Author Topic: XY ??? (Read 12284 times)

Swampy · « **on:** June 19, 2003, 02:47:20 PM »

Ok, so I've ran ORTF and DIN so far, but I decided I'm gonna try XY tonight. My question is this: how do you align the diaphrams, does it matter? On the OADE site, it has the diaphrams making a right angle: http://www.oade.com/Tapers_Section/micsetup90xyzoom.html . On the DPA site they make an X (see graphic) I don't even know that it even matters, but I just wanted to make sure! THANKS!

Swampy · « **Reply #1 on:** June 19, 2003, 02:55:59 PM »

Thanks for clearing that up!

wboswell · « **Reply #2 on:** June 19, 2003, 02:58:28 PM »

Both pictures appear to be the same, just different mounts were used.

Mic D · « **Reply #3 on:** June 19, 2003, 03:05:04 PM »

They're both the same. Just make sure you have your cables switched (i.e the mic on the right side should be the left channel because it is pointed to the left).

Kevin

Swampy · « **Reply #4 on:** June 19, 2003, 04:41:27 PM »

Quote from: wboswell on June 19, 2003, 02:58:28 PM

Both pictures appear to be the same, just different mounts were used.

The oade pic the caps form a 90* angle, in the DPA, they form an X.

Brian Skalinder · « **Reply #5 on:** June 19, 2003, 04:49:21 PM »

Quote from: AlexHerd on June 19, 2003, 04:41:27 PM

Quote from: wboswell on June 19, 2003, 02:58:28 PM
Both pictures appear to be the same, just different mounts were used.

The oade pic the caps form a 90* angle, in the DPA, they form an X.

I didn't get what you were saying initially, Alex, but I get it now. Puzzled me for a bit! FWIW, I don't think it will make a difference which way you go:

In the Oade pic, the ends of the caps on the long axis of each mic are aligned with the outer diameter of the other mic's short axis / width.

In the DPA pic, the ends of the caps are centered over the other mic's short axis / width.

Swampy · « **Reply #6 on:** June 19, 2003, 04:51:34 PM »

Alright, thanks!

rokpunk · « **Reply #7 on:** June 19, 2003, 04:52:14 PM »

wouldnt the angles that an "X" makes all be 90?

Wes · « **Reply #8 on:** June 19, 2003, 05:04:05 PM »

X look at the X and remember your trigonometry. 2 angles look to be about 90 degrees while the other 2 look to be about 110~120

Brian Skalinder · « **Reply #9 on:** June 19, 2003, 05:06:40 PM »

I think Alex's question has less to do with the angle - in both cases the mic caps are 90º offset from each other - and more to do with the the vertical capsule alignment with respect to the opposite mic. See my previous post above.

twoodruff · « **Reply #10 on:** June 19, 2003, 05:10:02 PM »

trig wasn't good to you wes, as a straight line is 180 degrees so if one is 90 so is the other. X All angles are 90 degrees.

Wes · « **Reply #11 on:** June 19, 2003, 05:14:48 PM »

if all angles were 90 it would be a +. lets not forget whos the engineer

twoodruff · « **Reply #12 on:** June 19, 2003, 05:18:23 PM »

my point is that if one angle is 90 the other is 90 not 110-120

Wes · « **Reply #13 on:** June 19, 2003, 05:22:14 PM »

i know. it would actually depend on the font your using if the all the angles in the x are 90 degrees or if 2 are 90 and the other 2 are obtuse angles of equal magnitude. you could as easily have 2 acute angles and 2 obtuse.

rokpunk · « **Reply #14 on:** June 19, 2003, 05:35:16 PM »

Turn that "+" 45 degrees...now what do you have? Perhaps it should be refered to as a "cross", not an "X", but I think the point comes across either way. When I record in an XY pattern, I space the capsules at a 90 degree angle with one on top of the other as close to each other as possible without touching. I don't do much field recording these days, but this pattern works great as a stereo overhead on a drum kit. BTW, the term "engineer" is a rather loose term....it can mean a lot of things. Anyone can refer to themself as an audio engineer since there is no governing standard to be one, or test to become one. I refer to myself as an Audio Engineer, but aside from my saying so, there isn't really a way for me to prove it. I do have a certificate from a recording institute, and a now expired membership to AES, but neither of those things make me any more of an audio engineer than anyone else.

Wes · « **Reply #15 on:** June 19, 2003, 05:41:40 PM »

i'm by no means an audio engineer. I'm a mechanical engineer, at least almost.. about a year and a half of school left.

