...to the joys of speakers without boxes 🙂
Our recent move presented the opportunity to set up a new music system. The difficulty here is that my wife is not keen on large speakers, especially cabinets. " why can't we have something thin" was her refrain. I can't entirely blame her, some of the "best" designs are spectacularly ugly
. It was then I remembered Magnepan's designs, and found some pictures on t'internet for her to look at. Mmmm, not bad came the reply and then all went quiet.
A few weeks later (last weekend) came my birthday. To my overwhelming delight, I was ushered in to see my surprise present - a pair of used but tidy Magnepan SMGa. We plugged in (a very nasty cd-radio "system" bought for $40..). The sound was dull, lifeless and when I turned it up, things rattled. Oh dear 🙁 .
The offending speaker was pulled apart, to reveal that the wires of the mid-bass panel had begun to separate from the membrane.
Over the last few evenings, I have cleaned and reglued as necessary. I also found that the "tweeter" protection fuses were blown in both speakers.
Finally, last night I plugged in again. Same lo-fi radioCD source - I wasn't expecting much, it was never intended to drive a 4 ohm load
Wow 😱 😎 Everything I thought I new about "hi fi" was wrong. These speakers, now 20 years old, are the best audio device I have ever heard. They just disappear, producing music effortlessly. What is more, my dear wife love's their "Danish Modern" appearence!
I have real amplification lined up in the form of an Adcom GFA585 power amp that I have just repaired, and can't wait to get things together. The Adcom came to me for free (broken) from a good friend, and seems on paper to be a good partner to the SMGs. We have a good system for little money and some DIY effort, always more satisfying than forking out hundreds (thousands?) at Hi fi dealers 😉
So I am fortunate to now be a member of the planar club - I am entirely converted, surprised and delighted. DIY thoughts abound...
Cheers,
Ed
Our recent move presented the opportunity to set up a new music system. The difficulty here is that my wife is not keen on large speakers, especially cabinets. " why can't we have something thin" was her refrain. I can't entirely blame her, some of the "best" designs are spectacularly ugly
. It was then I remembered Magnepan's designs, and found some pictures on t'internet for her to look at. Mmmm, not bad came the reply and then all went quiet.A few weeks later (last weekend) came my birthday. To my overwhelming delight, I was ushered in to see my surprise present - a pair of used but tidy Magnepan SMGa. We plugged in (a very nasty cd-radio "system" bought for $40..). The sound was dull, lifeless and when I turned it up, things rattled. Oh dear 🙁 .
The offending speaker was pulled apart, to reveal that the wires of the mid-bass panel had begun to separate from the membrane.
Over the last few evenings, I have cleaned and reglued as necessary. I also found that the "tweeter" protection fuses were blown in both speakers.
Finally, last night I plugged in again. Same lo-fi radioCD source - I wasn't expecting much, it was never intended to drive a 4 ohm load
Wow 😱 😎 Everything I thought I new about "hi fi" was wrong. These speakers, now 20 years old, are the best audio device I have ever heard. They just disappear, producing music effortlessly. What is more, my dear wife love's their "Danish Modern" appearence!
I have real amplification lined up in the form of an Adcom GFA585 power amp that I have just repaired, and can't wait to get things together. The Adcom came to me for free (broken) from a good friend, and seems on paper to be a good partner to the SMGs. We have a good system for little money and some DIY effort, always more satisfying than forking out hundreds (thousands?) at Hi fi dealers 😉
So I am fortunate to now be a member of the planar club - I am entirely converted, surprised and delighted. DIY thoughts abound...
Cheers,
Ed
Congratulations on your newborn Magnepans 🙂
I bet a Krellclone could really make those Maggies sing 😎
With kind regards,
Klaas
I bet a Krellclone could really make those Maggies sing 😎
With kind regards,
Klaas
I once had the honour of having the designer of the Dutch speaker brand 'Translator' dropping by at work... He mentioned he was designing a dipole speaker. He added that the distortion of a speaker without box was some 30% lower. After a short time I came across some old ESL-57's from Quad, it was love at first sight...
