As requested in another thread, here is the one to chat about hardware compatibility.
My own experience :
Sennheiser MM 450-X Bluetooth headeset : OK.
Plantronics M25 : OK

Wired Koss Korta Pro with microphone and button, no go.
The button is not sensed in either phone calls or media player.

Nokia BH-111: phone OK, media player all buttons OK.
(Headset volume button acts independently from Jolla volume set by rocker: volume will be 0-100% from Jolla volume. If not loud enough: use the rocker on the phone. BTW Interesting warning Jolla gives at higher volumes in media player. Good policy.)

Jabra Wave+ (Bluetooth) - works perfectly.
Koss PortaPro (headphones only) - works, but notification sounds still seem to play through the phone's speaker, at least when the screen is dark. Maybe this is a feature?

Some more: Nokia wired headset with four-pole plug (came with C7, no idea what type) - strong tapping sound in left channel; audio plays without tapping sound. If answer button is pressed during audio playback, volume increases a lot.

Another Nokia contraption (sorry, no idea what type, I've got closets full of these, having had dozens of Nokia phones since whenever) with media control buttons + answer button and a 3.5 mm socket - with Koss PortaPro headphones plugged into the socket, same tapping sound, the media buttons (play/pause, stop, forward, backward) do nothing.

A novelty handset with four-pole 3.5 mm plug and a polarity switch: if the switch is pushed in, no tapping sound. Haven't tried calling with this thing yet. This works perfectly with my C7 if the switch is out, and the answer button answers and hangs up. IOW something seems to be wired differently than in Nokia phones.

Yes, Nokia always had their own proprietary headset wiring and Nokia phones always needed special Nokia-compatible headsets. Jolla OTOH is not Nokia.

As noone else seems to have this trouble, I'm asking, what am I doing wrong? With regular volume on the ringtone I was listening to some J. Joplin through my Porta-Pro's, then I got a call. Felt as my ears was being destroyed, not pleasant. How can I lower the ringtone volume through headphones?

Edit: wrong thread?

Nokia Purity HD Headset (Bluetooth) : OK
JVC KD-R721BT (Car Radio Bluetooth) : OK

Car Radio plays also music via Bluetooth which my SGS2 never did

There were two headset wiring standards. Neither of which were proprietary as such.

OMTP was backed by Nokia, Ericsson and most of the European and Asian Manufacturers.

CTIA was backed by mostly American Manufacturers, most prominently, Apple.

http://en.wikipedia.org/wiki/Phone_c...#Mobile_phones

So far...

Nokia BH-221: Supports Bluetooth A2DP, AVRCP, HFP.

Jabra SP700: Bluetooth car kit - HSP, A2DP, AVRCP, HFP.

Phillips SHB-9100 headphones: Works fantastic. I'd given up using these on my N9. HSP, A2DP, AVRCP, HFP

Onkyo RBX500 bluetooth speaker: all works.

All the bluetooth devices have the same issues though for me.

1) There's no alert on the Jolla to show a bluetooth device connecting/disconnecting.

2) It uses the headphone's ringtone, not the one configured in the phone.

3) It doesn't resume playback of music after a call.