Last Speakers Aerial 20T or Vandersteen 5A

Which Last & Better Choice for only MUSIC not HT

I have Meitner DAC2 & Transport, Simone Yorke & Graham 2.2
Benz LP, CAT JL2 & SL1 Ultimate + VIOLA LABS SS Amps/Preamp.
size room 18 x 13 x 8.

Based on Fremer's review of the 20T, your room might not be big enough to get the best out of that speaker. Better try them both in your (very nice) system if you can.
Dude, listen to both of these loudspeakers in your own system, then YOU decide which is better!
Pursuing Drubin's remarks, I'd go a bit further and comment that your room size could be problematical with either speaker. I think, however, that the Vandy 5A might be the better choice since it offers the ability to contour the bass response using its built-in 11-band equalizer. Both of these speakers are fine performers, but if cost is an issue, the Vandy 5A is a much better value. Before you make a final choice at this price point, you need to evaluate both speakers in your listening room -- $15k to more than $20k is a big chunk of change to spend on a full-range speaker that may not perform well in your listening room.
Having heard of but never listened to any of the components or speakers you list, I figure I'm qualified to be wrong as much as anybody.

As to the room size, I don't believe that is an issue at all unless it is deemed a very 'live' room acoustically. But then that room would be a problem for any speaker. And that's assuming that the wall behind the speakers is one of the short walls and there's not many windows, etc..

In fact, having had a listening room with your dimensions, I would go so far as to say that your room dimensions are near ideal for this size speaker assuming it is truly rectangular and closed off.

If you have the right amp for the 20T's I would speculate that the 20T's could be a real contender with the 5A's. If not, then I think the V5a's are probably the better and safer route. But then again, you're talking about $7k difference in price too.

Sounds like too much speaker for your room. Both, that is. Listening will tell. How you do that, is another story....
According to the Stereophile review of the Aerial's and what i know of the Vandersteen's, the 5's would be a better choice in ANY given room. Not only are the Vandy's WAY less money, they provide at least two distinct advantages over the Ariel's. That is, the 5's allow you to tailor / fine tune bass response to achieve flatter, more natural response via active equalization. On top of that, the Vandy's minimize the strain on your amp by providing its' own subwoofer amp. Whether or not you like one presentation over the other is up to you and a matter of personal preference. As Timo stated, you would really have to listen and see for yourself.

As a side note and so as not to "contaminate" this thread, i was going to post something about the Aerial review and general "big dollar" speaker trends within the audiophile marketplace. I'll do that in another post. Sean
And here's another thought. The Vandersteens maintain their value better than probably any other speaker, so if it turns out you're unhappy with them they'd be easy to sell.

Also, I haven't heard the 20T, but I have heard the 10T several times and the Vandersteen is just a much better speaker -- if you're looking for coherency and accuracy, that is. IMHO.
I evaluated the Aerial 20T (and quite a few others) against the Vandersteen 5A, and chose the Vandersteen speakers.

Your room is a bit narrow though - is there a possibility that you could put the loudspeakers on the long wall?
I'm sold on time aligned and phase coherent speakers. With that said, I'm biased for the Vandersteen. It also allows for fine tuning of the bass (as Sean points out above) and it's much less money for just as well built but more accurate speaker.
The ribbon tweeter and dual ported woofers would scare me away immediately. I have never heard ribbons and dynamic drivers ever blend correctly to the point where I didn't think you had timing issues.
You may not prefer the Vandersteen, which is of course fine. A lot of Audiophiles do not get excited over truly accurate designs. The are use to hearing colorations and the tweeters sound arriving way before the rest of the speaker giving that "Illusion" of transparency.
Why only two choices? For this kind of money there are other fine performers. Your amps are not very common, and few here will know how any speakers will exactly sound with them. Would you be willing to replace them if you really like the new speakers? For example, Kharma speakers sound incredible with LAMM electronics. Or, Michael Green Audio Classic Chameleons with outboard crossovers have a unique design and sound signature. Also, the cost issue. Does it make any difference for you to spend $25000 instead of $15000 provided you get a much better sound? Vandersteen is a popular choice, not everyone's though. Do not get affected by the herd instinct. Trust your ears. You have one of the best front ends available, both analog and digital; it is going to be difficult for speakers to match it.
Inna: You make a good point. There are indeed lots of other great choices; however, the post specifically asked about the Aerial vs. the Vandy. And I'd hardly classify Vandersteen buyers as caving to "herd instinct" -- or mentality. In fact, many audiophiles, myself included, for many years dismiss Vandersteen as being too common -- until we've owned much more "exotic" speakers and discover that the Vandersteens actually deliver great sound for not that much money, relatively speaking.

Are there better speakers? Sure. But probably not for the money. IMHO.