Is it just me or is the M9 not that loud?

I'm coming from an S6 edge and max volume on the m9 seems to be only around 80% of the max volume that the S6 edge had. Side by side comparison the s6 seems much louder especially when it comes to notifications.
Just trying to figure out if my unit might be defective or if its normal.

I tested this on stock, currently on ViperRom

Video recording loud hiss

I just noticed that there is a loud hiss sound in the videos I record. Has anybody else experienced this? I tried recording in different resolutions but it does not make a difference.

Edit: I just recorded a video using Instagram and the hiss sound is gone. It has to be the Lg camera app that's producing the background noise.