I’ve noticed lately my soundcard (EMU 1616m) isn’t putting out as much volume as in the past. I’ve checked just about everything I know to check: Windows volume level, the volume in the DSP software, iTunes settings, Cubase settings… Previously, if I turned up the software volume control about half way, it was pretty full, and sometimes I had to back off it. Now, at that position, it’s not loud at all, and I have to turn it up much higher. Am I forgetting something?
Get your hearing checked 
What about the amp/speaker combination? or powered monitors, do they have a level adjustment on the back that may have got moved?
Check your physical connections at both ends. You might also want to purchase some DeoxIT®. It will keep those long term connections from deteriorating over time.
Stereo or Mono ? 
Definitely a factor, Doug, have you had a test lately?
+4/-10 settings in the emu software? I wouldn’t think it is a cabling problem if both channels are affected? You’ve probably checked this but in the emu mixer output routing you can select either mix or monitor for each output IIRC without firing up my daw.
Cheers
I know this won’t help much but is Doug a head phones or nearfields? heh heh heh, just kidding around, I don’t hat you Steve !
Mauri.
Steve Fogal
at 50 I am now experiening noticable hearing difficulties for the 1st time in my life
That’s too young to be getting significant hearing problems unless 1/ you supported “The Who” once or 2/ you’ve got earwax. Might be worth checking 2/, not joking! A drummer friend of mine started saying “Eh?” a lot and grumbling about everything sounding fuzzy. I could tell the day he had his ear syringed - his eyes were shining again! 
No, that’s the Brit “Eh?” pronounced “A” meaning “What?”
Good call – I belatedly discovered that the Patchmix interface actually has TWO volume controls, one that is a TINY fader on the actual output channel, and another one that is a BIG rotary labelled “monitor”… I always used the monitor knob to control output – never noticed the slider/fader next to the output channel. Somehow it had been brought down – according to the readout – “-8.59 dB.” Returning it to “0” restored my original volume levels. The whole experience proves that my hearing is actually pretty good 
I knew it was something weird because I’ve got my setup calibrated to K12 and lately I was having to push my Cubase faders WAY up to get the type of levels I was used to
Now, about that vision thing … 