I'm Steve and I think I could be of some help and offer solutions to pinpoint the source of the sound. I have recorded audio for studio shoots for workout videos for NIA Technique and I have also installed audio for karaoke suites for Voicebox Karaoke. There are a handful of things we can try as I have experienced and solved these issues in the past.
About me, I have a BA in Music Technology from Bloomfield College and my professional work experience includes MTV Networks, NFL Films, Goldcrest Post Productions, Audix Corporation, NiaSounds, Lyrical Systems, Happy Note Studios among others.