The discrepancy you heard between what the Maggies are doing in the bass region, and what the subs is doing, is primarily an acoustic room-interaction issue.
A single monopole subwoofer will produce a peak-and-dip pattern at the listening position, and these peaks and dips will be far enough apart that they will be audible even if you don't consciously identify them. Now you can move the sub or move the listening position and that will shift and re-arrange the peak-and-dip pattern, but will not eliminate it. You can equalize it and improve the smoothness over a small listening area, but that will likely make it worse elsewhere because the inherent peak-and-dip pattern will be very different in other locations, so instead of cutting peaks and boosting dips you'll be boosting peaks and cutting dips.
Instead, suppose we have two monopole subs, preferably places fairly far apart, and non-symmetrically. Each will produce a unique peak-and-dip pattern at the listening position. The sum of these two dissimilar peak-and-dip patterns will be smoother than either one alone, and because of the time it takes for the ear to register low frequency waveforms the two will be heard as one even if the path lengths to the listening position are somewhat different.
Now the output of a dipole is smoother than that of a monopole because a single dipole can be thought of as two monopoles with one of them displaced 180 degrees in phase rather than physically displaced in space.
My suggestion for achieving similar in-room bass smoothness to a pair of dipoles is to use four small monopole subs, scattered asymmetrically around the room. The result is significantly smoother bass not only in the sweet spot, but throughout the room. This will have in-room smoothness comparable to the bass you get from the dipoles, but with the ability to pressurize the room ("slam") that dipoles inherently don't have. Credit to Earl Geddes for the asymmetrical multisub concept.
I wonder what amp you are using Loomis?
Throw a ton of current at the Maggies and then listen to the bass.
Also pull them out from the back wall about 7ft (no kidding) the bass integrate with the midrange so much better.
first of all welcome to the Maggie fan club.
If the 1.6's didn't compare to other speakers in their price range, I would like to know what amps where used? I have never heard any speaker under $2k that can touch the 1.6qr's, but you need a lot of power, such as Innersound (sorry now SandersSound) Bel Canto's or high current Parasound's.
Same for the 3.6r's which I have had forever. They have a tremendous amount of slam, if you have the right amps (and as above correctly mentions, the right room set up). I have learned after many different amps that that you need to start with a low of 600w (into 4ohms) and go up from there. I find about 1000w to be right.
I do have a sub again now (Rel B1) and it really does fill in the bottom well, but after much time and effort to place it correctly and dial in the crossover, I have it set at 39 to just take over the very low notes, and the SLAM is well, SLAMMIN.
Good luck, if you get them concentrate on the amp(s) first them think of a sub. I would start with:
Cary CAD 500 MB (my favorites)
Bryston 14b SST (or 7b sst's, same thing)
Sanders Sound ESL amps (all great, or the older Innersound)
there are more, but get crazy expensive, and I haven't tried many of those with the exceptions of the high powered Pass amps, which are great.
At 30,000 feet, I'd agree with every word you said. However...
IME, dipole bass doesn't look just like 2 monopoles. True, the deep suckouts are dramatically reduced as they would be with a pair of monopole bass generators, but smaller suckouts occur more frequently with dipoles. It's a different (maybe more benign) problem, but a problem, noetheless.
As to EQ, your point re: "the sweet spot" is probably more relevant in theory than in practice. If EQ'd on-axis response is good, you needn't sit with your head in a vice. For most high end listening rooms, my guess is that EQ is extremely effective. It's certainly been the case for me.
OTOH, if a given system is in the "party" room, there may be more teeth in your argument.
thanks for the feedback. i auditioned the maggies in optimal conditions--acoustically treated room, speakers seemingly well placed at least five feet from the wall, driven by a big old boulder amp (certainly more than 500w + @4ohms)-- so i don't think the set up or associated gear was the issue. we also crossed over the REL at 40 (consistent with what macdadtexas does), but all of us still heard the disconnect. i'm sure audiokinesis's analysis of the room interaction is correct--he seems very knowledgeable--but i still wonder whether using one amp (rather than an amp to drive the maggies and the sub's amp)might be a more cost-effective solution; hence my initial question about using a passive sub.
