Harbeth 30.1 or 40.1

Vu of Deja Vu, who's a major Harbeth dealer, stated to me that the 40.2's needed 2' of clearance from side walls and 3' of clearance from front wall (behind them), all measured from the relevant edge of the cabinet.  The experience of the gentlemen in the link I posted earlier suggests that you can get away with less and still get very satisfying sound.

I have both the 30.1’s and 40.2’s in a room about 20’ x 20’ x 9’. Driving them with a Yggy DAC (one of the best), AR Ref 5SE preamp, and an A21 (to be replaced by a new AR Ref 150SE tomorrow).

They’re both superb, very much like a dynamic Quad ESL57 with bass - just like they sound on YouTube.

But... I think the 40.2’s are indeed almost too big for my room. They’re very loud and the bass is almost overwhelming - in a room that has no soft surfaces or upholstery to dampen the sound. But, the mids and highs are incredible, clear and detailed, without being strident, as well as rich and organic. And with a superb soundstage. Though, I do have a pair of Townshend Super-Tweeters, which adds tone, tenor and air. The bass is so strong, I’m thinking of using a DSP or Equalizer to tame it.

The 30.1’s have much the same sound, which fills the room, but a little less prominent bass.

I would note you really need an amp that can control the woofers - they require very careful system matching to perform to their potential.

I would likely use the same amps you see driving them so well on YouTube: the MA252 or MA352, or the Hegel H360, H390, or H590. Prolly the Hegel amps, which have superb damping factors, though the tube output of the McIntosh amps sound great with them too.

That’s one aspect I like about the set up I’m using, the AR Ref 5SE adds just enough tube sound to them to make them sound superb. I’m hoping the Ref 150SE maintains that sound, with a bit greater resolution, clarity and air, while improving the control over the woofers. The AR amps have a more neutral sound than many tube amps.

I’m not sure I would use other types of tube amps with them, other than possibly, something like the Atma-sphere M60, etc. - that have the current to properly control them, and to produce the resolution and clarity they can provide, if matched properly. Their sound is already very, very rich - almost too much so, without adding an overly rich tube sound.

But... I think... you would be pleased with the sound of the 30.1’s / 30.2’s driven by one of those amps. And... I’d get the Yggy, or one of the other R2R Dacs that sound similar or better (the Audio Mirror Trubadour or Dennifrips Terminator).  Though, the Hegel already has a superb DAC, though it may not have the R2R sound, it nevertheless sounds superb.  

So... one of the setups you see on YouTube that sound so incredible will probably please you the most. I’d prolly go with the Hegel and the 30.1’s / 30.2’s.  And what a bargain you have with the that set up!

Agree with @twoleftears , an 18' x 16' room is far from small and can accommodate at least 2-3 feet of clearance that most speakers need from surrounding walls to sound their best.  Based upon the listening preferences the OP described in his initial post, I'd be shocked if the 40.1's don't exceed his expectations.  

I have owned M40s, M30.2 Anniversaries, and SHL5's I have used in a room 12.5 feet by 22 feet by nine feet high. The M40s, in their original version, were not suited to my room and overwhelmed with bass regardless of placement or even stuffing socks in the ports. I understand the 40.1 and 40.2 iterations of that speaker have tamed the bass somewhat for domestic settings; provided, however, the people I know who have been happiest with 40.1s and 40.2s listen to them in remarkably small rooms, not large room. Have others noticed this?

I have heard the 40.2s sound stunning in a large room at Deja Vu West in La Jolla, California, and that made me want them badly, though I have not gone that direction because of my cautionary experience with the earlier model. I have also been reluctant to buy a speaker as large as the 40.2 as it was very large, heavy (83.8 pounds) and difficult to move.

The M30.2 did not suit my taste despite their obvious excellence. I think I like something with a bit more extended bass and rounder sound. YMMV. 

As for my SHL5s, I have owned them for many years and have always enjoyed them. I have never directly compared them to 40.1 or 40.2 models and when I had the M40s, the bass problems with the M40s prohibited me from thinking it would be a fair comparison. The SHL5s (not the "+" version) extend to 45 Hz on the bottom end versus 35 Hz with the 40.2s. If you do not feel comfortable owning and lugging the 40.2s around, the SHL5s or SHL5+s might deserve your consideration. At about 35 pounds, you need not become a gym rat to qualify as an owner. 

I have not tried the SHL5's, but they have a similarly impressive sound to the 30.1's / 30.2's, but with a bit less dominant bass, and somewhat brighter highs.  It's very possible that they would be just as pleasing to you, though they don't sound as impressive on the YouTube videos.  Sometimes I think I might try them for a pair that have less dominate bass and brighter highs, though maybe a bit less rich mids. 

But, if you're after the sound that you hear in the YouTube videos, I'd start with the 30.1's / 30.2's and a matching integrated amp.  I think you'll find they will provide just the sound you're after at lower to moderate volume levels.  

They're easy to sell, if you want to try one of the others.  Or, you might end up keeping them and using them in another room.