BlueNoise #4: Shop Chopper
Jan. 10th, 2010 10:57 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
tugrik(For more info on what these posts are about, please read the first one.)
BlueNoise #4
(Recorded in the workshop. Mechanical. 1/9/2010)
Download link: BlueNoise #4
Clip Details:
Revar and I needed to pick up some RC gear for a few potential projects. We're both pretty excited about the 2.4GHz spread-spectrum based radios out nowadays. I'm also pretty amazed at how cheap model aircraft are compared to when I was in the hobby some ten years ago. Back then I couldn't dream of having a palm-sized, fully-functional helicopter that only weighed an ounce, fit in the palm of your hand and had >5 minutes of flight time. The one we got to goof around with (as long as we were picking up the radio gear) was the Blade MSR.
One of my friends was visiting and wanted to play with the recorder I was using for these posts. We set it up and decided to fly the little micro-copter around it to see how positional the X/Y mic set would be. This will prove useful to compare with what's soon to arrive. More on that in a moment.
The sound file itself: Power-up and servo tests for the first few seconds, with the chopper off to the left of the recorder, me sitting just behind and to the left with the transmitter. You can hear the springs in the joysticks when I flick them. One quick flight that lasts until just about the 01m:00s mark. When the chopper passes 4' overhead of the recorder you can hear the puff of air direct on the microphones for a moment. Then landing and shutdown for a moment before taking off again.
The quick oscillation-spin sounds are the two times I have the chopper do a 'pirouette', spinning rapidly about its center axis by going ape on the tailrotor.
On the second 1+ minute flight I get the chopper to hover directly over the unit, within about an inch; that's the wind-noise of the chopper blade swash you hear, lasting for just a few seconds. Then it's back off to zoom around, sometimes as high as 16' (yay for high-ceilings in the shop) before crashing into the side of a large toolbox. Ooops. :)
The chopper is a tough little beastie. It's survived numerous crashes just like that. Still, they're embarrassing.
~~~~
The interesting thing here is that I'm using the built in "X-Y" array microphones (set to a 120degree pattern) that are built into the H4n recorder. While the stereo separation is decent, the semi-cardiod pattern is designed to exclude sounds outside the 120deg arc. It's not very good for catching an entire room. This is why you only really get good positional feel to the audio when the little chopper is crossing back and forth right in front of the mike. Additionally, even though the shop is quite sound-reflecting (cement floor and walls), that kind of array makes the place seem more tinny/boxy than it really is.
As part of getting more serious about audio recording I'm picking up a set of ribbon mics that work in what's called a "Figure-8" pattern. Stacked 90deg to each other and facing so that front-and-center is 45deg between them, you have what's called a "Blumlein Pair". This gives you a much more realistic sonic image of a space without being biased towards a forward-located subject; it's the preferred way to capture an environment instead of, say, a singer or an instrument. I'm going to re-create this same recording with them once they come in and see how the positional feeling of the two recordings compare.
The nice part about having a good Blumlein setup is that you can just rotate it 45 more degrees and voila, you've got a "mid/side" stereo setup. This makes it a very useful bit of microphone kit. But more on that later.
BlueNoise #4
(Recorded in the workshop. Mechanical. 1/9/2010)
Download link: BlueNoise #4
Clip Details:
Revar and I needed to pick up some RC gear for a few potential projects. We're both pretty excited about the 2.4GHz spread-spectrum based radios out nowadays. I'm also pretty amazed at how cheap model aircraft are compared to when I was in the hobby some ten years ago. Back then I couldn't dream of having a palm-sized, fully-functional helicopter that only weighed an ounce, fit in the palm of your hand and had >5 minutes of flight time. The one we got to goof around with (as long as we were picking up the radio gear) was the Blade MSR.
One of my friends was visiting and wanted to play with the recorder I was using for these posts. We set it up and decided to fly the little micro-copter around it to see how positional the X/Y mic set would be. This will prove useful to compare with what's soon to arrive. More on that in a moment.
The sound file itself: Power-up and servo tests for the first few seconds, with the chopper off to the left of the recorder, me sitting just behind and to the left with the transmitter. You can hear the springs in the joysticks when I flick them. One quick flight that lasts until just about the 01m:00s mark. When the chopper passes 4' overhead of the recorder you can hear the puff of air direct on the microphones for a moment. Then landing and shutdown for a moment before taking off again.
The quick oscillation-spin sounds are the two times I have the chopper do a 'pirouette', spinning rapidly about its center axis by going ape on the tailrotor.
On the second 1+ minute flight I get the chopper to hover directly over the unit, within about an inch; that's the wind-noise of the chopper blade swash you hear, lasting for just a few seconds. Then it's back off to zoom around, sometimes as high as 16' (yay for high-ceilings in the shop) before crashing into the side of a large toolbox. Ooops. :)
The chopper is a tough little beastie. It's survived numerous crashes just like that. Still, they're embarrassing.
The interesting thing here is that I'm using the built in "X-Y" array microphones (set to a 120degree pattern) that are built into the H4n recorder. While the stereo separation is decent, the semi-cardiod pattern is designed to exclude sounds outside the 120deg arc. It's not very good for catching an entire room. This is why you only really get good positional feel to the audio when the little chopper is crossing back and forth right in front of the mike. Additionally, even though the shop is quite sound-reflecting (cement floor and walls), that kind of array makes the place seem more tinny/boxy than it really is.
As part of getting more serious about audio recording I'm picking up a set of ribbon mics that work in what's called a "Figure-8" pattern. Stacked 90deg to each other and facing so that front-and-center is 45deg between them, you have what's called a "Blumlein Pair". This gives you a much more realistic sonic image of a space without being biased towards a forward-located subject; it's the preferred way to capture an environment instead of, say, a singer or an instrument. I'm going to re-create this same recording with them once they come in and see how the positional feeling of the two recordings compare.
The nice part about having a good Blumlein setup is that you can just rotate it 45 more degrees and voila, you've got a "mid/side" stereo setup. This makes it a very useful bit of microphone kit. But more on that later.
no subject
Date: 2010-01-20 03:18 am (UTC)