@caloyzki: Here's a good one I have on my Samsung Galaxy: Sound Meter
It's calibratable and once it's done with the AVR's internal test tones at 75 dB, the sub of course reads a 65(ish) dB. I think it's pretty much enough for relative measurement of multiple subs.
Which one do you use?
i have these, audio tool, noise meter, sound meter (lite).but i dont know how to calibrate this spl apps. and yes i noticed that after running aud. how come i test the sub trim it only reads 60+ db only? i thought it should be 75db?