[SteveFord]

I was given permission to share a Dealer's email so I would like to pass it along:

Dear Dealer,
Even we were surprised. The combination of 2 Maggie Bass Panels and 3.7s allowed us to demonstrate pipe organ (Pictures at an Exhibition) during CES. Jonathan Valin of TAS voted Magnepan's demo "Best Sound for Lowest Price".
Your mileage may vary, however, we were making a larger point. One-size-fits-all for men's socks, but bass diaphragm size must be tailored to each  individual room. Magnepan's modular approach to bass-radiating area allows just that.
We want each dealer to have Bass Panels on display. Custom Electronics in Omaha does not need bass augmentation for their 3.7s, but there are always customers that want more.  We look forward to the day when we never hear a report from customers that Maggies sounded thin and bright at one of our dealers due to lack of bass/midbass.
_______________________________________ _________________

Jonathan Valin, Executive Editor, The Absolute Sound Magazine
Best Sound for Lowest Price
At T.H.E. Show I got to hear $5,495 Maggie’s 3.7s coupled with Maggie’s DWM bass panels and, folks, you could not recognize the sound. I don’t really know how deep the DWMs are capable of going but where they play they add a lifelike density of tone color and dynamic excitement that the 3.7s alone simply can’t muster. A sensational showing.

Robert Harley, Editor of The Absolute Sound Magazine wrote--
Hi Wendell,
"Your room sounded fantastic, in the bass and everywhere else. I think that you're on to something with the bass panels. They sounded better than cone woofers, were perfectly integrated with the panels, and completely unobtrusive."
Best regards,
Robert

Neil Gader-- The Absolute Sound Magazine
Magnepan produced a compelling demo with its 3.7 loudspeakers augmented by a pair of "stealth" DMW Bass Panels ($795/each) custom designed not only for subbass extension near room boundaries which they accomplished seamlessly, but also to integrate fashionalby as furnishings like a side table or invisibly depending upon the whims of your decorator. A very satisfying modular approach.

The Audio Beat explains Magnepan's concept--
http://www.theaudiobeat.com/ces2013/ces2013_magnepan.htm
----------------------------------
This is Steve Ford again - when I had 3.7s I never found them to be thin and bright sounding. 
They certainly have more bass and lower midrange response than the 3.6s which they had replaced.

[clang]

"We want each dealer to have bass panels on display."
Agree whole-heartedly. I've been waiting for months for a chance to hear them.

[josh358]

Recently I was thinking about speaker placement and the 10 ms recommendation for delay from the sidewall.  This general rule applies to most speaker designs although it may be less important with planar speakers and their figure-8 dispersion pattern.  The intent is to separate reflected sounds from directly radiated sounds by a sufficient amount of time to minimize sonic smearing.  Acoustical studies apparently identified 10 ms as the minimum desired time delay.

So further thinking about planars I realized the same concept should apply to the front wall and its reflections.  Not being an expert with acoustics I sent a note to Jim Smith (I trust you all realize his relationship to Magnepan) asking if my concept seemed valid.  He concurred.

Since one ms is approximately one foot in distance, I realized the "ideal" placement for any planar should be at least 5' out from the front wall to provide the desired separation of direct from reflected sound (in this case more likely spatiality than smearing, although that could be an element too).  Understand that delay can also be achieved by diffraction at the front wall reflection point or reduced by absorption.  Thus Maggie and other planar owners can improve their set up with either of those applications when they must place their speakers closer than 5' from the front wall.

Yes, that's the right analysis. But it's also true that further out is even better! The ear determines the size of an acoustic space by timing the early reflections. So if an instrument is 20' from the rear wall of a stage shell, and your speakers are only 5' from the rear wall, the early reflection in your room is going to reduce the apparent size of the acoustic (I'm assuming no diffusion or other tricks). In practice, I've found that my ears arrive at a sort of compromise, and hear a "wall" about half way between the wall of my listening room and that of the hall.

Anyway, to make a long story short, folks with giant rooms report that the sense of depth keeps getting better until dipoles are 15' out from the wall! I've never had a room large enough to try it.

[Pryso]

"So if an instrument is 20' from the rear wall of a stage shell, and your speakers are only 5' from the rear wall, the early reflection in your room is going to reduce the apparent size of the acoustic"

Josh, if your example refers to a recording of an instrument 20' out from the shelll, then I'm reminded of J Gordon Holt's criticism of the Bose 901 speakers in Stereophile many years ago.  Dr. Bose claimed he was replicating the percentage of reflected sound in a typical concert hall with his design.  But Gordon pointed out nearly all recordings already captured those reflections so it was a false characteristic with the 901s.  If you meant compared to a live audition then ignore this.

