Others experience re: subs and Magmepan 20


I have a pair of Magnepan 20r’s. Have enjoyed them for years. In my room they go to about 30Hz, response way down at 25Hz.

I am experimenting with a pair of Janis subs. This gets the response to about 25 Hz then down a lot at at 20Hz. It adds a little something but not I am not bowled. over. I hear and feel a bit (in my chest) on some music.

I would like to hear about others have experience with adding subs to nearly full range speakers?

Did you feel you got your money’s worth for "a few silly Hz"?

Thanks
imdoc
I currently have Magnepan 20.7's paired with a single REL G-1 sub-bass driven by ARC 250SE mono-amps. I have found the sub provides an additional fullness and body to music which has been linearly recorded and accurately transcribed to less than 30hz (CD or LP). The improvement in overall presentation is also dependent upon the room size, and in my case, I listen in a 15ft wide by 22ft long room. I would note that I previously had Magnepan 20.0s, and the improvement with a sub was somewhat greater due to its more limited low end.  Due to the inefficiency of Magnepans, ample dynamic power is essential and probably more important than the addition of a sub.     
I have a pair of Magnepan MGIIIa s and now that I have a preamp with dedicated subwoofer ouputs with adjustable crossover points, I was thinking of adding an REL or a Magnepan DWM to the system.  I am thinking more like an 8" sub, since I want a faster response than I think the larger subs will provide (do not really need super powerful bass) and my listening room is not large.

Jim, Rythmik Audio has two sealed subs featuring dual 8" woofers, the F8 and FM8. The only difference between them is the FM was designed to be used as a mid-bass woofer, it’s x/o to a lower-frequency sub being 4th order at 50Hz. Both operate up to 250Hz, and both incorporate the Rythmik Direct Servo-Feedback amplifier.

Also, co-designed by Rythmiks Brian Ding and Danny Richie of GR Research is the unique OB/Dipole Sub, available with dual 8" woofers, though dual 12’s is the more common choice. This OB/Dipole Sub is the ultimate sub for use with all planar speakers, for obvious reasons.

By the way, both Brian and Danny are adamant that because of the design of the 8" and 12" woofers (designed in house specifically for open baffle implementation, and custom manufactured by TC Sounds for Rythmik and GR exclusively), and how they are controlled by the Rythmik Servo-Feedback circuit, the 12" is just as "fast" as the 8", but capable of considerably more output. The sense of "speed" in a woofer is in how quickly it returns to "rest" after the signal has stopped, not how quickly it starts (Rythmik/GR subs have been described as "stopping on a dime"). Subwoofer frequencies are relatively "slow", but woofers, once set in motion, tend to stay in motion. That’s where the Rythmik Servo-Feedback circuit comes into play. If you’ve ever heard the Infinity IRS loudspeakers, you know what I’m talking about. I formerly owned the mini-IRS, the RS-1b (featuring six 8" servo-feedback controlled woofers per side), and the pair of Rythmik Audio/Gr Research subs I now own are considerably better. Leaner, cleaner, no boom, no bloat. It’s the only Open Baffle/Dipole Servo-Feedback Sub in the world! Seriously, if you don’t have room for a pair of Magneplanar Tympani T-IV bass panels (great as subs for Maggie MG series speakers), this is the sub to own.

I am not going to spend the time reading all the posts. My impression is this; it seems the sub doesn't get you much farther down than the mains. While it may seem marginal, a sub that can do about 15-16Hz is SUBstantially, different - sorry, had to pun! - than one which can do 25Hz. BIG difference. 

I would not give up on subs without considering an alternative, as I'm sure others have suggested. 

My experience; I have the Kingsound King III ESL and love them with subs. I use the Legacy EXTREME XD Subs with them and wouldn't dream of runnning the King III for realism in listening without subs. Sure, the King III reaches similar to the 20.7, but the extra foundation is precious on genres of music. Imo. 

Disclaimer, prior to owning I reviewed both the King III and the Legacy EXTREME XD Subs for Dagogo.com