Choosing Sub-woofers. Please advise ASAP.

Hi Dave,

     Thanks for the explanation.

     The method you used, playing the sub at your listening position and then walking (squatting) around the room to find the spot where the bass sounds best and then locating the sub to that spot, is the exact same method in the distributed bass array system procedure that I used to place my first sub.

      Doing it again for the 2nd sub placement, while the optimally placed 1st sub is playing, is also the step#2 that I followed.

     However, I disagree with your statement : " You can certainly compromise for a good "all-around" placement but it will only perform optimally in one location in your room for a given listening position."

     I think you're correct if only 2 subs are utilized in the room.  The DBSA (distributed bass array system)'s use of 4 subs in a given room is the key and I found it has the remarkable and empirically proven affect of eliminating all bass standing waves in a given room.  The result is optimal bass response evenly distributed throughout the entire room.  

     The only reason your good bass is limited to a single optimum listening spot is because you stopped halfway through setting up a DBAS in your room.  I am reasonably certain that adding 2 more subs, following the exact same positioning method you used for sub# 1 and 2, will result in the very good bass response, that you're now enjoying only at a single optimal listening position, expanded to every possible listening position in your room. 

     I'm a huge advocate of the DBAS only because I use it and know how amazingly well it works.  It is a system developed by 2 PHDs in Acoustical Engineering, Dr. Gettis and Dr. O'toole, that is based on math and physics and been scientifically and independently proven to be effective numerous times in various rooms.  

     Their published White Papers on their research and experimental results state that as the number of sources of bass wave propagation (subs) in any given room increases,   the number of standing bass waves in the room decreases.  They mention their realization that there is a practical limit to the number of acceptable subs in any residential or commercial space.  

      In a crucial statement about their findings as it relates to home and commercial usage, they also stated that they discovered that a minimum of 4 sources of bass wave propagation (subs) are required to eliminate the vast majority of bass standing waves in any room tested in their research results with any additional subs only resulting in marginal improvements.  This is the reason  most DBAS utilize 4 subs.

     My opinion is that the above is critical information for the original OP, sautan904, to consider when setting up his new system. I'm not sure whether he understands  the info, believes it  or has just chosen to ignore it, however, since he has opted to go with just 2 subs.  My concern is that he doesn't realize the results are completely predictable and inevitable regardless of your room dimensions.  

      When he discovers his 2  sub system results in numerous bass standing waves and resultant uneven bass response in his room, the good news is it'll still be solvable by an extra couple of subs.  

Tim    

Nice to know Tim. Nothing like being set up by someone with an agenda to push posing as a real person with genuine interest in learning. Shoulda known.

I only listen from one position as I am only one person at any given point in time. As for having four subs, I am probably already in the extreme at having two. I am sure there are a few audiophiles that are able to overcome the expense and freedom from real-life constraints (WAF and such) that can or will take advantage of your recommendations. Bet you can count them on your fingers.

You can stop trying to solve the issue for the OP as he went a different direction. One more finger in reserve. Keep counting.

Dave

Dave,

     You stated:" Nice to know Tim. Nothing like being set up by someone with an agenda to push posing as a real person. Shoulda known."

    My wife has often accused me of 'posing as a real person' but I didn't expect this from you!

     I'm such a big fan of DBAS that I've probably seemed a bit too enthusiastic to some readers.  I actually can understand how some may question my agenda.   My only 'agenda' is spreading the word on DBAS due to its extraordinary effectiveness in generating great  bass performance in any room due to its ability to eliminate bass standing waves without the need for ANY of the usual expensive but comparatively ineffective tools such as bass traps, room analyzing microphones, room analyzing software, bass compensating software or bass compensating equalization.

     However, I can assure you I have absolutely no financial association in the manufacture or sales of distributed bass array systems. After many phone calls and emails communicating with James Romeyn, the owner of James Romeyn- Music and Audio LLC in Utah where I purchased my DEBRA DBAS, I do consider him a friend but there are absolutely no business agreements or arrangements between us.  


Dave, you stated: " I only listen from one position as I am only one person at any given point in time. As for having four subs, I am probably already in the extreme at having two. I am sure there are a few audiophiles that are able to overcome the expense and freedom from real-life constraints (WAF and such) that can or will take advantage of your recommendations. Bet you can count them on your fingers.   You can stop trying to solve the issue for the OP as he went a different direction. One more finger in reserve..".
 

