Sorry dude, but freq responses aren't flat, even with mid-range speakers. If you're going by reviews in places like Sound and Vision (formerly Stereo Review), then sure that's true. But that's only because they won't do a decent review with decay and frequency charts unless the speakers are at least $1000 per box. For those prices the response damn well better be fucking flat.
But even if what you're saying were true in general, there is still a huge difference between speakers in terms of the decay rate at various frequencies - what would normally be called clarity or crispness. My NHT classic 3's are significantly clearer than the Polk Monitor 40's. Maybe the 40's are more low end than mid range, but they're still pretty good and the NHT's aren't infinitely better, but enough so that the difference is quite obvious. And even those aren't as tight as I would like on the low end but they're still pretty amazing.
your totally full of shit. anytime you wanna throw down on a blind listening test in a proper accoustic enviroment for a serious bet, let me know. I'll test those golden ears. In fact I'd bet money that you couldn't identify your own speakers out of 3 pairs in a double blind test.
Your giving horrid advice, the answer isn't to blow more money on gear, its to get a handle on the enviroment, once you do that the gear works properly.
Most speaker system have sub 2db deviations across the bandwidth on average at normal 76db listening volumes.
No you're full of shit. Anybody who has ever picked up an audio magazine knows what I've said is accurate. And my hearing isn't at issue. Your ignorance is.
I don't see how anyone can think speakers all sound nearly the same - come on Thatguy! :shadedshu There's absolutely
huge variations in frequency response and tone, all caused by objectionable resonances, poor materials and the like. It's way more than just having a flat response. You can equalize two different-sounding speakers within 1db of each other with some super duper graphic equalizer and they'll still sound noticeably different, because of these effects. The more expensive ones generally sounding better, of course.
On top of that, no speaker has a 2db flat response from 20Hz to 20KHz, except possibly for the odd exotic high end job costing thousands. And since one driver can't reproduce all frequencies, what happens at the crossover frequencies?
In my experience - in general - a good system always sounds good and a bad one bad. Even if you do stupid extremes like position your quality speakers behind the sofa. They'll sound muffled for sure, but will still retain their general quality sound. They'll still sound 'good' even if you turn the bass and treble controls all the way down, so you get lots of peaky mid and no extremes. Even if you screw up that graphic equalizer with wild, random settings. The sound will be unpleasant, but the basic quality of those speakers will
always shine through. And you don't need bloody golden ears to notice, either.
On the other hand, a shit speaker will sounds, err, shit, whatever you do with it and however good the signal being fed it is. It can simply be improved noticeably, but will still retain all its annoying faults.
And yes, optimising room acoustics will of course help to get the best from a decent system and matter sod all to a poor one.
Modern electronics on the other hand, can and will sound remarkably similar, being largely free of distortion and frequency response variations. However, the differences are still there and can often be clearly heard. I can tell you that I can easily hear the difference between my CD player, onboard sound and two Creative sound cards (budget and md price) despite them all having a nearly perfect frequency response. Why? Because of the different coloration and distortion they introduce, including that caused by impedance matching. That alone can make a very noticeable difference.
To clarify the obvious, the audible differences between these different devices all stem from their analog side ie D/A converter and associated analog circuitry, not the digital side. The data is the same, regardless of how you transmit it. If it wasn't, then the existence of digital computers would be impossible and we wouldn't have physics as we know it.
So yes, twilyth is right.
On the other hand if you're talking optimal speaker placement, and obstruction minimization, then yes. 
, but this guy, or rather thatguy, wouldn't know a cross over from a light switch. Don't waste your time. I just want to see how far he can go before he has to bail. 