[richoval]

@richoval getting reading at 1dB is certainly better than nothing, but subjectively it's more than enough for the loudness alone to make us feel like it's more than loudness difference. Now a fast check on the apple store showed non free apps. Maybe someone familiar with the apple ecosystem knows a free app to do the job?
[/QUOTE]

Well, i bought two apps (dB meter and Decibel X) that seems to be quite alright. it was just hard to get a steady measurement, specially with decimal increments (basically impossible...)

 

[richoval]

Maybe the reason he has a hard time matching volumes is because it's not easy to get a stable SPL reading with using noise, especially if the app's averaging is fast. This wouldn't be a problem with a sine or any other cyclic signal. A sine wave has a better crest factor than noise so it's probably for the SNR as well.


These players have an output impedance of 1.5 and 1.6ohms according to moon audio's website which close if that's what you are worried about. I just think an "amateur" voltage measurement is going to be more precise then an acoustical measurement of similar quality.
As for the cables, I honestly expect him to have some cables lying around... 3.5 jack to 3.5 jack or 3.5 jack to RCA cables aren't special or hard to get. Although i thought he would have some audio input and I was wrong so who knows.

Since I‘m using the balanced output, i‘ll need a 2.5mm cable which is not that common i guess, but i‘ll buy something.