Topic: HRTF omni set up

[yates7592]

I am looking to use a sort of HRTF set up with DPA 4061 omni mics, hat-mounted, mics to each side of my head. Is there any advice anybody can give on making this work as well as possible? I will preferably be standing up front at or close to the stage, or should I move back? Thanks in advance.

[acidjack]

The whole point of HRTF with omni mics is to recreate the sound your ears hear as accurately as possible.

So, stand where it sounds best.  Generally that means somewhere in the center between the board and (at the maximum close distance) 10-15 feet from the stage, depending on the PA array.

Or stack tape, if you prefer that sound. Even then, depending on the PA, I've found it best to put a little distance between you and I, especially if it's a big stack, to avoid picking up just the woofer or just some other part of the speaker.

[yates7592]

Thanks for the advice. If I have the mics placed just above my ears, should they be pointing straight forwards or slightly out? I heard the latter but just checking.

[acidjack]

Thanks for the advice. If I have the mics placed just above my ears, should they be pointing straight forwards or slightly out? I heard the latter but just checking.

Straight. Just put them in the clips and clip the clips onto the had just forward of your ears. To be honest, it doesn't really matter that much. Just make sure your head is between the two mics.

[mysticeyes]

I did something like this recently. I had 4061's clipped above and to either side of the bill of a baseball cap, pointed a little more than 90 degrees apart, and plugged into a Littlebox and an M10. I was in a crowd, outdoors at a street festival, with a good size PA system. It was an experiment on my part, because I had always recorded openly by using clamps or a mic stand, and usually in small clubs where only the vocals are micced through a small PA. On this occasion, I just walked around until I heard the sound that I liked best, and that's where I stayed. I learned that it was tough to stand as still as possible for the duration of a set, especially since my friends were trying to get me to dance! I was happy to find out that the 4061's are rather resistant to handling noises, and I got a nice recording out of it too. In fact, I was surprised to hear a decent recording of a buncha PA stacks .

[acidjack]

Just note, if you put them on the bill of the cap,rather than further back where your head is between the mics, it's not really HRTF. The whole point of HRTF is to simulate how your ears hear, which involves, of course, the physical barrier of your head affecting how you hear in stereo. 

personally I have never used the bill of the cap for that reason. practically, I don't know how much difference there is.

[fotoralf.be]

Real HRTF necessarily includes the outer ear and the outer part of the ear canal. With those DPAs attached to a hat, you'll be getting something more along the lines of a baffled-pair recording, like with a Jecklin disc, a wedge etc. Nothing wrong with that, mind you, just not HRTF.

If you're seriously interested in HRTF recording using your own head, the only really convincing solution would be the OKM ear mics.

Ralf

[Gutbucket]

If you're seriously interested in HRTF recording using your own head, the only really convincing solution would be the OKM ear mics.

Only?

.. or other miniature omnis such as your 4061s placed as close as possible (or actually inside) the opening of the ear canals, well inside the outer fleshy portion of your ears (the pina).  Some miniature omnis have dedicated devices to help hold them in place, such as the OKMs and others including the inexpensive SP-TFA2, but that just makes mounting them easier in your ears. 

Around here, that technique is what most refer to as "binaural" microphone technique, meant for dedicated headphone playback, and HTRF mic technique is usually taken to mean omnis mounted just in front of but not inside the outer ear, like you are doing.  Technically, HTRF means Head Related Transfer Function, which includes the influence of the both the head, outer ears, and sometimes torso, on sounds arriving from various angles.  That's how it is used in academic literature, which actually equates it more closely to 'binaural' in recording terms, but like many other terms used around here "as commonly understood and used" and "as technically defined" are not always the same thing. Take for example the constantly misused concept of "unity gain" on this forum.

Even standard terms and definitions change. Alan Blumlein's development of a "binaural reproduction system" had nothing to do with microphones in ear and headphones, but rather other microphone techniques coupled with two speaker reproduction.. which would eventually be referred to as "stereo".  But that term didn't exist 20 years earlier when he was doing the groundbreaking research for Columbia/EMI.

[Len Moskowitz (Core Sound)]

Thats what our High End Binaural microphone set (HEBs) is intended to do. It uses a pair of DPA capsules and mount either near-ear or in-ear, but you could easily mount them to a hat.

For more details please see our post about it in the Retail Space forum here.