Best sub for VA Mahlers

I'm building a HT.
I have Vienna Acoustics Mahlers, Oratorio & 4 Waltz's for 7.1.
I need the .1.
The room is not enclosed which results in nearly 8400 cubic feet. Immediate listening area is 3400cu.ft.
I am considering REL Stentor, VeloHGS18, AerialSW12, Revel and (get ready) SVS B4+.
Can anyone recommend the best match?
Budget for sub is $5k.
Do you really need a sub with the Mahlers?
They do go pretty darn low (22hz or so).

Let us know what other electronics you have.


It would have to be at least the REL Stentor, because any smaller REL would not go much lower.

Is there a Tweeter, Etc. store in your area. They sell both Vienna's and REL's

You could maybe have Tweeter demo them for you. Just keep in mind that a lot of Tweeter salesperson's will very likely be a little clueless.
It's a virtual guarantee that the salesperson at Tweeter will be clueless! The last one I encountered never heard of Linn, Meridian, Chord or even Arcam! I'm sure some exceptions occur. Buying anything from Tweeter/Ultimate Electronics/similar chain stores is GIGANTIC mistake. When enough people do it, high end audio will cease to exist. If you are setting up a purely HT system and aren't listening to music, almost any larger subwoofer will be adequate for room shaking duties. I suspect that if your subwoofer budget is $5,000 you can afford to trade with an audio dealer who can offer meaningful advice a properly demo equipment for you.
Tweeter is clueless. They require half down just to order the REL. None in stock. Yes I listen to a lot of music.
In Charlotte NC there are no boutiques left.
Would 2 stadiums be better than 1 stentor?
I demo'd the Mahlers with a REL Storm III, but the Mahlers did not need the sub. When the dealer turned off the REL, the speakers still had plenty of low bass and sounded fantastic. If you need a sub for HT, get a pair of Storm III's.
I agree with Sugarbrie,

You are going to need to go with a Stentor to get more solid bass than you are currently getting.

I've heard that ONLY a Stentor (or 2) will improve on the Mahler's bass. That says a lot about the Mahlers' bass.