Those noise samples you provided don't qualify as music in my book, and after coming through my laptop speakers and all the CZcams compression, frankly, I didn't get any reality out of this
Can't help you much with the music, the tracks are just meant to be an A/B test. I'd suggest not using your laptop speakers (for anything) if you're interested in good sound though! Treat yourself to some headphones.
Hi Ben, thank you for this. I work directly in the field of audio, and I like to keep my ear to the ground to see what's happening in the DIY scene. Of all the vids I found yours to be the most useful and sensibly approached. Firstly, that response curve basically stays the same is absolutely fascinating. What this seems to indicate is essentially fully excited across all its harmonic modes in whichever position the device is placed, but that more devices are required to reach the optimum for the lower harmonics. The goal with the placements being off centre, to the membrane itself and each device, is not emphasise the same set of harmonics. I had wondered whether, by adding drivers in close but not exact proximity, each the same distance apart, would produce issues at about the 6.5khz region, and I do see a bit of variance there, but it doesn't look too bad. That's because in the air that would be the wavelength roughly that distance centre to centre. However, the speed of sound in well over 10 times that. I do wonder whether an exponentially related spacing (for instance x squared = y*2) would achieve more harmonically spread results, but maybe given the wavelengths inside the material that's entirely moot. Much appreciated!
As usual, a very interesting experiment. Thank you, Ben. As others have noted, the size of the panel may be a limiting factor. I noticed today that Office Works (and other outlets, no doubt) sell A2-sized 5mm foam panels (AUD19.00 for a 5-pack). These may work better for producing lower registers. I'm hoping to try these myself with a 20-W 4-Ohm exciter in each panel in a couple of weeks.
It's called wave cancellation. Placing another exciter at the dead zone creates a new dead zone between the two exciters as the exact same wavelengths cancel each other out.
Thanks for all your work in these DML speaker test videos. I'd be curious to see how 3 drivers wired "2 in parallel" wired in series to the 3rd driver for a total of 6 ohms would fit in to your series of charts.
Plugging that into the series/parallel calculator I linked gives total load of 2.67ohm so probably not a great idea. This is why I wired them in series until I had 4 of them.
Hi again Ben A few comments on this test: The higher frequency modes take relatively less energy to excite than the low frequency modes and in this case the panels are relatively small, are quite thick (for this size) and therefore stiff. A single 5W exciter would conceivably not have the punching power to produce decent low frequency bending waves in this panel so it follows that adding more power will improve this aspect up to a point. I would also expect that the 5W exciter coils would have a very limited Xmax. So in all, I don't believe that this test proves that multi exciters are better than a single one - just that if a panel is underpowered, adding power will likely produce more bass and mid-range. Once that saturation point is reached (as stated by @nakedlunch), I doubt any improvement will be found. A useful test may be to measure this panel with a single 20W exciter and compare the results to the 4x5W. Multi-exciters could conceivably be used to try and even out the response patterns in a panel but as others have reported, the resulting interference between the exciters can lead to a muddier sound. Cheers
Great idea on the 20w vs 4x5w test. I haven't had a chance to follow up on this video yet and I was a bit rushed on the day but I do agree that the multi-exciter setup sounds worse in clarity, particularly in the HF. Running a back to back test vs a single larger unit might help to illustrate this as well.
I've messed around a bit with DMLs and other than underpowering a panel, I suspect the other big improvement that comes from adding additional exciters is in added reaction mass. Remember that the exciter can only move a panel in proportion to its mass. A 20g exciter on a 200g panel is going to displace itself far more than it moves such a heavy panel, especially at low frequencies. A second exciter doubles the mass that the panel gets to push against, and I think it's easy to hear both the increase in both volume and low end response. From what I've found, just epoxying a weight to the back of the exciter can make a similar difference in low end response provided that the exciter has enough power to push the panel.
I just got 2 of those speakers to play with 7:40 Because you added the 4th speaker there the low frequency has more material (environment) to dissipate, you need a bigger panel you should think if the speaker is in the center of the square and has some frequencies produced, the rest of the panel will produce low frequencies, the area of rectangle - the area of square= lower frequencies
Thinking it's higher because the center of the 4 array is closer to the 180/252 point. Adding more exciters, but moving the center away is offsetting? Maybe not.
If you present these graphs, please show the noise floor as well. Since all measurements are only valid if the speaker noise is X db more than the noise floor. Thank you.
If the bottom part is fixed, the whole plate will vibrate and the bass will sound right. Great experiments. In another CZcams video, I can see that the plate vibrates as the reflected light is shaken, but in your video the reflected light is static.
For my actual speakers that I'm (very slowly) building, I am using a panel fixed in place using 6 screws (and rubber spacers) in a wood frame, so in effect the top, bottom and sides are all fixed. I guess there are many ways to approach it though as I was also very happy with my previous free hanging panels.
