Topic: ORTF with Hypers???

[stevetoney]

I've been doing some listening on archive and noticed more than once where people ran hypers in ORTF.  Am I missing something or doesn't ORTF kinda defeat the purpose?

[John Willett]

ORTF is cardioids at 110 degrees at 17cm spacing.

Any other pattern / angle / spacing is *not* ORTF.

[Javier Cinakowski]

hey, read that stereophonic zoom paper.  I don't think I will ever bother using a standardized configuration....

[Will_S]

What purpose do you think is being defeated?  Are you thinking of hypers as extremely directional beasts that are only good for pointing right at the sound source from a distance?  They're not shotguns.

Are you thinking hypers are just for cutting down on off-axis room noise?  I think they can be pleasing in better situations as well.

Hypers ORTF (for now accepting any mics 17cm apart and angled 110° are ORTF) will create a wider stereo image than card ORTF.  Hypers tend to have a pattern that's more uniform across frequency than cards are (i.e. a card is more directional at high frequencies than it is at low).  So if you want to create a wide stereo image, but maintain good frequency response for sources straight in front of you, hypers might work better than cards.  E.g. to get the same image width you would with ORTF hypers (assuming a fixed setup location of course, and for the sake of argument saying you didn't want to go wider than 17cm due to phase/timing considerations), you'd probably have to run cards at 130 degrees or more.  That's starting to put sources directly in front of you far enough off axis to sound colored with some cardioids.  Hypers, while attenuated more off axis, at least are more evenly attenuated across all frequencies, and so will color the central sound less.

Not to mention, some folks like the effect you get from the rear lobe picking up a bit of ambience out of phase.

[stevetoney]

ORTF is cardioids at 110 degrees at 17cm spacing.

Any other pattern / angle / spacing is *not* ORTF.

Ah sooo.  I missed that point about ORTF and was just focusing on spacing and angle.

[BC]

isn't ORTF intended specifically for cardioid mics?

[BC]

FWIW, just found this from wikipedia

http://en.wikipedia.org/wiki/ORTF_stereo_technique


ORTF combines both the volume difference provided as sound arrives on- and off-axis at two cardioid microphones spread to a 110º angle, as well as the timing difference as sound arrives at the two microphones spaced 17 cm apart.

[stevetoney]

What purpose do you think is being defeated?  Are you thinking of hypers as extremely directional beasts that are only good for pointing right at the sound source from a distance?  They're not shotguns.

Are you thinking hypers are just for cutting down on off-axis room noise?  I think they can be pleasing in better situations as well.

Thanks for the thoughts/opinions.  I wasn't debating their use in ORTF, but really was curious if the config was kinda oxymoronic.

So, while no I knew most hypers aren't extremely directional mics (your first question), I was thinking more along the lines that their primary use was decreasing off-axis noise (your second question).  

So, I appreciate the tech info.  Good stuff.  +T

[Brian Skalinder]

Not sure what you mean by "defeat the purpose".  Taking up boojum's chorus:  check out The Stereophonic Zoom (linked in the sticky at the top of the forum).  Hypercardioids at 17cm spacing with 110º included angle yield a sterephonic recording angle (SRA) of ~37º (for a total of 74º spanning L to R, or vice versa).  So if the sound source occupies roughly a 74º arc from the recording location, it seems a reasonable However, note this configuration risks capturing too much centered reverberation (see the SZ link for details).

I was thinking more along the lines that their primary use was decreasing off-axis noise (your second question).

That's one of the challenges, and why SZ is just a starting point.  It's a challenge to balance SRA, reverberation, and angular distortion.  Fun trying out different options, at any rate. 

[stevetoney]

FWIW, just found this from wikipedia

http://en.wikipedia.org/wiki/ORTF_stereo_technique


ORTF combines both the volume difference provided as sound arrives on- and off-axis at two cardioid microphones spread to a 110º angle, as well as the timing difference as sound arrives at the two microphones spaced 17 cm apart.

I'm not debating, but this statement is kinda generically true of any of the mic configs, isn't it?  Although of course the point of XY is to eliminate timing difference.

[stevetoney]

Not sure what you mean by "defeat the purpose". 

I guess my choice of words might not have been the best.  When I was referring to 'the purpose', I was referring to the rule of thumb that lots of people recommend hypers for minimizing room reverb.

[F.O.Bean]

Steve, I would also suggest trying hypers/NOS and see how you like that. I would suggest being DFC and pretty close to the stage. Here is my 12/31 RAQ recording, where I was 9th row/DFC w/ hypers/NOS

http://www.archive.org/details/raq2007-12-31.ka500.722.flac16

[jlykos]

Hypers ORTF run a greater chance of you having a hole in the middle of the soundstage because of their wider spacing.  I run hypers in DIN (17 cm / 90*) all the time and I like the results very much.  The narrower angle results in a more coherent soundstage.

[Roger Gustavsson]

You can find quite a lot of information on stetting up microphones on Sengpiel's homepage. This one gives a good view of how different setups work. http://www.sengpielaudio.com/Stereo-LautlokEines60.pdf

[waltmon]

I agree with the 90 degree spread on the hypers.  While I loved the sound of the instruments w/ the 150's @ 110...the vocals seemed distant.  The 90 degree change really tightened up the sound and pushed the vocals much more forward in the mix.