SoundLabs vs Magnepans?

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kevinh

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Re: SoundLabs vs Magnepans?
« Reply #20 on: 26 Aug 2011, 04:16 am »
I suspect the distortion produced my electrostatic speakers is not the type that is objectionable to the human ear. Earl Geddes has written on how some distortion which is produced in large quantities by loudspeakers is not annoying to the ear, I suspect this is the case with electrostatic speakers.

oboaudio

Re: SoundLabs vs Magnepans?
« Reply #21 on: 26 Aug 2011, 12:09 pm »

wow. I would love to hear your system. Can you describe the rotary sub some?
Rotary Subwoofer
1. Response is from 25 hz down to below 1 hz.
2. High efficiency at very low frequencies
3. No equalization needed for response to below 1 hz.
4. Has enough acoustic output to move an open door .5"
between 1 and 5 hz.
5. Transient response is near perfect
6. Requires a very large enclosure to absorb fan noise
(My enclosure is 8' long x 4' high x 4' wide)
7. Infinite baffle enclosure to prevent front and back wave
cancellation (I use my entire basement of 2000 sq. ft.)
8. Requires a low pass xover (recommended xover frequency
is between 15 hz and 25 hz (I use 25 hz at 18 db per octave)
9. For pitching the fan blades a 200 watt amplifier is required.
10. Requires a motor controller to control the speed of the
rotating fan and maintains constant speed when fan blades
are being pitched.
11. The motor controller allows for adjustment of speed to match
the size (volume) of one's room.
12. A minimum opening into one's room is 3' x 3'. (I use 4' x 4')
13. Produces very low bass utilizing low pressure (conventional
woofers utilize high pressure (cones move back and forth
madly to produce very low bass.
14. The rotary subwoofer matches the air load (impedance).
Horn enclosures do the same, but would require an enormous
enclosure
15. One needs an additional 120 vac outlet for the fan motor and
motor controller.
16. Distortion is very low down to 1 hz



Duke

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Re: SoundLabs vs Magnepans?
« Reply #22 on: 29 Aug 2011, 01:46 am »
I was invited to comment in this thread.  Normally I try not to get too subjective if I have a dog in the fight...

So the disclaimer:  I'm a SoundLab dealer and Maggie fan.  I've owned over a dozen pairs of SoundLabs, and a half-dozen pairs of Maggies (currently including some Peter Gunn/Magnestand MMGs). 

At one time back in 2000 or 2001, I had SoundLab M1s and bought a pair of Maggie 3.6s so that I could compare them.   I am NOT claiming this was a fair comparison given the size and price difference. 

Apart from differences that could be attributed to sheer size alone, the SoundLabs had more inner detail, and presented a richer harmonic structure than the 3.6s.  One would hope so, given the difference in price.  Not that the 3.6 was generally lacking in these areas, but imho the SoundLab truly excel in some areas, and these are among them.

Off-centerline listeners were also better served by the SoundLabs, as there is no spectral change across the angle covered by their faceted-curved panels.  I could hear some spectral change off to the side of the Maggies, which would be expected from their side-by-side driver layout.

The Maggies are wonderful speakers, especially for the price.  If I had a storefront, I would be a Maggie dealer.

Rclark

Re: SoundLabs vs Magnepans?
« Reply #23 on: 29 Aug 2011, 04:15 am »
You are exactly the type I want advice from.

Duke, If you see the thread just below this I am interested (have signed up for the que) in MMG Magnestands and have indeed gone ahead and purchased MMG's (which have yet to arrive and will be my first real experience with planars). Can you perhaps reply in that thread and give me some of your insight as to what they'll be like and what I'll notice going from stock to modded? I may have some other questions for you as well. If you're able, thank you.

 With that, please go on with this thread, it's quite a read so far.

josh358

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Re: SoundLabs vs Magnepans?
« Reply #24 on: 29 Aug 2011, 11:34 pm »
I find that hard to believe - esp. in respect to the bass capabilities of the 20.1s - there's quite a big difference in drive size between the two models.

HP seems to agree, he says in the September Absolute Sound that the 3.7's are the most accurate speakers he's ever heard. E-Stat, who had a chance to hear both at HP's house (though in different systems), says that the 3.7's are more stat-like, coherent, and have more low-level detail.

OTOH, everybody agrees though that the 20.1's have deeper bass, as you surmised. The smaller 3.7's seem to go down to 40 Hz or so.

Jon L

Re: SoundLabs vs Magnepans?
« Reply #25 on: 29 Aug 2011, 11:47 pm »
Personally, I've never heard an ES/Dynamic combo where the woofer can keep up with the panel and doesn't sound discontinuous.


