Monday 2 June 2014

More RTTAtuner

A bit more about the RTTATuner which might be of use to readers. Dan mailed me the other day after seeing the last blog with a few tips about using the tuner for flutes which in thought I'd pass on as hopefully being of use to all flute players.

"...................... an updated version of the RTTATuner app is now available, with an added “export” function. It exports an expanded view of the tuning display, showing all the octaves that you normally might have to scroll to get to. Text is also included in the export, in case you need to cut and paste the results into another program. Another things it improves on is that it stops the iPhone from going to sleep while recording. I’m about to announce it on some of the newsgroups.

I also wanted to give you a “heads up” about something. In your blog, the screenshot shows four octaves, starting with octave number three. I’m assuming the flute is a standard “D” flute and not for example a cannon going down to low A… The convention I use for octaves (there are a couple of different ways of numbering them) is that D4 is low D on a flute. So here’s what I’m seeing in your screenshot: an octave, from low D (D4) to middle D (D5), was played on the flute. The tuning is excellent and consistent. There are also some notes apparently registering in the 3rd octave. They must have been something else - I find that the male voice kind of spans a lot of the third octave, or maybe some outside noise of some kind. You can see from the thickness of the bars that there is a lot more variation in the pitch than was picked up in the flute itself; the noises were less “musical".

Why did this happen, and what can you do about it?

Firstly, the “min clarity” setting should be on 0.90 or 0.95. The higher it is, the more “musical” the tone needs to be before it is registered. I think I had 0.9 as the default. If you go much lower than that, then the program starts picking up random hums and noises, and registers a lot of notes that weren’t played, especially in the lower octaves. 0.95 should work OK with the flute, and I think might then filter out any talking, etc.

Secondly, for flutes, you can set the “Min Displayed Octave” setting to 4 and “Max Displayed Octave” to 6 - in which case all that extra noise won’t be picked up anyhow because octave 3 won’t show up.

Thirdly, you can set the “Min Readings” setting to 10, or even 20, or more - this will require that a note needs to register a fair few times before it shows up on the display. It stops little “blips” from showing up e.g. if you do an ornament or something.

Fourthly, you’re obviously better off avoiding noisy environments.

Finally, you’re better off it you don’t leave the thing running: press record, play something, and then press stop.

I just wanted to clarify this, as I don’t want any flute makers to be given the wrong idea! I’ve tested the app using an iPhone 4, iPhone 5S and iPad - all work pretty consistently, no problems and I’m happy with the results. If you find that you can’t get it to work well, I’d start worrying about the mic on your phone, I guess… But from what I see, the app does pick up the flute nicely, it’s just picking up other stuff as well, in that particular screenshot.

I'm wondering about what Dan said about the third octave notes being "something else". I think there my be a possibility that they may be overtones or other harmonic components? I'll find out and report back.

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