Looking forward to your next experiments... that HF response of the acrylic is very interesting, knowing that foam and wood boards somewhat lack highs, as per most of the results in the diy community. Thanks for sharing
Yes that was maybe the most surprising discovery, as I'd had the same relatively weak HF on my bamboo panels. Initially I was considering running a tweeter with these (having a taller frame, adding a 2nd smaller acrylic section on the top with a tweeter cut into it) but decided to run full length panels instead. If this result holds up then it seems like a win/win as I'll get good HF with extended LF (due to bigger panel).
Please stick on damping material in a circular pattern around the exciters. Don’t make a solid circle of damping material….leave some gaps. The peaks and valleys are my guess doubling and cancellations and adding damping material may reduce that. That material could be 15mm wide rubber attached with 3M double side tape. Try different weight material to help eliminate that resonance at those frequencies. This is all my uneducated guess work. Keep up the good work
I just got my exciters delivered today. Hoping this weekend I'll have them operational. For now I'm going with the foam core as my panels. I'm also using the fosi 100w amp. My question to you is how are you running yours with a sub? I have one but I don't have a receiver. And not sure what to use since the amp has Bluetooth. So far I have not come across any videos on people running additional speakers and power supplies. Also, are you running a crossover?
Hey Thomas, I'm using an active subwoofer with speaker-level inputs, so it's just a matter of wiring it in parallel with the main speakers. See example 2 in this diagram: soundcertified.com/wp-content/uploads/2020/06/how-to-connect-subwoofer-to-receiver-no-subwoofer-output-diagram.png Because the sub inputs aren't actually driving anything (just sending the signal into the sub's inbuilt amplifier) it doesn't present any additional load to the amp. The sub also has a built in crossover, which I have set to ~125hz currently. My current bamboo panels are running full range and I set the sub x-over to the point where the panels naturally roll off. For these acrylic panels I'm building, I plan to wire in a capacitor to roll off the low end, so it'll be all subwoofer below around 100hz. Hope that helps, enjoy your new panels!
@@TypicalBenYT I think its pvc foam with paper either side. I went to Office Works and roughly compared the weight and potential rigidity of two equal sized pieces, one of poster/foam board, and Coroplast. I ended up with Coroplast. The poster board would be an interesting alternative to try though....
I don't know if you do any post processing or just upload the stitched together clips but lowering the volume on the drilling would go a long way with headphone users. I'm getting ready to build two large panel DML speakers. Plan is two Dayton 4 ohm x 24 watt on each at the sweet spot. I was going to play with placing some rockwool insulation behind the panels to mitigate the bouncing frequencies... I'm just messing around, I don't know much about audio stuff but saw videos of these exciters and figured why not.
Hey James - thanks for the feedback I’ll keep that in mind! I reckon if you’re planning to wall Mount then then the insulation is a good idea. If you’re able to have them ‘out in the room’ like these floor standing versions, you might prefer to leave them open, or try both and see what sounds best!
Thanks in advance for your time and energy and for the great info. I was wondering what panel sizes you are using, I know they are 3 mm acrylic what are the external dimensions. I am about to start building an acrylic set 600x900 and was looking at the fixing points and the distance between each point. Will be using the dayton 4 ohm 40 w exciters. Will be trying single exciter first on a suspended panel and working my way up to 2 exciters on a frame with multiple fixing points.
Rather than rigidly screwing the sheet to the frame Ben, have you consided double sided tape of some kind, maybe soft sponge rubber or pvc foam tape....?
Yeah I have considered double sided tape. I’ll admit I decided to try the screw in method for aesthetic reasons - it has a nice sort of ‘floating panel’ look (sort of). I have also read about people having good results with various rigid setups, so thought it would be interesting to through my own method into the mix.
@@TypicalBenYT Quite so. I looked at the AER Goldy trying to figure out their mounting method, hoping for a cut-away view, but no such luck. There must be a dozen ways of mounting an acrylic panel, or any other material. Just a matter of finding out what gives the most pleasing results, aesthetically and sonically. All part of the fun without selling the grandkids into bondage...
@@TypicalBenYT also you use a section of pipe to hold the exciter in place for sweeps in various positions. That weight has to have a substantial impact? Does it just impact efficiency or does it impact response as well? Enjoyed watching your video thanks.
@@TypicalBenYT understood, have you done a reality check sweep? you can use your panel which has the exciter already installed on the acrylic and simply add the weight and see what it does to the response.
