I know why the max. output is restricted: to stop silly people blowing their heads off with excess volume. But with years of experience in sound studios I also know to turn the monitor volume down before plugging in headphones.
My problem is the volume is subjectively 6~10dB lower from a BT speaker (Brax3, iodeos 7.5-20260519-brax3, Developer Options enabled, Sony XB100) when compared to driving that speaker with the same audio material from a Lenovo Tab, or a Redmi 13C. Now the Redmi 13C is not stock: I used an adb app I found via xdaforums to adjust the maximum level from “240” to “255”. The app has a bunch of other useful functions, including to overcome this complaint of low volume.
Settings > System > Developer options > Disable absolute volume > I confess to being unable to subjectively hear any difference whether this is ON or OFF on the Brax3, and a subjective test may be confused by having to turn BT off before changing that setting, then BT on again. Unfortunately I no longer have access to lab eqpt to measure the sound output level.
I have had some issues with max volume being too low via bluetooth (using a cheap bluetooth - aux adapter in my car), making it hard to use particularly for phone calls.
There is a an App:
“32steps” on IzzyOnDroid.
It is an systemwide equalizer.
I use it for:
have 0 Level profile for my headset, a “device-music” and a “device-speech” profile configured.
With the equalizer you could try to raise the volume (+12dB). I don’t know if there will be distortion, but you could try it.
Sorry, I seem to have had a senior moment: I can now find no trace of the app or a link to it, although I clearly remember changing the values from my laptop. At the time I did regard the task as low priority, because I wasn’t intending to keep the Redmi, it was just a filler while I waited for the Brax.
That’s odd. I have two different cheap aux-BT adapters which both put the output from my radio tuner 10~12dB louder than anything from the Tab or phone.
Yes, I have seen various EQs or “gain booster” apps recommended on other forums. I regard these as a workaround rather than a fix, because they are yet another app running, an intrusion in the audio chain, and use more RAM and battery. The basic BT codec has had its level capped, and it ought to be possible to uncap it.
On this subject, there appears to be no choice of BT codecs available as on some other phones. is this a Brax or iodéOS feature? If we’re stuck with SBC that might explain the low volume and the inability to change it.