My point was to suggest clarification on why a minimum of 5' out for any dipole speaker would be helpful by separating direct sound at the listener's ears from reflected sounds.  It seems reasonable that greater distances than 5' could be even better.  However, it is nice to know there is a limit, even if very few of us could place our speakers more than 15' into the room! 

[josh358]

"So if an instrument is 20' from the rear wall of a stage shell, and your speakers are only 5' from the rear wall, the early reflection in your room is going to reduce the apparent size of the acoustic"

Josh, if your example refers to a recording of an instrument 20' out from the shelll, then I'm reminded of J Gordon Holt's criticism of the Bose 901 speakers in Stereophile many years ago.  Dr. Bose claimed he was replicating the percentage of reflected sound in a typical concert hall with his design.  But Gordon pointed out nearly all recordings already captured those reflections so it was a false characteristic with the 901s.  If you meant compared to a live audition then ignore this.

My point was to suggest clarification on why a minimum of 5' out for any dipole speaker would be helpful by separating direct sound at the listener's ears from reflected sounds.  It seems reasonable that greater distances than 5' could be even better.  However, it is nice to know there is a limit, even if very few of us could place our speakers more than 15' into the room! 

My point was that since reflections from the front wall of the listening room are inevitable, and will be about the same level as the front reflection, that reflection will tend to psychoacoustically mask the later, recorded reflection from the shell of the stage (or on many recordings, artificial reverb). Whereas if the first reflections come *after* the recorded reflection, the reflection captured in the recording will be used by the ear to determine the apparent size of the acoustic space.

In practice, things are a bit more complicated. The brain's neural network learns the characteristics of acoustic spaces and is pretty good at sorting out and discarding contradictory information, such as the false wall of your room vs. the real wall captured on the recording. However, the results aren't always what we'd wish and the brain will *always* tell us that a recording sounds false because of these contradictory cues. I've come to believe that, more than anything else, these two overlapping acoustics are the reason recorded sound sounds canned, no matter how good the system.

However, we can't do without room reflections because of the inadequacies of two-channel stereo. Played outdoors, even the best speakers don't image very well. In an anechoic chamber, stereo sounds awful, like a narrow slit stretching between the two speakers.

So what we end up with a properly-installed two-channel system is artificial reverb, added to whatever reverb is in the recording, real or artificial. I know, ouch, but the brain will hear those reflections and respond to them just as it responds to the settings on a reverb unit. It actually can work remarkably well -- as witness the spectacular imaging of dipoles and the even more spectacular imaging of true omnis -- but even in an optimal setup, it's one size fits all -- the same acoustic that works well for a recording made in a small venue won't work well for a recording made in a large one. There are also problems (which Holt also addressed) with tonal balance changing (in a hall, high frequencies are attenuated) and with the fact that spaces range from very dry (outdoors) to very wet (e.g., a cathedral).

In a sense, this makes acoustics and speaker setup as much an art as a science, at least, you have to tune to your preferences and do the best that you can. For example, someone on another group who prefers chamber music puts absorption behind his Maggies rather than the more usual diffusion, because he doesn't want that large space sound. But I think most people prefer large listening rooms (but not giant -- you don't want to get to the point at which you start getting discrete echoes!).

[jsm71]

So if placement experimentation and room treatments wasn't enough of an exercise for Maggie owners, Magnepan now wants its owners to tune their bass with one or more bass panels.  I am not doubting that properly done you end up with a great sounding speaker "system", but this marketing approach may confuse, frustrate, and price some into looking elsewhere.  If to make it sound right you now have to plan another $800 or $1600 outlay the value is starting to erode some.   Having said that, I enjoyed very much using a subwoofer with my 1.7s to make the system complete.  My sub was over $800 in cost.  It is just different when users drive themselves to these changes rather than the manufacturer "admitting" or suggesting panels alone may not be enough.  We'll see how well this is accepted with buying dollars.

[josh358]

So if placement experimentation and room treatments wasn't enough of an exercise for Maggie owners, Magnepan now wants its owners to tune their bass with one or more bass panels.  I am not doubting that properly done you end up with a great sounding speaker "system", but this marketing approach may confuse, frustrate, and price some into looking elsewhere.  If to make it sound right you now have to plan another $800 or $1600 outlay the value is starting to erode some.   Having said that, I enjoyed very much using a subwoofer with my 1.7s to make the system complete.  My sub was over $800 in cost.  It is just different when users drive themselves to these changes rather than the manufacturer "admitting" or suggesting panels alone may not be enough.  We'll see how well this is accepted with buying dollars.

I think the main problem Magnepan is facing with this approach is that the concept of tuning the woofer area to the room is new to most of us. Not as new as one might think -- after all, it's common knowledge that the big Maggies tend to make too much bass in small rooms, a point Steve has often discussed. Maybe less so that a small Maggie can make insufficient bass in a large one, because, after all, those Maggies have less bass extension to begin with.

