Home |
Search |
Today's Posts |
#1
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
Playing with MS more lately to solve another problem, and getting some
pretty amazing results. You may remember that I always listen in surround, and I have always sought a very wide and spacious sound. What I have found is that if you set the S channel just right (about +2 in my case) you can just about achieve surround sound for free. I got a new MS module for my Zoom H6, so I went to try it out on my jazz band that I record. The stereo call out test went almost perfectly, the soundstage spread evenly and perfectly across the entire width of the room, but a bonus was when someone else talked or played something during the test I heard them placed very accurately where they were actually sitting, front or rear, left or right. Additionally, it seems that MS is able to encode direction more accurately and finely than any other miking technique or scheme. I have tried. The ability to adjust the stage width afterward is a bonus that shouldn't be discounted. Along with that, I am wondering what the Stereo Width Control is doing in Audition is doing exactly - is it converting a normal stereo signal to MS and back again? Or is it just extracting some middle and making the difference signal greater? Gary Eickmeier |
#2
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
Gary Eickmeier wrote:
Playing with MS more lately to solve another problem, and getting some pretty amazing results. You may remember that I always listen in surround, and I have always sought a very wide and spacious sound. What I have found is that if you set the S channel just right (about +2 in my case) you can just about achieve surround sound for free. That's because the S channel decodes almost completely to the rears. The thing is, as something moves right to left across the soundstage, it will also move forward and back at the same time. Additionally, it seems that MS is able to encode direction more accurately and finely than any other miking technique or scheme. I have tried. The ability to adjust the stage width afterward is a bonus that shouldn't be discounted. Decoded MS and coincident cardioids are mathematically identical and they are very close to interchangeable with top-grade microphones. As you get to cheaper microphones that are less flat off-axis, the X-Y configuration becomes more of an issue since the center of the soundstage is off-axis on both mikes. Along with that, I am wondering what the Stereo Width Control is doing in Audition is doing exactly - is it converting a normal stereo signal to MS and back again? Or is it just extracting some middle and making the difference signal greater? There is no difference between these two processes. They are identical. Both basically come down to increasing the L-R component. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#3
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
"Gary Eickmeier" writes:
-snip- Additionally, it seems that MS is able to encode direction more accurately and finely than any other miking technique or scheme. I have tried. The You haven't tried 50 cm A/B with diffraction spheres, then (or perhaps the Jeklin disk, which I have not tried). MS has okay L-to-R imaging. But sometimes the LR soundstage "dimension" can be non-linear the further left or right you go. That is, you can have a somewhat clustered "centerish" soundstage that then suddenly zips out to far left and far right. Farther center left and farther center right can kinda be skipped over to jump directly to that far left and or right. Doesn't happen all the time, but it can. Aside from not having a reliably accurate left-to-right, my main complaint with MS and XY is the lack of true, pin-point, *front-to-back* imaging. That's why I largely abandoned MS when I heard 50cm A/B. That, and the ability to use omnis which, because of their much better low end response and more even response in general, brought on a whole new world of realism, particularly with orchestral work. ability to adjust the stage width afterward is a bonus that shouldn't be discounted. Typically, you don't want to do that with A/B because that's where the "room width" lives, and rarely is your "subject" as wide as the left and right walls. But if you want you can trim in the pan pots a touch to narrow the image and you'll do no harm. Along with that, I am wondering what the Stereo Width Control is doing in Audition is doing exactly - is it converting a normal stereo signal to MS and back again? Or is it just extracting some middle and making the difference signal greater? Several plug-ins have a width enhancer. Generally that's done by crossfeeding delay components or similar time-based trickery. Indeed it's handy -- if not overused. Now, there are some mastering processors that convert to and from a pseudo MS so that you can then raise or lower the center of the image, but I'm not sure it's truly MS. For one thing, as I understand these (have not used one), you do not change the width as you adjust the "center" volume. YMMV. Frank Mobile Audio -- |
#4
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
"Frank Stearns" skrev i en meddelelse
... "Gary Eickmeier" writes: -snip- Additionally, it seems that MS is able to encode direction more accurately and finely than any other miking technique or scheme. I have tried. The You haven't tried 50 cm A/B with diffraction spheres, then (or perhaps the Jeklin disk, which I have not tried). I actually think my best spatial rendering is an AB recording made like that with the microphones parallel. It was also the last time I changed a setup in the intermission, an old tape amateur friend, how had asked me to help him with the recording, suggested I should angle the CK22's outwards and it caused a collapse of perspective that was so annoying that I only ever burned the first part to CD. I also made a number of AB recordings in August 2014 because it allowed a less visually obtrusive setup, something that was specifically requested by the event photographer, a couple of them with CK22's but most of them with Sennheiser MKH106 and all of them with the mics positioned vertically. That setup of course required a treble boost in post ... O;-) ... but worked like a treat with mics only 2 meters above the floor. For deep ensembles, such as those with a concert grand I added an other omni on the piano, often but not always only one. Stereo miking of a concert grand for spot miking is grossly overevaluated and often causes more stereo problems than it solves, I trust the main pair to deliver the stereo image and just use the spot mic(s) - suiably delayed - to add focus. MS has okay L-to-R