I can understand the wanting more concept here, but my experience with DML is stick with a single driver, best you can afford and highest power, after that your just possibly increasing overall volume, but not going to gain any better mid or low frequency response, I have a set of pink panels 24"x24" with the standard 2/5- 3/5 placement a decent bluetooth /aux amp with a sub channel and they rock my socks off. In this instance the old K.I.S.S ( keep it simple stupid) applies. the sub I'm using is an old computer speaker sub 6" and is really! thumps I tried adding 2 and it was waaay too much bass very clear bottom end, but far too much of it.
Could you tell me what bluetooth amp and exciter you used. İ had this idea to build a panel speaker hanging from the ceiling. And then have the power from the ceilling as well so it can look all wireless
The "dead spots" on the panel change based on the frequency of the sound being produced. There may be one or more 'true' dead spots that are dead at all frequencies, but I have not found one. You can test yourself. I did it by placing the panel horizontal, putting a taped border around the edge of the panel, and pouring salt to cover the panel. I have used talc, rice, salt, flour and BBs. They all behave differently. But find what works for you. As you play different frequencies you can observe which areas of the panel are vibrating and which are dead. As the frequency changes the lively spots move. You can also observe how the sound falls off the corners of the panel, which is why the manufacturer recommends rounding the corners to eliminate that fall off. The 4 x 5 shape also keeps the sound in the panel which helps overall quality. Lastly, you commented on another video that the bass shakers were developed to limit bass (I'm paraphrasing), but that is not exactly correct. They were developed to deliver parts of the bass sound range that are otherwise inaudible and that can transfer through material and 'heard' in other ways. For panel speakers they can act like subwoofers and enhance the bass response without needing an actual separate subwoofer. When I post my configurations I'll tag you. I don't do any measurments, though, it's only about how it sounds. Cheers.
Thanks - that does seem like a much better way of measuring it. Re the bass shakers - I actually bought one of the dayton puck-style ones to test with, but I haven't had the chance to do so yet. I wasn't too hopeful due to the website saying things like the following: "When a BST-1 Bass Shaker is installed on a resonant surface, it increases the portion of tactile sound as being "felt" beyond what is normally produced by subwoofers and ordinary speakers." With no mention of enhancing audible bass. Very interested to see how you've applied them!
@@TypicalBenYT The same way exciters work the bass shakers sound will depend on the "MATERIAL", its attached to as most bass shakers are attached to the wood portion of the furniture.
A dead zone would be a node I would imagine. Each size panel would have differing node locations. I know guitar strings’ nodes are where the string is not moving and that’s also where harmonics come from. Panels work differently but they still have nodes or dead spots where you won’t get the full vibration of the material if you place an exciter there. This is all just my ponderings. I think if you find the top of the arc of each vibration you’d have the optimal placement for your excited.
Yeah you're not wrong - there will be almost infinite variations of panel dimensions and exciter number and placement/s. It's definitely something I'd like to dive into further when I can.
I'm enjoying following your progress. I plan on using a lot of your and other's when I build by own. I. Toyi g with the idea of using guitar or cello as well.
Hey James, thanks very much. I'm actually learning a lot from the feedback I get from my videos so it's definitely been a 2 way street. I've seen a video using acoustic guitars - interesting concept and I'd like to hear how it sounds in person. Not that I like the idea of butchering a nice guitar but it would be really interesting to see a comparison between a cheap DML guitar vs a nice Martin or something as well. Would like to hear/see how it goes if you do it!
Great video! Have a few questions. 1. Might have missed, but how thick is the panel? 2. Have you tried the other configurations of 4x exciters? I know Matty Hughes uses another one for his panels. 3. Have you tried doing measurements on 2 panels at once? That is same configurations but two panels in total?
Thanks! The panel is 4.5mm thick in this case. No - this configuration is listed as the default (the other is named ‘alternate’ or something in the guide. If I can unstick these without ruining them I could give it a go. My panel pairs have so far been single exciters. I am starting to tinker with different configs in preparation for my next build. I also don’t have 8 of these try it with sorry.
I haven't had much chance to test in more detail but I suspect you'd get the best results by attaching them at different distances from each other to avoid reinforcing the same frequencies across the board. I plan to test different combinations when I get the chance.
Ok, I’ve got hours into these videos and yours is the last one I’m going to watch. Cutting to the chase! What was the best setup in your experience. I’ve got tons of old Klipsch and Boston parts laying around and I want to try this. Just a simple 1234 answer would be great if you don’t mind please. Thanks Dan Hanson in Oregon.
