No its not an ideal DML material as its to soft. Its some type of softer polystyrene with paper on both sides.
I am using foam core panels. I can’t remember how big offgrid made his panels relative to the canvas.
Elmer’s is polystyrene foam core with stiff cardboard faced paper outer walls. It sounded pretty nice by itself. Actually similar to the first stuff I tried to kick this thread off in post 1. The Elmers is more dense paper than Dollar Store foam core.
I did a search and found your old post where you cut a hole in the canvas to keep it from damping the panel. That’s what I was afraid of is the canvas muffling the sound. But now how do you use it as artwork? Unless you cover it printed grill cloth.
https://www.diyaudio.com/community/...s-as-a-full-range-speaker.272576/post-7002874
There are places that will print your image on acoustically transparent grill cloth which you can cover the canvas as art.
Different subject: have you guys ever tried looking at “bone conduction” audio transducers? They are similar but tend to be smaller but a lot less expensive. Might be useful for smaller nearfield desktop panels? I bought these and will try them out.
US $6.22 21％ Off | AIYIMA 2Pcs 27MM Audio Portable Vibration Speakers Resonance Speaker 2W 4ohm DIY HiFi Full Range Speaker Stereo loudspeaker
https://a.aliexpress.com/_mtdqXH8
US $10.47 16％ Off | SHEVCHENKO 25mm Mini Speaker Bone Conduction Loudspeaker 4OHM 3W Full Frequency Resonance Horn Waterproof For Audio Accessories
https://a.aliexpress.com/_mKv4xkw
I have not bought this one but seems promising and looks quite powerful and designed for panel exciter. The prices are way better than Parts Express:
US $11.99 26％ Off | AIYIMA 2Pcs 30MM Vibration Resonance Speaker 8 Ohm 8W Mini Full Range Speakers DIY Home Theater Sound System Driver
https://a.aliexpress.com/_msXS1Qq
Elmer’s is polystyrene foam core with stiff cardboard faced paper outer walls. It sounded pretty nice by itself. Actually similar to the first stuff I tried to kick this thread off in post 1. The Elmers is more dense paper than Dollar Store foam core.
I did a search and found your old post where you cut a hole in the canvas to keep it from damping the panel. That’s what I was afraid of is the canvas muffling the sound. But now how do you use it as artwork? Unless you cover it printed grill cloth.
https://www.diyaudio.com/community/...s-as-a-full-range-speaker.272576/post-7002874
There are places that will print your image on acoustically transparent grill cloth which you can cover the canvas as art.
Different subject: have you guys ever tried looking at “bone conduction” audio transducers? They are similar but tend to be smaller but a lot less expensive. Might be useful for smaller nearfield desktop panels? I bought these and will try them out.
US $6.22 21％ Off | AIYIMA 2Pcs 27MM Audio Portable Vibration Speakers Resonance Speaker 2W 4ohm DIY HiFi Full Range Speaker Stereo loudspeaker
https://a.aliexpress.com/_mtdqXH8
US $10.47 16％ Off | SHEVCHENKO 25mm Mini Speaker Bone Conduction Loudspeaker 4OHM 3W Full Frequency Resonance Horn Waterproof For Audio Accessories
https://a.aliexpress.com/_mKv4xkw
I have not bought this one but seems promising and looks quite powerful and designed for panel exciter. The prices are way better than Parts Express:
US $11.99 26％ Off | AIYIMA 2Pcs 30MM Vibration Resonance Speaker 8 Ohm 8W Mini Full Range Speakers DIY Home Theater Sound System Driver
https://a.aliexpress.com/_msXS1Qq
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Below my signature on the left the link to AudioDIY_DML github page, open the first file "AStudyOfDMLsAsAFullRangeSpeaker.pdf" (better to download it as the github pdf viewer is not excellent) then 2 possibilities :
- in the history table, canvas panel => OffGridKindaGuy, post 877.
- in the canvas page, the realizations I listed. There is room for yours in a next update.
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Xrk971.
I have wondered about bone conducting exciters for rigid panels ?
It would be interesting to know your results.
Foamcore is not my favourite material , ( understatement).
The problem with foamcore is that it is already a heavily damped panel.
And adding the canvas and glue will damp this panel even more .
But let me know how it sounds to you .
Steve.
I have wondered about bone conducting exciters for rigid panels ?
It would be interesting to know your results.
Foamcore is not my favourite material , ( understatement).
The problem with foamcore is that it is already a heavily damped panel.
And adding the canvas and glue will damp this panel even more .
But let me know how it sounds to you .
Steve.
Aiyima 8 Ohm 20W bought in 2020.
