How to meaningfully audition speakers??

The best way to audition speakers in your home but like you said there are very few dealer or speaker manufacturers who would allow you to do that. I honestly will go through various forums, read reviews on speakers I'm interested in and if there are enough positive reviews I buy them. I'm also hoping and a praying that my results are like what I've read. If not then I re-sell at a loss. I think in this day and age that is the only way to go unless there is an audio society/club where you live and maybe you can audition different speakers there.

Buy, Try and Re-sell after some time is what I've had to follow.

There have been times I've gone to B&M stores and brought music I like to audition speakers. Other times I've worked with the associates to give them details about my listening area so we can try to simulate it in their demo room. Even then the music won't sound exactly the same with my gear in my room.

One of the best things I ever did was go to the Rocky Mountain Audio Fest where I could walk from room to room and hear all kinds of equipment and setups and ask questions about them. They may not have your exact setup, but there will be tons of things that you can get a good idea of in a couple days.

for this you need good microphone or good acoustic transducer(or few), good recorder(or multi-track... teac 4-track r2r is one of the great examples), good player, good room and possibly good amplifier. in addition you'll need a musical instrument that you're going to record. good ones to test are trumpet, sax, guitar, double-bass and certainly piano. you'll also need monitor headphones to adjust proper recording level when you test your instrument.

1. record any instrument handy(i'd use 15ips speed of recording on r2r gear)
2. adjust volume of amp to the same level as volume of your live instrument
3. play it through the speakers and analyze the difference.
4. if the difference minimal the speakers are good.

Ask to be able to spend a few hours listening to your choice at a store. Most stores have times they are not busy. Do not attempt to just walk in and expect to have a few hours alone with a speaker in a room.

Then bring a selection of either CDs or Lps you KNOW and love. AND which have various moments you can use as tests.
Listen to them for a long time with no interruptions at the store. Make it clear from the start you want to be able to spend a few hours listening without interruptions.
(If the salesman wants to chat while you listen, tell him to go away.)

You can see if the speakers can do well with certain key moments in your music.
For myself i like Mozart Extante Jubilante with Emma kirkby to listen to her solos.. Wonderful voice, and tells me if the speakers have a good upper range.
Sinead OConner for the wonderful air around her voice. Finess.
Then Carl Orff Carmina Burana, for drum wacks, and choirs.. The childrens' singing on Telarc CD is a good way to see if the speakers can spread out the voices into individual singers instead of a clump of noise.(same test with massed violins on other recordings, I prefer voices..)

Etc.. Thise titles were just examples of the sorts of things one can note and HOLD on to. Specific moments you CAN remember instead of hazy stuff. Then did the speakers make you happy? How did you feel, aside from trying to bother remembering the sounds. Remember how they made you FEEL.

Repeat at next store with other speakers. some will just not pass you personal tests. This may be due partly to electronics.. partly due to store staff pressures.(also you can ask to bring your own amp/integrated and Cd player.. SOME stores will allow, depending how hard it is for them to swap cables etc)

If the staff cannot keep from bothering you.. I suggest explaining the selling is in LISTENING, not talking.. But some salemen just cannot cope with it. Too bad. point out they can shut up or you can leave.

When I bought my speakers I brought my powerline conditioner to the second several hour trial. And was allowed to plug the electronics into it.
Since I wanted the amps too, the trial of speaker/amp was nice.

And afterwards.. If you do buy at one of the stores.. Tell the other stores what you did buy. and thank them for allowing you to audition at their store. Tell them you will tell your friends how nice they were.
And if you go and buy them online to save a few bucks after using the store to audition. Then you are a bad person.

Never judge a book by it's cover. If, for example, you've had bad experiences with planars or metal tweeters, or whatever, I'll guarantee that there's something out there that's going to surprise you.

Consider your room, placement of speakers and the amplifiers requirements of the speakers.

When you're comparing mediocre to mediocre, it can be difficult but listen to as much as you can, even if they're out of your budget, and when something outstanding shows up, regardless of the room or other equipment, you'll know immediately. Those kind of breakthrough moments, are memorable. Question becomes whether you can afford it now or sometime down the road.