Magnepan always drew my attention in the same way....
You may count yourself 'blessed'..😉
Magnepan always drew my attention in the same way....
You may count yourself 'blessed'..😉
By the way, many folks would render it an overkill on planars/esls, but I've connected class D to the esls...and wow! 
Discovering class D presented about the same revelation to me as the esls did...(even on dynamic speakers!)....
Discovering class D presented about the same revelation to me as the esls did...(even on dynamic speakers!)....
Remember Translator well, have listened to Reflexions a lot.
Must be the most open-sounding conventional speaker i've heard.
Needed lots of power though. You could easily drive a quad-606 into clipping without the speakers breaking a sweat.
With kind regards,
Klaas
Must be the most open-sounding conventional speaker i've heard.
Needed lots of power though. You could easily drive a quad-606 into clipping without the speakers breaking a sweat.
With kind regards,
Klaas
Yes we sold his speakers, so I heard a lot of them. The guy is much like
a happily disturbed professor (even looks a bit like Einstein 😛)...
He mentioned the dipole he was working on needed a whole lot of power, but added this was just necessary to get the performance he was looking for....
a happily disturbed professor (even looks a bit like Einstein 😛)...
He mentioned the dipole he was working on needed a whole lot of power, but added this was just necessary to get the performance he was looking for....
Yes , like dynaudio. Finding smart solutions to solve problems in conventional speakers, but these solutions throw away efficiency.
The problems that are left are for the amp-designer 🙂
Can sound marvellous though when the amp-designer does his job well 🙂
With kind regards,
Klaas
The problems that are left are for the amp-designer 🙂
Can sound marvellous though when the amp-designer does his job well 🙂
With kind regards,
Klaas
What's it worth? 🙂
...Thanks for the other replies everyone. The ESL/Planar section of the forum is a rather interesting place to read around. It also seems to be one of the (few?) areas in audio where there is still space for new ideas and experimentation.
Ed
After reading all restrictions to behavior as a member on this forum, I wonder if trading your wife is to be rendered legal in that perspective....
😛 😉
😛 😉
...not so much a trade as offering a service to counsel "significant others" about the virtues of audio components. 😉
*****************************
The Magnepans met the Adcom for the first time earlier in the week. V good.
Unfortunately, I only have a Sony CD walkman as source for the moment. This is fine except the output has rather little drive before it distorts, so I couldn't get even a "good" listening level.
Never mind... that means more work in the electronics den.
Cheers,
Ed
*****************************
The Magnepans met the Adcom for the first time earlier in the week. V good.
Unfortunately, I only have a Sony CD walkman as source for the moment. This is fine except the output has rather little drive before it distorts, so I couldn't get even a "good" listening level.
Never mind... that means more work in the electronics den.
Cheers,
Ed
Hey I'd say go ahead, I would have to feel sorry for Cal not to have the
'significant other' agree with his (their...) steps to audio nirvana...
Afterall large speakers can be shaped like art, or at least have aesthetic value just as small ones. But wouldn't anyone prefer the one with the greatest sound? C'mon Cal I got my girlfriend convinced.....😉
'significant other' agree with his (their...) steps to audio nirvana...
Afterall large speakers can be shaped like art, or at least have aesthetic value just as small ones. But wouldn't anyone prefer the one with the greatest sound? C'mon Cal I got my girlfriend convinced.....😉
Things are going extremely well.
Finally, I assembled something resembling a system :
SMGa speakers,
Adcom GFA 585 amp,
Potentiometer in a box level control "preamp",
Onkyo 703 CD player (it looked decent and cost me a staggering $10... at a surplus place)
The other speaker also had some wires detached from the panel. It is relatively straightforward to re-adhere wires to the panel and this is now finished.
