I use a certain “trick” to lower the maximum loudness of my speakers: http://i.imgur.com/8S84QCA.png
SR is unused, so now when I set the system volume to 100%, it only sounds like 25%. Much more granular control and less worrying about upsetting the neighbors. 
When I open Audacity, ALL of the levels get set to the system volume (so in the screenshot example, everything gets 4 times louder). This is irritating, to say the least. Can I disable this behavior?
Someone will correct me, but doesn’t that follow the Audacity playback volume slider (speaker icon)? My two volume controls “stick” where they are, so it’s possible yours may, too.
Koz
Please tell us your version of Audacity and Windows (see the pink panel at the top of the page). Your image looks like Windows 10, right?
What is the make and model number of this speakers device? Is if the built-in audio device? Do you have proper Windows 10 drivers for that device?
Certainly on some Windows 7 and earlier systems, recent Audacity resets the balance controls of multi-channel playback devices to centre. Either set the balance to centre and volume to 25%, or you could try Audacity 2.0.1 or 2.0.2 from here: http://www.oldfoss.com/Audacity.html.
Gale
