Audacity for measuring speed

I’m new to the forum and i’m having trouble setting up the software to measure speed of a shotgun.
I tried using the software with UV LEDS and sensors but the noise levels were too high and couldn’t figure out the peaks on the graph at which the pellets were passing in front of the LEDS-sensors.

After giving it some thought i want to try something else…using the MIC jack …i want to splice the wire( i don’t know which one) and create 2 parallel wires…the idea is for the pellets to cut the wires…one first and the other second thus creating 2 peaks on the graph were the resistance of the circuit is changed.

I don’t know whether this can work and don’t know which wires to use or if it will need an external battery.

if someone can help i would much appreciate it.

Bring the Mic-In connection out and split off the 5volt ring battery connection. Scroll down to the second illustration.

Connect that battery to a sensor wire which then goes to the Left of the stereo Line-In and also connect that to another sensor wire that then goes to the Right of the Stereo Line-In. (The top illustration).

Record the stereo Line-In (not the Mic-In)
Press record. When the first wire is broken, there will be a very significant jump in the Left sound track and when the second wire is broken, a similar disturbance on the Right. Measure the difference.

If you’re on a Windows laptop, you’ll probably need a way to get Stereo Line-In. You can do that with our favorite UCA-202.

You can’t use the Mic-In for a sensor like that. It’s way too sensitive and the instant you unshielded the cables (for the sensor wires) you’re dead. Buzz city. It may buzz anyway, but you may be able to get something valuable out of the system.

You may also be struggling with the sample rate of the recorded track. Depending on how far apart the sensors are, the measurement may be between the samples of the sound track.


How are you going to get somebody to hit two separated thin wires in the same shot? Can I watch?

Firing at 1m distance with a 3/4 inch pellet cloud keeping the 2 wires at a distance of 1-1.5m