Now we're getting somewhere. The sound is open, natural, smooth - everything I wanted.
The Adcom and Maggies are a great partnership!
Please excuse this rather long winded rambling, but I'd be interested if it provokes any thoughts from others. There is something very different about the speaker's design, in the way it presents itself to the amplifier. It has the following atributes:
Low impedance
Substantially invariant, non reactive impedance vs. frequency.
Weak motor coupling.
This is in stark contrast to conventional "cone+voicecoil" drivers with a very efficient motor (close coupled voicecoil and magnet) and "mass on a spring" diaphragm. These have a reactive nature, also, movement of the voicecoil generates an appreciable back e.m.f. This will cause the speaker and amplifier to have significant interaction. Certainly, the amp can control the speaker, providing damping, but it must work to do this, using it's feedback loop to react against the back e.m.f.
I remember once playing with a speaker, shorting out its terminals as I tapped the cone gently. When shorted, the effect of damping (and altered resonant freq) was noticable. I also observed this on another speaker when connected to and disconnected from an amplifier. The amplifier's "damping factor" provided an effective short-circuit, and this damping interaction is generally regarded as a good thing.
In contrast, the magneplanars (I suspect) interact very little with the amplifier - this speaker "doesn't know" it is connected to an amplifier - its resonance does not seem to change if the input terminals are shorted, nor is much voltage/current generated by movement of the panel (weakly coupled motor system). It is largely a current-to-motion transducer.
The amp, of course, must be able to supply current to the load, but is not presented with much reactance or back e.m.f. Hence there is little interdependence between the two. I imagine that a similar situation is the case with electrostatic speakers, excepting the predominantly capacitive load.
Does this hint at the (or another) real root of differences between panel speakers and "dynamic" speakers as broad families in Hi Fi?
Cheers
Ed
Finally, I assembled something resembling a system :
SMGa speakers,
Adcom GFA 585 amp,
Potentiometer in a box level control "preamp",
Onkyo 703 CD player (it looked decent and cost me a staggering $10... at a surplus place)
The other speaker also had some wires detached from the panel. It is relatively straightforward to re-adhere wires to the panel and this is now finished.
Now we're getting somewhere. The sound is open, natural, smooth - everything I wanted.
The Adcom and Maggies are a great partnership!
Please excuse this rather long winded rambling, but I'd be interested if it provokes any thoughts from others. There is something very different about the speaker's design, in the way it presents itself to the amplifier. It has the following atributes:
Low impedance
Substantially invariant, non reactive impedance vs. frequency.
Weak motor coupling.
This is in stark contrast to conventional "cone+voicecoil" drivers with a very efficient motor (close coupled voicecoil and magnet) and "mass on a spring" diaphragm. These have a reactive nature, also, movement of the voicecoil generates an appreciable back e.m.f. This will cause the speaker and amplifier to have significant interaction. Certainly, the amp can control the speaker, providing damping, but it must work to do this, using it's feedback loop to react against the back e.m.f.
I remember once playing with a speaker, shorting out its terminals as I tapped the cone gently. When shorted, the effect of damping (and altered resonant freq) was noticable. I also observed this on another speaker when connected to and disconnected from an amplifier. The amplifier's "damping factor" provided an effective short-circuit, and this damping interaction is generally regarded as a good thing.
In contrast, the magneplanars (I suspect) interact very little with the amplifier - this speaker "doesn't know" it is connected to an amplifier - its resonance does not seem to change if the input terminals are shorted, nor is much voltage/current generated by movement of the panel (weakly coupled motor system). It is largely a current-to-motion transducer.
The amp, of course, must be able to supply current to the load, but is not presented with much reactance or back e.m.f. Hence there is little interdependence between the two. I imagine that a similar situation is the case with electrostatic speakers, excepting the predominantly capacitive load.
Does this hint at the (or another) real root of differences between panel speakers and "dynamic" speakers as broad families in Hi Fi?
