watcher,
Okay, speaker level connections should work well and daisy-chaining from one sub to the next is convenient, too.
When I positioned my four subs, I decided to just follow the suggested procedure and locate the subs to optimize the bass performance in my 23x16x8 foot room that serves as a living/music/HT room. My audio equipment, tv and main speakers are along a 16’ wall with my listening chair about 12’ back from the center of this 16’ wall. I decided my wife and I could then do any necessary furniture rearrangement afterward. Here’s the procedure, based on the ’crawl’ method, that I used to position each of my four subs:
1. Power down system, disconnect speaker wires from main speakers and remove them from the room.
2. Connect Sub#1, power up system, set sub#1’s volume to 50%, crossover frequency to 65 Hz with the phase set at in-phase (’0’) and place it on its back (driver facing the ceiling) at the normal listening position. Play music that has good and repetitive bass.
3. Walk slowly along the perimeter walls of the room, starting at the front right corner of the room and moving in a counter-clockwise direction, listening for the exact spot that the bass sounds best to you; not exaggerated, attenuated or missing bass but detailed, solid, smooth accurate and natural bass. Walk slowly enough and you’ll definitely notice the exact spot it sounds best.
4. Place Sub#1 at the exact position you determined the bass sounded best to you.
5. Connect Sub#2, set sub#2’s volume to 50%, crossover frequency to 65 Hz with the phase set at in-phase (’0’) and place it on its back (driver facing the ceiling) at the normal listening position. Play music again that has good and repetitive bass.
6. Continue to walk slowly along the perimeter walls of the room, starting now at Sub#1 and continue moving in a counter-clockwise direction, listening for the next exact spot that the bass sounds best to you.
7. Place Sub#2 at the exact position you determined the bass sounded best to you.
8. Repeat this procedure for Sub# 3 & 4.
9. Replay the same music with good and repetitive bass, sit in the designated listening seat and verify the bass does not sound exaggerated, attenuated or missing and that the bass does sound detailed, solid, smooth, accurate and natural.
10. If it does not, repeat steps 1-9. If it does, reinstall your JBL speakers, ideally on the floor or on custom stands and about 3-4’ away from the front 16’ wall. Obtain an assistant and proceed to the 4-sub Custom DBA Configuration and Seamless Main Speakers Integration Procedures.
Following this procedure in my room with the Swarm subs, it resulted in two subs located along the front 16’ wall, with sub#1 located 2’ away from the right corner and sub#2 located 2’ away from the left corner. The other two subs sounded best toward the rear of my room with sub#3 along the left 23’ wall and sub#4 along the right 23’ wall, both about 2’ away from the nearest rear corners formed by the 16’ rear wall.
I’m not suggesting you save some time by just positioning yours like mine. I’m suggesting that you follow the same subs positioning procedure and that your subs are likely to sound best in a similar distribution pattern. Your room is the same 16’ width and rectangular shape as mine but it’s 7’ longer and I’m uncertain if your ceiling height is similar to my 8’ ceiling. In any case, there are enough differences that your subs may sound best in somewhat different positions; perhaps with only one sub along the front 16’ wall and the remaining subs in different positions along your 30’ side walls and even one or more along your rear 16’ wall.
I’m just not sure where they’ll ultimately be positioned for best performance. I suggest you just trust and follow the procedure, position each in sequence exactly where it sounds best and everything will probably work out fine.
I was also mentioning the overall distribution pattern of my four subs to give you an example to plan how you’d be wiring and connecting your four subs. I think the speaker level connections and daisy-chaining capability will work well. You just need to determine exactly how you’d prefer to distribute the two shorter SB subs and two taller PB subs. Unfortunately, I have a lack of knowledge and experience concerning how best to deploy two sealed subs (with rated bass extension down to 24 Hz) and two ported subs (with rated bass extension down to 19 Hz) for best overall performance. Theoretically, I believe it should not make a significant difference but you’re the only scientist among us that’s currently capable of carrying out the required scientific experiments to obtain the empirical but very personal and subjective results. If you have a preference doctor, even if it’s based on the trivial idea of having the taller PB subs being located in certain areas near the seating and doubling as end tables, I’d suggest that’s a good layout variable to begin your experimentation with.
I also strongly suggest you invest in a good pair of speaker stands for your JBL 4319 main speakers and positioning them at least 2-4 feet away from the 16’ wall behind them. You can thank me later and I saw several suitable pairs starting at $85 by searching for "speaker stands" on eBay.
I’ll post the 4-sub Custom DBA Configuration and Seamless Main Speakers Integration Procedures once you complete the subs positioning phase of this project.
Later,
Tim
