Or you could just use pink noise, and use a cheap calibrated microphone.
https://amzn.to/2v82vtC
Use it with Audio Tools, which accepts a calibration file. You can also play test signals from Audio Tools. Free for Android.
https://amzn.to/2v82vtC
Use it with Audio Tools, which accepts a calibration file. You can also play test signals from Audio Tools. Free for Android.