Fed my addiction today by putting "secret sauce" on the 4x4' pair. In plain English, "shellac".Whichever thread said to do this on the rear only so I did. For good measure, I also "treated" the floor of the bed room by spilling most of the 1 QT can 
While I make no secret of being a dilletante with my dumb hi-fi ideas, having never used Shellac before, I looked up the Wiki. I know man is a clever species, but I never had guessed that bug poop (?) mixed with perfectly good
alcohol would make a protective finish for wood and was even used to make plastic-like items, but mostly obsoleted by newer chemistry.
Xrk971: have you tried to build a cornu spiral or a transmission line using DML
While I make no secret of being a dilletante with my dumb hi-fi ideas, having never used Shellac before, I looked up the Wiki. I know man is a clever species, but I never had guessed that bug poop (?) mixed with perfectly good
alcohol would make a protective finish for wood and was even used to make plastic-like items, but mostly obsoleted by newer chemistry.Xrk971: have you tried to build a cornu spiral or a transmission line using DML
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I think it is actually the shells of the lac bug dissolved in alcohol is shellac. Not lac bug excrement.
No. I have not made a TL or BLH with DML yet. Hard to design those without TS parameters. I think the main attraction of the DML is the fact that tbe whole panel is omni. Making a TL or other defeats this main feature.
No. I have not made a TL or BLH with DML yet. Hard to design those without TS parameters. I think the main attraction of the DML is the fact that tbe whole panel is omni. Making a TL or other defeats this main feature.
I feel dizzy, is so simple, it is only a guide sound between two speakers only one of them carries a transformer and a capacitor, do not understand how it works, the speakers are together but the sounds are coming from the room ...The transformer arrangement is from a 1950 Chevi, (vacuum tube radio).
xrk971, I read your link in "foam core" about the initial exciter speaker. A good intro, but isn't a DML panel technically closer to a bipole radiator? So isn't this qutie different from an OB, which I assume is a dipole*?
In any case, I surrender my "best, cheapest" idea (the Polluto tube omni) and instead vote for most bang (well no boom with poor LF ) for the buck to the humble panel of [insert your choice of cheap material here] and one or more exciters = impressive audio.
For the guy who's using rare wood -- good luck, and don't get arrested or confiscated importing it! I am still dabbling in "faux finishing" and a skilled artist (not me!) can duplicate any wood finish. I can paint stuff brown or tan, so far So if I go down that "rabbit hole" I will have to decide how many layers and what colors do to the sound. Oil or latex? Raw sienna or Burnt Umber?
*Do not confuse with a frog in its juvenile stage, which is a tadpole. Besides, an amphibian is a poor transducer and will hop away when you are not paying attention.
In any case, I surrender my "best, cheapest" idea (the Polluto tube omni) and instead vote for most bang (well no boom with poor LF
) for the buck to the humble panel of [insert your choice of cheap material here] and one or more exciters = impressive audio.For the guy who's using rare wood -- good luck, and don't get arrested or confiscated importing it! I am still dabbling in "faux finishing" and a skilled artist (not me!) can duplicate any wood finish. I can paint stuff brown or tan, so far
So if I go down that "rabbit hole" I will have to decide how many layers and what colors do to the sound. Oil or latex? Raw sienna or Burnt Umber?*Do not confuse with a frog in its juvenile stage, which is a tadpole. Besides, an amphibian is a poor transducer and will hop away when you are not paying attention.
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Being standoffish about stand-offs
If you're using a real speaker for the exciter, like I am right now, do you really need standoffs? Yes and no. As shown earlier in the thread, surely they are needed, at least at instal time, to make sure the voice coil is more or less in the right positioin. However, once (in my case) the cone is adhered via the "puck" (of dried glue) to the panel, I had 4, then 2, and now zero, stand-offs per speaker. Even when down to zero, I had two drivers supported by a "timber" which was attached via two foam stand-offs at far ends of board, away from drivers.
Today, while troubleshooting rattle when trying to play low bass drones, I considered removing the entire timber frame and its two stand-offs. Result: the panel seems to work perfectly with the "exciters" connected only via the cones. What the puck! I don't think i've solved the rattle but I've simplified my "design"
Has anyone been able to get "decent bass" out of a panel alone, even with EQ? I am close, but I define decent bass as loud enough to feel in your gut* or rattle the sofa or other furniture. And not have the panel sound like it's mooing.