imaging. But sometimes the LR soundstage "dimension" can be non-linear the further left or right you go. That is, you can have a somewhat clustered "centerish" soundstage that then suddenly zips out to far left and far right. Farther center left and farther center right can kinda be skipped over to jump directly to that far left and or right. Doesn't happen all the time, but it can. Aside from not having a reliably accurate left-to-right, my main complaint with MS and XY is the lack of true, pin-point, *front-to-back* imaging. That's why I largely Enter what I also call xy - it is more misleading to call it ortf - namely some 12 to 22 centimeters capsule spacing and an angle between the microphone in the 45 to 100 degrees range, smaller angle if you are close or it is a wide ensemble, larger angle if you are further away. Adjust inter microphone angle for stable center and - my preference - a bit of room on the outside of the ensemble, just like the real world is. Under some circumstances a pair of omnis tend to blur far away sound sources in a very reverberant room, and then the image compensation abilities of a spaced xy pair can be most helpful. abandoned MS when I heard 50cm A/B. That, and the ability to use omnis which, because of their much better low end response and more even response in general, brought on a whole new world of realism, particularly with orchestral work. Omnis are kinder to any kind of transient than cardioids, it did not take long to learn than when using a MD211 together with a pair of MD4241's. And oh what imaging problems one can have when the helpful electronics guy who soldered mic cables for you can not read a Sennheiser cable spec properly and miswires the HL ... thinking back I still think that was way too uphill a way to start recording ... ability to adjust the stage width afterward is a bonus that shouldn't be discounted. Typically, you don't want to do that with A/B because that's where the "room width" lives, and rarely is your "subject" as wide as the left and right walls. But if you want you can trim in the pan pots a touch to narrow the image and you'll do no harm. Don't worry, forget theory and take it to ms and fix it and back, adjusting the S level is a good way to strengthen the center and if you have too much reverb then it also is likely to be helpful to eq the S signal. However using diffraction spheres does just about "all of that", something that needs to be understood. And it works in three dimensions, eq works globally. Along with that, I am wondering what the Stereo Width Control is doing in Audition is doing exactly - is it converting a normal stereo signal to MS and back again? Or is it just extracting some middle and making the difference signal greater? Several plug-ins have a width enhancer. Generally that's done by crossfeeding delay components or similar time-based trickery. Indeed it's handy -- if not overused. It is an MS tweak, but I've always preferred to make those manually. Now, there are some mastering processors that convert to and from a pseudo MS so that you can then raise or lower the center of the image, but I'm not sure it's truly MS. For one thing, as I understand these (have not used one), you do not change the width as you adjust the "center" volume. YMMV. The simplest ploy to fix a troublesome recording is usually the best. But we are seeing a lot of plug ins coming on to the market that a) do what most daw software can do out of the shrink wrap and b) capitalizes on user ignorance by offering to make the "difficult bits" as if MS was something exotic. It is akin to when Symantec sold Norton Tools for windows that basically just did what the OS could do anyway. That said, some of the time a plug in can offer a very neat short cut. As example no daw should be without Nugens "Mono", it is really a uniquely helpful image stabilizer if properly used, whatever that is. In principle I am against making the bass monophonic because some of the ambience information is in the VLF out of phase stuff, but in the real world so many people are playing back on mono subwoofer systems that one has to think compatibility. Frank Mobile Audio Kind regards Peter Larsen |
#5
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
"Scott Dorsey" wrote in message ... Decoded MS and coincident cardioids are mathematically identical and they are very close to interchangeable with top-grade microphones. As you get to cheaper microphones that are less flat off-axis, the X-Y configuration becomes more of an issue since the center of the soundstage is off-axis on both mikes. In other words, coincident XY is the same as MS with the M and S about the same gain, and also the XY can be converted back to an exactly equivalent MS pair that can be manipulated just as if the original were MS (?). Gary |
#6
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
"Gary Eickmeier" skrev i en meddelelse
... "Scott Dorsey" wrote in message ... Decoded MS and coincident cardioids are mathematically identical and they are very close to interchangeable with top-grade microphones. As you get to cheaper microphones that are less flat off-axis, the X-Y configuration becomes more of an issue since the center of the soundstage is off-axis on both mikes. In other words, coincident XY is the same as MS with the M and S about the same gain, and also the XY can be converted back to an exactly equivalent MS pair that can be manipulated just as if the original were MS (?). LR and MS (sum and difference) are different packaging of the same information as should be obvious from the simple mathematical operation that converts one to the other. Gary Kind regards Peter Larsen |
#7
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
Gary Eickmeier wrote:
"Scott Dorsey" wrote in message ... Decoded MS and coincident cardioids are mathematically identical and they are very close to interchangeable with top-grade microphones. As you get to cheaper microphones that are less flat off-axis, the X-Y configuration becomes more of an issue since the center of the soundstage is off-axis on both mikes. In other words, coincident XY is the same as MS with the M and S about the same gain, and also the XY can be converted back to an exactly equivalent MS pair that can be manipulated just as if the original were MS (?). Precisely. Assuming perfect microphones, of course. Now, the downside of this is that with MS and XY and Blumlein you get no phase imaging, only intensity stereo. This affects low-frequency imaging. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#8
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
субота, 31. јануар 2015. 14.07.17 UTC+1, Peter Larsen је написао/ла:
