Have the issue you are describing. Streaming through a Marantz receiver that has HEOS. Can adjust volume using receiver controls, or on the ipad using either HEOS app or the Marantz app. The volume difference from song to song can be dramatic...example, needing to turn one song up to level 50 and next down to level 35. Just not acceptable when wanting background music. Don't want to have to adjust every song. Maybe your algorithms need to include similar recording volume when selecting music. If you are using a Replay Gain factor, seems that would mean you already have a data value for recording volume and attempting to adjust. It's not working.
@mwaller I moved your post over to the Other Devices space.
Volume differences between songs:
Something to note, we don't alter music equalization on Pandora from how it appears on the original releases, unlike terrestrial radio, which compresses the entire broadcast. As a result, some songs sound louder than others. However, we do use the Replay Gain technique that encodes a fixed volume adjustment into the mp3/mp4 header so that the actual player (web browser, phone or device) can adjust volume just as the track begins playing.
If there are vast differences, it could also be due to different instrumentation or arrangements causing different apparent levels of volume where the actual decibel levels are the same.
It may help to run through some troubleshooting steps to see if that resolves the issue for you.
First make sure your device has the latest firmware by checking for a new update. If an update is available, try loading Pandora again once the update is complete.
If you're still having the same problem, then please try a few standard network troubleshooting steps:
You can also contact the manufacturer directly to troubleshoot your specific device and settings.
Hope this helps. Let me know how it goes.