Hello my friend, not sure why I watch these videos but every time I see anything regarding a DML build, I still watch. Drives me nuts every time I watch them (I was involved in the commercial development of a product or two using this type of technology. It's frustrating stuff but a lot of experimenting fun. and everybody, I mean everybody putting out these videos is doing it completely wrong. Doesn't help that the little PDF you get from providers is also littered with partial truths that are of little use to you as a builder). So here's the skinny on what's going wrong, you're using the wrong material at the wrong dimensions and definitely loading those exciters in the wrong manner at the wrong spot on the material. Here's a little hint you're trying to couple the force of those four exciters into one single episode of force per a cyclical motion. Cluster them tightly together in a diamond-like shape and put them down towards the bottom right corner using the same but modified ratio. try that first & see your results. The idea is not to spread the force too widely cuz then they're counteracting each other. Also try to invest in a handful of little foam damper pads you know the kind that go underneath objects so you can not scratch up surfaces of your table etc you know the kind sticky back type ones. Try different shapes of those, sizes and placement areas. once you start kicking off some of those anti nodes from your material it will really really bring out some great audio. I've been working with this type of electro-nodal acoustics since 2003. Good luck
@@AlexAlexBoBalex On the internet anyone can claim anything. If the comment would say the truth, there would be documentation confirming it. The documentation says itherwise though.
In theory yeah just wire them up with opposite phase and get a ‘push-pull’ effect. I haven’t tried it but from what I’ve read it doesn’t tend to do much. Interesting to try though for sure.
Great video! I was wondering if you have ever tried to hang the panels horizontally instead of vertically? I would like to know the quality differences between the two different hanging orientations, which I am equally curious about different methods of how to potentially hand them horizontally. The reason I am asking as I am interested in mounting these types of panels on my ceiling, ideally for a Dolby Atoms speaker setup.
Hey Grant, thanks! I haven’t tried that configuration. I guess you’d need quite a stiff material (or glue some bracing on the back of the panel) to stop them from sagging. Also you’d probably need to use a fairly light exciter on them as the weight of the driver magnet might affect performance.
Its pretty difficult to get this accurately ,best to use FEM simulation software Pansys dedicated for DML based designs.It will accurately predict the Frequency response and placement of multi exciters on the panel.
I thought after looking at the use of multi exciters on other sites that a second exciter should be placed in the centre? Yet you went to the opposite side of the first one towards the edge, is there a reason for that, that the others have not seen?
I was going by the guide linked in my description. I've never seen any evidence that 2/5 and center on the same panel is the best way. I think in the 1st Tech Ingredients video he uses those positions but on separate panels.
The cords you have suspended the panel with are dampening the panel. Using monofilament as recommended by manufacturers allows better sound by reducing the dampening.
Hey Steven. No doubt it all has an effect but I don't think that a little dampening is a bad thing. In my last design I rigidly fixed the panel to a wood frame in 10 locations (with rubber spacers) and produced a really nice sound.
The exciter produces frequencies flat to 70 hz or so - it's a shame you didn't test to the exciter spec. I am looking specifically at the exciter you chose specifically because of it's flat response curve on bottom.
Ben, If I see it right you have a lifting frequency response upto 20kHz measuring from a distance of 60cm? I would be interested to see a measurement from the listening distance ( also between 200Hz and 20kHz ) just to get an idea what actually will be possible in room. My prediction is that the panel will become less going up in the high frequencies ( would be good ) . If you make a measurement from a bigger (listening) distance, I think it would be good to do a mmm ( moving mike measurement) with REW, just to get a view of what the midhigh and high are really doing at the listening position. One sweep will not work on a bigger distance when measuring on 2 speakers. Do not use it for anything else than close mike in the frequencies above 5kHz. An alternative way of measuring is doing around 8 sweeps around the axis position and use average. But again mmm is most acurate and simple to do with REW . Use the generator on pink periodic noise and measure with the RTA function while moving the microphone ( on a stick ) in circular motions around the listening position . Be aware that in the end you want some sort of "housecurve" and not a flat line. A flat measurement is what you want if you measure a good speaker in an anechoic chamber on a distance of around 1m. That same speakerset in an average houseroom, measured on a normal listening distance will have a sloping curve towards the higher frequencies . And that is what will sound normal and good.
Really interesting, thanks for the info. I've never tried an MMM (in fact I'm not sure I've even heard of it) so this is really useful! I think my next 'measurement' type video will be comparing my larger panels - Plywood fixed and free, acrylic fixed and free configurations, so I will use it as an opportunity to up my measurement game as well! Regarding the sloping HF - that has been a feature of all panels I've tried (these small ones at 60cm and also my larger ones at ~1m). If I understand your comment, you're saying that it should flatten out at a greater distance, even on-axis? My assumption would be that the LF would drop off due to the wider dispersion.
