Patrick, >I dunno. It seems that recent releases from the likes of Bjork or the >Beasties have been designed specifically for headphones. This has been ignored for about 40 years; there could have been two editions of every major CD and LP ever released, but there wasn't. >It sounds like your software would be a very useful addition for the pop >music marketer running a Linux env. Good! I'm glad to hear that. I actually think that people's critical listening abilities will evolve, just as they have in the past. >GUI. Hmmm. Doing a good GUI is a large task, here made more complicated by the fact that there is considerable math and physics involved. It's going to take some time to get it right. I need to translate all of this to something that is more readily understood by people doing real work in the real world. What I may do is that which was suggested by J?rn and Steve: Release what I have and have some rounds with other developers. Some ideas of what to do (user models) may develop. I want to develop a user model that is flexible, so it won't necessarily be recognizable as a mixer board or any typical gear like that. Although the development of software that looks like studio gear has eased the transition for many studio workers, it isn't necessarily the best way to do things in the long run, just as the Windows O/S which emulated Apple's wasn't the best way to develop computer software, even though it eased the path for a lot of people who worked in paper-and-pencil offices into using computers. Dave.