For deep ensembles, such as those with a concert grand I added an other omni on the piano, often but not always only one. Stereo miking of a concert grand for spot miking is grossly overevaluated and often causes more stereo problems than it solves, I trust the main pair to deliver the stereo image and just use the spot mic(s) - suiably delayed - to add focus. Kind regards Peter Larsen Sorry if I already mentioned this. Some time ago, I've recorded a series of solo (prepared) piano concerts. However, the deal and the scheduelle was such taht I'd show there just before the very begining, plug my multitrack into their PA console and take the signal from inserts. People working there always did the same set up, - two cardioid mics (I forgot the model) close to strings and the lid - Kind of ORTF pair of C1000s' with omni capsules My job was to record 4 tracks and later mix them for CD (low number run, self published by artist). Which I did and ok... Story being, each time I got there, I asked those guys to reverse the setup for the next concert, put the omnies inside and have cardioids for ORTF, they'd alwasys say, mmm, cool, we'll do it for the next one and they never did. |
#9
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
"Gary Eickmeier wrote:
"Scott Dorsey" wrote in message ... Decoded MS and coincident cardioids are mathematically identical and they are very close to interchangeable with top-grade microphones. As you get to cheaper microphones that are less flat off-axis, the X-Y configuration becomes more of an issue since the center of the soundstage is off-axis on both mikes. In other words, coincident XY is the same as MS with the M and S about the same gain, and also the XY can be converted back to an exactly equivalent MS pair that can be manipulated just as if the original were MS (?). No, the gain doesn't come into it. You are reversibly and losslessly "translating" all the stereo information data from its listenable X/Y format into a not-directly-listenable M/S format (All the information in the MS format is available to re-create the XY.) The ratio of M to S that happens to result from the XY - MS operation will depend on (a) the polar pattern of the XY mics and (b) their angular splay. And as a corollary, the pattern and splay of a (virtual) XY pair is driven by the (a) the chosen M mic polar pattern and (b) the M to S ratio. This "about the same gain" is irrelevant. Think of XY - MS as a sort of translation process. Take a word "tree"; translate that into French using your an En-Fr dictionary; that may be unrecognizable for your kids, but once they consult a Fr-En dictionary it all becomes perfectly clear again. Many folks have a persistent notion that only MS allows width adjustment (via gain ratio changes.) Any coincident XY array can do that...just that it's a mite less convenient, entailing an extra step: MS - XY MS - ratio change - M'S' - X'Y' XY - M/S - ratio change - M'S' - X'Y' |
#10
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
On 1/31/2015 8:41 PM, Tom McCreadie wrote:
"Gary Eickmeier wrote: "Scott Dorsey" wrote in message ... Decoded MS and coincident cardioids are mathematically identical and they are very close to interchangeable with top-grade microphones. As you get to cheaper microphones that are less flat off-axis, the X-Y configuration becomes more of an issue since the center of the soundstage is off-axis on both mikes. In other words, coincident XY is the same as MS with the M and S about the same gain, and also the XY can be converted back to an exactly equivalent MS pair that can be manipulated just as if the original were MS (?). No, the gain doesn't come into it. You are reversibly and losslessly "translating" all the stereo information data from its listenable X/Y format into a not-directly-listenable M/S format (All the information in the MS format is available to re-create the XY.) ...big snip... Hmm, (on M/S not being directly listenable) I've often wondered about an M/S speaker setup. Sounds like something that might be right up Mr. Eickmeier's ally. Actually, it seems like an ideal technology for TV surround's left/center/right sound bar in a box type thing. Hard to imagine this hasn't been experimented with. == Later.... Ron Capik -- |
#11
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
On 2/1/2015 3:24 AM, Ron C wrote:
Hmm, (on M/S not being directly listenable) I've often wondered about an M/S speaker setup. Sounds like something that might be right up Mr. Eickmeier's ally. It's been done, and by our old friend Aspen Pittman, formerly of Groove Tube. He and Drew Daniels developed the concept in the late 1970s. Fender made a portable PA system half a dozen years ago using an M-S speaker setup. http://www.centerpointstereo.com/ -- For a good time, visit http://mikeriversaudio.wordpress.com |
#12
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
"Ron C" skrev i en meddelelse
... Hmm, (on M/S not being directly listenable) I've often wondered about an M/S speaker setup. Sounds like something that might be right up Mr. Eickmeier's ally. DR (danish state radio) or one of their enginesearchers built one in the 1950'ties or 1960'ties. Works great. One unit towards to and one behind it radiating to both sides. Has the interesting property that the closer you get the wider the image. Actually, it seems like an ideal technology for TV surround's left/center/right sound bar in a box type thing. Hard to imagine this hasn't been experimented with. And it has. Easy to emulate with a surround center box and behind it a surround fig8 box. Adding digitat processing to get them coincident comes to mind ... Ron Capik Kind regards Peter Larsen |
#13
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