@@TypicalBenYT This was a video that showed me how to do a mmm : czcams.com/video/6RiuwqzjqlQ/video.html&ab_channel=ProduceLikeAPro Recently I made a somewhat clumsy video ( saddly English isn't my native language) in my hometheater that shows the difference between a single measurement, multiple measurements averaged and a moving mike measuerement. you find it here : czcams.com/video/u3U2258k2IM/video.html&ab_channel=gvybin These measurements were done with the full 6.2 system working. The moving mike measurement is usefull when you do an in room measurement of a system or to measure the frequency response of a speaker in conjunction with the room it will be used around the listening position. The strange speakers are my hybrid electrostats ( ESL panels from 300 up to 20kH + 8" bass drivers from 80hz-300hz) + subwoofers from 17Hz-80Hz The sloping curve I get is equilized using equilizer APO with REW. My electrostat panels have a tendency to put out more treble but I worked the system down to a harman housecurve and it sounds way smoother , less harsh even on loud volumes, but powerfull in the bass. The bass extents to 17Hz and I cut it off below that as you can see in the measurement. You don't need that low bass extension for music, but for movie it is great
I guess you could. In fact now that you mention it I'm wondering if I should! I literally have just googled "Guitar amp frequency range" and the first result indicates ~ 70hz - 6khz is suitable, and if that's correct then I'd say it would be an ideal use case for this type of driver.
Yes you can. As long as they have the same impedance then the power will divide equally between the drivers. So if you had a 20w and a 40w driver together, power handling should be 40w (each driver receiving 20w).
@@jagejg7239 All else being equal they should be putting out the same amount of sound. Bear in mind that the watts rating is the driver's 'power handling' - basically how much power you can put into it. So in that example, both speakers would receive the same amount of power but if you kept cranking up the volume, one speaker would melt/crap out before the other.
@@TypicalBenYT well thanks for your help! I imagine DML speakers don’t benefit as much when it comes to driver diameter so I’ll just stick to a couple of low watt drivers connected in series.
@@jagejg7239 no problem at all. I’d just add that depending on your panel material, you might not need a lot of power as they can be very efficient (high volume for a given power level). For example with the foam panels (EPS) people seem to get by with relatively small exciters. Play around with it and enjoy the process!
By using different mounting techniques, materials, and lots of modifications on the transducers including close to 5 years of experimentation, you can hear the current version of my own design on my tiny YT channel.
This is definitely not how you wire them together. Good idea but you cant run power thru a speaker. You have the positive from the first to the negative on the second then the negative on the second to the positive on the third. Then with 4 its even weirder with the ground not connected to anything but another speaker. Not sure how or why you did it this way but pretty sure you got this completely wrong and almost positive most of them wernt even working for your test.
The 4 drivers sounded bad, at least on my end, like they had a diffusing chorus effect. Another thing... I understand that you have to use copyright free music, but does it need to be so digital? It's very poorly made and will sound bad on any speaker. It's not suitable for doing sound quality tests. Please use tracks with live recorded instruments and if possible - vocals. Thank you
Hey Jonathan, thanks for the feedback. Unfortunately I wasn't very well prepared for recording this and the two bits of music (single and multi) were recorded with different mics, which may exaggerate the effect, but in general yeah the single has a clearer, crisper sound. I hope to do more rigorous tests with various configurations soon. When building my larger panels, I am also hoping to up my recording quality to do some 'proper' listening tests/impressions. I'll take the feedback re the music into account for this.
Those noise samples you provided don't qualify as music in my book, and after coming through my laptop speakers and all the CZcams compression, frankly, I didn't get any reality out of this
Can't help you much with the music, the tracks are just meant to be an A/B test. I'd suggest not using your laptop speakers (for anything) if you're interested in good sound though! Treat yourself to some headphones.
Drrrrrrrrrrrrrrr
he can't test the response of the panel with music, batter test frequency from 0 to 20k, that's what you see there
Thank you for running these tests with measurement results, I really appreciate it! Looking forward to your next video. Cheers 🍻
No worries, glad you find them useful!
Hi Ben, thank you for this. I work directly in the field of audio, and I like to keep my ear to the ground to see what's happening in the DIY scene. Of all the vids I found yours to be the most useful and sensibly approached.
Firstly, that response curve basically stays the same is absolutely fascinating. What this seems to indicate is essentially fully excited across all its harmonic modes in whichever position the device is placed, but that more devices are required to reach the optimum for the lower harmonics.
The goal with the placements being off centre, to the membrane itself and each device, is not emphasise the same set of harmonics.
I had wondered whether, by adding drivers in close but not exact proximity, each the same distance apart, would produce issues at about the 6.5khz region, and I do see a bit of variance there, but it doesn't look too bad. That's because in the air that would be the wavelength roughly that distance centre to centre. However, the speed of sound in well over 10 times that.
I do wonder whether an exponentially related spacing (for instance x squared = y*2) would achieve more harmonically spread results, but maybe given the wavelengths inside the material that's entirely moot.
Much appreciated!
As usual, a very interesting experiment. Thank you, Ben.
