Haven't tried said loudness feature in Equalizer APO, but as mentioned before by pierre -- if you're comfortable with trying out a software solution for a PC -- you can route all audio through
JRiver directly first and let it automatically run its own Loudness DSP with just a few clicks:
Change the
Internal volume reference level to set at what volume level it starts to apply compensation:
I've posted the following measurements below before and briefly described it on
another thread (here):
In my desk's
standing position FR measurements (shown above), the compensation starts immediately as soon as I lower the volume below 100%; however, in my
sitting position I set it to start when adjusted below 80%. Since I've set the program to always upmix/downmix to 'pseudo' 5.1ch audio, it's really difficult to make a sweep of all channels at the same time without causing some kind of cancellation in the higher frequencies.
Below are
averaged RTA measurements with psychoacoustic smoothing -- hence the smoothness -- using the MMM (moving microphone method/measurement) of all channels playing at the same time at different volumes in my desk's sitting position:
*The slope of the higher frequencies with the averaged RTA measurements is somewhat less steep in reality. Also, I could probably use a few decibels off using a low shelf filter around 500Hz or so -- I'll have to re-evaluate this with longer listening sessions. Spent the entire day listening to various media content, there's not much reason to readjust anything at the moment.
The EQ settings here needed to be, of course, different as the response differs quite a bit while sitting down and it's worse in the sub bass (substantial null between 60-80Hz), and the HF slope actually looks different than if just doing just a regular sine sweep
a few dBs less until you get to the lowest volumes (I reduced the HF shelving & don't quite remember what mic calibration I used previously) -- but never mind that. The resulting compensation curves
will appear quite similar overall to the sweeps made in the standing desk position. Sorry, I'm currently too lazy to do an averaged RTA for all volume levels. Anyhow, you pretty much can get a picture what's happening with the Loudness DSP.
I ran a series of pink noise quite a while ago to see how well JRiver's Loudness DSP conformed with the ISO 226:2003 standard with volume change and I do think it does a pretty good job here.
If you've experienced using a really good Loudness DSP, it's
extremely hard to want to go back -- why the hell would you? It makes it enjoyable to listen to music at
all volume levels -- most esp. when set low like between 15-40%