Best type of Sub to consider?

I'm not looking for a brand or model recommendation at this time, but rather the best type of sub to fit my room and system. If you access my System pics, you will see that I have open corners behind my speakers and that my Horning speakers are rear ported. This has caused some energy loss, especially in the bass when compared to my previous setup in my other home.

I am a newbie to subs and see different design types that fire up, down, up and down, and forward. There may be other variations. So, does any of this matter when applying the best design type to a room, my room? My knee-jerk reaction is to go with forward firing in my situation, but that's complete speculation on my part, so why I'm asking.
What's interesting, is that the four woofers per Horning speaker in my system are in push-pull configuration and rear ported. I'm not sure if this is an isobaric design or not, but the bass can be excellent when set up properly. I've heard an almost identical system as mine at another audiophiles home with closed corners and careful setup, and the bass was wonderful.

l'm hoping to retain the extra detail that I've acquired, by the setup of my current system, plus reinforce the bass to the level that I've heard in that other system. That would do it for me.

My experience is the best Isobaric setup is a sealed (no port ala Linn Isobaric speaker)), but the box then needs to be bigger to get the lowest frequencies.

Cheers George

Hey bdp24- 

For discussion purposes I'd like to point out if a person was so inclined to run 4 dual 12" servo driven OB subs in the H frames like mentioned. Just how great this set up naturally circumvents the need for room correction or EQ measures and that multiple subs self cancel standing waves quite nicely on top of all the other plus's. A person would have quite a mighty system for music or movies. I'll also mention for the cost of 4 dual 12" with the amps etc. being around what $3600 maybe. (not sure how much flat pack H frames run) but WOW is all I can say. If I were to do this from scratch realizing my room is 23X19'-6" and my IC's are would be well over 10' long, I'd opt for the balanced version in the amps (XLR) inputs and outputs. It's like $20 per XLR too reduce noise. 

Actually jwt, a pair of the OB/Dipole Sub kits is $1500 shipped, and a pair of the H-Frame flat packs is $600 I believe (I got in on the first few sets made at an introductory price). So it’s about $2100 for a pair of the OB/Dipole Subs and really good H-Frames, CNC cut from 1.5" thick MDF! All that’s left is finishing the frames, paint or veneer. Each sub contains a pair of 12" Servo-Feedback controlled woofers facing in opposite directions (they don’t have to be, but doing so creates a couple of benefits), and the Rythmik plate amp with a dipole cancellation compensation shelf to counterbalance the acoustic roll-off inherent in dipole speakers. The amp is available in a couple of different configurations, one being balanced/XLR in and out. One band PEQ is provided, as are high pass and low pass frequency and slope adjustments, three levels of electrical damping, and, most importantly, a 0-15ms Phase Control. Do NOT buy a sub without continuously variable phase adjustment. A 0/180 switch is worthless, and that’s exactly what most subs have. This sub is made specifically for music reproduction, being optimized for sound QUALITY, gladly sacrificing maximum sound quantity to get it. The output of a pair of the OB/Dipole subs is about equal to a single sealed Rythmik. Are you willing to give up 3dB in output to obtain the OB/Dipole sound quality? I was.

In addition to the lack of sealed or ported enclosure resonances, an OB/Dipole sub creates cleaner bass also because it excites only the room mode of the dimension it’s front and back faces. If you fire it down the length of your room, the room modes of the width of the room are NOT engaged---the null created to each side of the sub prevents it. So elegant!

The sub is absolutely and without question the best sub in the world for any and all planar loudspeakers. Not only does it’s Open Baffle design and construction provide the same advantages (and liabilities) as does the non-box design of planar speakers, but it’s dipole acoustical properties and behavior matches that of planars, unlike ANY box sub in the world. The acoustical output of dipoles drops off at only half the rate of boxed speakers; if you balance your speakers and box subs at one listening distance, that balance is different at a different listening distance, and in all other parts of the room. Not so with the OB/Dipole Sub, as it shares with OB and dipole speakers (which is what planars are, of course) the exact same acoustic SPL drop-off with distance rate. Again, elegant!

And I haven’t even brought up the benefits of the Rythmik Direct Servo-Feedback system, designed and patented by Rythmik owner Brian Ding. Not just another servo design, but a new, better one. You think the servo-feedback woofers in the Infinity IRS were clean? Wait until you hear this sub! It’s sound has been described as "stops on a dime". It's the only sub I've found that isn't embarrassed by my Magneplanar Tympani T-IV bass panels. NO overhang, no boom, no bloat. The Rythmik Audio/GR Research OB/Dipole Sub---the only Servo-Feedback OB/Dipole Subwoofer in the world!

Kennythekey, nice setup. I have Casta model C's which are 98 efficient with custom horns(midrange and tweeter) with 15" bass drivers in a sealed cabinet. Crazy sound comes out of these. Then I purchased a Rel G1 and I run it high pass to my Audiozen Noah dual mono amplifier. Simply stunning. I will be adding another in near future. I think two of them In between your left and right would be amazing. I have mine in dead centre between the left/right. The bass nearly knocks my over 15ft away. Tight chest bass, palpable, extremely musical.  I do think your wall behind the speakers should interact well with the sub. Check them out....