Finally going to dive in and get a decent system for my home. The system will service a large multi-use room 21' wide, 44' long and 11' tall, that's 10,164 cubic feet, yikes! Keep in mind the first 1/3 of the room is for viewing/listening with the screen on the 21' wall and your back to the remaining 2/3 of the room.
One thing I've learned is that if you do already have a non-dedicated room in place, you need to have a reasonable budget (like $700-$1500 even) to get things setup right. "Simple" things like wire, measurement mics, mounts, bass traps, absorption, diffraction etc can pile up quickly. You may even want to lower your speaker budget with this in mind. If the room isn't in place you can plan it more properly once you've got some speakers. And honestly what you described does not sound all that great for acoustics. You may want to consider a bit more compromise if you wanna get this right.
I've choosen Onkyo TX-NR808 in the $1K range to power the system, good choice?
Not a poor choice necessarily but it is aa receiver. This can limit your choice in speakers to nominal 6 and 8 ohm loads. If the speaker is a nominal 4 ohm load or even worse has very low and sharp dips in its impedance response, you may find that getting a cheap (refurb) receiver IE Marantz SR5005(or 3 if HDMI 1.3 is enough) and pairing it with an affordable external 2, 3, 5, or even 7 channel amp (Emotiva has some options for you) will give you a comfort level and flexibility.
Considering SVS and Hsu to serve up the low frequency duties.
Both very nice choices... also consider options offered by Seaton Sound, Emotiva, JTR Speakers, Rythmik, Danley Sound Labs, Epik, and Funkywaves. I recommend holding off until Audioholics posts the subwoofer shootout which I think can really help you in your decision.
Because of the size of the room considering dual subs and, due to room configuration/wife factor, the subs will need to be placed along the viewing wall.
That's unfortunate, as that will likely take away the benefits of multiple subwoofers if you're placement limited like that. I'd even recommend triple or quad subs instead of dual! And of course integrating multiple subwoofers together is a notable budget investment as well.
Loud is not necessarily better for the bass. Accuracy is more important as the system will serve for some critcal listening when I can push the kids out from watching Blue-rays.
Accuracy is an interesting thing with bass.
A few things we have to consider:
1) Getting flat in-room bass response is difficult as it is. You can have the most so-called accurate subwoofers but if you're going to limit your placement you're likely going to end up with listening position nulls. Then you have to consider coupling. If the room is sufficiently large, you want to stay away from sealed subwoofers as they won't get sufficient low end gain. Likewise if a room is small enough, you want to avoid a sub that's flat down to 20hz or below... that will cause a rising low end response once room gain factors in. So you have to find the right balance for your specific room. EQ certainly helps in this regard but keep in mind that any time you EQ up, you're reducing useable headroom. EQ is best in order to tame room response peaks.
2) You may have a preconception that a smaller sub will be more accurate but that couldn't be further from the truth - at least within an ordinary subwoofer's passband - which we can usually imagine as something like (cough12cough)20hz to 160hz(where it would probably be 24db down). It's a lot about distortion and with subs, bigger subs (both driver and box) generally (but not necessarily) will produce less distortion. Obviously motor linearity is a very important factor but the reality is that a 15" driver example will more easily reproduce a 20hz tone than a 10" driver. The latter sub will require more exursion (which causes distortion), more power at lower frequences where it'll likely be less efficient( and thus heat which can = distortion) in order to move the same amount of air. So in a sense, a speaker that can "louder" (properly) should sound cleaner than a speaker that can't. The word "effortless" is something we all strive for.
3) Factoring in dynamic range. Maybe you like to listen at 75db. Not ear bleedingly loud but a reasonable listening volume. Let's say there's content within whatever you're listening to that DOES want to be loud - let's say something 25db hotter than what you're listening to is in the content. If you sub is limited in output and can't get as loud as the signal wants then what you'll find is that you're limited in reproducing the signal properly. You can't call that accurate.
4) How low do you want to go? Do you a sub that can reproduce infrasonics down to 12 hz(the lower limit of human "feeling")? Do you just want a sub that can hit 30hz without bottoming? Can you call it accuracy if your sub is "hiding" lower end information from you? At the very least, clean reproduction down to 20hz is usually important as that's roughly the lower end of human hearing. In order to do this you usually need a high mass, high excursion driver. Luckily these drivers also tend to have more cone surface area, and thus can get louder as a result! Keep in mind that movies can have content as low as 14hz! This is infrasonic bass and is "felt" not "heard". Do you consider it accurate if your subs are hiding this information from you? Or is it are only "audible" bass frequencies important?
So with all of the above: loud isn't
necessarily going to take away accuracy from you. It may in fact give you better perceived accuracy, as many who've dabbled in horn loaded subs just for example have noticed they sound cleaner than direct radiators (when EQed properly).
I'm not saying get the loudest possible sub, nor am I saying to get the sub with the lowest tuning frequency (okay maybe I am saying to get a few 21" Maelstroms tuned to 9hz >_>;;; ) - I'm saying that subs need a lot in order to be accurate and you need to make your decision carefully and accordingly.
To conclude, I think you need to hold on a sec, really examine the room, examine your goals, examine your budget, and then splurge! Do a lot more reading. A nice place to start is.. right here! Audioholics has quite a few very useful articles. If you're spending the money, you may as well do the research necessary - and that doesn't just mean reading reviews of products!
http://www.audioholics.com/education
Now regarding speaker recommendations - what do I recommend based on what I DO know?
Maybe see if you sqeeze together the following?
Receiver: 1 x Marantz SR5005 B-stock from accessories4less (550 when they've got em in stock... otherwise go with an SR5003 or 4 as HDMI 1.4 doesn't have too much to offer but that's your call)
Amp: 1 x Emotiva XPA-3 ($699, sometimes on sale though)
L/R/C Mains - 3x Emotiva ERM-6.3 LCR (Total: $1800)
Surrounds - Behringer (Total: cheap enough)
Subs - 2 x JTR Captivator Passive ( $2400)
Sub Amp - 1 x Behringer EP4000 (~400)
Sub EQ - Behringer DCX
Measurement Mic - Dayton Omnimic
Wire - Monoprice.com
Acoustic panels - GIK acoustics and atsa acoustics. DIY absorption if you can and get diffraction for sure. Also recommend heavy draping over any windows. If the floor is bare then get a rug at least. And move your seating position a bit further back, move the speakers a bit far out from wall. etc.
Yes, I do recommend monopole surrounds. Whether you need 7.1 or not is a bit tougher and I'd save that decision for after you've got other things paid for. FWIW Emotiva does make a great dipole surround if that's what you decide on. If I blew your budget out of the water, I'm sorry. I'm just evil.
