[satie]

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.

The 3.7 does not give you that much more extension than the 1.7, it gives you more output potential and less distortion. If you resorted to dual subs with the 1.7s you will probably want them for your 3.7s too. You obviously like your bass. The most likely difference is in how low you will cross over.

That said, you want to run the 3.7 full range for a while to get them broken in and to pick out the nits in the bass performance that you will want ameliorated with the subs, that will inform you about where you want to XO.

[Freo-1]

Check out the TBI Magellan sub line. They get rave reviews from owners. 

http://www.audiocircle.com/index.php?topic=111723.0

[pelliott321]

I use dual subs on the bottom of the llla's I rebuilt from what I bought from Steve 3 yrs ago.  I have a hi pass filter on the Maggy bass panel at 50hz and my subs are set at 40 on down. I still have a 50-55 bump in my room so I my raise the hi-pass to 60hz.  The llla's go fairly low if I let them go full range but I cannot play them 100+ db without Mylar slap. This is why I use subs. I can play the maggys very loud, get great dynamics with my complete system.

[Waker]

I am also running two REL Strata III's with Maggie 3.6R's.  My room is only 11 feet wide, so I have to have the subs back in the corners and a few feet behind each of the 3.6R's.  The sound seems to be well integrated, but haven't experimented with placement.  Are there problems with having subs behind Maggies? 

[SteveFord]

I was in the same boat and shoved the sub as far back from the speaker as possible. 
It seemed to work out okay.

[kevin360]

My 3.7s are over 9' out from the front wall and the subs are in the front corners. I originally had the subs out in front of the 3.7s. I'm happier with them where they are now. Of course, I've also added more bass traps to the room. I think getting the subs working in the room is a bigger problem than getting them to work with Maggies, but both require effort.

[medium jim]

Kevin:

Bigger rooms seem to be more difficult to tame.  One thing that seems to work is fake or even real ficus trees.  Place them on the front wall next to your subs to act as a diffuse.

Jim

[DTB300]

Some interesting articles on "fast/slow bass" for those who have not read these yet.....

Myth or Fact:
http://www.soundstage.com/maxdb/maxdb061999.htm

Woofer Speed:
http://www.stereointegrity.com/Files/WooferSpeed.pdf


Medium Jim:  Fiscus Trees?  Wouldn't that be reflection and not diffusion?

[kevin360]

Sorry Jim, but I can't see how a ficus (fake or real) is going to be of use at bass frequencies. I've invested in a forest of tube traps which are quite effective, but they aren't cheap.

[studiotech]

Sorry Jim, but I can't see how a ficus (fake or real) is going to be of use at bass frequencies. I've invested in a forest of tube traps which are quite effective, but they aren't cheap.

Correct, small trees behind audio gear has just become one of those audiophile band-aids in place of proper diffusion.  It certainly does nothing at bass frequencies.  In fact, there's really no product out there for a home environment that will diffuse at low frequencies, the wavelengths are just too large.  Tube traps work well because they diffuse at highs and mids while absorbing the lows.

Back to the fast woofers.  I find that many times when a sub sounds too tubby or disjointed from the main speakers it is due to poor integration of level, crossover point, crossover slope and phase.  Other than that, poorly designed ported subs can call attention to themselves are certain frequencies and poor quality subs in general with very high harmonic distortion will always stick out like a sore thumb even when crossed low.

A high quality driver in a well constructed, sealed box can best most store bought subs for much less money if they are positioned and adjusted to blend with the main speakers well.  I personally use a pair of 15" Rythmik servos, but any of the good drivers from Parts Express like the Reference Series drivers are excellent bang for the buck.  Despite what many manufacturers and audio mags might lead one to believe, there is no black art or voodoo to this stuff, just good engineering and some education in the fundamentals is all it takes to get your subs and audio system to the next level of performance.

Greg

[medium jim]

It's not (Ficus) about hitting the bass, contrary, it is about hitting the mids so they don't smear the bass...it is a good band aid, especially with planars to work on the 1st reflections on the front wall.  Something to be said about cause and effect. 

Jim

[studiotech]

My 3.7s are over 9' out from the front wall and the subs are in the front corners. I originally had the subs out in front of the 3.7s. I'm happier with them where they are now. Of course, I've also added more bass traps to the room. I think getting the subs working in the room is a bigger problem than getting them to work with Maggies, but both require effort.

  You need a measurement of the offset in sound btw the subs and the Maggies.  This is a very large separation distance.  If they are 9ft apart, that's about 9 milliseconds of delay without factoring in possible additional offset from the low pass filter in the subs.  Without adding delay to the 3.7's, the subs signal will be delayed in time.  You will not hear this as an outright echo of the signal, but it will affect how well they can be blended together.

Greg

[neekomax]

Some interesting articles on "fast/slow bass" for those who have not read these yet.....

Myth or Fact:
http://www.soundstage.com/maxdb/maxdb061999.htm

Woofer Speed:
http://www.stereointegrity.com/Files/WooferSpeed.pdf


Medium Jim:  Fiscus Trees?  Wouldn't that be reflection and not diffusion?