"Tom McCreadie" wrote in message ... "Gary Eickmeier wrote: "Scott Dorsey" wrote in message ... Decoded MS and coincident cardioids are mathematically identical and they are very close to interchangeable with top-grade microphones. As you get to cheaper microphones that are less flat off-axis, the X-Y configuration becomes more of an issue since the center of the soundstage is off-axis on both mikes. In other words, coincident XY is the same as MS with the M and S about the same gain, and also the XY can be converted back to an exactly equivalent MS pair that can be manipulated just as if the original were MS (?). No, the gain doesn't come into it. You are reversibly and losslessly "translating" all the stereo information data from its listenable X/Y format into a not-directly-listenable M/S format (All the information in the MS format is available to re-create the XY.) The ratio of M to S that happens to result from the XY - MS operation will depend on (a) the polar pattern of the XY mics and (b) their angular splay. And as a corollary, the pattern and splay of a (virtual) XY pair is driven by the (a) the chosen M mic polar pattern and (b) the M to S ratio. This "about the same gain" is irrelevant. Think of XY - MS as a sort of translation process. Take a word "tree"; translate that into French using your an En-Fr dictionary; that may be unrecognizable for your kids, but once they consult a Fr-En dictionary it all becomes perfectly clear again. Many folks have a persistent notion that only MS allows width adjustment (via gain ratio changes.) Any coincident XY array can do that...just that it's a mite less convenient, entailing an extra step: MS - XY MS - ratio change - M'S' - X'Y' XY - M/S - ratio change - M'S' - X'Y' Well, I am not sure how to word my question, but when you buy an MS recorder like the Zoom H6 with built-in MS module, you get an adjustment that goes from Zero dif between M and S in the plus direction all the way to RAW and in the minus direction (less and less S mike) to zero, or mono. This suggests that (if there are sounds all around you, not just a solo instrument up front) that the S = 0 would have both M and S gains equal, right? Then at that time the MS pair would be exactly equivalent to the XY Blumlein pair. But with other polar patterns for the M mike than Fig 8, this equivalency might not hold. Also interesting that coincident stereo is pure intensity stereo and is subject to this mathematical translation, but does that hold true for any of the spaced microphone techniques? I mean, obviously the signal doesn't know how it was obtained, so you could do the stereo width control on any stereo signal, right? I guess I should just record my MS in RAW and do as I please with it later, but I have always wondered how I should ideally be setting my gains while recording. Should I set both M and S knobs the same and let the signal rise and fall where it may, or should I set them so that both tracks are equally loud most of the time? Would that be equivalent to setting the Zoom S signal to zero difference from M? Fascinating stuff. And yes, I have and still am reading all about it. I would normally think that a little spacing between mikes would add something to the stereo mix (over the coincident techniques), but in practice so far MS has it hands down in both accuracy and spaciousness. Gary |
#14
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
On 2/1/2015 11:23 PM, Gary Eickmeier wrote:
I guess I should just record my MS in RAW and do as I please with it later, but I have always wondered how I should ideally be setting my gains while recording. Should I set both M and S knobs the same and let the signal rise and fall where it may, or should I set them so that both tracks are equally loud most of the time? I don't know the Zoom jargon, but see if there's an option that lets you record the mid and side signals separately, but monitor the decoded stereo. That way you can at least hear what you're recording in stereo. -- For a good time, visit http://mikeriversaudio.wordpress.com |
#15
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
"Gary Eickmeier" skrev i en meddelelse
... I guess I should just record my MS in RAW That would be the easiest. and do as I please with it later,but I have always wondered how I should ideally be setting my gains while recording. So that you do not clip the recording. Should I set both M and S knobs the same and let the signal rise and fall where it may, or should I set them so that both tracks are equally loud most of the time? You omit a variable: microphone sensitivity. However with matched microphones you should set the knobs the same and the signal in channels 1 and 2 should be the same or channel 2 (S) a few dB lower. If it is not like that then your mic stand is likely to be incorrectly positioned or mic directional patterns incorrectly chosen. Would that be equivalent to setting the Zoom S signal to zero difference from M? Doing it. Fascinating stuff. And yes, I have and still am reading all about it. I would normally think that a little spacing between mikes would add something to the stereo mix (over the coincident techniques), but in practice so far MS has it hands down in both accuracy and spaciousness. It is always a compromise to record, especially to record live events where positioning is often "where possible". But nice to hear that a compromise within solid theory fares better than one well outside it, as your spaced array most certainly is in the way you use it. Just never stop learning ... because there is always more to learn Gary Kind regards Peter Larsen |
#16
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
"Peter Larsen" wrote in message web.com... Just never stop learning ... because there is always more to learn Kind regards Peter Larsen Amen. Thanks to all. I think I have everything balanced fairly well now in the whole throughput from mikes to speakers. I like several miking tehniques now But MS is holding up as a great "go to" setup for maximum versatility and minimal intrusion into their show. My playback system seems well suited to it as well, being surround and semi reflecting. I can walk all around and the band stays put. I can go closer to them or farther away, just like live. Walk right up to between the speakers and almost "see" the band and everyone still where they belong! Gary |
#17
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
On Sunday, February 1, 2015 at 10:41:58 PM UTC-8, Peter Larsen wrote:
"Gary Eickmeier" skrev i en meddelelse ... .... Should I set both M and S knobs the same and let the signal rise and fall where it may, or should I set them so that both tracks are equally loud most of the time? You omit a variable: microphone sensitivity. However with matched microphones you should set the knobs the same and the signal in channels 1 and 2 should be the same or channel 2 (S) a few dB lower. If it is not like that then your mic stand is likely to be incorrectly positioned or mic directional patterns incorrectly chosen. .... Kind regards Peter Larsen This certainly doesn't match my experience. If I use matched or similarly sensitive mics and matched gain settings the S signal is _much_ lower than the M signal and if this were not the case I would start looking for my error. Fran |
#18
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
On 2/2/2015 8:23 PM, Fran Guidry wrote:
