Sounds of Music C

[elamuel]

I'm building a PVC pipe instrument this year and while testing the pitch of the pipes I found that it was consistently reading half the hertz value of what I was expecting it to. Has anyone else encountered a similar problem?

[gz839918]

I'm building a PVC pipe instrument this year and while testing the pitch of the pipes I found that it was consistently reading half the hertz value of what I was expecting it to. Has anyone else encountered a similar problem?

Perhaps you're using the equation for an open pipe , when in reality your pipe is a closed pipe, which should be . If you have any more specific questions, feel free to ask again with the details. Good luck!

[Micker]

Some clarification abt MIT sounds. Apparently our proctor at MIT just doesn’t know how to work a usb microphone because I tested using the same microphone that they’re using at nats and it picked up from a foot away. Maybe the proctor didn’t actually connect to the microphone and was using his internal microphone instead which sucks cause a lot of xylophones at MIT took Ls.

MIT Build ES here. We constantly checked throughout the day that the mics were connected and working. The only times that the mics didn't detect anything was in instruments that I myself would describe as incredibly quiet. These instruments were typically idiophones (mbiras, glockenspiels, etc.) that had either tiny or completely lacked resonator chambers. If you have a quarter-inch diameter tube glockenspiel with no resonating box, there's a good chance it's either too quiet or the fundamental will be too weak, causing overtones to be picked up. Note that this only happened to a handful of builds; there were plenty of successful idiophones and xylophones in particular. Several even got near-perfect scores. Perhaps the acoustics in the rooms weren't the best -- that's beyond our control. But the mics worked properly, and the only builds that didn't register were ones that I would have personally deemed questionable.

Yikes. I don't know, we used the same build and got first at Solon Invitational today.

[builderguy135]

Some clarification abt MIT sounds. Apparently our proctor at MIT just doesn’t know how to work a usb microphone because I tested using the same microphone that they’re using at nats and it picked up from a foot away. Maybe the proctor didn’t actually connect to the microphone and was using his internal microphone instead which sucks cause a lot of xylophones at MIT took Ls.

MIT Build ES here. We constantly checked throughout the day that the mics were connected and working. The only times that the mics didn't detect anything was in instruments that I myself would describe as incredibly quiet. These instruments were typically idiophones (mbiras, glockenspiels, etc.) that had either tiny or completely lacked resonator chambers. If you have a quarter-inch diameter tube glockenspiel with no resonating box, there's a good chance it's either too quiet or the fundamental will be too weak, causing overtones to be picked up. Note that this only happened to a handful of builds; there were plenty of successful idiophones and xylophones in particular. Several even got near-perfect scores. Perhaps the acoustics in the rooms weren't the best -- that's beyond our control. But the mics worked properly, and the only builds that didn't register were ones that I would have personally deemed questionable.

Yikes. I don't know, we used the same build and got first at Solon Invitational today.

chill dude. just because it works at one invy doesn't mean you have to flame another guy on the forums about your instrument not working at another invy. it's clear that all of the supervisors are extremely qualified and they know exactly what they're doing. the ES even said that "The only times that the mics didn't detect anything was in instruments that I myself would describe as incredibly quiet. These instruments were typically idiophones (mbiras, glockenspiels, etc.) that had either tiny or completely lacked resonator chambers." the only thing you're going to accomplish by complaining on the forums is making you and your team look bad.

congrats on your win at solon.

[itsDerk]

At Centerville, the Sounds ES used Audacity to isolate the fundamental frequency with a Fourier transform and used that to determine the cents off of everyone's instruments rather than something like pascioly or a phone tuning app which takes the overtones into consideration. I was wondering if anyone has seen the Audacity type of proctoring anywhere else because I know isolating the fundamental causes some issues for those who use strings/pipes.

Thanks :)

[smayya337]

At Centerville, the Sounds ES used Audacity to isolate the fundamental frequency with a Fourier transform and used that to determine the cents off of everyone's instruments rather than something like pascioly or a phone tuning app which takes the overtones into consideration. I was wondering if anyone has seen the Audacity type of proctoring anywhere else because I know isolating the fundamental causes some issues for those who use strings/pipes.

Thanks

That's interesting. I don't remember anyone using Audacity - last year, I mostly saw Google Science Journal, and this year, every ES I've seen (granted, only 2) has used pascioly. The use of a Fourier transform is probably unique to Centerville, and likely the specific ES. If anyone else has seen this before, I'd be very interested to hear about it.

[builderguy135]

At Centerville, the Sounds ES used Audacity to isolate the fundamental frequency with a Fourier transform and used that to determine the cents off of everyone's instruments rather than something like pascioly or a phone tuning app which takes the overtones into consideration. I was wondering if anyone has seen the Audacity type of proctoring anywhere else because I know isolating the fundamental causes some issues for those who use strings/pipes.

Thanks

That's interesting. I don't remember anyone using Audacity - last year, I mostly saw Google Science Journal, and this year, every ES I've seen (granted, only 2) has used pascioly. The use of a Fourier transform is probably unique to Centerville, and likely the specific ES. If anyone else has seen this before, I'd be very interested to hear about it.

