A Study of DMLs as a Full Range Speaker

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Chdsl.
If you are using something like 1inch XPS then yes, but it will have peaks and troughs at the rear in the response,
because of the exciter itself.
I heard this when they first demonstrated the podiums, you could walk round the back and it sounded like there was more life to the sound.
I tried this at home ,but I didn't take long to realise there was something wrong .
Try it yourself and see what you think.
Steve

I know it does. I asked the question to check if others hear the same. The back surface vibrates earlier than the front side, even if it is a split second. You turn the panels other way around, you hear a better, more sound. If the panel is so thin, there won't be much of a difference, but that sound coming from the back usually troublesome. So, you take the panels far away from the walls, to get that sound to die away (same as most of the OB users do).

It'd be interesting to find a way to dampen that sound completely, or if possible, turn it towards the front.

On the matter of the backside of the exciter, it also sends off vibrations, so that side can also be pasted to a panel, and the panel would give sound. In the conventional drivers, the magnet hangs in the air held only by the basket, which in turn has a gasket between the basket and the box face, so to stop any vibration moving in.
 
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I just noticed in my nxt rubbish link on post 2455 that I mentioned the kiss speaker by veiena acoustics ,this has a dome in the centre of the bmr:yikes:
And I thought it was my brainwave idea:D
I vaguely remember it now
Oh well.
Steve

This kiss dome?
 

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Taking into consideration the ideas of Peter Gansterer (Kiss Technology), one can try pasting ribs on the back of cone of standard driver and see, if the sound will be more prominent, and the bass is better etc. Or, instead of ribs, stiffening rings at different distances from the VC along the cone.

Here, it is a thin flat surface with ribs on the back and a tube to be glued to the VC. I've seen a disk like this in a electrical shop or in a piping shop, just can't remember where.
 

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Du hast again

Well would you Adam and Eve it!
I had my knife in my hand and was about to cut the paper off of the picture frame ,then I thought what if I give it one more try to tighten the panel.
Out came the 2inch brown packing tape and hay presto, it's not perfect, but works.
To put it through its paces I thought ,du hast,played loudly, let's see what happens.
The first recording was with the tls rolling off at 300hz the to card panels and frame in full range, my usual setup.
I recorded it and thought they did pretty well for a pasted up load of rubbish :D
Then thought I wonder what the card and frame panels would sound like on their own?
Well.
 

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Well would you Adam and Eve it!
I had my knife in my hand and was about to cut the paper off of the picture frame ,then I thought what if I give it one more try to tighten the panel.
Out came the 2inch brown packing tape and hay presto, it's not perfect, but works.
To put it through its paces I thought ,du hast,played loudly, let's see what happens.
The first recording was with the tls rolling off at 300hz the to card panels and frame in full range, my usual setup.
I recorded it and thought they did pretty well for a pasted up load of rubbish :D
Then thought I wonder what the card and frame panels would sound like on their own?
Well.

You'd better off with round paper disk, or even a cloth disk. It can be easily made with an embroidery ring.
 

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Chdsl.
I have already stated my interest in the embroidery ring, for testing different materials?
Whether the ring would be better depends on testing and comparing performance.
The main thing is that the card and paper in a frame works well:D
The card was already my second favourite panel material,having the panel going down to 40hz is a bonus.
Obviously more tests and comparisons need to be made for best sound.
Such a large sound from such a small panel is a plus too.
At some time I'm going to want to test the bigger panel and see what happens.
I do have some thin cotton sheets from an old duvet I intended to stretch,when I can get to the local art and craft store,covid allowing!
Canvas is too heavy for my liking,paper is even better,cotton?
We shall see
Steve
 
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Chdsl.
I have already stated my interest in the embroidery ring, for testing different materials?
Whether the ring would be better depends on testing and comparing performance.
The main thing is that the card and paper in a frame works well:D
The card was already my second favourite panel material,having the panel going down to 40hz is a bonus.
Obviously more tests and comparisons need to be made for best sound.
Such a large sound from such a small panel is a plus too.
At some time I'm going to want to test the bigger panel and see what happens.
I do have some thin cotton sheets from an old duvet I intended to stretch,when I can get to the local art and craft store,covid allowing!
Canvas is too heavy for my liking,paper is even better,cotton?
We shall see
Steve

When you are using the embroidery ring with paper or cloth, paste a small disk of aluminium foil (sourced from kitchen or a chocolate wrap) on the front side, to work as the tweeter.
 
What about thin leather skin? Could be good if skin with the right amount of stiffness(stretching) and damping(softness) Could be found. If not damped enough one could just spray som water on the skin surface and let the skin absorb the water. Drawback is offcourse that the water has to be reapplyed and alls that the skin might have to be retightened every nog and then due to the stretching
 
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Pepe.
There are a few options, but which ever is used it must not sound like a drum.
I have some bongos upstairs but have never put an exciter on them,they are too tight.
The good thing maybe, is that something like the embroidery hoop could easily be used to tune in the LF, if you make it too tight you can easily slacken ,lower the frequency.
At the moment I think the card is making most of the sound,I haven't done any tests yet.just listening at the moment.
I also didn't mention that in my attempt to tighten the panel I coated the paper in pva, this didn't help,it made it worse.
But the good thing is it made it stronger ,and easier to tighten, by hand the next day.
In the flexible panel patent they do mention the amount of pressure used to stretch the fabric but that doesn't mean much to me,so I will be using my ear and the rta.
Steve.