For consideration: If a person were to be a more complete audio hobbyist and make their own speakers - they wouldn't have heard them before buying components (drivers, wood, wire, crossover-parts, etc.). So, if they were to buy pre-manufactured speakers, it stands to reason that buying before listening would be perfectly legitimate.
Other considerations: Room plays a critical role. Reflecting and reverberating with the speaker output, producing a combined result that travels through the air medium to impart pressure differentials in our ears. Few among us have listened to what will be the audio room prior-to and as the primary consideration of home purchase. Try telling your real estate agent to filter by non-reverberant home and see how that works out.
Common-sense says listen if you can. If you can't, then research opinions of those you tend to agree with regarding sound like/dislikes. Also, buy from reputable sources offering a return policy - if you end-up hating them.
Purchases of pre-mfg/pre-designed speakers have been a mix of demo'd vs not-demo'd for me.
Demo'd beforehand examples: GoldenEar Triton series (still use Triton One and 3+ a bargain especially for HT), Martin Logan electrostats (got me hooked on dipole/open-baffle, replaced with LXmini + ob-subs).
Not-demo'd beforehand and liked examples: Tekton DI w/factory upgrade, Buchart, Elac, MartinLogan SLM-XL (for HT side-surround), MartinLogan CI (for HT ceiling Atmos), DIY Linkwitz LXmini and Phoenix(alt) OB-subs (for 2-ch system).
Finally, regardless of what you get, spend plenty of time listening in your room before making decisions. Human biology adjusts itself, adapting the interpretation of sounds - the more you listen to a set of speakers, the more you're inclined to like it, unless there are blatant issues.
Examples of 'blatant' issues I've experienced as inconsolable:
- Aluminum or "diamond" dome tweeters (like B&W) highs are bright/painful.
- MTM (D'Appolito) configurations (many examples) narrow vertical sweet-spot.
- Dipole panels (ML, Magnepan, etc.) produce narrow horizontal sweet-spot.
- Box: resonance, large front baffle (reflections), sharp edge (diffracting) corners.
- Inarticulate bass (many examples) slow, muddy, bloated sound foundation.
- Physical size too big or too ugly for common/size rooms = cohabitant denied.
Some of the above can be corrected (DSP/EQ), 'lived-with' (head in vice - only one good seat in the room) or compromised due to other advantages (spaciousness of dipoles) and some can't - each individaul and situation is a unique balance.