This certainly doesn't match my experience. If I use matched or similarly sensitive mics and matched gain settings the S signal is_much_ lower than the M signal and if this were not the case I would start looking for my error. Of course that makes sense since they're pointed so that the null is toward what you're trying to record. However, I usually adjust the preamp gain so that I get a good level out of the preamp and then adjust the mid and +/- side mix for the stereo spread that I want. -- For a good time, visit http://mikeriversaudio.wordpress.com |
#19
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
Mike Rivers wrote:
On 2/2/2015 8:23 PM, Fran Guidry wrote: This certainly doesn't match my experience. If I use matched or similarly sensitive mics and matched gain settings the S signal is_much_ lower than the M signal and if this were not the case I would start looking for my error. Of course that makes sense since they're pointed so that the null is toward what you're trying to record. However, I usually adjust the preamp gain so that I get a good level out of the preamp and then adjust the mid and +/- side mix for the stereo spread that I want. Agreed, and sensible advice. A reasonable start is with the applied M and S channel gains of the preamp/recorder at ca. 1:1 (after due allowance for any sensitivity differences between M and S mics), then tweak it in real time from there. If, instead, you fixated on setting the channel gains purely to ensure that the recorded signals on the meters flux at equal levels for M and S, you would almost always be recording with too much S. (Some people do hang on to recording with M and S both maximized, though, on the dubious rationale that it still contributes a little to a better S/N ratio or cleaner AD conversion.) I find it's important to home in fairly close to an optimum M:S ratio in real time before the concert starts, for only then are you able to properly address that other important parameter: direct to reverberant ratio. Image width and direct/reverberant ratio are alas not independent variables - if you widen the image by increasing the S to M ratio you always get a concomitant increase in the reverberant to direct ratio. So it pays to strive to nail the direct/reverberant balance at concert time, by adjusting the stand placement distance and height. In post in a DAW, one can always adjust the M to S ratio...but no DAW post-processing can ever re-adjust the stand position. |
#20
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
"Tom McCreadie" wrote in message ... Mike Rivers wrote: On 2/2/2015 8:23 PM, Fran Guidry wrote: This certainly doesn't match my experience. If I use matched or similarly sensitive mics and matched gain settings the S signal is_much_ lower than the M signal and if this were not the case I would start looking for my error. Of course that makes sense since they're pointed so that the null is toward what you're trying to record. However, I usually adjust the preamp gain so that I get a good level out of the preamp and then adjust the mid and +/- side mix for the stereo spread that I want. Agreed, and sensible advice. A reasonable start is with the applied M and S channel gains of the preamp/recorder at ca. 1:1 (after due allowance for any sensitivity differences between M and S mics), then tweak it in real time from there. If, instead, you fixated on setting the channel gains purely to ensure that the recorded signals on the meters flux at equal levels for M and S, you would almost always be recording with too much S. (Some people do hang on to recording with M and S both maximized, though, on the dubious rationale that it still contributes a little to a better S/N ratio or cleaner AD conversion.) I find it's important to home in fairly close to an optimum M:S ratio in real time before the concert starts, for only then are you able to properly address that other important parameter: direct to reverberant ratio. Image width and direct/reverberant ratio are alas not independent variables - if you widen the image by increasing the S to M ratio you always get a concomitant increase in the reverberant to direct ratio. So it pays to strive to nail the direct/reverberant balance at concert time, by adjusting the stand placement distance and height. In post in a DAW, one can always adjust the M to S ratio...but no DAW post-processing can ever re-adjust the stand position. Are you guys thinking that M will be stronger because it is pointing straight at the music, whereas S is just doing the sideways ambience? I smell a rat somewhere in there. So two questions: 1. What would the M and S gains register on the meters for a source exacty 45 from straight ahead? Equal, right? Admittedly, to this will be added the straight ahead sources, which will be in the null of the S mike, but then answer #2: 2. If you were doing Blumlein with two figure 8 mikes, the two channels would obviously be equal. In this case, a source at 45 would be max in one channel and in the null of the other. Question 2: What would the mathematically equivalent MS signals look like? I'm too tired to think right now, but wouldn't that answer the musical question? Isn't that what the Zoom H6 is doing with the S set to zero dif from M? That would be knob setting, not actual levels of course. Gary |
#21
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
"Gary Eickmeier" skrev i en meddelelse
... Are you guys thinking that M will be stronger because it is pointing straight at the music, whereas S is just doing the sideways ambience? Good stereo has S in the interval -6dB S M Gary Kind regards Peter Larsen |
#22
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
Gary Eickmeier wrote:
Are you guys thinking that M will be stronger because it is pointing straight at the music, whereas S is just doing the sideways ambience? I smell a rat somewhere in there. In a typical array placement in an auditorium, most of the sound energy will be direct sound arriving predominantly from the front. The sounds from side and rear will be predominantly lower level reflected sounds etc. Why do you find that so surprising? So two questions: 1. What would the M and S gains register on the meters for a source exacty 45 from straight ahead? Equal, right? Admittedly, to this will be added the straight ahead sources, which will be in the null of the S mike, but then answer #2: It depends on the pattern pf the M mic: _____________________________ 45 deg. off-axis M pattern dB drop _____________________________ 0.00 Omni 0.88 Subcardioid ("V = 0.67 + 0.33.cos.theta") 1.38 Cardioid (Zoom H6 M/S module ?) 1.77 Supercardioid ("V = 0.37 + 0.63.cos.theta") 3.01 fig- 8 ______________________________ 2. If you were doing Blumlein with two figure 8 mikes, the two channels would obviously be equal. In this case, a source at 45 would be max in one channel and in the null of the other. Question 2: What would the mathematically equivalent MS signals look like? I'm too tired to think right now, but wouldn't that answer the musical question? Isn't that what the Zoom H6 is doing with the S set to zero dif from M? That would be knob setting, not actual levels of course. If you take a stereo signal from a conventional +/- 45 deg. Blumlein pair and perform a standard MS operation on it, the resultant signal - if still played back as an XY signal - would be what would have come from a Blumlein pair aimed 45 deg left ("North-West") - but with the L and R ouput channels swapped. Clear as mud? :-) As for your Zoom H6 M/S module, let's assume firstly that the M mic is a cardioid pattern and that it has the same sensitivity as its S partner. Then an M/S with a cardioid for M and at 1:1 M:S gain setting translates mathematically to a virtual XY array of two supercardioid mics (pattern: V = 0.31 + 0.69 cos.theta), splayed at 127 deg. included angle Such an array would have an SRA of ca. 85-90 deg. -- Tom McCreadie "Ah, where would we be without humour." "Germany?" |