As others have noted, the size of the panel may be a limiting factor. I noticed today that Office Works (and other outlets, no doubt) sell A2-sized 5mm foam panels (AUD19.00 for a 5-pack). These may work better for producing lower registers. I'm hoping to try these myself with a 20-W 4-Ohm exciter in each panel in a couple of weeks.
It's called wave cancellation. Placing another exciter at the dead zone creates a new dead zone between the two exciters as the exact same wavelengths cancel each other out.
Nice one Ben, very interesting journey your taking us on, great work.
Thanks a lot! Glad you’re finding it interesting.
you're
@@jimbendtsen8841 Damn, and that children is what comes from a moment of relaxed insouciance.
Thanks for all your work in these DML speaker test videos.
I'd be curious to see how 3 drivers wired "2 in parallel" wired in series to the 3rd driver for a total of 6 ohms would fit in to your series of charts.
Plugging that into the series/parallel calculator I linked gives total load of 2.67ohm so probably not a great idea. This is why I wired them in series until I had 4 of them.
Thanks for sharing your experiments.
No problem!
Love the shirt Ben! Thank you for sharing your experiments!
Hi again Ben
A few comments on this test:
The higher frequency modes take relatively less energy to excite than the low frequency modes and in this case the panels are relatively small, are quite thick (for this size) and therefore stiff.
A single 5W exciter would conceivably not have the punching power to produce decent low frequency bending waves in this panel so it follows that adding more power will improve this aspect up to a point.
I would also expect that the 5W exciter coils would have a very limited Xmax.
So in all, I don't believe that this test proves that multi exciters are better than a single one - just that if a panel is underpowered, adding power will likely produce more bass and mid-range. Once that saturation point is reached (as stated by @nakedlunch), I doubt any improvement will be found.
A useful test may be to measure this panel with a single 20W exciter and compare the results to the 4x5W.
Multi-exciters could conceivably be used to try and even out the response patterns in a panel but as others have reported, the resulting interference between the exciters can lead to a muddier sound.
Cheers
Great idea on the 20w vs 4x5w test.
I haven't had a chance to follow up on this video yet and I was a bit rushed on the day but I do agree that the multi-exciter setup sounds worse in clarity, particularly in the HF. Running a back to back test vs a single larger unit might help to illustrate this as well.
I've messed around a bit with DMLs and other than underpowering a panel, I suspect the other big improvement that comes from adding additional exciters is in added reaction mass. Remember that the exciter can only move a panel in proportion to its mass. A 20g exciter on a 200g panel is going to displace itself far more than it moves such a heavy panel, especially at low frequencies. A second exciter doubles the mass that the panel gets to push against, and I think it's easy to hear both the increase in both volume and low end response.
From what I've found, just epoxying a weight to the back of the exciter can make a similar difference in low end response provided that the exciter has enough power to push the panel.
I just got 2 of those speakers to play with
7:40 Because you added the 4th speaker there the low frequency has more material (environment) to dissipate, you need a bigger panel
you should think if the speaker is in the center of the square and has some frequencies produced, the rest of the panel will produce low frequencies, the area of rectangle - the area of square= lower frequencies
Thinking it's higher because the center of the 4 array is closer to the 180/252 point. Adding more exciters, but moving the center away is offsetting? Maybe not.
If you present these graphs, please show the noise floor as well. Since all measurements are only valid if the speaker noise is X db more than the noise floor. Thank you.
If the bottom part is fixed, the whole plate will vibrate and the bass will sound right.
Great experiments.
In another CZcams video, I can see that the plate vibrates as the reflected light is shaken, but in your video the reflected light is static.
For my actual speakers that I'm (very slowly) building, I am using a panel fixed in place using 6 screws (and rubber spacers) in a wood frame, so in effect the top, bottom and sides are all fixed.
I guess there are many ways to approach it though as I was also very happy with my previous free hanging panels.
I can understand the wanting more concept here, but my experience with DML is stick with a single driver, best you can afford and highest power, after that your just possibly increasing overall volume, but not going to gain any better mid or low frequency response, I have a set of pink panels 24"x24" with the standard 2/5- 3/5 placement a decent bluetooth /aux amp with a sub channel and they rock my socks off. In this instance the old K.I.S.S ( keep it simple stupid) applies. the sub I'm using is an old computer speaker sub 6" and is really! thumps I tried adding 2 and it was waaay too much bass very clear bottom end, but far too much of it.
Could you tell me what bluetooth amp and exciter you used. İ had this idea to build a panel speaker hanging from the ceiling. And then have the power from the ceilling as well so it can look all wireless
The "dead spots" on the panel change based on the frequency of the sound being produced.
There may be one or more 'true' dead spots that are dead at all frequencies, but I have not found one.
