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Can anyone recomend which is best to use with my Rogue 120 Magnum tube amps ML-SL3 or ACOUSTAT 2+2
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Thanks alot guys for all the great info. I will pick up the Acoustat 2+2s this weekend and give them a listen while my Maggies go to Magnepan for a few weeks to be refurbished. No I dont think I will ever get rid of them. I thought I would delve into electrostats while the maggies were gone . The price for the 2+2 seems good ,700 bucks. I read that they are quite reliable. so who knows, these will be the first electrostatic speakers I have ever listened to. Hope my new amps can drive them ok.
that 10" woofer may not integrate well. Although you might want a Sub with 2+2's.
Oh yeah I currently have Magnepan MG IIIs am wanting to try electrostats to see if Im missing anything
Considering you have MG3s, you must've valued dispersion & sweetspot forgiveness. I think a flat ESL will be too confining of a sweetspot for you. That panel beams as would any panel of those dimensions reproducing those frequencies. IIRC, they call it the "headphone effect".FWIW, flat ESLs are more dyanmic, which is why Roger Sanders formerly of Innersound dropped curved ESLs after designing some in the 70s(?). He also prefers beaming sound. Less reflections.
♪ moderate Mart £ ♫ ☺ Planar Asylum
Switching from Maggies to Acoustats in the early 80s was a thrill, but in the end not a good thing. The beaming of the Acoustat simply drove me to distraction. After ten minutes or so I was ready to scream! Never could enjoy the things since I was constantly trying to make sure my head/ears were in the 1" square sweet spot!I agree with Roger Sanders that beaming is a good thing, to a point. It does help eliminate room interaction to a great degree, depending on frequency, but it need not be as beamy as the Acoustat or Innersound to get the job done IMO.
I would've expected a little better than an inch. I dunno. Perhaps a few inches, if one uses a laser pointer during set-up to aim the Acoustats.
♪ moderate Mart £ ♫ ☺ Planar Asylum
Accoustat have about 1-2 square inch sweet spot.I listen my 2+2 at 4.5 meters away and the sweet spot is still very small.
But when you are in, they are VERY hard to beat. I listen to CLS and they didn`t come close.
And, Accoustat didn`t need subwoofer since I reach about 24Hz@-3Db in my listening position!
But don`t use them as OB, Build an infinite baffle around them. Then the bass will come. (in fact, I use only 10Db 1st order EQ on my DIY direct-drive amplifier)
Martin: very nice set up! I used to do the same mod to short all the stator wires together (one side at a time). Must have done at least a half dozen pairs. Had to stop as it is just such a time consumeing job, a real PITA.
I agree with you about the Acoustat's Vs the CLS. Curious to know if you have experimented with a choke in your HV supply as some others have? Wouls like to have a look at your HV schematic to see what you have done.
I have uses small turnbuckles and a plate of wood at the ceiling. You place the plate on the ceiling and back off the turnbuckles to tighten them in between the top of the speaker panel frame and the plate. Would advise though that you reinforce the Acoustat frames in the middle of the vertical side pieces as I have seen these frames crack right in half more than once. Best regards Moray James.
Hi MorayYeah, the "shorting mods" is long to do but the result is very good, the high and medium are not the same...
No, I didn`t try a choke in the HV psu. My psu consist of an 300Va hammond transformer (that I already had on hand since a 20VA would do the job).that feed a serie of doubler. (from 625V to ±5300V)
As you recomment on DIYaudio, I put an snubber on the secondary (7.5ohm +0.4uF). But I didn`t hear any difference...
the resistor that feed the panel are 33Megohm.
Of course, My HV supply is always on.For the frame,mine is "temporary permanent". I build it in 3/4" MDF with 3 layer; But I still try to get some panel to transform my 2+2 into 3+3. Then, I will rebuild a more rigid frame with birch or steel (sand filled). But for now, when I play loud volume, the frame didn`t seem do enter in vibration mode. (at lest by touching it with hand.
that was not the case before reinforce it on the celling.
With a transformer of rhe size that you are useing perhaps winding resonance is not as much of an issue further the stock Acoustat transformer is not a very expensive one so resonance may well be more of a problem with it.
Have you tried the Izzy Wizzy mod? Carlos was kind enough to work out the values of a snubber for the output end of the supply. They are a 0.22 R in series with a 33-47 nf. Carlos also recommended an additional 0.01 uf cap right after the load resistor as well to further reduce the supply ripple.
Thanks for posting about your results and your system. 3 plus 3's wow they will kick some butt! Best regards Moray James.
3+3. I`m hurry to find some panel somewhere at good price...For the snubber, I`ll remove it and try to recycle the caps for try your suggestion.