#23
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
"Frank Stearns" wrote in message ... "Gary Eickmeier" writes: -snip- Additionally, it seems that MS is able to encode direction more accurately and finely than any other miking technique or scheme. I have tried. The You haven't tried 50 cm A/B with diffraction spheres, then (or perhaps the Jeklin disk, which I have not tried). MS has okay L-to-R imaging. But sometimes the LR soundstage "dimension" can be non-linear the further left or right you go. That is, you can have a somewhat clustered "centerish" soundstage that then suddenly zips out to far left and far right. Farther center left and farther center right can kinda be skipped over to jump directly to that far left and or right. Doesn't happen all the time, but it can. Aside from not having a reliably accurate left-to-right, my main complaint with MS and XY is the lack of true, pin-point, *front-to-back* imaging. That's why I largely abandoned MS when I heard 50cm A/B. That, and the ability to use omnis which, because of their much better low end response and more even response in general, brought on a whole new world of realism, particularly with orchestral work. Frank Mobile Audio My audio engineer friend who does most of the archival gigs in town uses the 50 cm omnis (DAP) and gets fantastic results. What is interesting is that this would be a purely time of arrival kind of stereo and my MS would be strictly intensity stereo, and both work well! I had thought that some combination of the two approaches with some shorter spaced cardioids aimed right and left would give the best compromise - the best of both - but I was wrong. On my MS experiment, I have arrived at a tentative conclusion that the S of 3 dB below M works best for my setup in surround sound. It gives a pretty much perfect spread of the frontal sound along with strong enough a surround signal to give the surround feel - actually hearing audience behind me. Crank it up to realistic levels and whammo, you are THERE. Gary |
#24
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
Gary Eickmeier wrote:
My audio engineer friend who does most of the archival gigs in town uses the 50 cm omnis (DAP) and gets fantastic results. What is interesting is that this would be a purely time of arrival kind of stereo and my MS would be strictly intensity stereo, and both work well! I had thought that some combination of the two approaches with some shorter spaced cardioids aimed right and left would give the best compromise - the best of both - but I was wrong. If he's using the DPA 4006 omnis, you'll find that they aren't really very omni. Add the balls onto them and they become even less omni, and that is what gives you actual intensity stereo. The M50, as traditionally used in the Decca tree, are even less omni. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#26
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
Frank Stearns wrote:
(Scott Dorsey) writes: The M50, as traditionally used in the Decca tree, are even less omni. Indeed. The higher frequency directionality adds an intensity component. And the M50 response is rather peculiar; my understanding is that in part the Decca tree technique was birthed to work around that odd response. Yes, I have tried, and seen others try, to make the Decca tree work with other microphones and never been satisfied with the results. It does seem very dependent on the weird beaming of the M50. Once again, KM183s (or 183Ds) using 50 cm spacing, 120 degree splay, 20 degree up-tilt, with the balls, is the most accurate imaging I've ever heard. Try the Jecklin! --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#27
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
On 10/02/2015 14:42, Scott Dorsey wrote:
Frank Stearns wrote: (Scott Dorsey) writes: The M50, as traditionally used in the Decca tree, are even less omni. Indeed. The higher frequency directionality adds an intensity component. And the M50 response is rather peculiar; my understanding is that in part the Decca tree technique was birthed to work around that odd response. Yes, I have tried, and seen others try, to make the Decca tree work with other microphones and never been satisfied with the results. It does seem very dependent on the weird beaming of the M50. I've had good results using a pair of Marshal MXL603's and an MXL604, which surprised me somewhat, as they're not by any stretch of the imagination omni. -- Tciao for Now! John. |
#28
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
All -
I am trying the Soundcloud program for aharing music files. Not as good as sending you a CD, but one way to show and tell about a recording session without the trouble of mailing. So here is the setup. These guys are some of them snowbirds from up north, some retirees from here. Anywayh, this is the breakoff dance band group from the big wind band the Lakeland Concert Band. They just have fun trying to be good enough to play for a dance with paying customers. And the old timers in the trailer parks are delighted to kick up their heels. And me to record them. OK, so the music is not GREAT, but I can still try for maximum realism in the sound and polish my recording techniques. Again, this one with MS from the AT 2050 multi pattern mikes in Fig 8 mode I was 10 ft from the front line of saxes, and the group was 24 ft wide and 14 ft deep. http://g4.img-dpreview.com/044FD4850...091C9EE57C.jpg http://g1.img-dpreview.com/9B5A5AD1E...090824AECC.jpg https://soundcloud.com/eickmeier-1/w...d-of-fool-3wav Gary |
#29
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
I loved the phone ringing. Maybe if you'd turn the whole mic set some 60 degrees clockwise?
