This is a very useful app for measuring sound. I can’t tell if it can take additional calibration files for calibrated microphones, and I am not sure if it is bypassing the high and low pass filters apple usually has in place. It would be nice to know if adding microphone calibration from say a umik-1 or one of the other various calibrated microphones is possible. Lots of good explanations and help within the app, aside from this. One issue so far is that sounds from internal speakers are muted somewhat when the app is running. So if I’m playing music on the phone, it is quieter when the app is running, so hard to use it to analyze sounds out of the speakers. Not a deal breaker, especially not for a free app! My biggest problem is there is not way to set a maximum/minimum sound level in dB that I want to see (no way to zoom in that I can find) so resolution is limited in the area of interest. I’m primarily using this to look for peaks/valleys in frequency response of various devices when I sweep the frequency or play pink noise.Five stars for the price, four stars for the features and functionality, zero stars for the data collection. I’d rather give a couple bucks to the developer than have the data collection.

I’m a little bitter that the previous iteration of Spectrum stopped working with iOS 16 and iPhone 14 models. I paid for both iPhone and iPad versions to use while mixing live performances. This time around, it’s free (for now) and includes the option to change sound measurement metrics from dB reading from negative numbers) to dBA (readings start from 0 and increase in the positive numbers). This also will tell you the nearest key/note that you’re pinpointing with your finger on the screen. It could have been rated higher but there are a couple of flaws. In Spectrograph mode, trying to pinpoint a frequency is near impossible on my 14 Pro. The graph numbers are obscured by the dynamic island. Also, on the other graph types, low frequencies are on the left and high are on the right. Since the spectrograph scrolls from left to right, low frequencies are now on the bottom. When touching the screen to pinpoint a frequency (since I can’t see any numbers under the dynamic island) the frequency does not align with the flowing graph. It would have been nice if the data would align, the graph was visible, and if the graph also included an axis that showed the elapsed time.

Best tool for a live performance yet! Actually see the difference live in real time! Displays are near perfect. Use the app to match your equipment. Every sound engineer needs this app. Allows the user to zero in on the exact frequency needing adjustments. Also a great tool to help level your volume mix to front of house. Use this app when mic checking and not only hear the difference but see the difference. A very useful tool and a must for every amateur musician. Oh so very cool. I will never run a soundboard without it. I use my iPad and love the bar display. A lot of very cool features. I am very impressed.

I’m just diving in to this sound calibration realm and was told by the dealer I got my gear from to use this app rather than the mic and Arcam tool. I’m a long time film and video editor and seen a lot of interfaces and clunky attempts at graphical heavy tools like this and sadly, most don’t keep me interested more than a few minutes or so. I may update later but I’ve just gone though a little get-to-know this program and I just say after looking at this and a couple other packages this guy has designed and I know this, he’s a pro! Cheers Sir Vlad!