     I understand the OP decided to use 2 JL F112-V2 subs in his system.  For current and future readers of this thread, however,  I'm going to list the main reasons I believe this was not a good choice for many who are considering the best choice for low bass performance in their rooms and also to refute some of your comments in your quote above.:

1.  PERFORMANCE-

     I know the JL F112-V2 are very good subs. My issue is not with the quality of the subs the OP chose but the quantity of subs and their positioning.  As I've stated multiple times on this thread, it has been scientifically proven that 4 subs setup in the distributed bass array system method is the best solution discovered thus far at eliminating bass standing waves in any room regardless of the room's size and dimensions. This results in very good bass response  that is accurate, smooth, extended and these qualities are consistent throughout the entire room.  

The JL F112-V2 manual also recommends the use of 4 subs for best results.  Here is the exact quote:

" Research indicates that the smoothest bass response for a large listening area can be achieved using four subwoofers, placing one at the midpoint of each of the four walls (although using two or three subwoofers can be almost as good) "

     This quote is accurate with the exceptions  of the positioning recommendation and that 'using two or three subs can be almost as good".  .  The JL positioning  method is rather rigid and may not work in every room.  The distributed bass array method is much more specific and is customized to each  room.
     I am not aware of any scientific proof that two or three subs perform almost as well as 4 subs at reducing bass standing waves.  I'm  not stating this statement is false, just that I'm currently unaware of any scientific verification.of this statement.

     To be fair and honest, I think 4 JL F112-V2 subs would likely outperform 4 Audio Kinesis subs (probably in deeper bass extension) if both were positioned using the same distributed bass array method.

   However, using just 2 JL F112-V2 subs could possibly sound good at 1 listening position if both subs are positioned using the distributed bass array system procedure with the listening position treated as the reference position  But this will also unavoidably result in multiple bass standing waves at numerous other spots in the room that will cause bass perception at these positions to be exaggerated(peaks), diminished (dips or nulls)or even non-existent(cancellations).  Not a problem in your situation but is much more important to many others.

     

2. WAF-

     We all know this is variable by user dependent on the quality and nature  of your 'W'.  My opinion is that most wives would be more amenable to the look, size and discreetness of the Audio Kinesis subs than the JL subs. Here are some facts and I'll let each reader decide based on their own W's likely reaction:

Each JL F112-V2 weighs 117 lbs. and is 15.1"W x18.5"H x17.8"D
Each Audio Kenisis weighs 67 lbs.and is 14.5"W x 23.75"H x 10.375"D

JL F112-V2, I believe, is only available in black gloss finish
Audio Kinesis subs are available in a wide variety of wood finishes

My opinion is that the Audio Kinesis subs, being smaller and available in numerous wood finishes, would be considered by most wives to be more discreet than the larger and gloss black JL subs

     After following the progressive setup procedure, my front 2 subs sounded best located along the front 16' wide wall of my 23' long by 16' wide living room.  Each front sub is located about 1' away from each side wall, hidden from view by a 6' high by 2' wide Magnepan panel speaker that is positioned about 3' in front of each sub and also 1' away from each side wall.  From my listening chair located in the middle of the back 16' short wall  opposite  the front, both front subs are completely hidden from view.
     Sub#3 sounded best along the 23' long left wall about 1' away from the back wall.  Sub#4  sounded best along the right 23' wall about 1' away from the back wall.  Sub#3 is hidden from view by a large leather recliner and sub#4 is hidden from view by a large wooden end table that is between sub#4 and my listening chair.  Overall, the 4 subs do not call attention to themselves and, therefore,  very discreet.
     
  .  

3. PRICE/VALUE-
     . 

The complete Audio Kinesis DEBRA system(:4 subs and a 950W amp) is priced at $2,990.

 The mrsp of 4 JL F112-V2 subs(optimal performance according to JL) is $14,800, although a buyer buying 4 would likely to get a significantly reduced price of I would estimate at about $12,000. The OP would be very fortunate to have struck a deal for 2 JL F112-V2 subs for twice the price of the Audio Kinesis system. Clearly, using 2-4 of the JL subs is significantly more expensive. than the Audio Kineses complete system.

     I would think more than a handful of audiophiles would be interested in a bass system solution that outperforms 2 high quality subs, has a higher WAF and costs thousands less.

" One more finger in reserve.."?

Later,
Tim  

 


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      . 

"One more finger in reserve.."?"

Meaning that the OP went with a different solution, not the middle finder salute. :)

I am sure that you have discovered something of merit, Tim. If anyone will listen, that's another matter. IME, doesn't help to oversell.

Dave

Dave,

"One more finger in reserve.."?"

    Cool.  Thanks for clarifying.

     I just wanted to put my thoughts down.  I know I have no control over what readers do with the info I give and that's fine with me.

     I think I'm just still a bit amped up on how well this system works for music and HT that I'm a bit too anxious to share the knowledge.

      I keep thinking my excitement of how well it works
will wear off.  But I've now had the bass system for about a year and it still makes me smile every time I listen.

Thanks,
  Tim