it's important when designing the room/tuning the room to get an even tonal balance. otherwise you will constantly chase your tail. also, what the clients hear will be not what you hear and you will always be at odds with one another.
another idea to keep in mind- the small details are not the music. one of the great realities of making a record is that it will never, ever sound the same as it does when it leaves your place- all rooms and speakers will be different. so it your mix leans on small details, you will not have a good mix. this is the real virtue of listening in mono on speakers that have good tonal balance but are short on detail (such as the ns-10).
If your mix only sounds good in a postage stamp sized area and you are holding your head still like a retriever to listen, your mixes will never be very compelling.
Try this. Get an ns-10, put it somewhere over your left shoulder about 6-8 feet away, and do all your eq and balances before you start panning and developing the stereo space. You will be amazed how much easier, faster, and better your mixes become.
