Faint call volume with bluetooth and aftermarket head unit + amp combo

[destrekor]

In a previous vehicle, I had a single-din Pioneer head unit with bluetooth and both music and phone volume was excellent from my Moto X.

Now, I have a double-din Pioneer unit and a small 4-channel Alpine amp driving the cabin speakers. Bluetooth streaming and radio both have excellent volumes (bluetooth has more inherent gain), enough so that, thanks to the 4v pre-outs, I have the gains on front and rears both set to basically the bare minimum.

I wanted to test the mic and get feedback from my dad on the other end. When I selected the contact through the head unit and selected call, I couldn't tell it was functioning: it is supposed to have a ringtone, but it's barely audible. I had my volume around 25/40, a comfortable not-quite-loud but probably difficult to hold a conversation volume level. Apparently my dad did answer and I strained to make out the "hello... hello?" repeating, then I cranked the volume to 40 and could hold a conversation, but I was still sort of straining to really hear it. I put the mic near the rear view mirror so that I might be able to have windows cracked and still be audible, but this... it would be impossible for me to hear the other end in that scenario.

I can set a Bluetooth volume/gain level on the head unit, but that also reflects music, and it's already louder than radio. I don't know if the answer is to actually bump up the bluetooth gain and end up having music volume only enjoyable at a max of 15/40 - that's not really enough of the volume range to handle all possible audio material imho.

Thoughts?

 

[Tuanies]

What was the volume on the phone?

 

[Midwayman]

This is going to be a phone thing. Most popular android phones have apps available that allow you to directly access the audio chip setting. Probably something in the market, but check XDA too. You should be able to go in and adjust mic gains there.

 

[Midwayman]

also found this if you still have the X
"I don't use my phone a lot for calls, I barely make calls, but I do receive some. So the first couple of times this happened, I assumed that the mic of caller was bad or something until today when I was in a relatively noisier environment and not being able to increase the call volume was frustrating. I swear I almost crushed that volume button in.

I use ATT and called 611 (customer care IVRS) just to listen to the IVRS on speaker, the speaker was not loud either. But the speaker was pretty loud while playing music and videos. So I was relieved that this was not a hardware problem.

After playing around with ATT 611 for like 10 times, I realized that the phone is defaulting the call volume level to some arbitrary lower volume state regardless the system showing a different call volume (max in my case as I almost crushed that volume button in, multiple times, lets call this the volume level the volume rocker state, as that was clearly not the speaker's state).

HOWEVER, a change to the volume rocker's state fixes it immediately, since I was at max and hitting up on the rocker wasn't changing anything but keeping it at max, nothing was happening. But if we reduce the volume once, then the volume rocker state goes to (max-1), and voila, the speaker instantly assumes (max-1) as well (which is much louder than what it defaults to). Once the rocker gains control, through a change of rocker volume state, it then works during that call. So pushing up again, would bring it from (max-1) to max and the speaker assumes maximum call value as well. But just for that call....repeat during the next call.

I rebooted the phone once and tried to replicate the issue on video, but after the reboot, the issue is not present. But I have rebooted many times and I have experienced the issue many times, as well. So there's something that triggers this as I use the phone, I can't know what, but hopefully a software update can fix this. I already have 4.4.2, so I don't know if I should expect anything new.

In any case, figuring out the volume workaround makes the phone usable. Was gonna return it if nothing came out of my effort. I can live with it now, cos the phone is otherwise just the best phone ever. I wanted to report it, so I registered and came here to find that someone already figured out this workaround, kudos. So I explained the apparent behavior making the workaround work, hoping for Motorola to take note. "

 

[destrekor]

Well, I never had a problem with my Moto X in my previous vehicle and Pioneer unit, so I don't suspect a phone issue.

I know Android can treat the Bluetooth stack a little different, and less consistently, than iOS, but this was weird.

However, I think I may have created the solution. Previously, I had chosen to leave my Ringtone and Notification volume unlinked. The notification volume was about 50%, and, I have heard that the Notification volume is what is used in this case. I used GravityBox to link them and made sure the Notifcation volume was at max and tested it out this morning. All is well. A little lower than I'd like, considering my head unit remembered the 40/40 volume setting for the phone call and I felt I would appreciate more headroom, but I might be able to address that with some more tweaking.
I might have to try that Max-1 and revert approach.
Either Android Bluetooth phone conversations in general, or specifically the way Moto Assist interfaces with bluetooth devices, especially head units, might be tied to Notification volume or whatever reason. I have never had any issues with Bluetooth audio for music, but that is also a different Bluetooth profile (A2DP for stereo music, HFP for mono phone use - there is also one for bluetooth headsets, HSP, and most headsets use both HSP and HFP... a head unit will typically only engage HFP in phone mode). I have a set of stereo bluetooth earbuds, but I have never tried talking with them.