I have been using the M-32C as my primary melodica for the past month and am really liking it. I decided yesterday to get accurate readings of its tuning. I am using gStrings Tuner on my Galaxy Note 10.1. The Note 10.1 has excellent speakers for a tablet, and these also function as its microphones. The gString settings allow for calibration to A=440 (the default) or whatever, and also for other parameters controlling microphone sensitivity and stability of readings. I am tuning to A=443, which has with other melodicas reinforced my impression that most are factory tuned to A=443 (not so clear with the M-32C). I am looking to tune keys to within 1.0 hz. I run through all the keys twice to recheck my initial readings, and then focus on just those keys that are confirmed as 1.0+ flat or sharp in relation to the A=443 standard. I then retest all those keys until I am satisfied that I have accurate readings. These are the keys I will tune to get them within the 1.0 hz margin. I don’t want to begin tuning until I am confident that I have good readings. The readings for my M-32C are somewhat unusual and have a pattern of sorts, as you can see. I’m not sure how much one can generalize about factory tuning from a sample of one, but it’s better at least than a sample of none. I will proceed with tuning my M-32C to A=443, even though it’s hard to guess what standard was being applied at the factory.
The M-32C readings are given to the right, and then the +/- 1 hz differences.