Taperssection.com
Gear / Technical Help => Microphones & Setup => Topic started by: BWolf on December 13, 2006, 02:17:22 PM
-
In reference to this thread: http://taperssection.com/index.php?topic=19866.0
Did we ever get an answer to this? I mean, whats the best way to run blumlien if you don't have a so called blumlien mount? I have the XY and midside mounts for the neumann actives, i think they would both work, but I'm just wondering....
If I put them in the XY, the lobes will be crossing at 90 with the mic diaphrams right on top of each other. If i put them in the M/S and they are side by side (like in the thread) then the will be crossing at 90 (slightly off).
-
The Neumann mounts are quite different.
The normal stereo mount is designed for a pair of cardioids (or hyper-cardioids) in an XY or ORTF arrangement.
(http://www.neumann.com/img/accessories/sth100.gif)
shown here in XY mode
The MS mode needs a fig-8 mic. and a different mount.
(http://www.neumann.com/img/accessories/daak.gif)(http://www.neumann.com/img/accessories/dakm.gif)(http://www.neumann.com/img/accessories/sth120.gif)
You can't really do one with the other.
-
alright, but if you put 2 fig 8s in the XY mount, with the front lobes facing outward (ie, one facing directly at us in that pic and the other at 90 degrees from that), wouldn't that be blumlien?
I have these mounts. the XY/ORTF and the first M/S mount. look at the other thread, 2 fig 8s were put into a m/s mount and set up to run blumlien (as long as its ok to put them side by side)
-
The top 2 pics are how I run blumlein now...It's a little bulky and has caused me to not run blumlein as much as I would like too...If you have anything like that handy Brad, then you can do it like that, but it is bulky(esp. seeing I do 4 mic mixes)...the bottom 3 pics are in the 3rd m/s mount pictured in post 2...Now from what I have read and understand, I should get the same results if I mount the 2 figure 8s like I have in pics 3,4,& 5??? Is this correct??? thanks for any clarification
-
with the c422, cant i just leave the capsules at the 90 degree split i use for m/s, and orient the mic so the angle is in the center (rather than the top capsule - so rotated 45 degrees clockwise) and then set the patterns on the s42 box both to fig8, right..?
-
with the c422, cant i just leave the capsules at the 90 degree split i use for m/s, and orient the mic so the angle is in the center (rather than the top capsule - so rotated 45 degrees clockwise) and then set the patterns on the s42 box both to fig8, right..?
/quote]
That sounds right to me, although I'm no expert vis-a-vis the c422.
-
yep
as long as everything is leveled up and squared properly, in relation to the soundfield.
blumlein is xy, coincident, with rear lobes
perfect, thats what i was thinking. i do have the midside mount like that also, so i might try that. now, i'm wondering, with them spaced, would it be advantageous to cross the figure 8s. ie in that last pic, if you rotated them so that the left one was picking up the right soundfield and the right one was picking up the left soundfield. that way, you weren't leaving that gap between them.... maybe thats just a moronic idea, but i'm just asking.
i'll probably just run them in the XY mount, and run them on the horizontal plane
-
The top 2 pics are how I run blumlein now...It's a little bulky and has caused me to not run blumlein as much as I would like too...If you have anything like that handy Brad, then you can do it like that, but it is bulky(esp. seeing I do 4 mic mixes)...the bottom 3 pics are in the 3rd m/s mount pictured in post 2...Now from what I have read and understand, I should get the same results if I mount the 2 figure 8s like I have in pics 3,4,& 5??? Is this correct??? thanks for any clarification
doesnt look right to me, theyre not coincident that way, one HAS to be over the otehr for that to happen :)
-
doesnt look right to me, theyre not coincident that way, one HAS to be over the otehr for that to happen :)
Quote from: todd e on January 23, 2006, 11:20:20 AM
Quote from: Teddy on January 19, 2006, 06:25:22 PM
they dont have to be on top of each other ...one can be across the other and acheive the same result.
Teddy - if you don't mind, what is your source for this recommendation?
Multiple Sources. Jerry Bruck being the first, and confirmed by a friend at schoeps, and also by Mr. Rich Mays, an engineer /location recording engineer, David Satz is another..... Sometimes There "can" be phasing issues, milliseconds of delay with side by side placement, and isnt like Mr Blumlein intended it, but in the absence of a mounting option to run head to head, it can be done that way(most people may say it isnt ideal, but necessity is the mother of invention). I asked twice, once back when I had u89s and didnt have a vert bar to accomodate the two LD mics, and the other day , when Nick bumped this....directional patterns are three-dimensional .
Im pretty sure that side by side will give the blumlein result as stated by Teddy from the thread Bwolf linked up top...just wanted to get another nod that it was correct
-
Placing the mics next to one another doesn't give exactly the same results as vertically aligned mics but with small diaphragm mics which may be placed with their diaphragms physically very close together, in all but the most critical applications, it's all but impossible to tell between vertically aligned and side by side setups.
In larger diaphragm/large bodied mics like C414s, U89s, etc., where the larger bodies and capsule housings make it harder to get the capsules close together (and where it's harder to mount them vertically without resorting to modified/specially built hardware) you may get more problems. In practice, many large diaphragm mic designs actually position the capsule closer to the top of the housing than the bottom - which moves it slightly away from the effects of body, more into free space, and makes it easier to achieve close capsule mounting to a similar mic when vertically aligned.
The main differences between side by side and vertical mounting are in the nature of the inter-channel delays and reflections/shadowing caused by the mic bodies and mounts.
