The results of the recording were generally satisfactory, but with the 650SS, we found that the sound would crack when the exhaust noise became louder.
The Audio-Technica Corporation external microphone used with the GoPro Hero 4 does not cause such sound quality problems.
In the future, we plan to consider ways to improve the sound quality of the AKASO external microphone, such as by improving soundproofing and the installation location.