[geowak]

Well, low bass is from 0-80 Hz., midbass 80-150 Hz. 80Hz. and below is usually not locatable (unless you are real close to the sub). If your speakers need more mid bass punch, then IMHO, you need to locate them as close to the mains as possible, and go higher than 80hz. High passing your mains may also help.

Right now running my mid bass subs at 90Hz. cut off, but that could change when all things I have going on are done.

AFAIK, Rythmik limits his servo driver / amp combo to a certain high frequency range, not sure about the ones you bought. The non-servo drivers I bought from him (quite a few years ago, discontinued now) go slightly higher than the equivalent servo model he sold at the time.

Anyway, will you be happy?...set them up and tell us! 

I will do this! (For the benefit of anyone interested to know). BTW if you are speaking about a crossover point higher in frequency than say 80Hz, then yes the GR Research driver option which is a paper cone with the Rythmik F12G, as opposed to the F12 with an aluminum coated driver cone, is stated to have a greater freq range, and consequently can be crossed over at a higher freq point (for example 100Hz).

[jk@home]

The non-servo drivers I have are aluminum ones, and I have thought about replacing them with the GR paper cones, as they are said to be more musical. Nice upgrade to think about later.

[mresseguie]

Geowak,

Hot damn! You ordered the same thing I've been on the fence over (for a couple weeks). Or, more accurately, I can't decide if I want 2 of the Rythmik F12Gs or 2 of the double 8" subs. They're equivalent, but the latter are slimmer.

How long must you wait till they are delivered? I'm thinking I had better hurry up and order mine as I will need them no later than September 10th.

I anticipate you will love having two Rythnik subs....and I suspect I will, too!

[geowak]

Geowak,

Hot damn! You ordered the same thing I've been on the fence over (for a couple weeks). Or, more accurately, I can't decide if I want 2 of the Rythmik F12Gs or 2 of the double 8" subs. They're equivalent, but the latter are slimmer.

How long must you wait till they are delivered? I'm thinking I had better hurry up and order mine as I will need them no later than September 10th.

I anticipate you will love having two Rythnik subs....and I suspect I will, too!

Yeah I've been wanting some fast subs to replace an older SVS NSD/2 ported/double down firing 12inch woofers for HT use. The SVS was too boomy and the BASH amp started acting up so I got rid of the monster. I never really spent the time to build or use a HT so I started to build a modest two channel rig. I am missing some mid to low tight bass with my speakers so I went looking for subs to be used as stereo subs. My first choice was Vandersteen, as I liked the way he designed them. Then I looked at REL, but both were very pricey. So I started to read about the Rythmik subs and they seemed to fit the bill, and were compact and fast. The GR Research guys seemed to be able to produce that good driver and overall I liked the servo approach. 18inch and 15inch subs seemed too big for me and 10inch and 8inch seemed too small. I liked the paper 12inch size since it reminds me of the older JBLs and Altec Lansing speakers of yesteryear that I wanted so badly, because they sounded so good!!
Who did not like the powerhouse Marantz, Pioneer receivers and JBL speakers of the old days!!!
Also I just ordered these Friday evening. Not even a clue as to how long I will have to wait for them. I used the Rythmik website and there was nothing posted that indicated a long time wait for the subs.

[geowak]

Well looks like the F12Gs are not available for another 3 weeks.

Still on the fence on this one. I would love anyone to drop in some more info on this topic. I am torn between dual stereo subs, either 12s or 15s from Rythmik. But have not ruled out using just one, that is very high quality with tight bass. I have read great things about the Martin Logan Depth i. Wondered if that would be as good as the Rythmik?

Can three 8 inch subs match two good 12s?

Here is a good discussion on the topic here; http://emotivalounge.proboards.com/thread/37864/stereo-subs-mono. Has anyone else gone down this road recently?

[mresseguie]

"Well looks like the FG12s are not available for another 3 weeks."

Did you actually speak to a human being at Rythmik? I've called once and emailed twice and I have not received a call back nor have I received an email response. If it weren't for so many people saying great things about Brian, I would be suspicious. I'll try to call again, but if I still get no contact,  I suppose I could try to locate a carrier pigeon or helium balloon. Bad karma. 

[NIGHTFALL1970]

I am contemplating getting a Rel T-9 for my Magnepan 1.7s.  Any thoughts about Rel?

[geowak]

"Well looks like the FG12s are not available for another 3 weeks."

Did you actually speak to a human being at Rythmik? I've called once and emailed twice and I have not received a call back nor have I received an email response. If it weren't for so many people saying great things about Brian, I would be suspicious. I'll try to call again, but if I still get no contact,  I suppose I could try to locate a carrier pigeon or helium balloon. Bad karma. 