Cheers
Ed
Can you describe more on how the lower frequencies sound? I was thinking of getting a set of Fountek ribbons (very low fs.) with cone bass drivers in OB, I want to compare it to home made (not ready yet) ESLs and some existing Quad ESLs...the idea of full range planars still draws me, but never heard any of'em sound really good...yet...
Interesting questions you have, I never found really detailed information on this (the amp to load reactions and vice versa, with comparison of different 'broad families'...types of amps...)...
It still all seems a pretty undefined area, maybe just to hard to generalize. Easier to measure or calculate per case....?
Anyone?
Interesting questions you have, I never found really detailed information on this (the amp to load reactions and vice versa, with comparison of different 'broad families'...types of amps...)...
It still all seems a pretty undefined area, maybe just to hard to generalize. Easier to measure or calculate per case....?
Anyone?
No problem V-bro:
You'll understand of course that my description can only be in the most general terms and is purely subjective, of course 😉
In fact, I have used the speakers in two rooms, which is perhaps helpful to illustrate their behaviour one is around 10x12 ft, the other, an irregular shape that is perhaps equivalent to 20x14 in area, with a sloped ceiling.
In the small room, the speakers are in the near field, say 6 ft from the listener. Low frequencies seem "complete", nothing appears to be missing from the music. The speakers do dominate the room though!
In the big room, things are similar, but the balance does change to a lighter tone. Personally, this is not something that I find problematic. The seamless, smooth response of the full range panel outweighs outright requency response. Of course this is a personal viewpoint - many choose to add a subwoofer.
In this light, I found that the SMGa was happy with all the types of music that I played (from Mozart to Maiden, Bach to Black Sabbath ). Good recordings of vocals seemed particularly well reproduced. The down side? Bad recordings sounded bad - there is less for them to hide behind!
One detail: To describe the SMGa as a full range panel misses the point that, though there is a single mylar membrane, it has two wire patterns (mid-bass and high frequency) fed by a simple crossover (one inductor and a capacitor). The membrane is also clamped in the centre about 2/3 up from the base, further dividing it & controlling resonance.
It makes me wonder though, if this 20 year old SMGa set - certainly not the top of the range even in its day - sounds so good, despite my novice repairs, what on earth do the new big panels have to offer?
Cheers,
Ed
You'll understand of course that my description can only be in the most general terms and is purely subjective, of course 😉
In fact, I have used the speakers in two rooms, which is perhaps helpful to illustrate their behaviour one is around 10x12 ft, the other, an irregular shape that is perhaps equivalent to 20x14 in area, with a sloped ceiling.
In the small room, the speakers are in the near field, say 6 ft from the listener. Low frequencies seem "complete", nothing appears to be missing from the music. The speakers do dominate the room though!
In the big room, things are similar, but the balance does change to a lighter tone. Personally, this is not something that I find problematic. The seamless, smooth response of the full range panel outweighs outright requency response. Of course this is a personal viewpoint - many choose to add a subwoofer.
In this light, I found that the SMGa was happy with all the types of music that I played (from Mozart to Maiden, Bach to Black Sabbath
). Good recordings of vocals seemed particularly well reproduced. The down side? Bad recordings sounded bad - there is less for them to hide behind!One detail: To describe the SMGa as a full range panel misses the point that, though there is a single mylar membrane, it has two wire patterns (mid-bass and high frequency) fed by a simple crossover (one inductor and a capacitor). The membrane is also clamped in the centre about 2/3 up from the base, further dividing it & controlling resonance.
It makes me wonder though, if this 20 year old SMGa set - certainly not the top of the range even in its day - sounds so good, despite my novice repairs, what on earth do the new big panels have to offer?
Cheers,
Ed
Interesting, I never really liked large bass, but since I have new TL subs (from 28 hz -3db) I changed my mind quite a bit.... but still don't mind to miss under 50hz... more important that it sounds controlled and tight..
