I tried to do a quick search on this, but didn't find anything. I apologize if it has been discussed before.

I'm not sure if this will work for anyone else, but I noticed this little trick to boost the volume.
While I am streaming music via Bluetooth from my iPhone 6 Plus, activate Siri, listen for the beep-beep, and then dismiss Siri. The music should then re-play from where you left off, but it sounds a lot louder/better than before.

It doesn't hurt to try. I've replicated it over and over and it works every time.

 

It's actually kind of a mess up. The only reason that works is because the iphone 6 has a issue where it magically bumps the volume down, even though it doesn't show on the volume screen. So this is actually bringing it back up to where it should be. But, a good thing for people to know.

 

There is the same bug with iPhone 5 and can be fixed via opening Music app - You will see that the volume slider is at the middle point (and it repeats every time when the phone connects to the car). Just turn it to the max setting and enjoy )

 

hmmm i just realize it now! thanks

 

True story, I have this issue with the iPhone 5 as well. Thanks for the share. I'm sure many people are asking the same question. It does it on my pioneer HU in my Scion FRS. Thanks!

 

6 plus here. i noticed when i used the bluetooth and stream music off soundcloud. once in awhile it lowers the volume by itself. When i go into the app and tap fast forward or reverse it goes back to normal loud sound. Is this the same problem you guys are talking about?

 

I have had this same issue with my '14 IS350, but inside the music app the volume is always up to the max. I haven't tried activating Siri, but I will.

I've tried just about everything I can think of to resolve this, phone settings, car settings, turning off bluetooth and re-connecting, playing another application and making sure the volume is up at max, connecting via USB and it's never fixed the issue. This has spanned 2 different iPhones, the 5S and now the 6. It's very inconsistent and frustrating.

 

make sure volume is all the way up on the phone when using bluetooth.

then turn the volume **** to around 35-40 for best sound of music

 

I've tried that and assure you that the volume on the phone is at max.

I tried to activate Siri, adjusted that volume to 100% and still didn't fix it. Un-paired the phone and re-pairing it to the car while also 'forgetting' the car connection on the phone. I've toggled the airplay from phone to car back and forth and tried to skip the music while it's playing both forward and back. I tried to connect the phone just as an ipod device and not a phone...still no resolution.

 

great to know... dislike it when i have bluetooth volume up high then switch over to radio and it blasts out so much louder than bluetooth... and well possible heart attack one day.

Thank you for saving me from a potential health hazard