Further reflections: with a DML, do we realy want any damping on the panel? Ideally, the panel is a resonator at all frequencies? Is ringing a problem? Appears some (commercial) offerings damp all the sides, other leave nearly free. I guess like so much else, some of this is art and so "it depends" ?
*Don't confuse this with the distant rumbing that is Mother Nature's way of warning of an impending need for you to either exit the room to the porcelain room, or at least politely warn others that they'd be well advised to leave
If you're using a real speaker for the exciter, like I am right now, do you really need standoffs? Yes and no. As shown earlier in the thread, surely they are needed, at least at instal time, to make sure the voice coil is more or less in the right positioin. However, once (in my case) the cone is adhered via the "puck" (of dried glue) to the panel, I had 4, then 2, and now zero, stand-offs per speaker. Even when down to zero, I had two drivers supported by a "timber" which was attached via two foam stand-offs at far ends of board, away from drivers.
Today, while troubleshooting rattle when trying to play low bass drones, I considered removing the entire timber frame and its two stand-offs. Result: the panel seems to work perfectly with the "exciters" connected only via the cones. What the puck! I don't think i've solved the rattle but I've simplified my "design"
Has anyone been able to get "decent bass" out of a panel alone, even with EQ? I am close, but I define decent bass as loud enough to feel in your gut* or rattle the sofa or other furniture. And not have the panel sound like it's mooing.
Further reflections: with a DML, do we realy want any damping on the panel? Ideally, the panel is a resonator at all frequencies? Is ringing a problem? Appears some (commercial) offerings damp all the sides, other leave nearly free. I guess like so much else, some of this is art and so "it depends" ?
*Don't confuse this with the distant rumbing that is Mother Nature's way of warning of an impending need for you to either exit the room to the porcelain room, or at least politely warn others that they'd be well advised to leave
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With current 45x48 panel, thou shalt not < 60 Hz
Ran some sweeps on the panels and pretty much giving up on the bottom octave or so.
Sinc re-checking today's mod (sans support framework) I noted that one of the "pucks" is a bit loose. As good a reason as any to go crazy (again) with the Gorilla Glue. Damn but I like this stuff!
Also I'm sealing the edges of the panel with it. Not sure if it'll make any difference, if nothing else it will help protect the foam and foil from getting more dings and tears in it.
It occurs to me that an expanding glue like GG is useful for a project like this, or said another way, I have adapted to my adhesive For "installing" the speaker/exciter, having something that can fill voids is good...like the void between the driver and the panel.
Next I may (pardon the pun but it's what i do...) screw around with affixing the driver's "puck" or contact area thru the panel to the other side, probably with a thin piece of wood on the "front" side of panel (opposite driver) and screwed with a couple short wood screws (with yet more GG on them of course). This should give a tighter fit to the puck of course and what else ...?
Ran some sweeps on the panels and pretty much giving up on the bottom octave or so.
Sinc re-checking today's mod (sans support framework) I noted that one of the "pucks" is a bit loose. As good a reason as any to go crazy (again) with the Gorilla Glue. Damn but I like this stuff!
Also I'm sealing the edges of the panel with it. Not sure if it'll make any difference, if nothing else it will help protect the foam and foil from getting more dings and tears in it.
It occurs to me that an expanding glue like GG is useful for a project like this, or said another way, I have adapted to my adhesive
For "installing" the speaker/exciter, having something that can fill voids is good...like the void between the driver and the panel.Next I may (pardon the pun but it's what i do...) screw around with affixing the driver's "puck" or contact area thru the panel to the other side, probably with a thin piece of wood on the "front" side of panel (opposite driver) and screwed with a couple short wood screws (with yet more GG on them of course). This should give a tighter fit to the puck of course and what else ...?
Dicovery out of topic
Sorry, let me explain: (please forgive my bad English)
My discovery was an accident and out of topic, I was working on my panel and decided to change the material (my small panel is just making sub-bass) I was walking with the panel on my hands in the way out of the room ...suddenly I noticed that pair of speakers on the floor (one next to each other but in an angle)...Are creating a wide stereo signal, the voice of Gloria Stefan (Can't stay away from you) is far away from the pair of speakers, to the left, and the weird drum is on the other side of the small irregular room.
