor” than an omni. As Fig. 10 shows, the distance factor (DF) for a cardioid is 1.7 while the omni is 1.0. This means that if an omni is used in a uniformly noisy environment to pick up a desired sound that is 10" away, a cardioid used at 17" from the sound source should provide the same results in terms of the ratio of desired signal to ambient noise. Among other microphone types, the subcardioid should do equally well at 12", the hypercardioid at 20" and the bidirectional at 17".

If the unwanted noise is arriving from one direction only, however, and the microphone can be positioned to place the null of the pattern toward the noise, the directional microphones will offer much greater working distances.
People whose posts I won't see: jerryfreak. The probationary period didn't last long...

Offline Gutbucket

  • record > listen > revise technique
  • (15)
  • Needs to get out more...
  • *****
  • Posts: 13812
  • Gender: Male
  • Gunther Theile nailed it!
Re: Schoeps mk41? Doubting to take the plunge...
« Reply #35 on: July 06, 2020, 07:19:08 PM »
One problem is that the distances over which those "distance factors" clearly apply are orders of magnitude smaller than typical taper recording distances.  I suspect distance factor loses applicably as the microphone is moved farther away than the critical distance from the source.  Note the largest distance mentioned in the AT text example has the microphone placed a mere 20 inches away from the source. 

The Ambient Sound Sensitivity measure from the Shure table is perhaps more useful for tapers, but I'm unsure how its calculated.  Average sensitivity outside of the Coverage Angle verses inside of it?

With respect to audience taping, the Rear Rejection Relative to Front measure is near worthless in my opinion partly because I consider it particularly misleading for tapers..  assuming it is a comparison between sensitivity directly on-axis verses sensitivity 180-off axis.  Consider all the "what about rear-lobe sensitivity" discussions around TS in regards to supercardioids verses cardioids and audience noise rejection expectations.  It is average sensitivity across the quadrant or hemisphere which matters in that regard for the most part.  Consider: If you were to point two microphones of equal sensitivity directly away from the stage rather than directly toward it, which will pick up the least amount of direct sound from the stage and PA sound in front: cardioid or supercardioid?

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<<

Offline kuba e

  • Site Supporter
  • (1)
  • Taperssection Member
  • *
  • Posts: 368
  • Gender: Male
Re: Schoeps mk41? Doubting to take the plunge...
« Reply #36 on: July 07, 2020, 01:28:57 AM »
I imagine it as energy, that there will be slightly less ambient energy in a hypercardiod signal compared to a cardiod. I'm also beginning to understand that the stereo image also has an effect for clearer listening. I listened to the recordings of multiple sources that tapers generously provide here (thank you, it's kind of everyone). I thought I could distinguish between the hypercardiod and the cardiod in the back of the room in a direct comparison. I tried to balance them with eq. It occurred to me that the hypercardiod sounded a little clearer. But it is possible that I was wrong. I will have to do listening test again.
« Last Edit: July 07, 2020, 01:39:22 AM by kuba e »

Offline aaronji

  • Site Supporter
  • (8)
  • Needs to get out more...
  • *
  • Posts: 3033
Re: Schoeps mk41? Doubting to take the plunge...
« Reply #37 on: July 07, 2020, 08:39:19 AM »
One problem is that the distances over which those "distance factors" clearly apply are orders of magnitude smaller than typical taper recording distances.  I suspect distance factor loses applicably as the microphone is moved farther away than the critical distance from the source.  Note the largest distance mentioned in the AT text example has the microphone placed a mere 20 inches away from the source. 

You are probably right, but I don't understand why distance factor would lose applicability at larger distances. Under the assumption that the ambient/reverberant noise (A/R for short) is uniform, then the denominator of the direct-to-A/R ratio for a given mic is a constant affected only by the (idealized) polar pattern of the microphone irrespective of position in the room. The numerator, the direct sound, is affected only by the distance from the source according to the inverse distance law. Since the denominators are constants, if you double the distance for an omni (from x to 2*x) the numerator will drop by 6 dB. For a card, which originally had the same ratio as the omni at 1.7*x, if you doubled the distance to 3.4*x, you would get the same 6 dB drop in the numerator so the distance factor of 1.7 would still be the same. Why wouldn't this apply for any value of x?

Obviously, there are lots of assumptions (uniform noise, ideal polar pattern, same sensitivity, mic pointed at sound source, etc.), but, to me, the concept is useful to get a sense of the problem. For what it's worth, there are examples on the web which use considerably larger distances (a meter to multiple meters) than in AT's example.     
People whose posts I won't see: jerryfreak. The probationary period didn't last long...

