Have to strongly disagree with that I'm afraid.
Any competent loudspeaker with have a fairly linear FR of +/-2db over it's working range.
The room will often result in frequency response aberrations of three to five times that and will therefore be the main arbiter of tonal balance and perceived detail retrieval - particularly when you take into account that in most cases over 70% of what you hear comes via the rooms walls and ceiling - not direct from the speaker.
A suck out in the mid to upper bass, often brought about by the first and second nodes of two room dimensions coinciding can make even a 15" Tannoy sound anemic. A speaker that rolls of at 45 hz will sound superb in a room that's 14' x 20' but will be troublesome in one that's say 11' x 13'.
If you know the maths, and the area you are likely to be putting your speakers, it's pretty easy to read specs and judge whether a particular model will be suited to the room. If you are computer literate you can use CARA of course.
But the room is crucial to tonal quality as that is the result of frequency extension, distortion components and spectral balance, and not IME, of pixie dust or drive unit material (although the latter is tied to the distortion components).