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-   -   Turning / Rotating your ESL. (http://www.diyaudio.com/forums/planars-exotics/188196-turning-rotating-your-esl.html)

owenhamburg 1st May 2011 10:07 AM

Turning / Rotating your ESL.
 
The big problem with ESL speakers and Dipoles in general is their directivity. The Quad ESL 63 I have has delay lines to simulate a point source but the approach only helps so much. The delay lines are not very effective with 70 degree off axis listening.

If the speakers are not pointing at you they loose their wonderful properties.

Since I want to regularly use more than one seat in my living room, it seems that the speakers should work around me not me around the speakers.

Since my ESL63 is in very good condition, (I have a factory refurbished model) and is only 1 year since their service, it seems a shame to try and build a rotating frame, which is the purist solution.

I am thinking of using PA speaker 35mm top hat mounts, and a short 35mm steel pole as the basis of the pivot, in a custom stand. Maybe I should use plastic laminated MDF to provide a friction ring around the top hat mounts to increase stability?


What do people think? Is their a better way to rotate my ESL's (I have also thought about sculptors wheels) so I can listen to them in more places in the room.

For me at least the solution should not be too expensive. I plan to remodel the stand at a later date (prototypes are form my experience worth while) as a probably sealed woofer crossed over at approximately 100Hz. I am thinking something less than 200 Euro build cost for the pair of stands.

Regards

Owen

geraldfryjr 1st May 2011 10:37 AM

When Mavric built his panels last year he had used some sort of lazy suzan device to set the position of his panels.
The kind you find on swivel bar stools and he told me that this worked very good.

Here is a link to the pictures. jer

http://www.diyaudio.com/forums/plana...ml#post2165250

CharlieM 1st May 2011 12:42 PM

Quote:

Originally Posted by geraldfryjr (Post 2557570)
When Mavric built his panels last year he had used some sort of lazy suzan device to set the position of his panels.
The kind you find on swivel bar stools and he told me that this worked very good.

Here is a link to the pictures. jer

http://www.diyaudio.com/forums/plana...ml#post2165250

Yeah, I saw those speakers first hand (Mavric used my workshop to build them). I think he picked up those lazy suzan things at a Home Depot or Lowe's... anyway, they're inexpensive ball bearing swivel bases that turn smooth and easy.

Consider, though, that by leaving the speakers at their same location and merely angling them to face different listening spots, you would introduce some phasing problems because two separated listening spots could not both be equidistant from the speakers.

Now, if you happened to have a DSP crossover with time delay and memory (like a Behringer DCX2496) you could setup and save a dedicated time delay for each seat location in the room. Another alternative would be putting wheels on the speakers so you could simply move and aim them equidistant to the chosen listening spot.

In my view, there aren't really any good ways to open up the sweet spot... opting for a wide dispersion speaker that sprays highs all over the room would destroy the magical imaging you can only get from being at the focal point of a narrow-dispersion ESL.

owenhamburg 9th May 2011 07:07 PM

plans
 
Dear all,

I think I am just going to use a bolt. and a laminated MDF surface (so it turns easier) to make a rotating platform upon which the Electrostatics will sit.

Regards

Owen

owenhamburg 10th May 2011 10:39 PM

Quote:

Originally Posted by CharlieM (Post 2557645)
Now, if you happened to have a DSP crossover with time delay and memory (like a Behringer DCX2496) you could setup and save a dedicated time delay for each seat location in the room. Another alternative would be putting wheels on the speakers so you could simply move and aim them equidistant to the chosen listening spot.

Every time I move into the electrostatics sweet spot I am blown away by the quality of the sound but I note rotating the speakers accurately is crucial to the sweet spots size or quality tight focusing is on one location is the best for one listener but with two listeners, its a nicer compromise to spread the focus a little more. (Quad are attempting to make a wider sweet spot wider than normal electrostatics with the 63 and above models anyway)

My thoughts are that accuracy of positioning is critical. A second argument against wheels is and bass may be effected. What do you think about the frame solidity argument? I think Quad ESL's where not designed as solidly as even their USA monitors where, so wheels might not effect bass, especially since I drive sub 100Hz to magnetic drivers (for fear of overloading my lovely ESL speakers, that i was lazy enough to buy, but I do think the bass units might be better built into the stand for looks mostly)

I think time delays could be done with a general purpose CPU with less processing power than the fan less AMD fusion motherboard I have. Now for perfection the physical and rotational position of the speakers could be controlled by the computer. Combined with time delay for one person you would have nearly the complete room covered if your location was reported to the computer. Dreaming away some thing like a Kinect motion detector could be used to find your position, and maybe pause the music when you leave the room, but more practically RFID or an infrared led on a hat could be used.