Offline heathen

  • (23)
  • Needs to get out more...
  • *****
  • Posts: 3155
Re: Schoeps mk41? Doubting to take the plunge...
« Reply #38 on: July 07, 2020, 08:54:00 AM »
Speaking only for myself and not trying to put words in Gutbucket's mouth, I think that distance factor quote from AT might lose applicability from taper distances because at the distances we're working with there is likely just as much reverberant sound as direct sound (or at least more reverberant sound than most people think).
Mics: AT4050ST | AT4031 | AT853 (C/SC) | Line Audio CM3 | Sennheiser e614 | Sennheiser MKE2 | DPA 4061 | CA-14 omni Pres: CA9200 | DPA d:vice Decks: Zoom F8 | Roland R-05

Offline aaronji

  • Site Supporter
  • (8)
  • Needs to get out more...
  • *
  • Posts: 3033
Re: Schoeps mk41? Doubting to take the plunge...
« Reply #39 on: July 07, 2020, 09:04:06 AM »
^ All that means is that the direct-to-A/R ratio is smaller. Obviously, as tapers, we generally want it to be as high as possible, but I don't understand how the distance factor concept changes if the ratio is one:million, 1:1 (critical distance), or greater than one...
People whose posts I won't see: jerryfreak. The probationary period didn't last long...

Offline audBall

  • (36)
  • Needs to get out more...
  • Posts: 6138
  • Gender: Male
  • Keep Stella (World Rally) Blue
Re: Schoeps mk41? Doubting to take the plunge...
« Reply #40 on: July 07, 2020, 09:11:49 AM »
The "angles of minimum sensitivity" (AT chart) still apply regardless of distance or where the microphone is placed in space.  So it seems rational to select a pickup pattern, at distance in a highly reverberant location with low direct:A/R ratio, that minimizes the pickup (in amplitude) of reflected sounds at as many angles to the microphone as possible.

Offline Gutbucket

  • record > listen > revise technique
  • (15)
  • Needs to get out more...
  • *****
  • Posts: 13812
  • Gender: Male
  • Gunther Theile nailed it!
Re: Schoeps mk41? Doubting to take the plunge...
« Reply #41 on: July 07, 2020, 11:08:59 AM »
One problem is that the distances over which those "distance factors" clearly apply are orders of magnitude smaller than typical taper recording distances.  I suspect distance factor loses applicably as the microphone is moved farther away than the critical distance from the source.  Note the largest distance mentioned in the AT text example has the microphone placed a mere 20 inches away from the source. 

You are probably right, but I don't understand why distance factor would lose applicability at larger distances. Under the assumption that the ambient/reverberant noise (A/R for short) is uniform, then the denominator of the direct-to-A/R ratio for a given mic is a constant affected only by the (idealized) polar pattern of the microphone irrespective of position in the room. The numerator, the direct sound, is affected only by the distance from the source according to the inverse distance law. Since the denominators are constants, if you double the distance for an omni (from x to 2*x) the numerator will drop by 6 dB. For a card, which originally had the same ratio as the omni at 1.7*x, if you doubled the distance to 3.4*x, you would get the same 6 dB drop in the numerator so the distance factor of 1.7 would still be the same. Why wouldn't this apply for any value of x?   

The measured SPL at any position in the room is the sum of all the direct and revereberant arriving sound, however the balance between the two is not constant and instead changes with distance. The level of direct-arriving sound decreases according to the inverse square law as distance from the source is increased, while the level of the reverberant-arriving sound remains more or less constant.   At distances less than the critical-distance (aka radius-of-reverberation) the direct-arriving sound dominates. Farther away than the critical distance, reverberant-sound dominates.  Moving farther from the source, the direct-sound becomes increasingly attenuated compared to the reverberant-sound, until the direct-sound component becomes masked by the reverberant-sound rendering it essentially inaudible.

Consider an hypothetical super-directional microphone which is able to completely reject pickup from every direction other than a super narrow on-axis window, like a laser-beam.  All of the direct sound arrives along one axis, so we point this super-directional microphone directly at the source to maximize "pickup as much direct sound as possible".  So far so good.  But recall that the reverberant sound is arriving from all directions equally, including the directly-on-axis direction.  As the microphone is moved increasingly farther away, the balance of sound at the microphone position becomes increasingly dominated by reverberant-sound, despite our super-directional microphone that is able to reject sound arriving from all directions other than directly on-axis.