But I think most people think in terms of a woofer being "flat," and that everything will then fall into line, assuming there are no terrible room problems. Which isn't actually true of any speaker.

I know that Wendell has been frustrated by some of the confusion surrounding this concept. The most common misapprehension is that the Maggie doesn't make *enough* bass, that it somehow needs the panel to be flat in it -- when in fact, the issue here is tuning the bass area to the room. Another is that the DWM is a sub, when it's really good down to 40 Hz or so. However, in many setups, it *acts* like a sub, extending bass down below what either the DWM or the big speaker can actually do! Try to explain that to a customer.

In essence, the DWM is acting like the "wings" that are sometimes used to enhance bass response, except that they're active (well, 1/4 active, if you include the side wall and floor reflections).

Finally, Wendell makes a point that's frequently made by others as well -- problems with midbass are extremely common, and have more of an effect on the sound than limited bass extension. This is the part of the bass that gives instruments body and substance, whereas the bottom octave has very few fundamentals in it and is mostly useful to reproduce a sense of ambiance.

So all a long way of saying I agree, this is a tough sell, which is why Wendell arranged the demonstration and came up with the accordion concept. However, the impression I get is that he was trying to replicated the legendary Tympani midbass with the other speakers, and found that he could do so by adding the DWM's -- then decided to experiment with the MMG's, and made the fortuitous discovery that the combination could go lower than either the DWM or the MMG could alone.

I also think the DWM could be a godsend to people who are using some of the cool drivers out there to DIY speakers, e.g., JohnR's current project. What usually happens is people will combine a stat or planar or ribbon driver with a dynamic midwoofer, and that never really works, because you can hear the transition.

[rw@cn]

OK, I am interested, but I am also confused. Visit Magnepan's web site and read the manuals for the DWM or DW1 http://www.magnepan.com/product_manuals, then read the following http://www.magnepan.com/using_DWM. Sorry guys but there is not a lot there to get me to buy a pair of DWM's.

What we really need (for those of us that are still struggling with this DWM concept is a clear document/white paper that that starts at A and goes to Z  in explaining theory  and application. Since we are discussing pairing these with 1.7s and above, the discussion should emphasize set up with these speakers.

It also seems to me that some sort of crossover and volume balancing scheme should be used.

Help me out!

[josh358]

OK, I am interested, but I am also confused. Visit Magnepan's web site and read the manuals for the DWM or DW1 http://www.magnepan.com/product_manuals, then read the following http://www.magnepan.com/using_DWM. Sorry guys but there is not a lot there to get me to buy a pair of DWM's.

What we really need (for those of us that are still struggling with this DWM concept is a clear document/white paper that that starts at A and goes to Z  in explaining theory  and application. Since we are discussing pairing these with 1.7s and above, the discussion should emphasize set up with these speakers.

It also seems to me that some sort of crossover and volume balancing scheme should be used.

Help me out!

What you want I think is the "How to use the DWM Bass Panel with full-range Maggies" link you gave. It has complete instructions for setup. I don't think the instructions can be much more specific because what works best is going to be dependent on room geometry and placement, not to mention the specific model. As the instructions say, it's going to take some experimentation.

Except with the MMG setup (which use different instructions), the DWM is run in parallel with the mains so you don't need to add a crossover. Putting the DWM's 90 degrees to the wall puts the listener off axis -- the DWM is much wider than a tweeter so it beams and if they're near the wall you'll be listening off axis and the highs will naturally be attenuated. This provides low pass filtering. It's then a question of trying the DWM's systematically at various positions along an equidistant arc from the listening seat with a radius 12" shorter than the arc that the main speakers are on, until you get the best balance. Picture the minute hand of a clock sweeping from the wall to 12" in front of the main speaker. If there's too much bass, you would then add attenuating resistors in place of the jumper until the balance is right, just as if you were adjusting the tweeter level on the main speakers. Wendell suggests that if minor attenuation is required, the same thing can be done by using thin speaker cable to the DWM. This is because for a given length of cable, the thinner it is, the higher its resistance. You're using the copper in the cable as an attenuating resistor.

There are a number of concepts here that audiophiles (and for that matter engineers) might find unfamiliar but the actual procedure is I think simpler than it seems -- attach in parallel, orient DWM 90 degrees to wall, experiment moving them from against the wall to the main speakers in an arc, add resistors if you have too much bass. Just follow the instructions step by step and any questions can be answered along the way.

[SteveFord]

Josh is the man!
And, of course, you may not need them at all.
My question is did anyone here actually attend the show and go to this demonstration?

[JohnR]

Sorry, dumb question: the DWM is the exact same thing as the woofer panel that comes with the mini Maggies?

[josh358]

Not a dumb question at all. As far as I know, there are no differences. They also sell a pedestal version for use under a center channel speaker.

