Binaural recording of 4th of July fireworks

[zapnspark]

A binaural recording of fireworks that I made on
July 4th 2007.

http://tinyurl.com/yoqt7j

[sandyK]

zapnspark
I loathe and detest MP3,however, I must admit that when I played your binaural recording through my PC headphone amplifier, it did sound very 3 dimensional. I would have loved to have heard it before conversion to MP3.
BTW, why not join in a very recent thread about soundstages?
I don't think they believe that 3D sound stages are quite achieveable from many quality recordings.

SandyK

[sandyK]

zapnspark

The thread is "Holographic Sound ?" in "Everything Else"

SandyK

[zapnspark]

SandyK.

I also dislike MP3. I had no easy choice since the hosting service only accepts MP3 format and a file size less than 16 megabytes.
(lightningmp3.com)

The WAV file captures some of the subtle things that can create a very convincing "soundstage". I found that the MP3 format dulls these things -- but not enough to ruin the sense of space.

Unfortunately, I can't find a free host for a >230 megabyte WAV file.

Thanks for suggesting the "holographic" thread. I'll check it out.

[Netlist]

Interesting recording. Could you disclose a bit more on the editing process?
The sound looks like it has been compressed somewhere along the line. Peaks are clipped although I admit I took a rather crude snapshot.

/Hugo

[zapnspark]

The microphones I used are flat back electret omni LECTRET model 5200 lavaliers.
These are really quite remarkable microphones. Slightly lower noise than small Panasonic capsules, very low handling noise, and a reasonably flat frequency response. They also handle 145 db SPL at 1% distortion.
I found these as surplus closeouts many years ago. The list price was over $60 each. I got them for $5 each. Sadly, they are no longer available.

The method I used was a dummy head. The cheapest and most available dummy head was my own. No snide remarks please ;-)

As luck would have it, the LECTRET microphones nestle very comfortably in my ears with the microphone opening just directly over the entrance to the ear canal.

I recorded using a Sony MZ-R30 minidisc recorder. Power for electret capsules is provided by this model. The MZ-R30 has ALC engaged but I found none of the usual audible artifacts using this recorder. (Artifacts being the breathing and pumping associated with compressors and ALC circuits)
There does appear to be clipping at various spots although I used a minimum sensitivity setting on the recorder. I'll work on that problem the next time I try this.

I made a digital transfer of the minidisc recording to a TASCAM 2488 DAW. The only editing done on the TASCAM was to chop out 10 minutes of extraneous neighborhood noise from the beginning of the recording. I saved the recording in WAV and MP3 format. The WAV file is >230 megabytes.

I hope this answers some of the questions.

ZAP

[Netlist]

I think the ALC is to blame, not your creative way of doing the recording.
It would be nice to see the difference without ALC.
Funny thing is that I’m pretty sensitive to this kind of clipping in normal pieces of music but it doesn’t seem to be the case here with the explosions. I think the perceived distance of the firework in contrast with a mic close to e.g. a drum could explain it.

/Hugo

[zapnspark]

I finally found the manual for the Sony MZ-R30.
There is a convoluted way to turn off ALC and set levels manually.
Darn!
Next time I'll remember to use it.

Here are a couple of photos of the microphones and ear placement.

[Netlist]

Nice. Do you actually hear what your are recording?
I guess not or not as well with those mics in your ears.
Pardon my ignorance but why don't they just make some kind of headphone-style like microphone that keep your ear entrance free?

/Hugo

[zapnspark]

Hugo,

That is a poorly shot picture.
That photo is taken at an odd angle and it makes it appear that my ear canal is obstructed.
If I used a lower angle for the shot, you could see the microphone opening and that there is still room around the sides of the microphone to hear clearly.

The Neumann dummy heads place the microphone right in the "ear canal" of the dummy ears. I'm pretty close to that with this arrangement.

I agree that a binaural headset could be designed that achieved proximity to the ear canal and still allowed close to normal hearing.

The LECTRET microphones were designed as lavalier or lapel microphones.
Only someone as crazy as myself would stick them in my ears.

Aside:
Wow! My Irish ears are really ugly and bloodshot ;-)