I agree, except for the Sanders Sound 10C with the digital crossover, which offers very steep 48dB/octave slope.  Combine that with the well-thought-out transmission-line bass, one can truly get a coherent hybrid..  The 94dB sensitive 'stat panels are a great advantage as well, not requiring huge amplification to sound great.

josh358

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Re: SoundLabs vs Magnepans?
« Reply #26 on: 30 Aug 2011, 12:14 am »
Regarding ringing in full range electrostatics.
I have read about the phenomena on and off over the years.
I have had full range electrostatics (Acoustat spectra 22s) for more than 20 years and have never heard any "ringing".
I have heard most of the full range electrostatics over this time and have never heard this "ringing".
My friends who own full range electrostatics never mention it.
The planar sites only mention it in passing once in a blue moon.
Maybe some one can tell me what to listen for.
Does this "ringing" occur only in specific and unusual circumstances?
Has it been designed out of electrostatics now or is this just an example of people looking for a small problem to magnify?
Can some one illumine me a little on this one?

Ringing occurs to some extent in all speakers. It's an unavoidable fact of life, we're dealing with a mechanical system that isn't completely damped. The audible effects depend on frequency.

In addition, low frequency ringing is actually designed into many planar speakers, including Sound Labs and Maggies. The reason is that by underdamping the woofer, you can counteract the 6 dB/octave bass cancellation that occurs in any dipole. If the woofer weren't allowed to resonate, you'd have to use external equalization and a huge amplifier. (Some dipole woofers do use this active approach, e.g., Siegfried Linkwitz's dynamic dipoles.)

So what does it sound like? Pretty much like what you'd expect from the name, it muddies bass transients by extending the decay of the notes.

However, in my experience, dipole bass sounds more detailed and natural than dynamic bass. I think there are several reasons for this, but insofar as ringing is concerned, I think the main one is that listening rooms ring in the bass as well, and the ringing is a lot worse than the ringing in a woofer. So in practice, in a real room, you don't much hear differences in woofer ringing. What's more, to an approximation, dipole line sources trigger only one of the three orthogonal room modes, so in a real listening room, and in the absence of elaborate acoustical treatment, you're actually hearing less ringing with a dipole than you are with a monopole woofer.

BruceSB

Re: SoundLabs vs Magnepans?
« Reply #27 on: 10 Sep 2011, 04:36 am »
Thanks Josh for your clear and careful explanation.
As well as helping me it probably helped lots of other people as well.
I may well have heard it in the past and put it down to room resonances.
Certainly my room, like everyone else's do have its resonances.
I have found that shifting my listening chair solves the problem.
I am going to get a base trap but given my room's configuration, that is, no available corners, no available front wall (it is heavy curtain over windows), and a limited rear wall (which is where I plan to put a base trap) there is not a lot that I can do, but anyway shifting my seat has pretty much solved the problem.
Just as a matter of interest can you give me a bit of an idea of the frequency/frequencies that ringing typically occurs from full range electrostatics?
Thanks again for that very helpful explanation.
Much appreciated.

*Scotty*

Re: SoundLabs vs Magnepans?
« Reply #28 on: 10 Sep 2011, 05:55 am »
If there are uncontrolled resonances in the physical structure of the electrostatic speaker their frequencies would vary dependent the size and nature of loudspeaker design.
 If the ringing referred to is a panel resonance it will depend on the size of the panel.
Martin Logan deals with this by using notch filters centered on the offending frequency. When the impedance curve of the ML is examined the impedance rise looks just like what would be seen from a crossover when in fact it is the notch filter at work.
 I have heard the Soundlabs and if I was thinking of purchasing a large electrostatic loudspeaker they would be at the top of the list for an audition. I didn't notice anything odd when I heard them, just a very clear window into the performance.
I would also ask these questions directly of the manufacturer and require answers that were understandable and not obscuficatory in their content.
Scotty

Duke

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Re: SoundLabs vs Magnepans?
« Reply #29 on: 10 Sep 2011, 06:12 am »
If there are uncontrolled resonances in the physical structure of the electrostatic speaker their frequencies would vary dependent the size and nature of loudspeaker design.
 If the ringing referred to is a panel resonance it will depend on the size of the panel....
 I have heard the Soundlabs and if I was thinking of purchasing a large electrostatic loudspeaker they would be at the top of the list for an audition. I didn't notice anything odd when I heard them, just a very clear window into the performance.

Roger West of SoundLab exploits this behavior via what he calls "distributed resonance" to offset the effects of dipole cancellation:

http://www.soundlab-speakers.com/tech_dr.htm

One of Roger's longtime friends tried to persuade him to sue Martin Logan when the latter used a version of this technique in their CLS model, but Roger declined.



