With both maxed out, you get a blended, huge sound with ear pounding bass! It's too much for sure. These really show off the effect of crossfeed too, more so than any ear/headphone I've ever plugged into the Arrow. Crossfeed always seemed hardly noticeable at all, but with the 900s you really can hear the difference. It gives me new admiration for how well implemented the feature is on the Arrow. I think both at max almost did blow my ears out! Ha ha.
So when are you picking up a pair of 900s? They're amazing, even fresh out of the box.
I may get them soon or I may wait a bit. I already have great phones, including an ortho I want to mod. I think I might put some money into the phones I have by modding them and getting an equalizer and amp instead of buying a new phone. I will probably buy the 900s at some point, just not now. The orthos I have, the ubiquitous Fostex T50RP, can really put out some great bass, with the amazing ortho mids. That is why I am not strongly hankering for the 900s right now. Don't get me wrong, I have wanted a pair of Pro 900s for almost a year now, but I can wait for good things.
I hear ya about other plans for the time being. That's cool about the orthos... I just recently had a pair of the Thunderpants (is that what you're going to mod/build on your own?), but they just didn't do it 'all' like I wanted. I think they just didn't quite fit right either.
It's funny when you know you'll cave eventually for a pair of phones you've been craving for a while. From what I'm hearing with these in the early stages, and what I heard with the TP, and Sony Z1000, the Pro 900s will be a great choice still. It's totally a grooving headphone. I have a big grin while I'm listening so far, trying to get some work done!