You can test yourself. I did it by placing the panel horizontal, putting a taped border around the edge of the panel, and pouring salt to cover the panel. I have used talc, rice, salt, flour and BBs. They all behave differently. But find what works for you. As you play different frequencies you can observe which areas of the panel are vibrating and which are dead. As the frequency changes the lively spots move. You can also observe how the sound falls off the corners of the panel, which is why the manufacturer recommends rounding the corners to eliminate that fall off. The 4 x 5 shape also keeps the sound in the panel which helps overall quality.
Lastly, you commented on another video that the bass shakers were developed to limit bass (I'm paraphrasing), but that is not exactly correct. They were developed to deliver parts of the bass sound range that are otherwise inaudible and that can transfer through material and 'heard' in other ways. For panel speakers they can act like subwoofers and enhance the bass response without needing an actual separate subwoofer. When I post my configurations I'll tag you. I don't do any measurments, though, it's only about how it sounds. Cheers.
Thanks - that does seem like a much better way of measuring it.
Re the bass shakers - I actually bought one of the dayton puck-style ones to test with, but I haven't had the chance to do so yet. I wasn't too hopeful due to the website saying things like the following:
"When a BST-1 Bass Shaker is installed on a resonant surface, it increases the portion of tactile sound as being "felt" beyond what is normally produced by subwoofers and ordinary speakers."
With no mention of enhancing audible bass.
Very interested to see how you've applied them!
@@TypicalBenYT The same way exciters work the bass shakers sound will depend on the "MATERIAL", its attached to as most bass shakers are attached to the wood portion of the furniture.
A dead zone would be a node I would imagine. Each size panel would have differing node locations. I know guitar strings’ nodes are where the string is not moving and that’s also where harmonics come from. Panels work differently but they still have nodes or dead spots where you won’t get the full vibration of the material if you place an exciter there. This is all just my ponderings. I think if you find the top of the arc of each vibration you’d have the optimal placement for your excited.
Yeah you're not wrong - there will be almost infinite variations of panel dimensions and exciter number and placement/s. It's definitely something I'd like to dive into further when I can.
Subscribed. Belated Yuletide Felicitations by the way. Please keep doing this, thanks
The shirt got my like!
Great job! Thanks for sharing.
Thanks I hope it's somewhat useful.
Couldn't you have just wired a resistor to it to increase impedence? Or am I missing something?
Another factor that changed on your 4th test, was the placement of the driver. Perhaps this is why you had a better result.
I'm enjoying following your progress. I plan on using a lot of your and other's when I build by own. I. Toyi g with the idea of using guitar or cello as well.
Hey James, thanks very much. I'm actually learning a lot from the feedback I get from my videos so it's definitely been a 2 way street.
I've seen a video using acoustic guitars - interesting concept and I'd like to hear how it sounds in person. Not that I like the idea of butchering a nice guitar but it would be really interesting to see a comparison between a cheap DML guitar vs a nice Martin or something as well.
Would like to hear/see how it goes if you do it!
I agree about compromising a good instrument. I'm considering damaged, very cheap ones, or a guitar body from a Chinese kit guitar
Great video! Have a few questions.
1. Might have missed, but how thick is the panel?
2. Have you tried the other configurations of 4x exciters? I know Matty Hughes uses another one for his panels.
3. Have you tried doing measurements on 2 panels at once? That is same configurations but two panels in total?
Thanks! The panel is 4.5mm thick in this case.
No - this configuration is listed as the default (the other is named ‘alternate’ or something in the guide. If I can unstick these without ruining them I could give it a go.
My panel pairs have so far been single exciters. I am starting to tinker with different configs in preparation for my next build. I also don’t have 8 of these try it with sorry.
I wonder if you could get something similar to a line array if you put the 4 drivers at every fifth of the panel vertically.
I haven't had much chance to test in more detail but I suspect you'd get the best results by attaching them at different distances from each other to avoid reinforcing the same frequencies across the board. I plan to test different combinations when I get the chance.
Ok, I’ve got hours into these videos and yours is the last one I’m going to watch. Cutting to the chase! What was the best setup in your experience. I’ve got tons of old Klipsch and Boston parts laying around and I want to try this. Just a simple 1234 answer would be great if you don’t mind please.
Thanks
Dan Hanson in Oregon.
Hello my friend, not sure why I watch these videos but every time I see anything regarding a DML build, I still watch. Drives me nuts every time I watch them (I was involved in the commercial development of a product or two using this type of technology. It's frustrating stuff but a lot of experimenting fun. and everybody, I mean everybody putting out these videos is doing it completely wrong. Doesn't help that the little PDF you get from providers is also littered with partial truths that are of little use to you as a builder). So here's the skinny on what's going wrong, you're using the wrong material at the wrong dimensions and definitely loading those exciters in the wrong manner at the wrong spot on the material. Here's a little hint you're trying to couple the force of those four exciters into one single episode of force per a cyclical motion. Cluster them tightly together in a diamond-like shape and put them down towards the bottom right corner using the same but modified ratio. try that first & see your results. The idea is not to spread the force too widely cuz then they're counteracting each other. Also try to invest in a handful of little foam damper pads you know the kind that go underneath objects so you can not scratch up surfaces of your table etc you know the kind sticky back type ones. Try different shapes of those, sizes and placement areas. once you start kicking off some of those anti nodes from your material it will really really bring out some great audio. I've been working with this type of electro-nodal acoustics since 2003. Good luck
So........where's the best place for DML build instructions then in your opinion?
