Trying to record a call but voice qualityis poor pl help

hello

i am trying to record calls in asterisk but the voice quality of those call is pathetic

i have treid lot of option please help me what is wrong with my configuration

sip.conf
[115]
host=115
type=friend
host=dynamic
allow=g729
secret=115
nat=yes
context=outgoing

[81.9.22.71]
host=81.9.22.71
secret=rics
type=friend
insecure=very
allow=g729
canreinvite=no

extensions.conf

[outgoing]
exten => _X.,1,monitor(wav|${CALLERIDNAME}|m)
exten => _X.,2,Dial(SIP/${EXTEN}@81.9.22.71)
exten => _X.,3,Hangup

calls are getting recorded there is no issue in that but voice quality is poor
in recording calls only otherwise when i am making calls the voice quality at that time is ok