But i`m not sure if a caps after the load resistor is a good idea. For the ripple reducing, it will be good but for the sound, i`m not so sure.
why not simply ommit the load resistor. Even use a regulator on HV supply!I`ll post my result.
Hey Martin: I can't see how the load resistor will prevent any sonic impact that are the result of all the caps already in the multiplier can you? The load resistor limits available current being delivered to the diaphragm in the event the diaphragm crashes onto a stator or just gets close enough to arc. Further it is a major saftey feature. I have run my panels with out a load resistor but put it back in just to be on the safe side.
Have you considered building yourself a brand new set of twelve panels. If you use 30 guage heavy build magnet wire you can have anywhere from 20 to 32 wires per inch as opposed to the present 6 (actually less than that if you measure and account for grid space). Your panel efficiency should go up at least 12 db or more. No rocket science involved. You could probably pay for all the materials with the proceeds from selling your old Acoustat panels. Worth considering. Best regards Moray James.
Current, that exactly what I think.
If you put some extra capacitance, is there will be some joules aviability.
When the membrane move, charge migration will occur and the extra energy the last caps will provide may worsen the thing, especialy at high spl...
Accoustat have only around 2.5Kohm resistance per inch...
For building panel myself, it' s a good idea but a bad too.
because, you need to build several panel to try different combinaison of: size, tension, coating type, gap, glue, mylar, wire size, dielectric type,etc.
this job is very very time consuming. If I would build some panel, I buy a kit on the web like ER audio or any other.
Martin
Martin: I agree that a cap on the diaphragm side of the load resistor will do exactly what you say. The voltages involved and the physical condition of the stator dielectric combined with program material, your amp (how many volts it can swing) and how loud you like to play will decide if this is a workable idea or not. Later models of Acoustats had higher surface resistivity than did older models. I will check at the ESL Circuit where Andy Zasbo has quote the exact values.
With respect to replicating (or improveing upon) Acoustats I think that all the information is now available. Stators were built on 1/2 inch cube light louvre (3/8 is available and works better). Size is not an issue just make the new panels the same size as the factory units (though slightly smaller or the same size with some dot spacers will yield diaphragm stability). Diaphragm tension is not an issue either if you use the same diaphragm material (DuPont HS65) and shrink to tension you will achieve the identical results (I have some stock of this). Thinner films have resulted in spectral tilt toward the top end (docummented) so you will need the ability to equalise if necessary should you chose a very thin film. Coating for the diaphragm, well I think it's fair to say that it has been established that powdered graphite will do an excellent job. There are a number of materials available which should all do as good or a better job than the factor coating. Gap is just a little over a 1/16 inch (stator surface to diaphragm) which is a readily available size at plastic supply houses. The material is Styrene. Adhesive was in Acoustats case ground Styrene dissolved in Methylene Chloride (sp?) though IPS Weldon #4 is a better choice again readily available. Wire size is your choice, if you want a direct copy of the Acoustat look for a heavy build (high dielectric strength PVC coated wire), 24 guage or pick the wire dielectric of your choice just adjust spacers to keep the diaphragm to stater surface distance at just over 1/16 inch. For bonding the diaphragm to the stator spacers and the two stator halfs together you can use 3M Acrylic transfer tape or non solvent contact adhesive or any number of other available adhesives that will all do a fine job. I would say that there is next to no guess work involved anymore. Some elbow grease yes, always in short supply but will and determination are the most reliable suppliers of these comodities that I know of, available in a person near you now.
As always there is considerable time and effore along with the expense of collecting all the necessary materials for such a project (in small quantities) and I agree with you that for the money there are good kits which eliminate all or most of the fuss. This is a real and valid concern and if the end product is your number one concern the kit option is probably the most logical choice. Remember though that a kit panel is an unknown comodity too and if you just want to drop in brand new identical Acoustat panels the only way to do that is to build your own.
I do believe that the stock Acoustat is probably the best most reliable ESL panel that the commercial market has ever seen. I also believe that superior panels can be consistantly built by DIY constructors but that is for another letter. Very best regards. Martin I would really love to hear your system! Moray James.
Morray, very interesting answerI`ll keep this one in my archive!
Is the HS65 6.5 micron ?
why the 3/8" will be etter than 1/2, 1/2" will be more rigid... and diffraction between 3/8 and 1/2 may not be too different.
If you travel near the "french canadian province", I`m near Quebec city, E-mail me, you`re welcome anytime.
Martin: started my journey in Ottawa used to work in Hull. Skied at Mt. St. Anne amongst other places near there.