If we then extended this model with maybe N speakers where N is greater than the number of sound channels, each rotated accurately and sound sent depending my position in the room the complete room could be covered, this is an expensive and complex idea better prototyped with wide dispersion uniform and cheap speakers.

Some disks of wood with accurately drilled holes with pegs (to prevent worries about speaker movement, or alignment LED's (light emitting diode) might be easier and cheaper.

The more I think of it drilled holes and an alignment LED appeals as in the simplest form of all, you can repeatably turn the speaker to see the LED, and toggle lights for set angles, highlighting important points, or alternatively rotation encoding for computer readout with a slotted sheet of cardboard.

Solid Nylon on Solid Nylon is quiet low friction, and might eliminate the need for ball bearings, putting the power needed to rotate speakers within the range of power for a stepper motor. If computer controlled angle could be detected with a mouse per speaker, but its relative not absolute so might need recalibrating on reboot.

I think I have a minimal idea (the LED alignment) that might just make having ESL's tie me to the sweet spot less.I will try to build it when I get time.

Regards

Owen

owenhamburg 31st August 2011 07:15 PM

500mm Lazy Susan Aluminum Bearing
 
Dear all,

In the end I went for a 500mm Lazy Susan Aluminum Bearing from http://www.vxb.com/. I imagine its designed for putting a very large table top on it. Coming from the USA and not being familiar with importing goods to Germany, (I come from the UK and have poor german) postage was fraught with problems. VBX had great customer service but the USPS (Shipping company in USA) really do have the worst customer service of any organisation I have dealt with in years.

While its not precision engineering (and dropped by 10 USA Dollars) it contains a LOT of ball bearings and looks well engineered for the purposes of rotating speakers. The friction is about right for the task on axis, if anything a touch too smooth, and the play is minimal in the directions I don't want so I am a happy buyer. I think putting a really heavy weight would dramatically increase friction and may not be wise.

I am happy with the result. I will live with them for a bit longer before I decide on my plans for Bass enhancement for the ESL 63's. At the moment I have some Linn Helix speakers with the cross over taken out. After living with them like this a little longer, I may decide if the Quad ESL 63 stands should be a large dipole Bass, or if I should use smaller opposing bass units.

Since the combination sounds good with a 4th order crossover between the Quad ESL 63's and the Linn bass reflex, I may leave it longer than I thought I would. Being able to rotate the speakers makes the beaming directive reproduction of the Quad ESL 63's much less of an issue for me when I want to sit in different places in the room. Even if the Quad ESL 63's do have better off axis reproduction than most Electrostatic speakers it is still the only difficulty I have with the Quad speakers performance.

Regards

Owen

esl 63 19th September 2011 10:01 PM

Owen I have used esl 63s since early ninties, and i have noticed the same sensational listening experiences as you and many other Quad listeners.
One day I turned the ESL 63 to point invards, or to be more accurate: I let the speaker axis to cross 30-40 cm in front of the listening position. Note also that i have 7 meters behind the speakers for late reflections! And i have absorbers to absorb 1st reflections on sidewalls, roof and floor.
Anyway, by letting the speakers "to in" in front of the seat, people who is sitting next to you experience almost the same magic as in sweet spot!
Try this out, and remember to delete all first reflections.

esl 63

JarreYuri 20th September 2011 08:26 AM

There is no speaker in the world that would sound any good when sitting 70 degrees of axis.
Even if You would turn both speakers to the place (off axis) that You were sitting, You would definitely have great timing faults between the speakers as one would be closer to You then the other.

esl 63 21st September 2011 06:45 AM

As I wrote.. a toe in is an improvement both for sweet spot and for off axis listeners in the sofa. My fiend has the biggest Beveridge speaker model and it was after some experiments and some analysis of the direction patterns that we both tried this QUAD placement. He also has the 2905 speakers and they are almost identical to ESL 63, only two panels added and a more rigid frame. everything else is identical.

The most amazing with the Beveridge is that you have no sweetspot, its the same stereopattern and depth even if you are not centered. So we managed to place the QUADs in a way that the sound field was almost as good, toe in!

You have to have clearense behind the QUADs, no early reflections from the back side, thats why my room with 7 meters behind them sound so good.

owenhamburg 28th September 2011 05:51 AM

Thanks for the suggestions "esl 63",

I will try toe in but I don't have the space you do. I only have about 1.5 meters behind the speakers. I would like more but its just not practical. I have noticed that the disadvantage of the ESL 63's dipole nature is they are greatly effected by whats behind them. To partially solve this I have made the shelving symmetric so at least the reflections don't effect the stereo image any more. A second effect of having the ESL's on a rotating base is that the shelves are now more accessible.

Regards

Owen


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