To integrate a sub you have to play around with location a bit. I heard a pair
of JL 212s with a pair of Maggie 20.1s and the integration was seamless. it
was put together by Seattle's best high end shop, who definitely knows what
I would think that a really good sub candidate for Maggie would be the
Martin-Logan powered subs. Since they're made to integrate with
electrostatics, they are very fast and light, and fill that 40-100 Hz area very
well. One of the ways subs have trouble supplementing panel speakers is that
many of them are relatively slow. The JL and Martin-Logan are lightning-fast,
Also, Maggie makes a separate woofer. Not quite a sub, but it supplements
the bottom end and makes sure it's flat to 40 Hz. They are passive, made to
blend with decor, and are reportedly fairly inexpensive. They are easier to
blend because, being panels, they're as fast as panels, and they have a
frequency response up to 7KHz.
The Magnepan passive woofers are made of a smaller version of the bass
panel of a 20.1.
good thoughts, johnnyb--i've generally assumed that subs aren't so placement critical nad didn't really think of the spped of the panels relative to the sub (esp. since everyone claims how musical the REL is). i'll hunt around to see how users like the maggie/ml sub combo or passive woofer.
again, many thanks.
Right now Audio Advisor has a sale on ML subs. They're certainly some of the most nimble and musical I've personally heard.
Thanks for your comments.
A dipole can be modelled as two monopoles separated by a path length (the wrap-around distance) with the polarity reversed on one of them. In fact, that's what a dipole is! Take a Maggie and build it into a wall, and on either side of that wall you'll have a monopole source.
It's true that a dipole does not have the same in-room behavior as two asymmetrically-placed monopoles, but both of them more closely approach the same desirable end result: Greater in-room bass smoothness. This is backed up by several AES papers, and I can dig up citations if you really want but frankly would rather not go to the trouble. My point is, their effect is similar enough to make them easily compatible in the crossover region.
Regarding equalization, if it's addressing a global problem then it will be an improvement throughout the room. If it's addressing a local problem, then it will improve the response in one location but may well make it worse in another. How big that "location" is depends on the specifics, but I agree it's not a head-in-a-vice thing.
Suppose in one location you have a +3 dB peak at 50 Hz, and elsewhere you have a -6 dB dip at the same frequency (this is not at all far-fetched with a single-sub system). That's a 9 dB difference. Equalization cannot fix the 50 Hz region at both locations simulaneously; it can fix one, but at the expense of making the other even worse.
Note that one worthwhile advantage of a distrubuted multisub system is that the variation in bass response from one location to another throughout the room is greatly reduced. So any remaining significant problems are more likely to be global, and therefore EQing them is more likely to be beneficial throughout the room.
What I've been talking about in my posts here is only one aspect of getting good in-room bass from a subwoofer system, but it's the one most relevant to integrating well with dipole main speakers.
Thanks for the reply.
My comment re: a dipole = 2 monopoles was intended to illustrate my actual
experience measuring such designs in my room. I assume (as you allude to
in your post) that the problem with the analogy is that it's frequency
dependent. The bass region, where we're lurking, finds monopole speakers
delivering omnipolar response, so perhaps the analogy is least applicable
As to dipoles being "easily matched" in the x-over region, I've had
the opposite experience. I get pretty smooth reponse from my Maggies down
to app 80hz (I use bass busters which help in the octave or so above this
frequency), but it gets pretty ragged below there. IME, the smoothest
"handoff" occurs when the subs and mains are precisely level
matched through a region that is both free of "humps/divots" and
appropriate in level for good overall octave to octave balance - no mean feat.
The Maggies have proved tougher than either omnis or monopoles for me. I
eventually got good results - with a fair bit of EQ - but it was WORK.
The point about local vs global EQ is simply that - if you look at the virtual
systems links - almost all of these set-ups limit the listening area sufficiently
to allow effective EQ while ignoring any "global" room issues.
BTW, I use 2 subs and this helps reduce the need for EQ. However, fine
tuning with EQ, particularly right around the x-over point, is still - IME -
extremely beneficial, particularly for dipoles.
