A Tinny Speaker Is Not Automatically a Codec Problem
Field feedback described the speaker as very tinny even though the digital call path was working.
acoustics
One Microphone or Two Is a System Decision
Microphone count changes acoustics, PCB, enclosure, DSP assumptions and factory test.
From Demo-Ready Audio to Production Acceptance
One strong call can prove a candidate is promising but not that it is ready for manufacturing or field release.
V117 Taught Me to Revert a Bad Audio Architecture Quickly
A rebuffer/AEC/volume experiment produced obvious bad crackle instead of the intended stability improvement.
Why V116–V131 Did Not Automatically Replace V115
Later queue, PLC and timer experiments looked more sophisticated on paper but repeatedly introduced crackle, echo or additional delay.
A Tinny Speaker Is Not Automatically a Codec Bug
Acoustic complaints have to be separated into source, amplifier, transducer and enclosure effects.
Speaker Quality Needs a Reference Signal Before Subjective Listening
Listening tests become more useful when the input and operating point are controlled.
High-Volume Echo Moved the Bug into the Physical Product
After digital timing became stable, echo increased at high speaker volume and could no longer be treated as only a network or queue problem.
Echo and Feedback Are Not the Same Failure
A delayed copy of far-end speech and an unstable acoustic loop require different diagnosis.
Echo at High Volume Is Partly an Acoustic Design Problem
AEC has finite cancellation authority when the speaker physically couples strongly into the microphones.
V132A: Turning Clear Audio into a Preserved Release Asset
A working phone is not a release unless the exact artifact and source context can survive the next experiment.