A Study of DMLs as a Full Range Speaker

I went to the Staverton audio show yesterday.
One of the first things I noticed was as soon as you moved off centre of the listen position, you lost the central image.
I only had to move a foot to the left and all I could hear was the left speaker.
I even sat in on a Nordost demonstration of their power cables , people were saying how the cables improved the depth of the sound stage, but I was sitting on the right and could only hear the right chanel ,half mono !
I am so used to being able to stand to the left of the left DML panel and still hear the right chanel perfectly well, I just take it for granted.
I have not listed to ordinary speakers for at least 2 years, so was a little surprised at this, now remembered, restriction!
Let alone all the other differences.
Steve.
 
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I went to the Staverton audio show yesterday.
One of the first things I noticed was as soon as you moved off centre of the listen position, you lost the central image.
I only had to move a foot to the left and all I could hear was the left speaker.
I even sat in on a Nordost demonstration of their power cables , people were saying how the cables improved the depth of the sound stage, but I was sitting on the right and could only hear the right chanel ,half mono !
I am so used to being able to stand to the left of the left DML panel and still hear the right chanel perfectly well, I just take it for granted.
I have not listed to ordinary speakers for at least 2 years, so was a little surprised at this, now remembered, restriction!
Let alone all the other differences.
Steve.
nice
 
These sounded pretty good in a large room, I LOVED the look, I asked my wife if I could have a pair in my front room .
The answer was a very quick and loud NO !
I didn't ask how much they cost , but I should imagine they are way out of my budget 😳
Steve.
 

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I only read a bit of it, but the patent seems to use a similar principle as this video on magnetic gears.

See also the (mechanical) harmonic drive. eg

Incremental movement of a rotor by exploiting the stepwise alignment of teeth on rotor and stator with different numbers of teeth in an harmonic relationship, such that at any particular position, the closest teeth always pull the rotor cyclicly.

If this principle were to be used with an exciter, I suppose the teeth would need to be on the circumference & arranged axially, like a stack of discs. Seems very fancy for the manufacture of a cheap device. I always assumed that 'steered flux' in the context of exciters just meant that the magnetic field was 'focussed' to give a greater field strength where it was needed. I suspect this is a different meaning of 'steered flux'?
 
I only read a bit of it, but the patent seems to use a similar principle as this video on magnetic gears.

See also the (mechanical) harmonic drive. eg

Incremental movement of a rotor by exploiting the stepwise alignment of teeth on rotor and stator with different numbers of teeth in an harmonic relationship, such that at any particular position, the closest teeth always pull the rotor cyclicly.

If this principle were to be used with an exciter, I suppose the teeth would need to be on the circumference & arranged axially, like a stack of discs. Seems very fancy for the manufacture of a cheap device. I always assumed that 'steered flux' in the context of exciters just meant that the magnetic field was 'focussed' to give a greater field strength where it was needed. I suspect this is a different meaning of 'steered flux'?
I suspect you're dead correct
Eycy
 
Another linaem type panel and a standard planar speaker.
We missed out a few rooms as we were running out of time ,7 hours isn't long enough 😄
I will stick with my DML panels , not just because they are easy to build , but because I prefer the sound.
I have been playing around with the small acrylic CD panel( not my favourite) since I have almost finished with the decorating ☹️
They need a lot of work to get a half decent sound from them.
But it is interesting.
Steve.
 

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Another linaem type panel and a standard planar speaker.
We missed out a few rooms as we were running out of time ,7 hours isn't long enough 😄
I will stick with my DML panels , not just because they are easy to build , but because I prefer the sound.
I have been playing around with the small acrylic CD panel( not my favourite) since I have almost finished with the decorating ☹️
They need a lot of work to get a half decent sound from them.
But it is interesting.
Steve.
Very cool mediaeval graphics...👍
Worthy of some blatant copying 😁
Eucy
 
While I was playing with the CD panel I thought how it would sound on a canvas panel as in the pictures.
These are not glued , it is just a demonstration of what might be possible?
As long as the panel is not mounted hard up against a wall it might sound OK?
The canvas might damp some of the problem sounds caused by the acrylic?
The cd on its own has trouble going loud , but damping or clamping seems to help this a little.
The frequency response is pretty lumpy as well, but the damping or clamping seems to help this too.
The response of the CD seems to go down to about 200hz or lower depending on how it is housed ?
For a novelty art picture it could sound OK, maybe?
I have still got a few more tests to do, so you never know?
Steve.
 

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Eucy.
my friends comment as we left the room was , they, sounded boxy to me !

anyway ,i mad a quick recording of the CD panel this morning .
last night i glued the CD to a ring mounting, using a lot of PVA , so had to wait a long time to dry, I will show some pics and plots later on if wanted .
surprisingly i managed to get a decent sound out of the CD panel (i think ?) and handling more watts.
the CD panel goes down to about 250hz and that was were i made the XO .
the CD panel was in mono and on its own , accept for the two left and right bass units .
steve.
 

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Eucy.
my friends comment as we left the room was , they, sounded boxy to me !

anyway ,i mad a quick recording of the CD panel this morning .
last night i glued the CD to a ring mounting, using a lot of PVA , so had to wait a long time to dry, I will show some pics and plots later on if wanted .
surprisingly i managed to get a decent sound out of the CD panel (i think ?) and handling more watts.
the CD panel goes down to about 250hz and that was were i made the XO .
the CD panel was in mono and on its own , accept for the two left and right bass units .
steve.
Thanks Steve
Pics would be good

On the panel speakers, I guess the magnetic force is applied evenly across the panel? If so it would make for lowered efficiency away from the centre as the tension in the membrane restricts deflection.

I can imagine it would be possible to semi replicate this type of speaker using a tensioned mylar panel with multiple spine supported exciters ... Not unlike the Podium concept

Eucy