I suspect you holding the exciter on the panel as opposed to it being attached my cause undue interference in your measurements as you cannot maintain the same pressure each time you move and hold the exciter again Ben.
Hmm you might have a point. I can test this by taking several measurements in the same position but deliberately varying the force on the exciter. I’ll give it a go and comment the results!
I thought the whole idea behind DML panels is NOT to be fixed, rigid but free hanging exactly for the reason to vibrate freely from the excitors otherwise the sound would be damped. So I am not sure what you experiment here.
People usually make them free hanging (as I have with my other panels) but they don’t have to be that way, and some kind of damping is often a good thing. What I really want to do is find a way to make a DML that sounds good and looks good too, hence I’m trying different things.
@@TypicalBenYT I think by fixing them you will dampen the lower frequencies. But think about it. These speakers work based on the principle that the vibration is transferred from the exciter to the membrane so if you fix the membrane, make it more rigid, you actually limit the vibration. Now, that cannot help in any way unless you try to to separate the frequencies on purpose, to make like separate bands, channels, i.e. treble, medium and bass.
@@zberteoc If that were true, it would show up in the measurements - but in fact I got my best bass response by adding even more points of attachment to the panel. You are maybe thinking about the movement of a traditional speaker, where subwoofers require the most excursion to push out low frequencies. On a DML panel, the ability to play down low is affected by the longest dimension of the panel, but seemingly not by the excursion of the panel itself.
Yes I do think that shaping of panels could lead to very interesting results. When I’m done building my current project I’d like to try 4 or 5 different shapes of the same material to see how they compare.
Unsubscribed
Thank you.
@@TypicalBenYT My pleasure.
Excellent experimentation, & know it's doing alot of Good for all we experimenters out here! Tanx, & pleez don't stop :-)
Thank you Antoniio!
Looking forward to your next experiments... that HF response of the acrylic is very interesting, knowing that foam and wood boards somewhat lack highs, as per most of the results in the diy community.
Thanks for sharing
Yes that was maybe the most surprising discovery, as I'd had the same relatively weak HF on my bamboo panels. Initially I was considering running a tweeter with these (having a taller frame, adding a 2nd smaller acrylic section on the top with a tweeter cut into it) but decided to run full length panels instead. If this result holds up then it seems like a win/win as I'll get good HF with extended LF (due to bigger panel).
Please stick on damping material in a circular pattern around the exciters. Don’t make a solid circle of damping material….leave some gaps. The peaks and valleys are my guess doubling and cancellations and adding damping material may reduce that. That material could be 15mm wide rubber attached with 3M double side tape. Try different weight material to help eliminate that resonance at those frequencies. This is all my uneducated guess work. Keep up the good work
Great job Ben. Really interested as you progress with your research. Wishing you all the best!
Thanks so much Greg!
That’s a lot of detail ! Thanks
Good job...
I just got my exciters delivered today. Hoping this weekend I'll have them operational. For now I'm going with the foam core as my panels. I'm also using the fosi 100w amp. My question to you is how are you running yours with a sub? I have one but I don't have a receiver. And not sure what to use since the amp has Bluetooth. So far I have not come across any videos on people running additional speakers and power supplies. Also, are you running a crossover?
Hey Thomas, I'm using an active subwoofer with speaker-level inputs, so it's just a matter of wiring it in parallel with the main speakers. See example 2 in this diagram:
soundcertified.com/wp-content/uploads/2020/06/how-to-connect-subwoofer-to-receiver-no-subwoofer-output-diagram.png
Because the sub inputs aren't actually driving anything (just sending the signal into the sub's inbuilt amplifier) it doesn't present any additional load to the amp.
The sub also has a built in crossover, which I have set to ~125hz currently. My current bamboo panels are running full range and I set the sub x-over to the point where the panels naturally roll off. For these acrylic panels I'm building, I plan to wire in a capacitor to roll off the low end, so it'll be all subwoofer below around 100hz.
Hope that helps, enjoy your new panels!
My first thought of material for DMLs was art store foam core board. I would be interested in how it compares.
Great work, and Subscribed!
Thanks Lou. Is that stuff anything like the XPS panels people make?
@@TypicalBenYT I think its pvc foam with paper either side. I went to Office Works and roughly compared the weight and potential rigidity of two equal sized pieces, one of poster/foam board, and Coroplast. I ended up with Coroplast. The poster board would be an interesting alternative to try though....
I don't know if you do any post processing or just upload the stitched together clips but lowering the volume on the drilling would go a long way with headphone users.