|
#30
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
On Thursday, February 12, 2015 at 1:30:44 PM UTC-5, Gary Eickmeier wrote:
All - I am trying the Soundcloud program for aharing music files. Not as good as sending you a CD, but one way to show and tell about a recording session without the trouble of mailing. So here is the setup. These guys are some of them snowbirds from up north, some retirees from here. Anywayh, this is the breakoff dance band group from the big wind band the Lakeland Concert Band. They just have fun trying to be good enough to play for a dance with paying customers. And the old timers in the trailer parks are delighted to kick up their heels. And me to record them. OK, so the music is not GREAT, but I can still try for maximum realism in the sound and polish my recording techniques. Again, this one with MS from the AT 2050 multi pattern mikes in Fig 8 mode I was 10 ft from the front line of saxes, and the group was 24 ft wide and 14 ft deep. http://g4.img-dpreview.com/044FD4850...091C9EE57C.jpg http://g1.img-dpreview.com/9B5A5AD1E...090824AECC.jpg https://soundcloud.com/eickmeier-1/w...d-of-fool-3wav Gary Gary, not bad [love the studio talk!], but it sounds like an old recording. GENERALLY I think that was due to the lack of an electric bass guitar. Rather rearrange (group) the horns, you know sax on left, trumpets center, maybe trombones at right, use several mics, one for each group, then mix. But what do I know!? Maybe some swing would perk my ears up! I love horns, and big bands!! Footnote, even though I "LOVE" stereo, it's hard for me to really like a lot of Sinatra recordings [example]. First, you hear the band on the right (intro), then Frank (vocals) in the center, then finally the strings on the left. Many songs were recorded like that. I didn't mind the clams! :-) |
#31
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
On Thursday, February 12, 2015 at 2:08:14 PM UTC-5, Luxey wrote:
I loved the phone ringing. Maybe if you'd turn the whole mic set some 60 degrees clockwise? Luxey... From the 1941(?) Glenn Miller film! Someone found the film audio had two tracks. Someone, I guess, simulated the stereo of the band, but you can definitely hear the vocals are separated!! I GUESS this was done to balance singing and music in monophonic! Just so neat to hear!!!... http://www.angelfire.com/empire/abps...hoochoo-s2.mp3 Jack |
#32
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
"Gary Eickmeier" writes:
All - And me to record them. OK, so the music is not GREAT, but I can still try for maximum realism in the sound and polish my recording techniques. Again, this one with MS from the AT 2050 multi pattern mikes in Fig 8 mode I was 10 ft from the front line of saxes, and the group was 24 ft wide and 14 ft deep. https://soundcloud.com/eickmeier-1/w...d-of-fool-3wav Seems like the biggest sonic problem is the drop ceiling -- early (and uneven) reflections in the higher mid and top, then more oddities as the mids and bass reflect off the harder, denser surface that's a few feet above the drops. This leads to some odd image hot spots, along with some peculiar phasiness. Might be nothing wrong with the technique but I'd not want to judge it one way or another until it was possible to record in a more acoustically friendly room. Stay at it. Frank Mobile Audio -- |
#33
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
"Frank Stearns" wrote in message ... Seems like the biggest sonic problem is the drop ceiling -- early (and uneven) reflections in the higher mid and top, then more oddities as the mids and bass reflect off the harder, denser surface that's a few feet above the drops. This leads to some odd image hot spots, along with some peculiar phasiness. Might be nothing wrong with the technique but I'd not want to judge it one way or another until it was possible to record in a more acoustically friendly room. Stay at it. Frank Mobile Audio Interesting comments all. This is just a rehearsal of course, but they usually arrange themselves the same way in most performances. I have no say in that. The rooms would be a lot larger at the performances. I nailed the problem of the heavy bass tonight. Heard it again during tonight's rehearsal. Things were going along fine until suddenly there was this excess hum from the electric bass speaker. Then during that song I heard the dreaded Thum thum thum of the bass overwhelming everything and everybody. I had to speak up and have him turn it down because it was ruining every song. Later, the guitarist confided that he wore two hearing aids and had his speaker positioned behind him so he couldn't hear much of anything out of it and turned it up all the way. I wonder why the leader didn't hear it and look for the problem and get a better balance. Gary |
#34
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
On Friday, 13 February 2015 11:58:09 UTC+1, Gary Eickmeier wrote:
I wonder why the leader didn't hear it and look for the problem and get a better balance. Gary Because he's not that f*ck'n' awesome, like you are, my dear Gary. |
#35
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
"Luxey" wrote in message ... On Friday, 13 February 2015 11:58:09 UTC+1, Gary Eickmeier wrote: I wonder why the leader didn't hear it and look for the problem and get a better balance. Gary Because he's not that f*ck'n' awesome, like you are, my dear Gary. He is a volunteer and has other problems to deal with than recording quality sound. Gary |
#36
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
A possible new problem has come up with MS, namely some imaging anomalies at
different frequencies. When I do my stereo test and even during a performance, I have noticed that higher frequency percussive sounds will image in the center more than at left or right. Like, the drum set is at stage left, but there are some pings and other sounds that come from the center. Is this some well known principle, or fault, of MS? Ever heard of it? Gary |
#37
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
"Gary Eickmeier" skrev i en meddelelse