So heres a serious question. XY should always be run at 90? If I'm far from the sound source i usually tend to close the angle a bit making it less than 90, i am sometimes pleased with my tapes and other times not. So is the 90 degree angle really that important to produce the stereo image?

rokpunk · « **Reply #16 on:** June 19, 2003, 05:45:08 PM »

This mic pattern is simulating the x-y axes on a graph. The capsules of the mics are placed in very close proximity and pointed at or around a 90 degree angle (coincident pair.) This placement eliminates phase problems because the wave hits both mics at the same time.

twoodruff · « **Reply #17 on:** June 19, 2003, 05:45:54 PM »

wes you used to run v2>ad2k+, you can do whatever you want from now on

Wes · « **Reply #18 on:** June 19, 2003, 05:47:01 PM »

wouldn't the wave hit the mic at the same time no matter what as long as they share the same vertical axis? i don't think i'm following

Wes · « **Reply #19 on:** June 19, 2003, 05:51:43 PM »

i dunno trey, i'm not real pleased with that allstars from hal and mals.. you say yours sounds good?

twoodruff · « **Reply #20 on:** June 19, 2003, 05:55:14 PM »

i know its xy with the hypers, you ll learn one day

rokpunk · « **Reply #21 on:** June 19, 2003, 05:55:33 PM »

This is from Modern Recording Techniques by Huber and Runstein :

The XY technique is an intensity-dependent system; it uses only the cue of an amplitude to discriminate direction. With the XY technique, two microphones of the exact same type are placed with their grills as close together as possible (without touching) and facing at right angles to each other. The midpoint, or 45 degree angle, between the two mics is faced toward the musical instrument and the mic outputs are panned left and right. Even though the two mics are placed together, the stereo imaging is excellent - often better than when using the spaced pair method. There is the added advantage of having no appreciable phase problems due to the close proximity of the mics. The angles of the two mics may be changed to fit the occasion, with the preferred angles being from 90 degrees to 120 degrees. The generally accepted polar pattern is cardioid, although two crossed bi-directional mics can give excellent ambient results.

Help any?

Wes · « **Reply #22 on:** June 19, 2003, 06:00:29 PM »

yeah. that really clears it up. i've heard that you are ONLY suspose to run xy 90 degree and I just didn't agree. +t. good info

jlykos · « **Reply #23 on:** June 19, 2003, 06:17:30 PM »

Quote from: Mic D on June 19, 2003, 03:05:04 PM

They're both the same. Just make sure you have your cables switched (i.e the mic on the right side should be the left channel because it is pointed to the left).

True, true. I have a crystal-clear on-stage tape of Garaj Mahal run XY. Only problem is, the entire soundstage is BACKWARDS! Switched cables suck.

zhianosatch · « **Reply #24 on:** June 19, 2003, 06:42:42 PM »

Quote from: jbandtheboys on June 19, 2003, 05:04:05 PM

X look at the X and remember your trigonometry. 2 angles look to be about 90 degrees while the other 2 look to be about 110~120

2(90) + 2(120) = 420*
That's one bad-ass circle, lemme tell you

Armen

Wes · « **Reply #25 on:** June 19, 2003, 07:18:47 PM »

jlykos,
just about any music editing software will let you swap channels. i know for sure wavelab does

Simp-Dawg · « **Reply #26 on:** June 19, 2003, 07:49:10 PM »

Quote from: zhianosatch on June 19, 2003, 06:42:42 PM

Quote from: jbandtheboys on June 19, 2003, 05:04:05 PM
X look at the X and remember your trigonometry. 2 angles look to be about 90 degrees while the other 2 look to be about 110~120

2(90) + 2(120) = 420*
That's one bad-ass circle, lemme tell you
Armen

now that's MY kind of math!

+T!!!

Swampy · « **Reply #27 on:** June 19, 2003, 09:26:51 PM »

Quote from: Brian Skalinder on June 19, 2003, 05:06:40 PM

I think Alex's question has less to do with the angle - in both cases the mic caps are 90º offset from each other - and more to do with the the vertical capsule alignment with respect to the opposite mic. See my previous post above.

Yep. Its pretty funny how stuff ends up on this board! Thanks for the help guys!

Swampy · « **Reply #28 on:** June 20, 2003, 10:43:28 AM »

Well I tried XY last night, and I was suprised. XY sounds a lot better than I thought it would, thanks!

twoodruff · « **Reply #29 on:** June 20, 2003, 10:49:11 AM »

its all about the angle