@@AlexAlexBoBalex On the internet anyone can claim anything. If the comment would say the truth, there would be documentation confirming it.
The documentation says itherwise though.
I wanna know why some have a threaded hole in the back. Hmm
Could you put one on the direct opposite side in reverse wiring to amplify it
In theory yeah just wire them up with opposite phase and get a ‘push-pull’ effect.
I haven’t tried it but from what I’ve read it doesn’t tend to do much. Interesting to try though for sure.
Great video! I was wondering if you have ever tried to hang the panels horizontally instead of vertically? I would like to know the quality differences between the two different hanging orientations, which I am equally curious about different methods of how to potentially hand them horizontally. The reason I am asking as I am interested in mounting these types of panels on my ceiling, ideally for a Dolby Atoms speaker setup.
Hey Grant, thanks! I haven’t tried that configuration. I guess you’d need quite a stiff material (or glue some bracing on the back of the panel) to stop them from sagging. Also you’d probably need to use a fairly light exciter on them as the weight of the driver magnet might affect performance.
did you end up doing this? planning on doing the same for next holiday project
Its pretty difficult to get this accurately ,best to use FEM simulation software Pansys dedicated for DML based designs.It will accurately predict the Frequency response and placement of multi exciters on the panel.
I have heard that modelling software did exist but have never been able to find it. Do you know how one can get their hands on this?
I thought after looking at the use of multi exciters on other sites that a second exciter should be placed in the centre? Yet you went to the opposite side of the first one towards the edge, is there a reason for that, that the others have not seen?
I was going by the guide linked in my description. I've never seen any evidence that 2/5 and center on the same panel is the best way. I think in the 1st Tech Ingredients video he uses those positions but on separate panels.
Big or small panel ?
The cords you have suspended the panel with are dampening the panel. Using monofilament as recommended by manufacturers allows better sound by reducing the dampening.
Hey Steven. No doubt it all has an effect but I don't think that a little dampening is a bad thing. In my last design I rigidly fixed the panel to a wood frame in 10 locations (with rubber spacers) and produced a really nice sound.
The exciter produces frequencies flat to 70 hz or so - it's a shame you didn't test to the exciter spec. I am looking specifically at the exciter you chose specifically because of it's flat response curve on bottom.
Did you find any good exciters yet?
@@ERR0RR Not yet . . . still actively searching
How many watts to power? Could 16w do it?
It really depends on the size and material of the panel - with the right combo I'd say it'd be ok in a smallish room. So many variables though.
Have you ever given thought (as Wilbur said) .... to using an additional bass shaker?
Yes I have one in a box that I bought for testing. It might make an appearance in my next build but I haven’t done much testing with it yet.
what software are you uaing to graph the response??
Room EQ Wizard: www.roomeqwizard.com/
Ben,
If I see it right you have a lifting frequency response upto 20kHz measuring from a distance of 60cm?
I would be interested to see a measurement from the listening distance ( also between 200Hz and 20kHz ) just to get an idea what actually will be possible in room.
My prediction is that the panel will become less going up in the high frequencies ( would be good ) .
If you make a measurement from a bigger (listening) distance, I think it would be good to do a mmm ( moving mike measurement) with REW, just to get a view of what the midhigh and high are really doing at the listening position.
One sweep will not work on a bigger distance when measuring on 2 speakers. Do not use it for anything else than close mike in the frequencies above 5kHz.
An alternative way of measuring is doing around 8 sweeps around the axis position and use average.
But again mmm is most acurate and simple to do with REW . Use the generator on pink periodic noise and measure with the RTA function while moving the microphone ( on a stick ) in circular motions around the listening position .
Be aware that in the end you want some sort of "housecurve" and not a flat line. A flat measurement is what you want if you measure a good speaker in an anechoic chamber on a distance of around 1m.
That same speakerset in an average houseroom, measured on a normal listening distance will have a sloping curve towards the higher frequencies . And that is what will sound normal and good.
Really interesting, thanks for the info. I've never tried an MMM (in fact I'm not sure I've even heard of it) so this is really useful!
I think my next 'measurement' type video will be comparing my larger panels - Plywood fixed and free, acrylic fixed and free configurations, so I will use it as an opportunity to up my measurement game as well!