I have his email address, that is how I was able to communicate with him. Do you want a PM? BTW I was told by him he is waiting for containers? I think that means the cabinets for the F12. I assume these are made in China or somewhere. I also contemplated getting a
Rythmik driver in a Salk box. He sells them and can make any veneer you may want. A bit more pricey....

[geowak]

I am contemplating getting a Rel T-9 for my Magnepan 1.7s.  Any thoughts about Rel?

Yeah that is another one I have looked at, along with the T-7. But it's not servo, but REL has a very good rep....

[srb]

I also contemplated getting a Rythmik driver in a Salk box. He sells them and can make any veneer you may want. A bit more pricey....

Not saying the Salk/Rythmik isn't worth it, but it's more than a "bit" more pricey .....

For the 12", 48% more ($1295 vs $874) and for the 15", 53% more ($1495 vs $974)

The Salk uses a  1" thick cabinet vs 3/4" and with more extensive bracing (and of course real wood veneer vs vinyl).  I don't know if there are any other differences (such as upgraded amplifier or metal spike feet included, as unfortunately the Salk subwoofer page doesn't have a specs or options page like the majority of the other Salk speakers).

Steve

[geowak]

Yeah....I guess your right, Salk marks up his stuff after he makes that rigid box and veneer. Maybe that is not the route I will go....
Well back to other options.

[Gzerro]

Here is a thread on the Salk cabinet.

http://www.audiocircle.com/index.php?topic=103880.0

The extra cost seems pretty reasonable for a much improved, custom veneered cabinet made in the USA IMO.

[jk@home]

That's nice brace work, mine was a little simpler.

https://imageshack.com/i/pabQyh3Bj

https://imageshack.com/i/eyuFk7M5j

https://imageshack.com/i/kmmTcL6hj

I remember at the time, the cabinet to build was the GR Research "sandbox". I can image how heavy one of those are.

http://www.audiocircle.com/index.php?topic=53675.0

[JLM]

If you search swarm here at A/C or better yet read Floyd E. Toole's "Sound Reproduction" you'll find out that every room needs at least 2 subs (but 3 or 4 spread around the room is better, for 2 they should be located at opposite ends of the room).

In room bass acts like waves moving end to end in a shallow tub.  Depending on frequency and location the sound waves will either add, subtract, or anything in between resulting in up to +/- 20 dB variations in the sound pressure levels.  This cannot be solved by treatments or EQ.

[woodsyi]

I use 4 subs.  The only proper way to do it.

I use 4 too.  2 VMPS Larger (12" + 15" with passive) driven by Crown K2 and 2 18" sealed boxes driven by Dayton SA1000 each -- 2 in front firing with the mains and 2 in the back firing back out of phase to cancel modes. 

[bzr]

  I'm using 2 Wilson Benesch Torus Infrasonic Generators with the WB Trinity speakers, absolutely loving it. Have heard Magnepan 20.7's & 1 WB Generator in my room too & the added generator alone was so good. No they aren't cheap but jaysus they are good....

[cody69]

I use a pair of servo GR SW-12s in sealed enclosures in my main music system along with Vandy 2Ce Sig speakers. The subs add a nice bottom foundation that augments the Vandys with low end presence and punch.

I like the servo technology, tight and clean for music -- May not be optimal for HT use. 

[thunderbrick]

I have Maggie 20.1s and added a pair of vintage sealed Dahlquist DQ-1W subs that I've had for over 25 years.  Powered by vintage Perreaux amp, crossover is Dahlquist DQ-LP1 set at about 45 hz.

Adds quite a bit of low end body, but they could be faster.  Subs are stacked near one corner but it can generate a standing wave on occasion.  Would wiring one of the subs out of phase help?

Room is 22x26x10.  Music only, no HT.

[John Casler]

I use 4 too.  2 VMPS Larger (12" + 15" with passive) driven by Crown K2 and 2 18" sealed boxes driven by Dayton SA1000 each -- 2 in front firing with the mains and 2 in the back firing back out of phase to cancel modes. 

Sounds familiar. . . 

[John Casler]

I have Maggie 20.1s and added a pair of vintage sealed Dahlquist DQ-1W subs that I've had for over 25 years.  Powered by vintage Perreaux amp, crossover is Dahlquist DQ-LP1 set at about 45 hz.

Adds quite a bit of low end body, but they could be faster.  Subs are stacked near one corner but it can generate a standing wave on occasion.  Would wiring one of the subs out of phase help?

Room is 22x26x10.  Music only, no HT.

If you leave the subs "stacked" wiring out of phase would only tend to cancel the energy.

You could try "dipole" configuring, by having one fire in the opposite direction.

If you want to try one out of phase, move it to the opposite side of the room and wire it out of phase like Woodsyi.