The biggest issue you're going to face is your subwoofer. You say that you have a large, open room, so filling that space with enough sound pressure is going to be the biggest challenge. You're also going to want efficient speakers, but that is less of a challenge.
Ideally, you'd be going for something like the Rythmik FV15HP or SVSound PB12-Plus. These are the sorts of subwoofers that can output extremely loud bass that also truly plumbs the 20Hz depths of any soundtrack, but still maintain very good control with tight transients and realtively low distortion. Of course, these sorts of subs also cost in the $1200-$1400 range. And to make matters even worse, both Rythmik and SVSound are currently back-ordered on these models as they await large incoming containers from China.
Given your budget, you might not want to spend more than half on the subwoofer alone. The Rythmik FV15 can't quite match the output of its twice-as-powerful FV15HP brother, but at least it's in stock and goes for $1000. If you're ok with a tall-ish cylinder rather than a big box as the shape of your subwoofer, then there's SVSound's PC12-NSD DSP, which at only $700 is easily your most budget-friendly choice and the biggest bang-for-buck choice out there! I would strongly favor the SVSound PC12-NSD DSP in your case, but its cylinder shape and black carpet exterior aren't everyone's cup of tea, so I would understand some possible complaints from the decor committee
If you're more comfortable with the big box shape for a sub and you want to stick closer to the $700 price range, then the HSU Research VTF-3 MK3 would be another good option. HSU's VTF subs are tuned a little higher. If you go for lots of output (which you'll likely need in your large, open room), then you can expect the really deep bass to roll-off below 30Hz or so. You can opt to plug one port and lower the overall output in favor of flatter response to a lower frequency. But going super low AND super loud isn't really HSU's forte.
So anywho, that's the sub. Regardless of which subwoofer you choose, please be sure to decouple your subwoofer from the floor. All of these subs that I've suggested produce physical vibrations. If they are in direct contact with the floor (even a concrete floor...concrete is NOT inert...it moves!), the vibrations of the subwoofer are transmitted into the floor. This becomes structure-borne sound transmission and it is the reason why you can so easily hear bass thumping away in other rooms, even when you cannot hear the higher frequencies. When you decouple your subwoofer from the floor, you greatly reduce this structure-borne sound transmission. The biggest benefit is that you greatly reduce the unwanted bass that is heard in other rooms. Obviously, this means happier significant others and happier neighbors! There is also an audible benefit inside your theater. By greatly reducing the physical shaking of your room, you cut down on rattles, audible vibrations and an additional source of distortion and soundwave interference.
The devices I recommend for decoupling are the Auralex GRAMMA and Auralex Great GRAMMA. The GRAMMA is a 15" x 23" platform that sells for $50. The Great GRAMMA is a larger 19" x 30" platform that sells for $80. And if you get a really big sub, you can always just use two of the regular GRAMMA risers to create a 23" x 30" platform for $100. There is also the Auralex SubDude, which is a square 15" x 15" platform that sells for $50 also (the SubDude works perfectly under the SVSound cylinder PC12-NSD DSP subwoofer).
So with a subwoofer, shipping and a GRAMMA or Great GRAMMA, you're looking at about $850 - $900 as your least expensive recommendation from me, and as high as $1550 if you were to wait for a back-order on the SVSound PB12-Plus with flat rate shipping and an Auralex Great GRAMMA.
So I'm going to just use some rough math and figure that you'll have somewhere around $1000 for your 5 speakers. You're using a good, but not hugely powerful receiver and you've got a large room, so the focus should be on efficiency and high output with low distortion.
I certainly don't mind the Axiom speakers as an option. The QS8 surrounds, in particular, are a real treat IMO. The new v3 tweeter is also a star - I've been extremely impressed with it. It has higher output, wider dispersion and better imaging than the previous v2 and Ti tweeters and it gets closer in performance to some of the really expensive Beryllium tweeters that are personal favorites of mine.
My only quibble is that I'm really not a fan of Axiom's center speakers, except for the VP180, which is HUGE and expensive and huge (and did I mention huge?). The VP180 is awesome, but it won't fit within your budget, nor would it make any sense to have a center speaker of that size and price in amongst a much smaller and less expensive system overall. Don't get me wrong, I think the VP180 is completely worth the money if it fits within your budget and listening setup. But I just think it wouldn't really fit in in this particular case.
I just can't give my recommendation to the VP100 or VP150. They present a different timbre and tone vs any of the Axiom bookshelf speakers and that leads to one of my worst pet peeves in audio where the sound audibly changes as a sound pans across the front from left-to-center-to-right or vice versa.
There are a couple of solutions:
- if you can make a vertical bookshelf speaker fit within the looks and space that you have for it, then something like three identical M3v3 Axiom speakers across the front would be superb! I actually prefer the M3v3 over the M22v3 when it is used as a front speaker in a surround sound setup. A pair of M22v3 mated with a subwoofer for music alone in a 2.1 setup is something that I would consider. But for a 5.1 system, I would personally opt for 3 M3v3 across the front any day! The M3v3 is not so tall that it would look extremely strange when used vertically as a center speaker. This really would be the best way to go in terms of audio quality. And it would fit nicely within your budget!
So I would recommend:
3 Axiom Audio M3v3 bookshelf speakers (for Front L/C/R)
1 Pair Axiom QS8 Surrounds
That's $1026 shipped (you still get the 5% discount because it's 5 items)
If you need the smallest footprint and don't mind a fairly tall, black carpet exterior cylinder, go for the SVSound PC12-NSD DSP with an Auralex SubDude...shipped, that's going to be about $850
If you can't stand a cylinder and don't mind a BIG black box instead, I think the winner right now will be the Rythmik FV15, which will fit nicely on an Auralex Great GRAMMA...shipped, you're looking at about $1220.
Hope that helps!