[JohnR]

Thanks Josh. Are there two sets of binding posts for connection to left and right amplifier channels? Magnepan's documentation seems contradictory:

"The DWM can be driven simultaneously by 2 separate amplifiers (typically the front left and right channels). A built-in crossover provides a high-pass output for use with "small" Magneplanars."

But also:

"(Note- There are no left or right inputs or outputs on the DWM Bass Panel.)"

http://www.magnepan.com/manual_DWM

If there are two sets, then does connecting a single amp channel only drive half the panel? 

[josh358]

Yeah, I admit I was thrown by that for a moment. I think what they're saying is that while there are two inputs and two outputs respectively, left and right don't make any difference to the DWM. But if you're using the internal crossover to feed the Mini Maggies, you'd have to make sure that the left amplifier was attached to the same side as the left satellite panel and vice-versa, otherwise the satellite channels would end up reversed.

Next question -- does each of the inputs drive half of the panel, as you suggest? And if so, what part of the panel, e.g., are they arranged top/bottom or left/right? I can think of various ways of doing this, including running the left and right wires on the diaphragm side by side or on opposite sides of the diaphragm so that either input will drive the entire diaphragm surface. That would allow the same woofer to be used for summed stereo as in the Mini Maggies, or as an individual channel, with the entire driver area driven in both cases. The cost I guess would be half the Bl product when used as an individual channel.

[rw@cn]

Josh,

I carefully read both of your recent posts. The first is quite clear and IMO much better than the information (somewhat contradictory) that what Magnepan presents. The second post illustrates some of the confusion that exists concerning the application of connecting the DWMs to a system.

I am going to contact Magnepan this week and see if I can get some clarity.

[jsm71]

So what do I do if I'm a dealer and being asked to show this concept.  For illustration let's say I'm going to do this with the 1.7s.  Do I:

1.  Show the 1.7s with just one - cost now $2,800?

2.  Show the 1.7s with two - cost now $3,600?  This is starting to suggest other options at this price.

3.  Show them stock.

With options 1 or 2 what happens when the (non Maggie) customer says let me hear them without the bass panel(s)?  Assuming the bass panels in fact make a marked difference the buyer will likely think the setup is inferior without the add on.  Confusion and the feeling that the higher cost is now the comparison bar.   

It seem dealers have had no issue at all selling the 1.7s or other models stock until now.   I'm not so sure I would demo Maggies this way unless I had a current Maggie owner request the demo who knew what they were asking to hear.  Now if the buyer suggests the bass or midbass sounds a little thin, only then would I bring out the support panels and start the explanations.

[SteveFord]

If I were the dealer, I'd ask the customer what size their room is, what they're using, what they listen to, all of that kind of stuff.
I'd show the 1.7s by themselves and then come back later and ask if they wanted to hear them with a DMW and then come back later and ask if they'd like to hear them with 2 DMWs.
I would take the time to explain that every room, system and listening preference is different.
It's about giving the customer options and then letting them decide what's right for them.

[jimdgoulding]

J Gordon Holt is right when he says that when a recording is made on site the ambience of the locale is already in the recording.  At least it is in analog made recordings.  This is what has kept me away from Maggies for so many years, but I'm trying to hear some 1.7's locally to see what I think in actual practice.  JohnR is calculating the delay as the time it takes to hit the wall and the time it then takes to reach the plane of the speaker coming the other way*.  I can give the speakers 5' off the wall and nothing more.  So, to calculate the time delay should I multiply the distance to the wall behind times 2?

Next question.  How low should the crossover point be to a single bass panel?  The reason I am asking this is because I would try to get by with one panel if the signal is undetectable as mono.  Or, is that even possible?

Thanks.

*Is that right, JR?

[josh358]

Josh,

I carefully read both of your recent posts. The first is quite clear and IMO much better than the information (somewhat contradictory) that what Magnepan presents. The second post illustrates some of the confusion that exists concerning the application of connecting the DWMs to a system.

I am going to contact Magnepan this week and see if I can get some clarity.

I don't think there's really much to the connection in practice -- just keep left input with left output and right input with right output -- but I know that Wendell has been helpful in the past when people have called up with DMW hookup questions (or any kind of hookup question, for that matter).

[JohnR]

Aha, Google image search reveals all:



From: http://parttimeaudiophile.com/2011/11/15/first-listen-magnepan-mini-system/

I also found http://www.avguide.com/review/magnepan-s-mini-maggie-speaker-system-revisited-playback-53?page=1, which says "DWM uses a planar magnetic mid/bass panel that, by design, features dual conductors or “voice coils” (one set for the left channel of the Mini-Maggie system, the other for the right channel). Note, however, that while the DWM panel can be used with two-channel inputs, it also works fine with a single-channel input."