Voip .call file sounds worse than live sip or iax calls

I’ve been using .call files for a while along with other live voip calls with asterisk 1.2.14 and other most recent asterisk files. I’ve used different codecs, different days (even weekends when only thing going on in office is .call file) and I notice a consistent diffenece in the quality of .call files using voip compared to lives voip calls.

Any thoughts why there is a difference? Anyone else experience this?