Erratic Volume Output From Speakers (App notifications, keypad tones, Ringing Volume)

Question

Just purchased a Z1 over the weekend and was happily fumbling with the new phone. Got it updated to the latest 4.4.2 as well.
Noticed a glaring problem with the volume output from the speakers.
During use of instant messaging apps like Whatsapp and LINE, notification tones come in at times at the level that i set it at (max) and sometimes they come in really soft, to the extent i can't even hear them and sometimes none at all. All these happening when i've set the volumes to MAX on each of the available options under settings>sound>volume. Might i also add that the volume for notifications is really too soft even at MAX.
I'm not sure if this is happening due to the updating of the software or it was already an issue prior to the update. I've seen a couple of posts online where some users are experiencing the same erratic behavior of the internal speakers. 
I hope someone can shed some light on this so we don't judge too quickly on an otherwise excellent phone.

Answer 1

I have the problem with my xperia Z1 speaker and ear phone not detect after update 4.4.2 in kitkat version.
phone purchasing date : 28.02.2014
Before update my Z1 runing in 4.3 jelly bean and phone is working properly....i have only one issue in 4.3 during call accept automatically call going in speaker.
1 Problem after update 4.4.2  kitkat version sometimes movies app playing video song but  voice is not out from phone speaker and song voice playing in ear speaker then i press play/pause button in movies app then song voice play in phone speaker
2 Problem  i connect my ear phone in my Z1  and phone is  not detect ear phone i play the song in walkman app so song voice is out from phone speaker and not lising voice in ear phone then i restart my phone ear phone is working properly.
 2 times done my Z1  software repair but not fix the problem........please tell me what can i do for fix my Z1 problem
Thanks & Regards
Shekhar Jaiswal