Ideally, for Blumlein, to minimise interchannel delays, the capsules should be vertically mounted, however, with physically small mics mounted side by side, the interchannel delays may actually be smaller than with some larger mics, mounted vertically. The only difference then is that, with vertically mounted mics, the interchannel delays are greatest in the vertical alignment so (in theory) impact less on the accuracy/stability of the horizontal stereo image (on the basis that people are less sensitive to variations in median plane auditory imaging) . Side by side mounting increases the horizontal interchannel delays so impacts more on the percieved stereo image.
As for shadowing/reflection, if figure-8 mic capsules are mounted vertically above one another, the closest pieces of hardware are in the response null of the polar pattern, and the bodies are physically as far apart as possible, so reflection effects are minimised. Mounting fig-8 mics side by side in anything other than a parallel configuration (e.g. a Faulkner Array (http://www.sengpielaudio.com/TonyFaulknerPhasedArray06.htm) ), causes one mic to some extent to shadow the polar pattern of the other and can result in reflections off the structure of one mic interfering with sound entering the other. Improvised, or less than optimally designed mouting systems can also cause reflection problems but whether or not, in practice, these are audible/problematic is another matter.
Purpose built coincident stereo mics like the C422/C426, SM69, VM1S, MC742, etc., etc., have an advantage (apart from practicality) over using pairs of the mono equivalent mics in that they reduce the amount of hardware around the capsules - one mic body, no need for complex stereo mounts, etc..
The strength of these various delay/shadowing/reflection effects varies from setup to setup and, at it's best, some side by side mounts will be less problematice than some of the worst affected vertically aligned pairs but, in general, vertical mounting of a given pair of mics will always achieve fewer errors/more perfect results in Blumlein/MS than side by side mounting.
Having said all that, the differences between vertical and side by side mounting normally are small and practicalities like availability of mics and mounting hardware, together with positioning and rigging considerations usually outweigh any advantages/disadvantages inherent in the chosen mounting method. In other words - side by side isn't the best way to do Blumlein or MS but, done with care and a little consideration of the details, doesn't usually make enough difference to bother anyone so do whatever works for you. It might, however, be technically wrong, to describe anything other than vertically mounted fig-8s as 'Blumlein', in the same way that patterns other than cardioid can't be used to produce true 'ORTF' arrays. (It might not be wrong as Blumlein specifies co-incidence, which is physically impossible, and side by side may, in distance, be as (or more) physically 'coincident' as vertical mounting. I'm not sure whether Blumlein's description differentiates between horizontal and vertical mounting - I'll check when I have some time.)
-
with the c422, cant i just leave the capsules at the 90 degree split i use for m/s, and orient the mic so the angle is in the center (rather than the top capsule - so rotated 45 degrees clockwise) and then set the patterns on the s42 box both to fig8, right..?
correct
-
ok, so nobodys answered my question:
can i use the XY mount, have the fig 8s in the horizontal plane and on top of each other? isn't this the same as mounting them vertically with the ends facing each other?
-
yes it is.
its absolutely acceptable in the real world, but not obsessively perfect.
You'll forever get people debating the horizontal vs. vertical mounting.
Most important in this, is making sure the mic caps are "squared up" properly to the soundfield, and not having one cap aiming more downward, and the other off-kilter in some other fashion.
I ran the TL's this way, several times, in circumstances where I didn't have another option, and the results were fine.
sweet. thanks moke. now the other question is, do you just record blumlien to two separate chanels, or do you use some sort of martix algorthm (like the m/s)?
-
its a straight to tape technique. no mix or matrixing.
sweet moke, you're the man. +t
-
its a straight to tape technique. no mix or matrixing.
you don't want to get too close with blumlein.
I've gotten too close in acoustic music, and ended up with cross-over of players from the rear lobes.
just keep in mind that you want the soundfield to be contained within the combined axis angle of the front lobes, just like , xy, din, ortf. The rear lobes of blumlein are for ambient information, and not so much direct sound (as the front lobes will get).
very cool. the tape is going to be at Radio City, hopefully right in the middle of the floor about halfway back (basically dead center). i'll let ya'll know how it comes out.
thanks for all the tips and advice.
-bw
-
very cool. the tape is going to be at Radio City, hopefully right in the middle of the floor about halfway back (basically dead center). i'll let ya'll know how it comes out.
thanks for all the tips and advice.
-bw
Who said I was sending my other ak20 ;) I might want to run it now ;D... Thanks Ovu for the information...That really does help out and was what I was looking for +t...I talked C.Fox into running blumlein at Radio City this year for Panic(cause I wasnt there)...He ran from row XX...Think his tape came out pretty good, but it was also a 4 mic mix...I ran blumlein at the Greek this summer from the ots and the tapes sound unreal...better than cards(ak40s), hypers(ak50s), or cards(km84i) from the same spot...Neumann blumlein rocks and Im sure you'll be wanting to order another ak20 after using it NYE
-
alright, but if you put 2 fig 8s in the XY mount, with the front lobes facing outward (ie, one facing directly at us in that pic and the other at 90 degrees from that), wouldn't that be blumlien?
No, I don't think so.
Firstly, the fig-8 is larger in diameter.
Secondly, I don't think the diaphragms will line up correctly (though check it and see) - the diaphragms should ideally be one above the other in vertical alignment.
(http://taperssection.com/index.php?action=dlattach;topic=76768.0;attach=49131;image)
-
with the c422, cant i just leave the capsules at the 90 degree split i use for m/s, and orient the mic so the angle is in the center (rather than the top capsule - so rotated 45 degrees clockwise) and then set the patterns on the s42 box both to fig8, right..?
Yep! That is exactly how I used to do it with my c34. Just set up as if you were going to run XY and switch the S42 to fig8. Carl Beck, who now ownes my old c34, runs Blumline all the time like this with damn fine results. Just make sure you are pretty close as Blumline can get real muddy if you are too far back in the room.