About how I think you are going to have that stereo image in a panel I will post in a minute, an image with my try.
Thanks for asking
Sorry, let me explain: (please forgive my bad English)
My discovery was an accident and out of topic, I was working on my panel and decided to change the material (my small panel is just making sub-bass) I was walking with the panel on my hands in the way out of the room ...suddenly I noticed that pair of speakers on the floor (one next to each other but in an angle)...Are creating a wide stereo signal, the voice of Gloria Stefan (Can't stay away from you) is far away from the pair of speakers, to the left, and the weird drum is on the other side of the small irregular room.
About how I think you are going to have that stereo image in a panel I will post in a minute, an image with my try.
Thanks for asking
Señor Soldermiser !!!!
Señor Soldermiser !!!!
Esos woofers con ventilación (como mi bocinita) pasar un trocito de madera ligera, poner una segunda araña del mismo tamaño en la parte trasera, bien centrada, luego puede cortar el cono y la canasta cuando haya secado el pegamento...un Soldermisexcitador
These woofers with ventilation (like my little driver) pass a piece of light wood, put a second spider at the same size, well centered, at the rear, then can cut the cone and basket ... a Soldermisexciter....Sexy !!!
Señor Soldermiser !!!!
Esos woofers con ventilación (como mi bocinita) pasar un trocito de madera ligera, poner una segunda araña del mismo tamaño en la parte trasera, bien centrada, luego puede cortar el cono y la canasta cuando haya secado el pegamento...un Soldermisexcitador
These woofers with ventilation (like my little driver) pass a piece of light wood, put a second spider at the same size, well centered, at the rear, then can cut the cone and basket ... a Soldermisexciter....Sexy !!!
Si, comprendo amigo!
Screw + glue "test" seems ok. Can't say better but no worse. So I will maul 2nd panel today. Meanwhile, I googled and discovered that yes, you can thin Gorilla Glue. And it doesn't foam so much. Hmmm....wonder how it would work as a layer on the panel? New noise last night: when turned up, the aluminum skin is "singing". This is an argument to avoid aluminum facing on next panel
Meanwhile, 5 days remain and two papers due
Screw + glue "test" seems ok. Can't say better but no worse. So I will maul 2nd panel today. Meanwhile, I googled and discovered that yes, you can thin Gorilla Glue. And it doesn't foam so much. Hmmm....wonder how it would work as a layer on the panel? New noise last night: when turned up, the aluminum skin is "singing". This is an argument to avoid aluminum facing on next panel
Meanwhile, 5 days remain and two papers due
More bilungual blathering ...
Mexican: Ud. me ha dado una idea quizá mejor para fijar un bocino normal en vez de exciter. En lugar del método Soldermizer (pegar el cono al trasero de pantalla con o sin el "puck"), a ver si uno podría pegar el trasero del bocino a superficie de la pantalla. Pues fijar un palo (de madera) entre el cono y el superficie frente de la pantalla.
Mexican gave me another idea for how to use a "normal" driver as an exciter. Instead of the Xrk971/Soldermizer method, one simply glues the back of the driver to the backside of the panel. Then a dowel or other rod is passed through the center of the magnet/voice coil through the back plate (there IS a hole there, isn't there? In mine yes.) and simply affix the other end to the panel's front (and middle.) If nothing else, this method should insure perfect(-er) voice coil alignment.
Mexican: Ud. me ha dado una idea quizá mejor para fijar un bocino normal en vez de exciter. En lugar del método Soldermizer (pegar el cono al trasero de pantalla con o sin el "puck"), a ver si uno podría pegar el trasero del bocino a superficie de la pantalla. Pues fijar un palo (de madera) entre el cono y el superficie frente de la pantalla.
Mexican gave me another idea for how to use a "normal" driver as an exciter. Instead of the Xrk971/Soldermizer method, one simply glues the back of the driver to the backside of the panel. Then a dowel or other rod is passed through the center of the magnet/voice coil through the back plate (there IS a hole there, isn't there? In mine yes.) and simply affix the other end to the panel's front (and middle.) If nothing else, this method should insure perfect(-er) voice coil alignment.