*Scotty*

Re: SoundLabs vs Magnepans?
« Reply #30 on: 10 Sep 2011, 06:28 am »
Duke are you aware of any ringing issues with the Soundlabs. I suspect that if you hit them with a simple impulse signal,(ie,a click) you might see a near perfect reproduction of the impulse.
 I don't think we would see any over-shoot but I haven't seen a test like this done on any of their speakers.
Scotty

Duke

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Re: SoundLabs vs Magnepans?
« Reply #31 on: 10 Sep 2011, 07:26 am »
Duke are you aware of any ringing issues with the Soundlabs. I suspect that if you hit them with a simple impulse signal,(ie,a click) you might see a near perfect reproduction of the impulse.
 I don't think we would see any over-shoot but i haven't seen a test like this done on any of their speakers.
Scotty

I haven't seen any impulse responses of SoundLabs, sorry.   Subjectively I would say they excel at low-end pitch definition and articulation, but not at chest-whumping impact (which I think is a result of their dipole nature). 

josh358

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Re: SoundLabs vs Magnepans?
« Reply #32 on: 12 Sep 2011, 02:29 am »
Duke are you aware of any ringing issues with the Soundlabs. I suspect that if you hit them with a simple impulse signal,(ie,a click) you might see a near perfect reproduction of the impulse.
 I don't think we would see any over-shoot but I haven't seen a test like this done on any of their speakers.
Scotty

John Atkinson said a while back that when he measured the Soundlabs Stereophile bought for J. Gordon Holt they rang like crazy.

Check out this nearfield frequency response measurement of the MG 3.6:

http://www.stereophile.com/content/magnepan-magneplanar-mg36r-loudspeaker-measurements

It gives you a feel for the magnitude of the resonance you need to counter dipole cancellation. Note that most of this isn't audible at the listener's seat:

http://www.stereophile.com/content/magnepan-magneplanar-mg36r-loudspeaker-more-comments

According to the second letter, the underamped dipole woofer technique has been in use at least since Peter Walker designed the Quad!

josh358

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Re: SoundLabs vs Magnepans?
« Reply #33 on: 12 Sep 2011, 02:44 am »
Just as a matter of interest can you give me a bit of an idea of the frequency/frequencies that ringing typically occurs from full range electrostatics?

As Scotty pointed out, that's a function of panel size. Essentially, the bigger the panel, the lower F equal, and the lower the frequency at which you need to start compensating for the 6 dB/octave rolloff. Here's a table that shows F equal and F peak for circular baffles:

http://www.diysubwoofers.org/dipole/

kevinh

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Re: SoundLabs vs Magnepans?
« Reply #34 on: 12 Sep 2011, 05:15 am »
John Atkinson said a while back that when he measured the Soundlabs Stereophile bought for J. Gordon Holt they rang like crazy.

Check out this nearfield frequency response measurement of the MG 3.6:

http://www.stereophile.com/content/magnepan-magneplanar-mg36r-loudspeaker-measurements

It gives you a feel for the magnitude of the resonance you need to counter dipole cancellation. Note that most of this isn't audible at the listener's seat:

http://www.stereophile.com/content/magnepan-magneplanar-mg36r-loudspeaker-more-comments

According to the second letter, the underamped dipole woofer technique has been in use at least since Peter Walker designed the Quad!


Holt's A3's were about 20+ years old at thsi point a couple of generations in the past not distributed resonance or a bunch of other improvements.

SteveFord

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Re: SoundLabs vs Magnepans?
« Reply #35 on: 12 Sep 2011, 06:47 pm »
What's there to discuss when you can own something that looks like this?




kingdeezie

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Re: SoundLabs vs Magnepans?
« Reply #36 on: 12 Sep 2011, 07:20 pm »
I recently heard a pair of Sound Labs U1's at a friend's house.

They were my first experience with anything resembling their design, meaning electrostatics, dipoles, etc, etc, etc, etc.

They were very impressive. Like, I believe Duke said earlier, their low end articulation was crazy good. They didn't pack much of a wallop, but the delineation of the low register was excellent, and very natural.

They were also in a small room, and amazingly, because of their design, did not overload the room like I have experienced with my small room with the myriad of box speakers I have had in my room.

We listened to some jazz and classical and it was really sweet. I would be interested in listening to some rock and blues on them to see if they could service the music I like with the same aplomb. 


TONEPUB

Re: SoundLabs vs Magnepans?
« Reply #37 on: 12 Sep 2011, 08:52 pm »
I've owned every other panel speaker BUT Sound Labs, but I'd still like to have a pair someday.  Regardless of what you might think about the ringing, etc etc, they have always struck me as very musical.  And as mentioned here, like my original Acoustat 2+2's that coherence is pretty addictive.

Every panel speaker has a different signature and different requirements.

One thing that HP and Valin both fail to mention is that they have relatively small rooms for a speaker like the 3.7.  This will dramatically effect the sound.

josh358

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Re: SoundLabs vs Magnepans?
« Reply #38 on: 12 Sep 2011, 09:45 pm »
I know Valin's room isn't all that big, but I thought HP's was 25' long?

Wendell Diller of Magnepan said he'd never heard the 3.7 sound as good as it did at HP's house.

kevinh

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Re: SoundLabs vs Magnepans?
« Reply #39 on: 12 Sep 2011, 10:03 pm »
The MAggie's are very good speakers but it helps to kiss HP's derriere and place ads if you want good reviews. I trust the word's of owners over magazine's with a commercial interest.