If you want to try to develop a good target response while you're still waiting for Focus-A, you could also try tuning them with some equalization in the areas where they're brightest. If you feel like yours sound similar to the measurements in this thread, then you'll have an idea where to start and can start subtracting a couple dB from problem areas to see if that corrects the problem for you.

You could further compare that to using Focus-A without EQ once they come in and compare it to any modifications you make afterward. That is, if you don't want to just put away the 560 for a month. If you have something good to listen to while you wait for the pads to come up again, then you can just listen to that.

I've been playing with EQ to investigate what sort of EQ changes make the 560 sound better to me.  I've been using the EasyQ parametric EQ plugin.  It works, but has a tendency to harm the sound.  Makes high-res no longer sound high-res.  A clue that I need to try some different EQ plug-ins. So maybe I'll spend the month investigating some other parametric EQ plug-ins instead of thinking about the 560.  EQing well is also difficult.  I'd fail as a mastering engineer. 

My goal is to get the 560 to sound good to me without needing any EQ.  I'm curious to find out if the 560 will do the trick for me for classical music listening.  My main headphone now is a LCD-2 rev2.  It's not what I would consider a master of classical music.

I've been playing with EQ to investigate what sort of EQ changes make the 560 sound better to me.  I've been using the EasyQ parametric EQ plugin.  It works, but has a tendency to harm the sound.  Makes high-res no longer sound high-res.  A clue that I need to try some different EQ plug-ins. So maybe I'll spend the month investigating some other parametric EQ plug-ins instead of thinking about the 560.  EQing well is also difficult.  I'd fail as a mastering engineer. 

My goal is to get the 560 to sound good to me without needing any EQ.  I'm curious to find out if the 560 will do the trick for me for classical music listening.  My main headphone now is a LCD-2 rev2.  It's not what I would consider a master of classical music.

How large were the changes that you were making? I've been using the same equalizer in Foobar, and haven't felt that it's been degrading the sound very much.

Then again, I'm also not listening to high-res tracks, because I haven't heard much above 16-bit lossless that sounded much better to me. It would be interesting to get an album or two in high-res and play around with EQ some more to see if I could hear what you're hearing.

To be honest, I think the EQ helps it just enough that if I don't have money for the Focus-A pads till the next batch, I'm not too worried about what I'm missing out on. Maybe they could help even further, but EQ has already brought me to better sound and I feel comfortable stopping there for now.

I avoid doing extreme EQ changes.  Try to keep it as mild as possible.  My current EQ for my 560 is a -3 dB 0.8 octave dip at 3400 Hz and a -0.8 dB 3 octave shelf for the rest of the treble.  I'm not happy with that though.

The sound quality loss I hear is a loss of the envelope that is around the sound the room sound and some of the individual sounds (instruments).  High-res seems to sometimes have an envelope like that that CD res seems to lack.  It's subtle, and not always there.  If you don't believe in high-res you'll probably never hear it.  Believe in it and you just might. It's not a bat hearing ultrasonics hearing thing.  The EQ sometimes loses that.  I need to try some good linear phase parametric EQs and see if that makes a difference.

Maybe it has to do with how you're shelving almost all of the treble a little bit? I don't hear much to take exception with in the upper treble, past around 9 kHz or so, so I used two dips instead. Or it could be the equalizer itself, like you say. It's hard telling, without being able to hear exactly what you're hearing.

For reference, I'm using -3 dB, 0.5 octave at 4 kHz and -2.5 dB, 0.6 octaves at 8300 Hz. I chose that spot because I found 7-ish kHz to 9-ish kHz slightly bright and found that somewhere between was where it was the worst, so I just made a small, slightly broad dip there to try to reduce the whole region a bit.

I like the sound that they produce with these settings. It's a blunt tool, for sure, but I think that for a headphone that had a mostly agreeable tonal balance, a blunt tool may be all that's required to tune them appropriately, for some people. If you wouldn't mind, give it a try, and tell me what you think. It's possible you won't like these settings, either, but I'd like to know if your impressions change with a slightly different curve.

I'll try that.  In general I've found that shelving has less damage to the sound than peaks/dips, even broad peaks/dips.  So I tend to go with shelving rather than a broad peak/dip if a shelf seems to do what I'm after.  At least with EasyQ.

I'm looking forward to hearing your impressions. If you still find that it degrades the sound a bit, then I hope you find a better equalizer for the task.

I got the Focus-A pads on Tuesday.  Much better than the stock pads.  At least I can listen to the headphones now without EQ.  But the Focus-A pads don't bring me all joy.  The HE-560 with the Focus-A pads still harshes my mellow.  Not pleasant listening.  Ear fatigue sets in quickly.  So something is still not right with the sound.  I'm not sure what exactly.  Seems to sound like a little too much midrange still.  Or something else.  I'm not very good at zeroing in on and identifying theses sorts of problems by ear.

I'll keep listening to them to try to better identify what the problem(s) are to me.  Then I'll have to think about whether I want to open them up to mod and try to fix those problems or give up and sell them.