I'm getting ready to build two large panel DML speakers. Plan is two Dayton 4 ohm x 24 watt on each at the sweet spot. I was going to play with placing some rockwool insulation behind the panels to mitigate the bouncing frequencies... I'm just messing around, I don't know much about audio stuff but saw videos of these exciters and figured why not.
Hey James - thanks for the feedback I’ll keep that in mind!
I reckon if you’re planning to wall Mount then then the insulation is a good idea. If you’re able to have them ‘out in the room’ like these floor standing versions, you might prefer to leave them open, or try both and see what sounds best!
Thanks in advance for your time and energy and for the great info. I was wondering what panel sizes you are using, I know they are 3 mm acrylic what are the external dimensions. I am about to start building an acrylic set 600x900 and was looking at the fixing points and the distance between each point. Will be using the dayton 4 ohm 40 w exciters. Will be trying single exciter first on a suspended panel and working my way up to 2 exciters on a frame with multiple fixing points.
No problem. Those ones are 1200x400mm. I prefer the narrow/tall aspect just for aesthetics.
I have found the sweet spot to be approx 20 -25cm between mounting points. At least on this shape of panel.
Rather than rigidly screwing the sheet to the frame Ben, have you consided double sided tape of some kind, maybe soft sponge rubber or pvc foam tape....?
Yeah I have considered double sided tape. I’ll admit I decided to try the screw in method for aesthetic reasons - it has a nice sort of ‘floating panel’ look (sort of).
I have also read about people having good results with various rigid setups, so thought it would be interesting to through my own method into the mix.
@@TypicalBenYT Quite so. I looked at the AER Goldy trying to figure out their mounting method, hoping for a cut-away view, but no such luck. There must be a dozen ways of mounting an acrylic panel, or any other material. Just a matter of finding out what gives the most pleasing results, aesthetically and sonically. All part of the fun without selling the grandkids into bondage...
@@logotrikes 100% agree!
Thanks. Have you considered using less symmetry on your panel mounts?
To be honest that didn’t even occur to me. I’m thinking about it now though!
@@TypicalBenYT also you use a section of pipe to hold the exciter in place for sweeps in various positions. That weight has to have a substantial impact? Does it just impact efficiency or does it impact response as well? Enjoyed watching your video thanks.
@@morayjames92 yeah the intention was just to maintain some pressure on the exciter to avoid buzzing.
@@TypicalBenYT understood, have you done a reality check sweep? you can use your panel which has the exciter already installed on the acrylic and simply add the weight and see what it does to the response.
I suspect you holding the exciter on the panel as opposed to it being attached my cause undue interference in your measurements as you cannot maintain the same pressure each time you move and hold the exciter again Ben.
Hmm you might have a point. I can test this by taking several measurements in the same position but deliberately varying the force on the exciter. I’ll give it a go and comment the results!
I have an idea to connect these to a massage table for acoustic experience?
I guess you could do something like that. It could be pretty cool to hear and feel the sound of it works out.
I thought the whole idea behind DML panels is NOT to be fixed, rigid but free hanging exactly for the reason to vibrate freely from the excitors otherwise the sound would be damped. So I am not sure what you experiment here.
People usually make them free hanging (as I have with my other panels) but they don’t have to be that way, and some kind of damping is often a good thing.
What I really want to do is find a way to make a DML that sounds good and looks good too, hence I’m trying different things.
@@TypicalBenYT I think by fixing them you will dampen the lower frequencies. But think about it. These speakers work based on the principle that the vibration is transferred from the exciter to the membrane so if you fix the membrane, make it more rigid, you actually limit the vibration. Now, that cannot help in any way unless you try to to separate the frequencies on purpose, to make like separate bands, channels, i.e. treble, medium and bass.
@@zberteoc If that were true, it would show up in the measurements - but in fact I got my best bass response by adding even more points of attachment to the panel.
You are maybe thinking about the movement of a traditional speaker, where subwoofers require the most excursion to push out low frequencies. On a DML panel, the ability to play down low is affected by the longest dimension of the panel, but seemingly not by the excursion of the panel itself.
perhaps consider circular acrylic shape
Yes I do think that shaping of panels could lead to very interesting results. When I’m done building my current project I’d like to try 4 or 5 different shapes of the same material to see how they compare.
@@TypicalBenYT it makes sense since drums are all circular
@@TypicalBenYT also perhaps try round painters canvas as they would simulate a drum
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