I'm all hyped up about this. 😀
Being audio geeks you have certainly seen photos like this one:
There is a good collection of these photos about acoustic devices for aircraft detection in the days before RADAR.
https://rarehistoricalphotos.com/aircraft-detection-radar-1917-1940/
But have you ever wondered what one of these might sound like? Or wondered if the spacial acuity was actually enhanced? Well I did. Today I did something about it.
Hyper-Stereo for only $3.25 OK, I already had the mics, the headphones, the little Sony recorder - so all I bought were the clear spheres and some coat hangers.
Does it work? Yes, surprisingly well. Very pin point. When a source is directly in front of me, it's very obvious. And if the sound source is off to the side, it's very obvious to which side. Tested on birds, insects, cars down the hill through the trees, roosters, kids and the TV. All blazingly east to pinpoint. And to my surprise, I can tell when a source is behind me. Cicadas and small birds are very much easier to locate than without the rig. Maybe that's a frequency range limitation. I haven't used it to detect aircraft yet, because we get so few here. Maybe one a week, if that. But when that vintage twin engine Beechcraft survey plane flies over again, I'll track it.
BOM
Being audio geeks you have certainly seen photos like this one:
There is a good collection of these photos about acoustic devices for aircraft detection in the days before RADAR.
https://rarehistoricalphotos.com/aircraft-detection-radar-1917-1940/
But have you ever wondered what one of these might sound like? Or wondered if the spacial acuity was actually enhanced? Well I did. Today I did something about it.
Hyper-Stereo for only $3.25 OK, I already had the mics, the headphones, the little Sony recorder - so all I bought were the clear spheres and some coat hangers.
Does it work? Yes, surprisingly well. Very pin point. When a source is directly in front of me, it's very obvious. And if the sound source is off to the side, it's very obvious to which side. Tested on birds, insects, cars down the hill through the trees, roosters, kids and the TV. All blazingly east to pinpoint. And to my surprise, I can tell when a source is behind me. Cicadas and small birds are very much easier to locate than without the rig. Maybe that's a frequency range limitation. I haven't used it to detect aircraft yet, because we get so few here. Maybe one a week, if that. But when that vintage twin engine Beechcraft survey plane flies over again, I'll track it.
BOM
- 1X TASCAM headphone (closed)
- 1X SONY digital pocket recorder as mic preamp and headphone amp
- 2X PUI Audio POM-2730L-HD-R mic capsules
- 3X meters miniature mic cable
- 1X 1/8" TRS phone plug (for mics)
- 1 Clear plastic Christmas ornament
- 3 Wire clothes hangers
- Dozen Zip ties
- Glue (plastic hemispheres to coat hanger)
The ears are close at 400Hz. I shouldn't be surprised that you could tell the direction of a clean tone lower than before.
Hmmm. That’s worth an experiment.
I was out this morning trying to make some recordings and realizing that the rig will be difficult to demo. Yes there is good stereo separation, but the fact that the wide separation follows your head movement is what makes it work so well. It feels very natural.
I was out this morning trying to make some recordings and realizing that the rig will be difficult to demo. Yes there is good stereo separation, but the fact that the wide separation follows your head movement is what makes it work so well. It feels very natural.