After reading your post and some of my posts about the up-firing actuator touching the edge of a panel bring out room filling music(I tried EPS, glass, hardboard, Ikea plates etc), I thought why go to all that trouble making heavy magnetic stacks, flat coils etc, when one could use a normal transducer without a cone, but with the bobbin top free to be used (or an available excitor with an open bobbin), and two semi rigid flexible panels joined together at one edge to each other. Went on searching and found this patent. Maybe this was what you were trying to do. If you drop the transducer making part, then the rest is quite easy to understand.
Well, it is quite easy to bend a panel as above, but interesting how would a bouquet of panels bent this way,
would sound?
Last edited:
The other day I mentioned to my friend who I hadn't seen for a few years, that I would make a panel for him to use with his guitar amp.
But he wants a smaller panel than I expected.
I think he has a small room full of all his touring gear.
I was thinking maybe the proplex, but I'm not sure how that will work in a small size.
The only other thing I can think of is maybe the canvas art panel.
This should give a good low end but I am not sure my exciters are up to it.
I could use 2 exciters to beef it up a bit .
But I think he is thinking to use it more for home recording and personal use.
I have sent him some old recordings and a video on WhatsApp, he is surprised how good it sounds and why it has not caught on ?
I'm not sure he is fully convinced.
Trying to explain DML to someone who has used PA for year ,is not easy.
To them it does not make sense.
It is too good to be true.
I have no idea how a panel will sound hooked up to an acoustic or a electric guitar?
Have I done the right thing?
Is ten watts enough for home use?
I think he has a small pro amp with internal speaker .
I'll have to ask him for more information.
Any ideas, would be helpful .
Steve.
But he wants a smaller panel than I expected.
I think he has a small room full of all his touring gear.
I was thinking maybe the proplex, but I'm not sure how that will work in a small size.
The only other thing I can think of is maybe the canvas art panel.
This should give a good low end but I am not sure my exciters are up to it.
I could use 2 exciters to beef it up a bit .
But I think he is thinking to use it more for home recording and personal use.
I have sent him some old recordings and a video on WhatsApp, he is surprised how good it sounds and why it has not caught on ?
I'm not sure he is fully convinced.
Trying to explain DML to someone who has used PA for year ,is not easy.
To them it does not make sense.
It is too good to be true.
I have no idea how a panel will sound hooked up to an acoustic or a electric guitar?
Have I done the right thing?
Is ten watts enough for home use?
I think he has a small pro amp with internal speaker .
I'll have to ask him for more information.
Any ideas, would be helpful .
Steve.
This could also maybe be used as another type of whizzer on the front of a panel ?
I have a few ideas and I can also try this as well, might be interesting.
Steve.
Chdsl
Yes it is a good drawing of what I tested. The point is to understand which characteristic of the membrane to choose to have HF.
The reason to try to make an exciter is to reach different characteristics... what to improve is a question. I see 2 characteristics : higher force factor for a higher efficiency, a better R/L ratio for the HF. Low moving mass for a light membrane is also a need for HF. What has not be explored for now is the role of the stiffness of the exciter suspension.
PS : very interesting document with many details. Among techniques to lower the voice coil mass (mandatory in my opinion to get HF), damping... For the membrane : 2mils polyester (0.05mm?)
Does somebody know what would be a source of 0.05mm polyester (PET)?
Last edited:
@spedge
These are patents of Paul W. Paddock: US Patent 4,903,308, US Patent 5,198,624, US Patent 5,230,021, US Patent 5,249,237, US Patent 5,446,797, US Patent 5,450,497, US Patent 5,570,429 US Patent 5,604,815, US Patent 5,652,801, US Patent 5,727,076, and US Patent 6,061,461. (I found them yesterday) I had time to read only 2. All these patents have expired.
As the thread heading says, we are studying DMLs as a full range speaker. The tech ingredients idea is really no longer interesting. I mean anyone can stick an excitor on an EPS panel and get a sound his own ears like. It might not be the same to his wife's ears. Since finding out about Ammos (which won't appear as a product) and Sony marketed product, I've been experimenting with edge transfer of sound vibrations to a flat panel, mostly on glass panels, glass one-side-closed objects, glass both-sides-open objects, etc. Even EPS sounded way better.
Now, Rubanoide came into the scene, where the flat panel became the voice coil itself. Interestingly, the flat panel is bent into half a cylinder. It so appears that only one panel, bent onto one side is quite enough to give out excellent sound. The 2nd panel bent the other way gives some aesthetic feeling, and also acts as an additional speaker - one voice coil with two speakers. If the two flat panels go around the back symmetrical to the front, you have 4 speakers. And, that with just one voice coil!
