I've always thought the main point of Studio Monitors was to be able to hear the entire frequency as evenly as possible (Hence the desire to have a studio monitor as flat as possible). This means, you won't be stuck in a sitution where once you are done and finalizing a project, you have frequencies that YOU personally didn't hear on your specific NON-flat speakers. In this case, someone with a different set of speakers (Both higher-end ones or lower) may hear them loud and clear.
Again, you (with the nice and flat studio monitors) can hear the entier spectrum right off the bat and can get the perfect mix accross the entire spectrum. Hence, once played elsewhereit should translate well in all situations.
Basically, if you mix on consumer level speakers (Boom box, 2-inch kitchen radio speakers, car system, etc) you will as mentioned, mix for THAT particular speaker type and THAT respective frequency response.
I'm no pro here by any means, but the "If the mix is right, it'll sound right, if it's not, it's only going to sound right on the right speakers" saying pretty much sums this all up.
As an audio engineer, you are required to hear EVERYTHING and not just what the standard consumer level speakers provide. This is because you have to cater to ALL of those consumer level speakers in the world.
Hmm, I guess I'm saying the same thing over and over again. Anyway, if I'm wrong here, then someone correct me. I'm just joining this thread because I'm about to spend a lot of money on studio monitors myself and I definitely feel I understand the reason for having them.
As an added note, I definitely know what it's like to have recorded something only to have it sound completely crappy in a car stereo - washed out, bass-heavy, bland highs, etc. I know it would be easier to work with monitors instead of my computer Speakers
But from the other side, I guess it is completely true to state "once you learn your speakers (monitors or not) you can mix well on them". This could be true I suppose and be what you are talking about, Manning1. So then at any rate, having studio monitors DOES make things easier in the least, no?