[jaylevine]

Hi All,

Getting very excited about a new (to me) pair of Maggie 3.7s that I'm working on. One of the questions I have is about the definition of a 'fast' sub-woofer.

I've read on numous posts that because planars are so fast, if you try to mate them with a sub-woofer it also needs to be 'fast'.

Does anyone have a definition of 'fast'? I have a set of Rel Strata IIIs that I used to use with my old Maggie 1.7s. Do Rel Strata III fall into this catagory? What makes a sub-woofer 'fast' enough to work with either planar or electostatics?

If Rels aren't considered optimal for this application, what brands/models are?

Jay

[kevin360]

I think 'fast' is a misnomer. What you don't want to use is a sloppy subwoofer, which would be the case for music listening regardless of your main speakers. Your RELs are fine, really fine - excellent, in fact. I wouldn't hesitate to use them with my 3.7s.

BTW, I ended up incorporating a crossover (Bryston 10B Sub) to direct the bottom end away from my 3.7s and to my subs. I had been running the subs parallel. I much prefer the system as it is now. The 3.7s seem 'happier' (reduced IM) without being asked to do the serious grunt work, but they still are producing bass down to around 60Hz.

Enjoy the 3.7s - terrific speakers (love mine).

[Cheeseboy]

Something like the subs here.  http://www.rythmikaudio.com/ or DIY them here at GR Research.  They have a circle here at Audiocircle. 

[nickd]

I second the GR / Rythmik recommendation
personally, I would invest in the open baffle subs from GR. Bass doesn't get any faster. I am also a fan of REL. Having owned both a REL and the GR Open baffle, I would choose the latter if space and budget permits. The open baffle subs just seem like a natural choice.

[medium jim]

Fast is a relative term as bass isn't fast by the nature if the beast.  Room integration is paramount.  I personally like B&W subs...

Jim

[SteveFord]

Planars are going to stop and start faster than cones (no kidding).
You may not need subs at all with your 3.7s depending upon your room and what you listen to.  I never bothered with a sub with 3.7s but your REL is a nice one.
Another thought is what they did with multiple DMWs; it's not going to hit the lowest of the low but the speed of the panel will match the big speakers.
I'd worry about it after you get the speakers in place and see what you've got going on.

[sfdoddsy]

Depending on where you are planning on crossing, I'd also look at open baffle subs. The GR ones are likely to be as good as any.

The issue with integration isn't likely to be 'speed'. It is more likely to be different radiation patterns.

That said, if you are crossing low enough the RELs should be dandy.

[jaylevine]

Thanks for all of the input. I already own the two Rels (along with a DSPEAKER 8033s unit), so sounds like the consensus is if you are going to use a set of subs with the Maggies my Rel Strata's fit the bill nicely.

I'm very excited about the Maggies. My current room is probably a bit small (narrow and long) for them, but we are in a rental until later this year. Plan is to purchase a home sometime this fall and when I do a prerequisite will be enough space for a dedicated listening area with acoustic treatment

[Emsquare]

I think 'fast' is a misnomer. What you don't want to use is a sloppy subwoofer, which would be the case for music listening regardless of your main speakers. Your RELs are fine, really fine - excellent, in fact. I wouldn't hesitate to use them with my 3.7s.

Enjoy the 3.7s - terrific speakers (love mine).

I'm going to have to seconds this and Medium Jim's observations here. A fast subwoofer is kinda like a fast turtle. It may be fast for a turtle but are we really talking about fast? Many are fast enough to keep up with the bottom two or three octaves which is where they are mostly used for Magnepan's. I typically see people using somewhere between 40 to 100 Hz as a crossover point for them. For a near full range speaker this is probably the best idea. Much of why we like Magnepan's to begin with is the glorious mid-bass they have to offer. Why pass that off too soon to a transducer that just isn't as good as the 3.7's are in that range? Like SteveFord wrote "Worry about it after you get the speakers in place and see what you've got going on". And remember that you will probably experience additional bass extension as they get a chance to 'break in'. After that you can ponder the right questions for bass enhancement if you like. Your REL's are well thought of and should be pretty darned good for this purpose.

[Crimson]

I use Vandersteen 2wqs with a Bryston 10B. Works very well.

[rooze]

If your sub's are slow, move them closer to you, relative to the position of the main speaks, give them a little head-start as it were..

[medium jim]

If your sub's are slow, move them closer to you, relative to the position of the main speaks, give them a little head-start as it were..

Now that is funny!

Jim

[Pryso]

I'm with Kevin and Jim here.  I think it is very unfortunate that the term "fast" is applied so often to speakers.

Suppose you want your subwoofer to produce a 32 Hz organ note.  What would "fast" mean?  Would it become 35Hz? Or 48 Hz? Even 64Hz? Aren't those "faster" frequencies?  And would we want that to happen?

I think what we are talking about is rise time.  Is a subwoofer able to produce any given frequency with a similar rise time to the bass of a Maggie?  That's my non-engineer perspective so I'd appreciate a better explanation if I'm off base here, or off bass for that matter. 

[medium jim]

Actually, Steve is on point, the speed or how fast a speaker is is relational to how fast the cone or diaphram is.  The planar doesn't have to move as far as a conventional cone speaker does, e.g., less distance or movement is faster, we are talking about milliseconds.

Kevin is correct that a subwoofer needs to be tight and not flubby or woofy.  Bass is energy and it radiates in a room differently than does the mid's and high's.  This is where sub placement in the room is integral to the integration.  One of the keys is to have no smear, or that the bass doesn't radiate against the mid/high's.  Bass sounds best on or near the floor and will create a more realistic soundfield.

Steve was also correct that you might not need subwoofer augmentation with the 3.7's.

Jim

[SteveFord]

I always remember Paul Elliott coming over to measure my old 3.6s and then he looked over at my subwoofer.
His comment was, "What the hell do you need that thing for"?

[rooze]

Now that is funny!

Jim

Maybe so, but I think many bass/sub integration issues can be resolved by getting the subs out of the corner and into the room. We're talking about timing issues, phase relationships and types of waveforms, so at least two of these three elements can be adjusted mechanically without the need for processors such as Tact, Lyngdorf etc.
Just a thought.

[berni]

Dipole subs with dynamic drivers , maybe U frame can do similar things then planar also the dipole pattern allows a better integration in the room.

[jaylevine]

I always remember Paul Elliott coming over to measure my old 3.6s and then he looked over at my subwoofer.
His comment was, "What the hell do you need that thing for"?

Well, I let you know once I get my 3.7s installed and situated in about 2 weeks. Who knows, maybe I'll have 2 Rel Strata IIIs and a DSPEAKER Eq for sale.

[rooze]

Dipole subs with dynamic drivers , maybe U frame can do similar things then planar also the dipole pattern allows a better integration in the room.

Agreed, and one of the reasons I have better results with the Carver Amazing than with Apogee or Magnepan. But there are downsides too (compromises), as with everything. 

[berni]

Agreed, and one of the reasons I have better results with the Carver Amazing than with Apogee or Magnepan. But there are downsides too (compromises), as with everything. 

Yea , you need a big amp to drive them... I have two 18" Fi IB318 drivers which performed great in tests, but notme to o further.. A disadvantage is also that with a dipole sub, the lowest possible Fq is determinated with the room size..