What process did you use to integrate multiple subwoofers for 2 channel listening?

@audiokinesis Thank you for your questions. A few answers:

* I do not know if the bass bumpage is throughout the room. After a LOT of work yesterday, I got it down to about a pretty narrow peak which is +4db between 79hz and 93 hz with a +6.5db peak at 88 or so. In exchange for all my work knocking down a pretty big peak between 50hz and 80 hz, I wound up with continued/more nulls at 33.5 (-6.5db), 127 (-8db), 208 (-11db), 244 (-11db). These are now my major problems to figure out without retarding the bass progress I made.

* My front ported Salk SS 6M speakers are listed as rolling off at 35hz.

* These Rythmik F12SE subs have a wide range of controls, including variable phase, crossover, gain, low pass switch (50hz/24 vs. AVR12/80hz/24), a "Rumble filter,", Extension filtering switches for Frequence (14, 20, 28hz) and Damping (low, mid, hi). Details about these switches are here: https://www.rythmikaudio.com/download/PEQ3_sealed_quickguide.pdf

* I have a lot of freedom in this room. I did extensive listening, measuring, moving of speakers, etc. in the room and I think LP and Speakers are close to optimized but I’m open to revisiting.

Again, thank you for the questions. I feel like I made progress yesterday - I moved everything, turned and changed dials and knobs, moved treatments around, the works. I was systematic and cautious, changing one thing at a time. I listened at the end of the day and it sounded very satisfying. It’s now those big nulls which are leftover problems I feel compelled to solve.

Any suggestions you make will be experimented with ASAP. I'm a dog on a hunt.

@hilde45

Can you replace your old graph with a new one, and include measurements for the mains only. I think you'll find those nulls (127Hz, 208Hz, 244Hz) will remain unchanged with or without subs. This is where DSP might be of help to you if you're looking for perfection.

Fun stuff. 

@golfnutz Updated -- https://systems.audiogon.com/systems/9064/edit

You're right!

Hi Hilde45,

Just in case it’s not clear, you already have a DBA, which is basically 3 or more subs in a room, as long as they are asymmetrically placed in the room.  Whether they are powered or passive is a matter of preference. As with everything there is pluses and minuses to both. If you want a 4 sub DBA in the future all you need to do is add a 4th powered sub to what you already have. They do not have to match.

Do your main speakers have a port? If they do, I would plug it, I would also set the low pass filters of the subs at the same frequency as the -6 db down point of your mains as a starting point. (Usually the lowest frequency the speaker is rated for) Though plugging the port should effectively raise the -6 db down point. If you have too much frequency overlap between the 3 sub drivers, the low frequency drivers of your mains and the ports of your mains and they are not in phase, you will get a tubby/muddy sound in the overlapping frequencies. Does your REL have a passive radiator? If it does it also could be causing some phasing issues with the Rythmiks. As an experiment I would also try to muffle that by placing something like a pillow under the cabinet and see if you hear a difference.

I do not understand why so many are against adding a crossover between a sub and the main speakers. I don’t think that too many would buy a main speaker that didn’t have a crossover between the low frequency driver and the mid/hi diver(s) but when it comes to adding subs, adding a crossover seems to be seen as the worst thing you could do. Crossovers can be passive or active, analog or digital, with pluses and minuses to each design. IME adding a crossover between subs and mains may have been the most substantial upgrade to my system in regards to sound quality, clarity and performance.