Speakers for a very large room?


Reader of posts for a few years but have not posted a serious question until now. Currently have McIntosh integrated tube amp with some old KEF speakers. While I enjoy it in my current setting, I am moving to a house where my listening room will be 30' x 40' x 10'. It has polished concrete floors. Sounds like a grocery store but it is not. I suspect I will need to change speakers but really have no clue where to start. I listen mostly to progressive rock but also anything in the same general area. I don't know where to start with such a room? I am at least 3 hours from any major city. I did experience Treo CTs once and to bright for my ears and Wilsons but did not care for the visual appearance though liked the sound better. It was a few years ago so can't better define what I liked.  Not a great resume of listening experience but it is what it is at this point. For some reason, which may be completely wrong, I am thinking electrostatic may work well in this setting. I could easily move them 5 feet out from the back wall but then again I really don't know what I am talking about. Any kind comments would be appreciated.

Rich
ricmci
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McIntosh Tube Integrated + Big Room = Klipsch.  The amp would seem to suit the horn loaded speakers inherent high sensitivity.  Plus you got the big room to put in the K-horns, and many of us are jealous of that and want you to make it happen for us! I have Maggies in a room half the size of yours, and my MA-6200 (Mac SS integrated, so not totally equivalent) had a hard time rolling “London Calling” uphill this morning before work.  Sounds great, but not authoritative.  Wolf Garcia makes a great point about your listening area being more important than having great sound everywhere.  My loft experience in the 90s had people listening in a specific area of the raw space.  I would try the KEFs out first before making a move.  My experience with some legacy 103.2s on stands and 100+ wpc makes me think you might have a starting point already in hand.
I was not familiar with JBL Studio Monitors until you gave your strong recommendation for them. I am sure they sound just fantastic in your set up.

OP: 
I think there is a misunderstanding.

1 - It was not a "strong recommendation." It was a suggestion for you to see if you liked the sound and it fit your budget.
2 - I don't own JBL, I make my own. The recommendation was based on your room size and music preference, which is not my own. :) I think you should see if you can find used in your price range.

I only wish I could upgrade to that level of listening that you endorse. Maybe one day I will be so lucky. Thanks for your insight. We all should be so greatful to receive such well thought out replies.

I think it would be a good idea to have asked about your budget first. Used studio monitors in the size I am thinking of are probably in the $2k range. Perfectly reasonable to rock out in a large room. Of course, you could spend a lot more with JBL than that. :) 
Best,
E

Rich, you might give Eric Alexander of Tekton a call.  He makes speakers that can fill a big room and sound very good doing so.  I think he may have a demo pair of his big new Ulfberhts for sale. 

Duke