The DuPont HS65 is a 65 guage film. The 3/8 louvre would seem to have a higher resonant frequency as the depth of the 1/2 square wells is shorter and I suppose the air damps them more readily. I think that the overall structure is a lot lighter and so a lower Q resonance in the end and just about as stiff as the 1/2. My partner is from Montreal and if she visits home again I will tag along and come to hear your most wonderful system. Go Habs go!!! Best regards Moray James. PS did you ever meet Denny Roberts in Montreal a bud of Ed Meitners with a great sounding set of Acoustats?
Sorry I copy the wrong URL...This time, It will work.
- http://cf.pg.photos.yahoo.com/ph/etalon9/album?.dir=b730&.src=ph&store=&prodid=&.done=http://cf.pg.photos.yahoo.com/ph//my_photos (Open in New Window)
aha, perhaps a glowing plasma tweeter?
♪ moderate Mart £ ♫ ☺ Planar Asylum
HiI can' t see the picture.
But a plasma tweeter is already on my "to do list".
One day, I'll take the time.
was joking but apparently the joke is mePS: it just was one of your darkroom glowing tube amp pics
♪ moderate Mart £ ♫ ☺ Planar Asylum
I just remembered that I have an Yahoo photos account...New picture will be uploaded soon. (with description)
Regards
.
that's the stuff a tweaks page is all about! I'll host it. Please write something up, preferably with pics for other DIYers.
♪ moderate Mart £ ♫ ☺ Planar Asylum
OK, I' ll will.Just let me time to clean my mess before taking some picture...
mess: the trademark of a fellow guru, or as we call it random acoustic room treatments.
♪ moderate Mart £ ♫ ☺ Planar Asylum
HAHAHAVery good point
Do you know an online site where I can put my picture?
email it/them to me @ mleach@pica.army.milAlong with some lessons learned, and/or plans/sketches. What you might suggest to do differently. Some sort of jewels to cast before us swine...
♪ moderate Mart £ ♫ ☺ Planar Asylum
sitting a fair distance, say 10 - 12 feet away so that the panels can blend better. Near field doesn't work well with Acoustats because of their radiation pattern.
Perhaps 1" is stretching it a bit, but not far. Once you find the sweet spot, even the slightest movement of your head will have you out of the sweet spot. At least with the Acoustat. Not a good speaker if you like to chair dance!Then again perhaps 1" is overly optimistic. At any rate, prepare to have your head in a vise and sit absolutely still. No movement allowed. Not for this kid.
The Innersound is perhaps better, but it can't be much. I just see no good reason to have a speaker beam this severly. No need to beam that bad to eliminate room effects. I think this is really more marketing hype than reality. Because of the design, the speaker beams severely and we have to have a positive for this rather large negative. The Quad ESL, as an example, has about 70-80 degree horizontal dispersion. This is still narrow enough to eliminate room interaction, especially first reflection points, in most environments yet still allows for a big sweet spot by comparison.
Not trying to trash the Innersound. I have never heard this speaker, would very much like to, and it has received many rave reviews. Still, I can just about say it is not the speaker for me just by looking at the geometry of the panel. It will be a real beamer.
I lived with various Acoustat models for over twenty five years. Regardless of their attributes, some folks have trouble with their beaming characteristics.Naturally, Roger West of Sound Labs would disagree as to the desirability of using a curved panel. With my U-1s, I particularly like their 90 degree radiation angle. As with conventional speakers, one must treat the first reflection points and control the back wave for the most coherent image.
BTW, now that I've had them for a while, I will be submitting a review shortly.
The SoundLab panel is really not curved like a Martin Logan. It is facetted with enough small flat cells to create a nice arc. Looking at the stator structure on the U-1, I note an ever so small arc to the thing in the horizontal plane, but perhaps it is just my eyes playing tricks. If there is any curve to the thing it is very minimal at best.The Logan is completely different and is a true curved panel.
until I got my pair of U-1s. While the faceted frames do tend to flatten out each "cell", the diaphragm itself is quite curved. Pictures really don't do them justice in that regard because of the spandex. My system pic only hints at it.rw
So my eyes don't deceive there is a slight curve to the panel. Pics would not show this detail.
There is no curve to the membrane in Sound Labs whatsoever: each vertical section is flat, angled slightly from the ones next to it to give an effective arc, without the inherent shortcomings of a truly curved membrane (more on the Sound Lab website on this). The edges of the support ribs are curved, against which the grille cloth rests.The spacing of the vertical support ribs, combined with the angle from one section to the next, were worked out long ago such that no beaming or 'picket fence' effect could be heard. The result is a virtual line source (this radiating principle was intentionally designed in by Dr. West, for psychoacoustic reasons as well as reducing room interaction) which gives dramatically different results from that of flat panel speakers.
That is what I thought Brian.Given the huge overall curve of the panel, looking at an individual cell can give the illusion of some curve.
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