Awesome post, especially the first article:

"In fact, bass speed is virtually 100% a function of how ideally the midrange and woofer are integrated. Bass linearity is greatly involved also; you may see a flat frequency-response curve, but the speaker can still sound like it has lumpy bass response because of less-than-ideal phase (or other) relationships between the midrange driver and woofer."

 Seems pretty intuitive now that I think about it. One of the reasons that audiophiles (less so now than before?) tend to be skeptical of systems with subwoofers for critical listening - it's too easy to have a problem with the sub integrating with the midbass drivers of the mains. I think it's one of the reasons that my Soundfield Audio monitors sound so "right'... the subs are part of the speaker system, so they were designed to integrate correctly with the KEF Uni-Q drivers that take over above ≅ 200 Hz...

[jaylevine]

The 3.7 does not give you that much more extension than the 1.7, it gives you more output potential and less distortion. If you resorted to dual subs with the 1.7s you will probably want them for your 3.7s too. You obviously like your bass. The most likely difference is in how low you will cross over.

That said, you want to run the 3.7 full range for a while to get them broken in and to pick out the nits in the bass performance that you will want ameliorated with the subs, that will inform you about where you want to XO.

Sounds like a good approach. The 3.7s are used so they are broken in, but your point is well taken--I will run them w/o the subs for a couple of weeks to see how they sound using various "reference" songs I use.

[SteveFord]

While I think of it, using Mye stands (or homebrewed knock offs) seemed to increase the amount of bass output as well.
Too much bass in my case so off they came.

[jaylevine]

While I think of it, using Mye stands (or homebrewed knock offs) seemed to increase the amount of bass output as well.
Too much bass in my case so off they came.

My 3.7s, which are scheduled to arrive this Saturday, are also coming with Mye stands (I had them on my 1.7s as well). My .02 was the Mye stands absolutely tighened up bass response on the 1.7s. Even if they didn't contribute to the overall sound, I would have kept them since they made moving the 1.7s so much easier when I want to reposition them to accomodate various seating/listening arrangements. I can only guess that the 3.7s are just that much more a pain to move around due to their size.

[SteveFord]

Looking forward to the weekend, I'll bet.

[kevin360]

You need a measurement of the offset in sound btw the subs and the Maggies.  This is a very large separation distance.  If they are 9ft apart, that's about 9 milliseconds of delay without factoring in possible additional offset from the low pass filter in the subs.  Without adding delay to the 3.7's, the subs signal will be delayed in time.  You will not hear this as an outright echo of the signal, but it will affect how well they can be blended together.

Greg

Well, the 3.7s are 9' out from the walls but that doesn't place them 9' in front of the subs - those subs are in front of the walls too. That spacing is more like 6'. Although that is fairly significant, it's not so great at the frequencies in question and the phase knob helped too. I'm not using any filtering in the sub; that function is handled by an active crossover.

Here's a photo of one of my 3D subs...


Here's a little demonstration of the principle behind tuned radiators in case anyone is curious...
http://www.youtube.com/watch?v=Ngj6HCfFnJo&feature=player_detailpage

My 3.7s, which are scheduled to arrive this Saturday, are also coming with Mye stands (I had them on my 1.7s as well). My .02 was the Mye stands absolutely tighened up bass response on the 1.7s. Even if they didn't contribute to the overall sound, I would have kept them since they made moving the 1.7s so much easier when I want to reposition them to accomodate various seating/listening arrangements. I can only guess that the 3.7s are just that much more a pain to move around due to their size.

Congratulations - awesome speakers! The Mye Stands make it easier to move the 3.7s. They make perfect and secure handles.

[Emsquare]

Well, the 3.7s are 9' out from the walls but that doesn't place them 9' in front of the subs - those subs are in front of the walls too. That spacing is more like 6'. Although that is fairly significant, it's not so great at the frequencies in question and the phase knob helped too. I'm not using any filtering in the sub; that function is handled by an active crossover.

Just to ask... How do you know your subs are in phase with your main speakers? The way I understand it is that the phase control doesn't really do much in terms of signal delay and is more like a baffle step correction. And if I understand baffle step correction filters (questionable) then they are almost indistinguishable from a frequency response control. So here's the "if / then" question. "If" that is so (questionable) then how do you get the phase right between the two? I'd like to do it as a step response but I'm not equiped to measure that. Is there a logical tool that is reasonably priced to do that? I could see doing it with a scope and microphone perhaps. So, just to throw it out there for some sort of intelligent response to the question. It seems like there should be a better way without tapping the all digital solution.

These are the kind of questions that rattle around in my fuzzy little mind when no one is looking.

[studiotech]

Well, the 3.7s are 9' out from the walls but that doesn't place them 9' in front of the subs - those subs are in front of the walls too. That spacing is more like 6'. Although that is fairly significant, it's not so great at the frequencies in question and the phase knob helped too. I'm not using any filtering in the sub; that function is handled by an active crossover.

OK, fair enough, 6FT it is.  That is still a long way off in terms of wavelength matching at the crossover point.  I'm not trying to beat a dead horse, just get folks to recognize that making fair judgments about a subwoofers performance is much tougher than plugging in an RCA cable and a power cord and firing the system up.

And you ARE filtering the subwoofer.  Maybe not within the subs circuitry, but your outboard crossover is filtering and unless it is phase linear FIR digital filter, then that is adding a delay to the signal too.

Greg