By being less sensitive to sound arriving from off-axis, a directional microphone provides an increased proportion of direct-arriving sound, but is only able to do so until the pickup of reverberant-sound which is also arriving inside the microphone's on-axis coverage angle begins to dominate over the pickup of direct-arriving sound.  That's clearly what happens at distances closer than the critical-distance, and it continues to work beyond the critical distance to a lesser and lesser degree until eventually even the signal from our imaginary super-directional microphone becomes dominated by on-axis reverberant sound.
« Last Edit: July 08, 2020, 11:50:17 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<<

Offline heathen

  • (23)
  • Needs to get out more...
  • *****
  • Posts: 3155
Re: Schoeps mk41? Doubting to take the plunge...
« Reply #42 on: July 07, 2020, 11:18:15 AM »
Exactly what Gutbucket said!

I'll also add that I suspect the distances most of us record from (other than on stage or stage lip, obviously) lie very close to, or past, that critical distance.  Of course I can't say this for certain, because measuring that is way way beyond my very limited knowledge.
Mics: AT4050ST | AT4031 | AT853 (C/SC) | Line Audio CM3 | Sennheiser e614 | Sennheiser MKE2 | DPA 4061 | CA-14 omni Pres: CA9200 | DPA d:vice Decks: Zoom F8 | Roland R-05

Offline aaronji

  • Site Supporter
  • (8)
  • Needs to get out more...
  • *
  • Posts: 3033
Re: Schoeps mk41? Doubting to take the plunge...
« Reply #43 on: July 07, 2020, 11:36:15 AM »
The SPL at any position in the room is a combined measurement of the direct and revereberant arriving sound, however the balance between the two is not constant.  It changes with increasing distance. The level of direct-arriving sound decreases according to the inverse square law as the distance from the source is increased, while the level of the reverberant-arriving sound remains more or less constant.   At distances less than the critical-distance (aka radius-of-reverberation) the direct-arriving sound dominates. Moving farther away than the critical distance, the direct-sound becomes increasingly attenuated as compared to the reverberant-sound.

Right, that is exactly what I said. The reverberant is assumed to be constant and the direct decreases linearly with distance (like in the picture; I think that is "inverse distance", not "inverse square", though).

Consider an hypothetical super-directional microphone which is able to completely reject pickup from every direction other than a super narrow on-axis window, like a laser-beam.  All of the direct sound arrives along one axis, so we point this super-directional microphone directly at the source to maximize "pickup as much direct sound as possible".  So far so good.  But recall that the reverberant sound is arriving from all directions equally, including the directly-on-axis direction.  As move increasingly farther away, the balance of sound at the microphone position becomes increasingly dominated by reverberant-sound, despite our super-directional microphone that is able to reject sound arriving from every direction except on-axis.

By being less sensitive to sound arriving from off-axis, a directional microphone provides an increased proportion of direct-sound, but is only able to do so until the pickup of reverberant-sound which is also arriving inside the microphone's on-axis coverage angle begins to dominates over the pickup of direct-arriving sound.  That's clearly what happens at distances closer than the critical-distance, and it continues to work beyond the critical distance only to a lesser and lesser degree until eventually even the signal from our imaginary super-directional microphone becomes dominated by on-axis reverberant sound.

Obviously, there is a distance at which the proportion of direct sound becomes too small to be of value to the recordist (whether that is within or outside of the critical distance). Wouldn't that distance be 1.7 times further for a card than an omni?
People whose posts I won't see: jerryfreak. The probationary period didn't last long...

Offline Gutbucket

  • record > listen > revise technique
  • (15)
  • Needs to get out more...
  • *****
  • Posts: 13812
  • Gender: Male
  • Gunther Theile nailed it!
Re: Schoeps mk41? Doubting to take the plunge...
« Reply #44 on: July 07, 2020, 12:41:49 PM »
Obviously, there is a distance at which the proportion of direct sound becomes too small to be of value to the recordist (whether that is within or outside of the critical distance). Wouldn't that distance be 1.7 times further for a card than an omni?

Up to the point where the direct sound becomes swamped by the reverberant sound, yes.

The graph I linked above doesn't show a plot line for combined direct and reverberant sound integrated together at microphone position.  Below is another.  Check the red line labeled mixed overall sound.  Once the direct-sound sinks more than a few dB below that line (not sure how much), it becomes dominated by reverberant sound regardless of pickup pattern.  The flattening of the slope of the red line with increased distance is directly related to the loss of the ability of distance-factor to compensate at increasing distances.

« Last Edit: July 08, 2020, 11:54:35 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<<

 

RSS | Mobile
Page created in 0.057 seconds with 43 queries.
© 2002-2020 Taperssection.com
Powered by SMF