I know it has been a "standard assumption" on the internet to choose a speaker first, been mulling it over, how would one know how the speaker actually sounds without the electronic components? May I suggest testing all the components together if in store but preferably in a home test. Usually there is a return time policy for either an online purchase or from a store.
That would allow one to spend some time with speaker placement for maximum fidelity and/or looking for flaws in either speaker or component(s).
There is a very general pattern of sonic issues with each.
The speaker tends to be specific, such as a bright, harsh, or lack of highs tweeter, flabby bass, thin bass. The room also tends to be in the same category, being specific. Most times the resonances are less than 1/3 octave width.
On the other hand, electronic component FR deviation, though small, is over many many octaves and influencing many harmonics, causing perceptioin issues such as lean throughout the entire frequency range, highs, mids, and lows, or the opposite, too full bass, the mids, the highs, etc. Of course there are deviant issues such as harshness, smearing etc as well from a component.
I think one would be surprised if one knew just how far off the electronic components are from accuracy/naturalness, how much the output sounds different from the input of a component.
I find it difficult to accept one purchases the speaker first without auditioning with the electronics one might be interested in. To me it is a package.
My .02.
steve