Low Bluetooth volume for B50?

I just set up my B50 a couple of days ago and really like it so far. It is connected to my TV via HDMI (ARC), driving two Micca OoO bookshelf speakers.

When connected the TV via the HDMI speakers, the output volume from the speakers is plenty loud – working fine/as expected.

However, when connected to my iPhone via Bluetooth to play music (typically via the iOS Music app), the volume level is quite low. When my iPhone volume is set to 50%, I can barely hear the music from the B50 and I have to adjust the volume to at least 75% to hear the music (very quietly).

I have looked at the iPhone audio settings to turn off “headphone volume” protection, etc. but haven’t found a culprit/solution yet. I also “forgot” my Bluetooth connection to the B50 and re-paired with no improvement.

I am hesitant to update the firmware (to 52-452f344c) of this unit (currently 50-0ce1e3ac-8) because of other comments in this forum regarding the firmware updating negatively impacting HDMI/ARC behavior, since HDMI/ARC for TV is my primary use case.

Is the preamp(?)/volume path via Bluetooth just very low for some reason?

Any suggestions about something I am missing would be appreciated. Seems like there must be a setting/option on my iPhone or the amp that I just haven’t found yet.


I have to say, it’s nearly impossible to unify all the input and output levels. But the device have standalone volume for each input, to handle condition as you’ve mentioned. So you could normalize the output level for the listening experience.

You can adjust the gain for each of the input sources with ACP workbench.
Some manufacturers that use a similar MV silicon DSP chip distribute software that may work with your device. (http://files.sure-electronics.com/download/BDM&BRU_PCUI_ACPWorkbench_V2.24.2(2).zip)
I have the original software purchased from Arylic. Many of the issues on these forums relating to sound can be addressed with DSP tweaks via ACP workbench. I think Arylic should make a better guide to ACP workbench and distribute the software free of charge.


William, thank you for the note about the ACP workbench; I’ll check it out.