Hello lyle1975,
After reviewing your post, it sounds like the volume on the AirPods is low only when connected to the Mee transmitter and not when connected to the iPhone. I would recommend you use this article to help troubleshoot the issue.
The majority of issues on the Connect can be resolved by a full reset. To perform a full reset, hold the pairing button "A" located on the right side of the unit for approximately 6 seconds. Previously paired devices will be cleared from memory and you will have to re-pair any devices you wish to use with the Connect."
"Issue:Low volumeResolution:Adjust the volume both on your Bluetooth headphones and on the TV or other connected device as both may control the volume.
On some TVs the volume is fixed for each output. Try a different connection method.
If your Connect is plugged into the TV’s the 3.5mm (headphone) jack and TV volume cannot be adjusted while the headphone jack has something connected to it, unplug the Connect from the headphone jack and adjust the volume, then plug the Connect back in."
MEE audio | Connect Support Guide
Please don't hesitate to let us know if the steps resolved your issue or if you need additional assistance.
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