What are considered to be the best Subwoofers for 2 channel music only ?

I think there are lot's of good to very good subs.  Folks need to figure out what they can even bring into their rooms due to looks, some not so pretty boxes, larger etc...  

I also feel that there is a lack of coherency with most sub set ups.  I personally like a full range speaker where they can share an octave of sound to cross over.  For whatever reason, these seem to be the most seamless set ups I've heard over time (nothing is absolute).  Most monitors/sub combo's have left me cold.  JMHO

What AK says about using 4 subs makes sense on paper.  For most, they can't put those subs in a room.  Even if you do, you still need to put them where they sound best in the room and it's hard to do if it's not a dedicated room.  

IF you get better subs than the AK's, you can do the same 4 unit set up adn get better sound.  I LOVE what Vandersteen does with his Sub 3's (all his subs) using the analog EQ (no digital nasties).  What I've found using his subs are the best in room bass I've ever experienced in my house.

I agree with mijostyn.  As for me saying 'on paper', I was just pointing out he has a white paper on it.  I agreed with what he come up with, but I also know that his actual subs are not at the same quality as most if not all the subs we are discussing here.  

I have heard the Vandy subs in a 4 array and with the EQ, it's even easier to dial things in.  Bottom line is that there are some very good options.  In my room, I can't/won't fit 4 subs as I don't have the room.  I had no problem setting up my active subs using the EQ and a Radio Shack meter.  

Others swear by the REL or other subs.  The biggest thing is trying to integrate them into the main speakers. 

Also, you mentioned 'real world' and I agree. Vandersteen also voices his speakers in his living room, because it's a real world situation.  

As I stated, I agree with your principle about using 4 subs.  
I didn't feel I was slamming you at all.  What I was looking at are subs that cost more than yours after looking online to see prices, so that's probably not fair.  I have heard your system a few years back and liked it a lot, but I do feel that the Vandy sub 3 or the REL are using better quality drivers and internal components.  You will pay more of course, but that's my perception based on what I have seen and heard over the years.  

I'm sorry if you take that as slamming your product, but it's not what I'm trying to do.  For the price, it's a very good value and I've even stated that to friends and on other forums.  
Thanks Pete

Guys, we all often use the incorrect words when typing on forums. I live on OU sports forums as well as about 10 audio ones. Having MS, I do have cognitive issues that are very real. It's why I cant work anymore (13 years this week I came down with transverse myelitis and MS. I'm one of only 2000 world wide with both and am part of a study at National Institute of Health in Bethesda MD.  It's the top research center in the world and works closely with all the top places in the world).  I am a retired Naval Commander and was an Executive Recruiter prior to getting these diseases.  This is why I am on boards as I can't leave the house on many days.  No pitty party please.  

As I told Duke, I wish I could hear his subs in my system, but that's not happening anytime soon, lol.  It's all good and I will never hide behind a moniker.  Back to the real discussion.  Pete

You'd really need to ask the dealer or designer that question as all systems are a bit different. I know with Vandy's, they use crossovers etc... but I would think that any of them are very easy to set up for four.