I've only seen pascioly.org/sounds be used at competition. Anyone know when the website was created? Not sure if it was there last year.

[TheSquaad]

At Centerville, the Sounds ES used Audacity to isolate the fundamental frequency with a Fourier transform and used that to determine the cents off of everyone's instruments rather than something like pascioly or a phone tuning app which takes the overtones into consideration. I was wondering if anyone has seen the Audacity type of proctoring anywhere else because I know isolating the fundamental causes some issues for those who use strings/pipes.

Thanks

That's interesting. I don't remember anyone using Audacity - last year, I mostly saw Google Science Journal, and this year, every ES I've seen (granted, only 2) has used pascioly. The use of a Fourier transform is probably unique to Centerville, and likely the specific ES. If anyone else has seen this before, I'd be very interested to hear about it.

I've only seen pascioly.org/sounds be used at competition. Anyone know when the website was created? Not sure if it was there last year.

It was released prior to nationals, but I think after most state tournaments.

[Giantpants]

At Centerville, the Sounds ES used Audacity to isolate the fundamental frequency with a Fourier transform and used that to determine the cents off of everyone's instruments rather than something like pascioly or a phone tuning app which takes the overtones into consideration. I was wondering if anyone has seen the Audacity type of proctoring anywhere else because I know isolating the fundamental causes some issues for those who use strings/pipes.

Thanks

Centerville was our seventh competition this year, and the six we attended prior all used pascioly.org/sounds, but this was our first one using Audacity. I was kinda excited to see the results with a spectrogram, since it should disregard the overtones our instrument naturally produces, but it ended up being worse for us...

With pascioly.org we have always gotten single digits cents off, almost always within 1-3, but with this method we were getting whole integers of Hertz off?? When we were building our instrument, we tuned it with pascioly.org and a spectrogram on my partners phone, and both displayed consistently perfect results, so what was different this time? It was kinda warm in the room, but I don’t think that should make thaaaat big of a difference? Maybe it was leaving it in the cold bus overnight? But I have done that before and it’s never been an issue, idk. Regardless, we lost about 2.5 points on the instrument, which was slightly irksome since we’ve only not gotten full credit on it once (when we lost half a point on a fluke) lol. Honestly I thought that would cost us a medal since we thought the test was pretty easy, and I figured those 2.5 points would be a big deal, but luckily we still did alright lol

To anyone else who went to Centerville: did you guys have a particular issue with it? I’d love to hear more stories!

[gz839918]

At Centerville, the Sounds ES used Audacity to isolate the fundamental frequency with a Fourier transform and used that to determine the cents off of everyone's instruments rather than something like pascioly or a phone tuning app which takes the overtones into consideration. I was wondering if anyone has seen the Audacity type of proctoring anywhere else because I know isolating the fundamental causes some issues for those who use strings/pipes.

Thanks

At the two invitationals where I supervised, I used the pascioly.org applet whenever it could register the note, and I used Audacity as a backup. Audacity offered several advantages for use as a backup:

• It records anything. The pascioly.org web app did not read notes that were too silent, and without Audacity, some teams would have had to receive a skipped note even if I could hear a clear distinct pitch.
• I have control over analyzing pitch. pascioly.org is a black box with nuts and bolts I can't see. if pascioly.org suddenly jumps to a cents-off reading before returning to no note detected, I can't always tell whether the web app suddenly started working again, or whether its invisible internal machinery set off a false alarm by giving me an incorrect reading (for example, because of a spike in background noise).

Disadvantages of Audacity include...

• Audacity rounds fundamental and overtone frequencies to the nearest integer, which is not super great since several notes may be spaced within only a few hertz, and so this may increase the cent difference. Case in point, E₃ and F₃ are only 10 Hz away, and if Audacity rounds up by 1 Hz to the nearest integer, that could increase a team's cents error by around 10 cents for that note.
• Audacity can't discern when the frequency is not equal to the pitch, such as when partials move but spectral envelope (overall shape of the spectrogram) is unchanged. This problem is very rare for strings and pipes however, and I think I saw it only once.
• In some idiophones, there's no clear apparent pattern amongst partials. So what the heck do I measure? (I usually chose whatever peak frequency was closest to the target note, but due to the bullet point above, I know this wasn't a great idea because it resulted in huge cent differences from the target note. My reasoning was that it was better than giving teams zero points when pascioly.org stopped working.)

I prefer the pascioly.org web app over Audacity whenever I have a professional microphone, but since I can always see the raw waveform in Audacity, it helps if pascioly.org isn't working. I would discourage Audacity to event supervisors except as a backup. Another possible backup method which I haven't tried out is to use cell phone microphones with a tuning app. These days, even cell phone microphones are legit actually quite good.

Not specific to Audacity though, many compelling reasons exist for why pitch shouldn't be measured as the fundamental frequency. These issues could occur with the pascioly.org web app too; some supervisors simply choose to ignore the measured values and wait until pascioly.org displays the pitch they want it to display.