Four DML speakers with just one voice coil.
I must be the only one saying this.
These are patents of Paul W. Paddock: US Patent 4,903,308, US Patent 5,198,624, US Patent 5,230,021, US Patent 5,249,237, US Patent 5,446,797, US Patent 5,450,497, US Patent 5,570,429 US Patent 5,604,815, US Patent 5,652,801, US Patent 5,727,076, and US Patent 6,061,461. (I found them yesterday) I had time to read only 2. All these patents have expired.
As the thread heading says, we are studying DMLs as a full range speaker. The tech ingredients idea is really no longer interesting. I mean anyone can stick an excitor on an EPS panel and get a sound his own ears like. It might not be the same to his wife's ears. Since finding out about Ammos (which won't appear as a product) and Sony marketed product, I've been experimenting with edge transfer of sound vibrations to a flat panel, mostly on glass panels, glass one-side-closed objects, glass both-sides-open objects, etc. Even EPS sounded way better.
Now, Rubanoide came into the scene, where the flat panel became the voice coil itself. Interestingly, the flat panel is bent into half a cylinder. It so appears that only one panel, bent onto one side is quite enough to give out excellent sound. The 2nd panel bent the other way gives some aesthetic feeling, and also acts as an additional speaker - one voice coil with two speakers. If the two flat panels go around the back symmetrical to the front, you have 4 speakers. And, that with just one voice coil!
Four DML speakers with just one voice coil.
I must be the only one saying this.
Well not really. Paul W. Paddock filed for patent in May 1998.
With the Rubanoide idea, the membrane edge is one stiff edge with the flat voice coil, so every point moves the same way at the edge as the voice coil moves.
In this patent, Paul Haddock tries to use an ordinary transducer voice coil, but had to get the parts that doesn't touch the top of the voice coil bobbin as stiff as possible, but not that rigid, so he used a double edged window tape, or roofing tape, most probably a roofing tape.
Of course, what he doesn't say is that there are two (DML) speakers in one. Nothing anywhere near a DML...
Not really. He is making a lamp from a drinking glass.
Last edited:
Hello Tagis
Very nice and clean DIY. This is a firing down speaker. Canon had something like that inspired the speaker below made for a friend years ago with a small fostex.
My pictures in post 7410 are with an ordinary speaker. It is not a rubanoid which is more complex to build. Where the patent is inventive is in the shape and material at the fold.Well not really. Paul W. Paddock filed for patent in May 1998.
With the Rubanoide idea, the membrane edge is one stiff edge with the flat voice coil, so every point moves the same way at the edge as the voice coil moves.
In this patent, Paul Haddock tries to use an ordinary transducer voice coil, but had to get the parts that doesn't touch the top of the voice coil bobbin as stiff as possible, but not that rigid, so he used a double edged window tape, or roofing tape, most probably a roofing tape.
Of course, what he doesn't say is that there are two (DML) speakers in one.
Not really. He is making a lamp from a drinking glass.
That's why I posted the patent pertaining that speaker using an ordinary transducer. Here's the link again.
You can buy double sided butyl tape made by Novia. I suppose available in France.
One panel > one speaker > bent to left
Second panel > second speaker > bent to right.
Here is a review on the Sony LPSX-3SX "Glass speaker" it turns out the organic glass is just a acrylic plastic tube
I agree with the reviewer that it is way over priced
Here are the piezo elements https://product.tdk.com/system/file...ten/catalog/piezolisten_commercial_phu_en.pdf
I agree with the reviewer that it is way over priced
Here are the piezo elements https://product.tdk.com/system/file...ten/catalog/piezolisten_commercial_phu_en.pdf
Chdsl.
I remember the linaems LX5 ,my friend had 2 pairs and used to stand the second pair upside-down on top of the other pair, so that the two tweeters were next to each other.
I borrowed a pair for a while and loved the tweeters.
These two speakers are basically the same using rubanoide drivers.
Steve.
I remember the linaems LX5 ,my friend had 2 pairs and used to stand the second pair upside-down on top of the other pair, so that the two tweeters were next to each other.
I borrowed a pair for a while and loved the tweeters.
These two speakers are basically the same using rubanoide drivers.
Steve.
Attachments
I was thinking the same thing - better coupling. But this geometry opens the back side & may reduce the SPL a lot.
Rubanoide is similarly appealing in it's simplicity as DML. Regarding the magnets, it looks to me that they are arranged in this video so that N-S poles are on the front & back rather than facing one another across the gap, correct? In that way, the design uses the side-to-side field lines as they curve around at the edges of the gap in opposite directions at the front and back.
A better design would be to have the wires go in just one direction, so that you can take advantage of the higher flux through the middle of the gap.