These points are only based on my own (reasonably extensive) in-room
experience and measurements. It's always possible that my specific
experience is idiosynchratic.
Well I can't discount your experience, especially since you were taking actual measurements, nor can I explain it.
In an AES paper entitled "Dipole Loudspeaker Response in Listening Rooms", researcher James M. Kates compares the response of monopole and a dipole at various listening positions and toe-in angles, and he finds the dipole to be usually (but not always) smoother in the bass region.
In an unprinted supplement to his review of the dipole-bass Gradient Revolution, Robert E. Greene records its in-room frequency response, which he finds to be remarkably smooth in the bass region. You can see this supplement at his website:
Again, I cannot explain your experience. Perhaps the Maggies do not start out "flat" in the bass region; I recall seeing a Stereophile measurement that did not look flat, but it may have been their measurement technique.
I checked that link. If you can get that kind of in-room response (app +/- 4db down to 25hz!) without EQ, my hat's off to you. I've never gotten close in any of my rooms with monopoles, omnis, di-poles, or even bi-poles (Sunfire CRM) until I added EQ. Pretty impressive.
ML Depth with my 3.6 maggies has worked well for me.
Well Marty, the resolution of Greene's posted measurement is pretty low, showing 1/3 octave bands in one dB averaged increments. So I doubt that the actual curve stayed within +/- 4 dB... but that's still impressive in-room performance (which isn't recognizable as such unless you're all-too-familiar with how truly horrible most in-room bass response really is!).
Thanks to all for unusually good and thoughtful feedback.
After digesting it all, my continuing quandry is whether the Maggies are truly worth the commitment--upgrading power amps, adding one or perhaps several subs, tweaking the room, etc.--when some more traditional full-range speakers are more of a plug-and-play (and certainly cheaper) proposition. As a sick Agon freak, I know much of the fun is in the setup, but I have to mull this over.
Again, many thanks--lots of smart people weighing in.
I have operated 3.6's with a Vandersteen 2W for years. It has the reputation of being very fast and musical. This version is not recommended for home theater applications. I have hosted many listening sessions and the participants were continuously surprised when I pointed out the sub. IMO that is a statement that the sub has been "dialed" in correctly and has been seemlessly intergrated. Take care and enjoy your search.
I use two active def tech subs in line with the midrange/bass panels of my 3.6R's (left and right outboard)and it sounds amazing. Switched my sub cables to Morrow Sub3's, which have tremendous speed and definition.
Loomis, enjoy the maggies for what they do independently of a sub. I added a few different sub's to mine...and even though one integrated reAlly well (an inexpensive servo controlled Yamaha from best buy)I just prefer what they can do all by themselves. Yes...I said best buy. So sue me.
ultimately, i decided to pass on the maggies and stick with my revel f32s. notwithstanding the maggies' fantastic qualities, my ears still demanded a sub, and i just couldn't deal with the psychic and financial investment in upgrading power amps, finding the right subs and explaining to my wife that the giant monoliths in the living room were actually new air filters or something.
Get a Velodyne Digital Drive Sub. Place it close to you and keep the output under 50 HZ. I do it and it's great.
My wife actually thought they were the nicest looking and sounding speakers we ever owned:O) Maybe someday?
I run my 3.6's with a pair of powered Vandersteen 2WQ subwoofers with the Balanced high pass Model 5 crossovers.
Read Dick Hardesty's treatise on why the 2WQ is a seamless solution. It is a cogent and well-written article.
Dual subs are the way to go. Jimburger, have you tried putting your subs on sub-platforms? I put mine on 4" thick solid wood which are brass spiked into my floor, with the subs spiked into the sub-platforms...THAT was a HUGE improvement in sound...more definition, less boom and better slam. The response improved so much that my system sounds as good in the bass as my W/P 6's did in my previous system.
Jimburger, tell more about the dual subs in terms of the sonics. I have talked about this with Richard Vandersteen as a side bar to seeking an upgrade for my 2W. He advised me that adding another old 2W would provide better performance than upgrading to the 2WQ.