Resonant Freq(FO):60Hz
Freq Response:60Hz-20KHz
Sensitivity:86db±3db
Horn Diameter:50mm
Voice Coil Size:28mm
Height:30.5mm
Net Weight:268g
(Official parameters)
Tough enough to make 18mm thick 150cm x 60 cm wardrobe door sing. Used on practically everything found at home. Much nicer sound comes from underneath tall glass vases, and edge transfer on glass panels.
Xrk971.
The naked ply panel should have the same frequency response as the canvas panel , except the canvas extends the low frequency performance down to about 40hz.
Cutting the canvas away does give you more of the ply sound.
I prefer a 2mm or 3mm ply and probably a more bendy ply.
Rigidity can be a problem ,giving a very harsh sound.
Steve.
The naked ply panel should have the same frequency response as the canvas panel , except the canvas extends the low frequency performance down to about 40hz.
Cutting the canvas away does give you more of the ply sound.
I prefer a 2mm or 3mm ply and probably a more bendy ply.
Rigidity can be a problem ,giving a very harsh sound.
Steve.
Wow really? and people call me the expert. lol I guess your panels are superior to Goebels?
Does it explain how the sound that comes out of the cone speaker goes in the plane which is at 90 degrees to the to and fro motion of the bobbin?
Does it explain how the sound that comes out of the cone speaker goes in the plane which is at 90 degrees to the to and fro motion of the bobbin? That plane has 360 degrees around it. Turn that ear up and above the speaker's to and from motion. below the speaker's to and fro motion, and so on, in-plane with the speaker's opening.
In other words, when we stick an exciter on a flat panel, how does the sound comes from the edges, which is at 90 degrees to the movement of the voice coil. Consider the thickness the flat panel <1mm to understand the question.
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Just a thought experiment, 20+ years ago, would need a fair bit of engineering to do if possible or worthwhile and more an outdoor party novelty than anything.
Fiberglass canopy, structurally enhances as needed, one with big windows on the side. Panels installed where windows were, exciters mounted to them. Next level would include back window and perhaps front towards the cab, after than whole roof, parts of the roof in different sizes, etc......I thought it would be fun to show and really get it on with no visible drivers installed, a nice conversation piece.
Another version, the panels, roof, etc, long excursion surrounds, several 15, 18, 21 etc drivers or one of the 32" subs I had seen mounted in a band pass, etc, enclosure inside.....a few horn mid tweeters, huge bass...for those than mostly like bass.....
Or, one of the above but a section reserved for the tailgate party gear.
Just a fun set of ideas though I did have very experienced audio engineering assistance available that would of helped me with it if I wanted to pursue it
Rick
Fiberglass canopy, structurally enhances as needed, one with big windows on the side. Panels installed where windows were, exciters mounted to them. Next level would include back window and perhaps front towards the cab, after than whole roof, parts of the roof in different sizes, etc......I thought it would be fun to show and really get it on with no visible drivers installed, a nice conversation piece.
Another version, the panels, roof, etc, long excursion surrounds, several 15, 18, 21 etc drivers or one of the 32" subs I had seen mounted in a band pass, etc, enclosure inside.....a few horn mid tweeters, huge bass...for those than mostly like bass.....
Or, one of the above but a section reserved for the tailgate party gear.
Just a fun set of ideas though I did have very experienced audio engineering assistance available that would of helped me with it if I wanted to pursue it
Rick
@Audiofrenzy Tone it down a bit. This is a place for friendly discussion. Please stay within the spirit of the community.Depends it you're talking about displacement, velocity, or pressure. The graph Christian posted is showing pressure.
I've been doing lot of experiments with edge transfer of sound to panels, flat or curved, and found that sound coming out of the panels were much clearer and fuller than placing the exciter on face. Of course, that idea was nudged by Ammos and Sony. Later I found that Telefunken had been selling speakers between 1926-1932 with that kind of edge transfer of sound, that too through a spike. (I have given the links to that in earlier posts.) Yesterday, I found a US patent of January 12th, 1925 by Lee De Forest,
Patent was granted in November 1925.
A few days ago, I've been playing with the idea of bending the panel in the middle and placing the exciter/sound source to the edge of the bend in the middle, before I found this patent. Some sketches,
Measurements are indicative. I was thinking of making the triangle more curvy, but forgotten how to draw that in Sketchup.
Patent was granted in November 1925.
A few days ago, I've been playing with the idea of bending the panel in the middle and placing the exciter/sound source to the edge of the bend in the middle, before I found this patent. Some sketches,
Measurements are indicative. I was thinking of making the triangle more curvy, but forgotten how to draw that in Sketchup.
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