Topic: Visualization of various stereo mic configurations

[DigiGal]

Here is a fun link demonstrating the various stereo mic configurations.  You can vary the mic patterns and angles in real time within any of the listed configurations and see how your coverage is affected. 

DINa is not included seems DINa is never mentioned.  Who came up with DINa?  You can visualize it, however, by selecting the DIN configuration and changing the microphone distance from 0.20 to 0.17 meters.

I've duplicated this topic including the link in the TS Knowledge Base / Archive since it makes an excellent reference.


http://www.sengpielaudio.com/Visualization-ORTF-E.htm

[ArchivalAudio]

very fun!
nice to see the additional info on arrays!

--Ian

[Gutbucket]

This is a good resource for comparing differeces in mic setups if interpreted correctly.

Grey zone  = stereo recording angle (usually different than the angle between mics)
Colored lines = spatial distribution of individual sounds from pickup to playback

The colored bars tend to attract more attention in this visualization and help to understand some of the sonic differences between setups, but the size and limit of the grey zone is probably more important in the grand scheme of choosing a configuration for a specific recording location.

Other links to this visualization have been posted here a few times over the last few years. I remember a more in depth discussion of it at one point, which might be worth a search for anyone interested.

Here's another useful one that's been posted previously where you can enter different angles, spacing, patterns, delays, etc. and get similar data but in a different fomat- http://www.hauptmikrofon.de/ima2-folder/ImageAssistant2.html

[stevetoney]

Wow, the one you posted Gutbucket totally put me into sensory overload trying to figure it out. 

I really like the first one posted though.

My only comment on that first one would be that it would have been useful to include distances as inputs rather than Orchestra Angle...or they could have had the option for calculating that angle based on distances between speakers/orchestra and distance to mics so that the program could calculate the angle.  Reason is that I can't measure an angle, but I can approximate distances.

Otherwise, it looks like a cool little tool.

[Brian Skalinder]

Reason is that I can't measure an angle, but I can approximate distances.

Approximating angles is easy:  http://taperssection.com/index.php?topic=137228.msg1784150#msg1784150

[stevetoney]

Reason is that I can't measure an angle, but I can approximate distances.

Approximating angles is easy:  http://taperssection.com/index.php?topic=137228.msg1784150#msg1784150

Nice Brian.  Thanks! 

I do remember now reading this suggestion, but had forgotten.

Wouldn't it be cool to have that somehow plugged into an iphone app where you could point the phone at the various extremes to get the angles and then enter the other info to get the SRA's in the field.  I know it can be done manually, but it would be pretty cool to have something that does it quick and easy from an electronic device.   

[DigiGal]

Reason is that I can't measure an angle, but I can approximate distances.

Approximating angles is easy:  http://taperssection.com/index.php?topic=137228.msg1784150#msg1784150

Nice Brian.  Thanks! 

I do remember now reading this suggestion, but had forgotten.

Wouldn't it be cool to have that somehow plugged into an iphone app where you could point the phone at the various extremes to get the angles and then enter the other info to get the SRA's in the field.  I know it can be done manually, but it would be pretty cool to have something that does it quick and easy from an electronic device.

You could always use an inexpesive protractor (pictured below) to get the angles right.  Alternately there are several protractor apps available for the iPod Touch/iPhone too.  It would be awesome if the original program I linked were available in a mobile app.

[Gutbucket]

The phone app thing would be sweet for those that carry a smart phone.

I've struggled with a protractor once or twice trying to sight read angles and it just didn't work for me 'off the flat page'.  Michael Williams (Stereo Zoom author) builds his own angle viewers out of a fish-eye peep-hole door lens.  I think he sells them too.  Nicely crafted beautiful wooden construction, but a bit big in pocket. http://www.mmad.info/MSS/mmss.htm  You look like a serious recordist when you pull that out!

[stevetoney]

Looks like you could also peep in on the neighbors or navigate by stars with that...or just keep it around in case Rover needs dentures.

[Gutbucket]

10 degree fist method works for me.  I have gotten a few odd looks occasionally doing it, which I usually consider a bonus.  A flowered young girl once asked as I pointed a fist towards the stage and squinted at it, "you seem so happy and mellow, what's up with that psychically punching out each of the performers thing?" 

[MIQ]

The Sengpielaudio Visualization is fun to play with.  I wanted to be able to compare a bunch of configurations for cardioid mics on the same sheet, so I drew a few up in a drafting program.  See attached PDF.  I modeled my Busman BSC1 mics and used them in the drawings for reference.  

By studying the diagrams you can get a feel for how time delay and intensity are traded to vary the recording angle.  By comparing the four configurations at the bottom of the sheet (the angle between the mics is a constant 90 degrees), you can see that increasing the distance between mics (increasing inter-channel time delay) causes the recording angle to decrease.  By comparing ORTF and DINa (the distance between the mics is a constant 17cm), you can see that decreasing the angle between the mics (decreasing inter-channel level differences) causes the recording angle to increase. 

To increase the recording angle - move the mics closer together and/or decrease the angle between them
To decrease the recording angle - move the mics further apart and/or increase the angle between them

The Shure and Schoeps guides, with diagrams similar to this, don't include DIN or DINa. It is nice to see most of the common cardioid configurations tapers use on one sheet. 

At Gutbucket:  Doesn't Williams call his contraption the "crocodile"?  I can see why...

-MIQ

[achalsey]

bump...  I've got a pair of hypers and subs coming soon so I've been playing around with this.

One question though, what does "Orchestra angle mean?"

[ScoobieKW]

bump...  I've got a pair of hypers and subs coming soon so I've been playing around with this.

One question though, what does "Orchestra angle mean?"

Orchestra angle is 1/2 the angle formed between the left of your sound source and the right of your sound source with you at the vertex. The further back you are from your sound source the smaller this angle will be. The reason it's 1/2 the angle is that Orchestra Angle is expressed as a +/-

[achalsey]

Ooohh...So the closer you get (say onstage) you might get an angle closer to +/- 50/60 depending on how far the band is spread out?

[ethan]

Sweet now I know why I like XY for onstage