Audio Chronograph

If you shoot across the laptob/mic you should be able to forget mach correction. By shoot across, i mean pc at 5 metres, target at 10 metres.

I disagree, you want audacity to simulate "real time", but when the mic is on the barrel, the impact time is offset (sound delay). However when it is in the middle, both the muzzle sound and the impact sound are delayed by the same amount (assuming mic is in the middle). Think of it as +1/60sec correction for muzzle and +1/60sec for impact, cancelling each other out. It makes sense to me, correct me if I am wrong. All my method does is avoid a little math and put a laptop in the line of fire.

Really I am just talking out my a** here, it would be way more practical to have the laptop at the same place as the gun. If you use sheet metal as a target you can be sure to get a good sound footprint at 5-10m so there would be no advantage to having mic in the middle.

Edited by pattison - 16 July 2006 at 4:00pm

pattison wrote: I disagree, you want audacity to simulate "real time", but when the mic is on the barrel, the impact time is offset (sound delay). However when it is in the middle, both the muzzle sound and the impact sound are delayed by the same amount (assuming mic is in the middle). Think of it as +1/60sec correction for muzzle and +1/60sec for impact, cancelling each other out. It makes sense to me, correct me if I am wrong. All my method does is avoid a little math and put a laptop in the line of fire.

    My mic was in the middle of the line of fire. The sound of both the shot and splat take time to get to the mic, they both make the length of the shot seem longer. They do not 'cancel out'. Wherever the mic is you will need to subtract the time it takes sound to travel the entire distance of your shot from your measured time.

Monk wrote: doppler affect does screw things up a bit, that why Id rather just put the mic next to the barrel.

    I believe that doppler effect only matters if you are interested in the sound that the ball (or any object) makes while it is moving relative to the mic. The only sounds were are interseted im are not(tree and gun.)

Doppler would matter if we worried about pitch, does that count. lol

Ok, I think I see what your saying. But audacity wouldnt hear it at +.117, it would hear it at +.134. because the need to account for the time it takes sound to get to you after the impact.


Edited by Monk - 16 July 2006 at 6:24pm

This is awesome. I love physics.

*goes to buy mic*

Ugh, i need to take a break. Between my accounting of my checkbook in my head, and trying to figure out why my generator wont recharge the bugs battery. My brain is fried.

Ill attempt to understand all this whoha some other time. For now, I concede defeat. lol.

But the idea for the chrono still remains...Kickass.