I doubt the newer panels will sound a lot better, off course very subjective but I honestly never heard better midrange than from my old (1958!) Quad ESL-57 panels... That's why I was thinking of the fountek ribbons....I wouldn't mind fixing something second hand though...just curious what the bleep can outperform them..😕
I also have a room with a sloped ceiling (40 square meters and 4.5 meters high...) I like the acoustics of my room a lot, never have much problems to make any good loudspeaker sound great here....( I think the slope breaks a lot of resonances and standing waves...).
What new big panels did you have in mind by the way?
I doubt the newer panels will sound a lot better, off course very subjective but I honestly never heard better midrange than from my old (1958!) Quad ESL-57 panels... That's why I was thinking of the fountek ribbons....I wouldn't mind fixing something second hand though...just curious what the bleep can outperform them..😕
I also have a room with a sloped ceiling (40 square meters and 4.5 meters high...) I like the acoustics of my room a lot, never have much problems to make any good loudspeaker sound great here....( I think the slope breaks a lot of resonances and standing waves...).
What new big panels did you have in mind by the way?
Well, there's the Magnepan 3.6 for a start, but of course the flagship 20.1
At the moment, I'm most interested in the amplifier-speaker relationship (or lack of it) as an issue in sound reproducition. Of course the low mass, dipole nature of panels accounts for much of their "flavour".
Thinking about this some more, it is perhaps instructive to place systems into categories of source and driver combination. for example:
1) Strongly coupled dynamic drivers in a box e.g. a typical 2-way bass reflex + solid state "voltage" amplifier system.
2) Strongly coupled dynamic drivers in open baffle + voltage amplifier.
3) Strongly coupled dynamic drivers + low/no feedback amplifier (e.g. full range driver + non feedback tube amp)
4) Weak-coupled dipole driver (ESL, magneplanar) + Voltage amp w feedback
5) Weak coupled driver + non feedback amp
Of course there are more variants that we can think of e.g. current source amplifiers, but this gives an idea of the range of operating conditions. Of course (5) above might be less than practical - I can't imagine running 4 ohm magnepans from a 300B SET amp 😀
The issue in my mind is that conventional amplifiers and speakers systems are desiged "blindfold" from one another. The amp designer assumes a 4 or 8 Ohm load and the speaker designer assumes a blind voltage source with zero output impedance. It is the job of the unwitting hi fi customer to find two components that complement each other, or perhaps I should say two that fight each other the least
A problem? Something that few people want to talk about?I'm inclined to think that this "only one way to look at the world", and that alternative approaches might open up new and interesting ideas in audio. What if the interaction between the components is deliberately removed, minimised or at least considered. The SET movement has addressed this issue through one approach. There is perhaps much to be offered in consideration of the loudspeaker - just look at the complex impedance curves of some typical 2 and 3 way designs!
Maybe what we want is a speaker that is boxless, has low driven mass for good transient response, is electrically non reactive and generates little back e.m.f? Oh yes, and higly efficient 🙂
Ed
This I find extremely interesting, a while ago I planned on creating a tube amp that can create voltage higher than 1KV. To combine it with ESL drivers without needing two large transformers (maybe one small one...)
I haven't managed to get a good design like it, but a couple of people mentioned they'd seen a design like this.....so maybe it's getting time to design something myself....
Any thoughts on this?
I haven't managed to get a good design like it, but a couple of people mentioned they'd seen a design like this.....so maybe it's getting time to design something myself....
Any thoughts on this?
I know there is a schematic for a tube amp to drive ESL's in Morgan Jones' "Valve amplifiers" book. I have the second edition, so later or earlier copies might not include it. Brilliant idea! No output Tx's on the amp... or ESL's.
Direct from tubes to panels. As far as I can remember, Jones uses balanced line from source to speaker for this one. Good book.
Direct from tubes to panels. As far as I can remember, Jones uses balanced line from source to speaker for this one. Good book.
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