Regarding the sloping HF - that has been a feature of all panels I've tried (these small ones at 60cm and also my larger ones at ~1m). If I understand your comment, you're saying that it should flatten out at a greater distance, even on-axis? My assumption would be that the LF would drop off due to the wider dispersion.
@@TypicalBenYT
This was a video that showed me how to do a mmm : czcams.com/video/6RiuwqzjqlQ/video.html&ab_channel=ProduceLikeAPro
Recently I made a somewhat clumsy video ( saddly English isn't my native language) in my hometheater that shows the difference between a single measurement, multiple measurements averaged and a moving mike measuerement. you find it here : czcams.com/video/u3U2258k2IM/video.html&ab_channel=gvybin
These measurements were done with the full 6.2 system working. The moving mike measurement is usefull when you do an in room measurement of a system or to measure the frequency response of a speaker in conjunction with the room it will be used around the listening position.
The strange speakers are my hybrid electrostats ( ESL panels from 300 up to 20kH + 8" bass drivers from 80hz-300hz) + subwoofers from 17Hz-80Hz
The sloping curve I get is equilized using equilizer APO with REW. My electrostat panels have a tendency to put out more treble but I worked the system down to a harman housecurve and it sounds way smoother , less harsh even on loud volumes, but powerfull in the bass. The bass extents to 17Hz and I cut it off below that as you can see in the measurement. You don't need that low bass extension for music, but for movie it is great
@@gvybin oh great thanks, I’ll have a look at these when I get a chance. Appreciate the info!
Ce sunt astea, difuzoare? Au vreun indicativ?
I was using these:
www.daytonaudio.com/product/1174/daex19ct-4-coin-type-19mm-exciter-5w-4-ohm
@@TypicalBenYT OK,mulțumesc,se pot folosi și difuzoare normale de bandă largă ? Sper să nu fie o întrebare deplasată..
How's the bass?
Have you ever given thought to stacking two drivers?
Do you mean installing them front and back in a push/pull type configuration?
Let me ask you. Can you use one of these drivers with a guitar or bass amp. If not why not?
I guess you could. In fact now that you mention it I'm wondering if I should!
I literally have just googled "Guitar amp frequency range" and the first result indicates ~ 70hz - 6khz is suitable, and if that's correct then I'd say it would be an ideal use case for this type of driver.
Just keep having fun with it, please bye some cloths man.
Can I connect drivers of the same impedance but different watts?
Yes you can. As long as they have the same impedance then the power will divide equally between the drivers.
So if you had a 20w and a 40w driver together, power handling should be 40w (each driver receiving 20w).
@@TypicalBenYT so essentially the stronger driver would be running at half power?
@@jagejg7239 All else being equal they should be putting out the same amount of sound. Bear in mind that the watts rating is the driver's 'power handling' - basically how much power you can put into it. So in that example, both speakers would receive the same amount of power but if you kept cranking up the volume, one speaker would melt/crap out before the other.
@@TypicalBenYT well thanks for your help! I imagine DML speakers don’t benefit as much when it comes to driver diameter so I’ll just stick to a couple of low watt drivers connected in series.
@@jagejg7239 no problem at all. I’d just add that depending on your panel material, you might not need a lot of power as they can be very efficient (high volume for a given power level). For example with the foam panels (EPS) people seem to get by with relatively small exciters.
Play around with it and enjoy the process!
By using different mounting techniques, materials, and lots of modifications on the transducers including close to 5 years of experimentation, you can hear the current version of my own design on my tiny YT channel.
This is definitely not how you wire them together. Good idea but you cant run power thru a speaker. You have the positive from the first to the negative on the second then the negative on the second to the positive on the third. Then with 4 its even weirder with the ground not connected to anything but another speaker. Not sure how or why you did it this way but pretty sure you got this completely wrong and almost positive most of them wernt even working for your test.
PS Ben
Did you receive my follow up emails?
Cheers
Yep will get to them shortly… just had our hands full here in brissy over the weekend! All good now though.
The 4 drivers sounded bad, at least on my end, like they had a diffusing chorus effect.
Another thing... I understand that you have to use copyright free music, but does it need to be so digital? It's very poorly made and will sound bad on any speaker. It's not suitable for doing sound quality tests.
Please use tracks with live recorded instruments and if possible - vocals.
Thank you
Hey Jonathan, thanks for the feedback.
Unfortunately I wasn't very well prepared for recording this and the two bits of music (single and multi) were recorded with different mics, which may exaggerate the effect, but in general yeah the single has a clearer, crisper sound. I hope to do more rigorous tests with various configurations soon.
When building my larger panels, I am also hoping to up my recording quality to do some 'proper' listening tests/impressions. I'll take the feedback re the music into account for this.
Are you listening faster than 1x speed?
I had the same issue and realized I was listening at 1.25x.
@@VulgrDisplay I only started speeding up the vid a week or two ago. When I wrote this, I had never touched that setting