... A possible new problem has come up with MS, namely some imaging anomalies at different frequencies. Yes and no, ie. I trust them to be there and they are not a result of MS, MS and XY remains mathematically equivalent. There is then the issue of stereo acceptance angle, ie. the room segment that is placed between L and R, see also the paper "The Stereophonic Zoom". When I do my stereo test and even during a performance, I have noticed that higher frequency percussive sounds will image in the center more than at left or right. Like, the drum set is at stage left, but there are some pings and other sounds that come from the center. Is this some well known principle, or fault, of MS? Ever heard of it? You are using large membrane microphones AND you tell us you evaluate stereo played back as 5.1. All bets are off for both reasons, the most likely cause is however large membrane anomalies. To evaluate mic off axis behaviour: set up recorder to record one channel connect one microphone to recorder set recorder to record hold microphone in a straight arm in front of you be on axis recite Mary had a little lamb, entire poem rotate microphone so that you are 45 degrees off axis recite Mary had a little lamb, entire poem rotate microphone so that you are 90 degrees off axis recite Mary had a little lamb, entire poem rotate microphone so that you are 135 degrees off axis recite Mary had a little lamb, entire poem rotate microphone so that you are 180 degrees off axis recite Mary had a little lamb, entire poem Listen to recording and evaluate, fft analysis may or may not be informative. If you are really bored repeat with the other three microphones, they will probably be somewhat different. The expected difference is that any treble "issues" will be more prominent off axis if correlated with resonance in the housing, but you'll be the first to know. Consider one microphone aimed at the drumkit and linear on axis and one microphone aimed 90 degrees away from the drumkit BUT "almost omni"" from 7200 to 8800 Hz because of a resonance and it gets obvious why the intensity information will cause the highhat to move towards center. Speak at one meter, even if only on axis, is a very good fast way to compare microphones and select the best sounding. It was such a test that made me skip buying calrec condensers in the early 1980'ties, however I also didn't really have very much use for them then, if I had really needed them I had asked for some more to compare and selected the two best. Gary Kind regards Peter Larsen |
#38
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
"Gary Eickmeier" writes:
A possible new problem has come up with MS, namely some imaging anomalies at different frequencies. When I do my stereo test and even during a performance, I have noticed that higher frequency percussive sounds will image in the center more than at left or right. Like, the drum set is at stage left, but there are some pings and other sounds that come from the center. Is this some well known principle, or fault, of MS? Ever heard of it? Of course, it's called lousy microphone response. Stop and consider for a moment running your side level up and down, and what that does to stereo width. Then think about 10, 15, 20 dB variances of response in your micropphones at various frequencies. It's like running the side level up and down -- at those frequencies. Your off-axis response of the side mic probably isn't very good, and/or there's a serious level mismatch between the M and S microphones at various frequencies. Just one more reason why I appreciate a technique where I can use good omnis. Frank Mobile Audio -- |
#39
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
Gary Eickmeier wrote:
A possible new problem has come up with MS, namely some imaging anomalies at different frequencies. When I do my stereo test and even during a performance, I have noticed that higher frequency percussive sounds will image in the center more than at left or right. Like, the drum set is at stage left, but there are some pings and other sounds that come from the center. Is this some well known principle, or fault, of MS? Ever heard of it? It's a room problem. Move the mike. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#40
Posted to rec.audio.pro
|
|||
|
|||
Fascinating MS
On 14/02/2015 18:09, Gary Eickmeier wrote:
"Scott Dorsey" wrote in message ... Gary Eickmeier wrote: A possible new problem has come up with MS, namely some imaging anomalies at different frequencies. When I do my stereo test and even during a performance, I have noticed that higher frequency percussive sounds will image in the center more than at left or right. Like, the drum set is at stage left, but there are some pings and other sounds that come from the center. Is this some well known principle, or fault, of MS? Ever heard of it? It's a room problem. Move the mike. --scott Great responses - thanks to all. I will try some of the tests you suggest. Could well be a mike problem, changing the M to S ratio with frequency. Don't know what the test results might be, but all I can tell you is that I am using the Audio Technica 2050 variable pattern mikes in Fig 8 pattern. These are reasonable quality for a beginner like me and I would expect that would work reasonably well, and maybe my MS mix isn't quite perfiect yet. And BTW the same phenomenon holds true looking at the lissajous pattern, or phase response window in Audition, so it is a recording problem and not so much playback - but I do realize how the rear speakers can affect perceived frontal direction as well so I will do more testing in stereo only. You could try altering the EQ on the S channel to alter the relative levels of the HF percussion. If it moves in and out, you've got a frequency response problem. Then you need to find out how much is the room and how much is the microphones. -- Tciao for Now! John. |
Reply |
|
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Fascinating tour of Kudelski/Nagra | Pro Audio | |||
NYOBs fascinating find | Audio Opinions | |||
An ever-fascinating subject: Quad II | Vacuum Tubes | |||
See the Most Fascinating Music System on the Market... | Marketplace | |||
See the Most Fascinating Music System on the Market... | Marketplace |