Harbeth 30.1 or 40.1


I would like to get a pair of Harbeth, and wondering if 30.1 or 40.1 is better.  My room size is about 18’ x 16’.  I currently have a pair of Spatial Audio X5 with large 12” mid range driver.  I would say I listen in low to low-medium volume for Jazz and vocals.  Is 40.1 too big for my area?  I am afraid if I am not listening to what it is supposed to sound like if I don’t turn up the volume.

however, if I buy the 30.1, is that I should get a pair of sub?  Versus for 40.1, I assumed I don’t need subs?
gte357s
I own the Super HL5 Plus 40th Anniversary Edition and absolutely love them.  I'm looking forward to hearing the 40.2.  I'll post my impressions.

Yes!  One of the more significant changes from 40.1 to 40.2 had to do with the bass, which made the 40.2 a lot more room-friendly in terms of positioning vis-a-vis the 40.1.  That being said, yours is a decent-sized room and if you have some leeway to experiment with positioning within it, I'd definitely consider the 40.1.  Do the Spatials threaten to overload the room now?  If not, then that's another indicator that the 40.1 should work OK.

I've posted this link before of the 40.2's in a much smaller room.https://www.whatsbestforum.com/threads/harbeth-monitor-40-2.25222/

I presume you're considering 40.1's for, err, economic reasons.

Thanks for all the reply.  I believe the only way to find out if I will the Harbeth is to buy one and use it at home.  Although not yet audition the Harbeth, based on my past experience, it is not that useful; because the room is different, the amp, the source ... everything are different.  So, my approach is buy used, bring it home, and if it doesn’t work out, I will sell it out hopefully won’t lose too much.  
It seems now the determining factor is the price.  Not only the 40.1 is more expensive, I believe it needs a more powerful amp as well which is also more expensive.  
@mapman can you please elaborate on your experience between the Spatial and 40.2?  Which model of Spatial you hear?  Are they in different settings, different room and different equipment?  
Since the Spatial is open baffle, I hope or expect it gives a bigger sound stage and more life-like.  This is one of the reason I buy it, and it is true compared to my Zu Omen Def MK I.  The X5 has a big Air Motion Transformer for high frequency of 1k and up.  It provides more detail and sound more transparent than the Zu, but at the same time, I need to be careful about pairing equipments.  For instance, I bought a Toppings DX7 pro which also offers all the details, and I feel fatigued after an hour of listening and need to turn down the volume.  
By comparing YouTube videos and my X5, I believe the Harbeth gives warmer sound.  But I hope it also gives the same level, or a bit less, of detail and clarity.  I expect the soundstage May get smaller.  I hope the instrument separation is still good.