[falconcry]

Falconcry, I am a little unclear of what the SVS website is saying concerning the Dual SVS PC12-NSD sub-woofers.
Is the price on the website the cost for two subs or one sub? If it is for two subs than it appears to be a bargain.
Scotty

Yep, the dual price, $1399, is for (2), which is a $100 discount off buying (2) singles at $749 a piece. Actually, they'll give you an even larger discount if you buy a quad (4). Then the total is about 2700, or 675 a piece. I'm thinking about splitting a quad with my dad...

[TRADERXFAN]

Svs is easy to recommend for simple solutions.

However, if you have space for it, take a look at Chase home theater offerings. 
For example
https://www.chasehometheater.com/index.php?page=shop.product_details&category_id=29&flypage=flypage.tpl&product_id=668&option=com_virtuemart&Itemid=135&redirected=1&Itemid=135

I use two of their 18.2 subs in my HT with dayton 1000 amp and dcx2496. More than enough for my tastes.   

If you consider external amplification, think about an Inuke with DSP sub amp. There is  built in dsp eq capability and lots of power... once you remedy room mode cancellation/reverberation problems which aren't really effected by EQ.

I would say go for TWO subs rather than one, of any kind, to give you better chance to smooth it out.  But this is more complicated and most folks are not willing to expend energy with it...

[TRADERXFAN]

Sorry, I didn't read OP as carefully as I should, you already are looking to get 2.

For chase products, and sub 20hz performance. check the 18.1s. 2 of those are small enough, and will have extended shallow roll off, being sealed. This is assuming you would get inuke 3000dsp for approx <$400, its 1400 package + shipping.

DSP  control is required on this speaker to boost the lower end for this. I wouldn't like mine without this turned on. If you don't want to get some form of eq, then this is not for you.  Then I would say get svs...

Edit
well haven't been looking at svs in a while, and it appears prices have gone up quite a bit since I bought mine.  I don't see how you can really get the sub 20hz output with them at this price point, in pairs.

2nd edit:
I bought the pair of subs along with 7 speakers as a package. I tried out one sub with the dayton when it arrived, before I built the HT,  and it was very powerful.

One 18.2 is equal to two 18.1s...  The two 18.2 is complete overkill and I use very little of the capability, the 2nd one provides smoothing, so I keep it.

And you could definitely mix your subs for  smoothing.  The 2nd sub could be for "fill" where its output/capability  is relatively lower than the primary sub. Look up thread on Geddes multisub for his approach in this way, for more info...
So this approach you would spend money on getting a deep high output primary "corner" sub, but not much on filler sub. But filler needs to be clean and probably downfiring/bandpass if it is going to sit close to you for integration purposes.

[falconcry]

...well haven't been looking at svs in a while...I don't see how you can really get the sub 20hz output with them at this price point, in pairs.

The PC12-NSD I recommended will definitely get you nice sub 20hz output. Quasi-anechoically, it's down 5db at 18hz, and down 10db at about 15hz. In-room response would be even better. A pair is 1399 delivered.

[TRADERXFAN]

If it was tuned to say 16hz I would feel more comfortable with the ported options. But this sub does concern me, if he wants high output at sub 20hz frequency...

limitations of vented subs (from wikipedia)...
"Another trade-off for this augmentation is that, at frequencies below 'tuning', the port unloads the cone and allows it to move much as if the speaker were not in an enclosure at all. This means the speaker can be driven past safe mechanical limits at frequencies below the tuning frequency with much less power than in an equivalently sized sealed enclosure. For this reason, high-powered systems using a bass reflex design are often protected by a filter that removes signals below a certain frequency."

Then at high spl, there is effect of port compression.

For these reasons, I don't expect to drive vented subs below the tuning point and therefore believe it is prudent to go sealed if  possible for deeper extension. But there are always tradeoffs/constraints that come into play. 

--Not saying that this wouldn't be good performer, just think if the goals are really high output at sub 20hz, there may be better choices

[Rclark]

.. 4 sealed 15's....

[TRADERXFAN]

probably would help the guy if you were a bit more specific...

[pearsall001]

I'd add one of these DSPeaker Anti-Mode 's to your existing sub to control your room before adding another sub. They are rather inexpensive ($395 new, about $300 used). You will be amazed at the before & after effect, you just might rethink picking up another sub. But if you do you'll still want to correct your room for maximum bass. They are really little gems!!! Easy as pie to set up & use, no computer or fancy graphs needed. I won't run another sub without one.

http://www.dspeaker.com/en/products/anti-mode-8033.shtml

[Rclark]

probably would help the guy if you were a bit more specific...

you should read page 1.

[TRADERXFAN]

So are you just repeating yourself about the sold out Epik subs with no ETA?
 
-They also look like a good option if they get put back in stock... but they say price is going up.

[medium jim]

So are you just repeating yourself about the sold out Epik subs with no ETA?
 
-They also look like a good option if they get put back in stock... but they say price is going up.

He tends to do that...

Jim

[Rclark]

^ huh?

Anyway TFan, I don't think the price is going up, I think they will perpetually be intro price. I talked to Chad on the phone a few months ago.

[TRADERXFAN]

 year old used pair 18.1s, with the dayton sa1000 amp, offered for 1k
https://www.chasehometheater.com/forum/showthread.php?t=5447

[kevinh]

Buy 3 $500 subs and deploy them as per E Geddes.

Like these:

http://www.svsound.com/subwoofers/sealed-box/sb-1000#.URhv8h0T18E