Here's the first revision. Note, this project did NOT start as a DML project. That came up unexpectedly looking at speaker options for a tough space. I haven't had a home audio system beyond headphones since 2006 (due to family, as a bachelor, I had a killer home theater). I have space constraints -- the boxes are workable because they weigh nothing and I can hang them up elsewhere when not using. Here's the first round:
40 watts and it sounds pretty incredible at desk listening distance. Speakers are the 6$ exciters. The sub is the Goldwood 406D which is now 15$. I didn't mount the plate to it as I've heard some people have trouble with a good seal and also want the option to upgrade. Back can be opened to upgrade the woofer at some point also. It's reclaimed 3/4" hard maple. I didn't even know about these tiny amps. I recycled a great vintage Yamaha because I just don't have room plus the weight. If I knew about these little amps you can get, I might have started this project a few years ago. The aesthetics of this setup is the biggest issue. I had issues with my 1/4" round bit which I think would look better for the woofer and also it could use a couple padauk pinstripe inlays. The box on right should be unfolded to match the print of the box on the left.
So, version 1.1? I got the DAEX32 EP4 exciter, 40w, and mounted the first one to the typical pink insulation square; rounded corners, sanded. Haven't listened to it since gluing it on. In the press-against tests they sounded better with the squares than the cardboard towers; to me the little ones were better with cardboard. I'll get to a proper test in the next couple of days. Turns out I have a space on one wall I can make these work, I think. Not ideal listening position but...
I haven't thought about audio in so long I've forgotten just about everything. I have 2 studio monitors with 6.5" drivers -- they are heavy as sin and no way for me to use them in the space I have. However, they can be wired "bi-amp" so I should have tried using one of those as a sub before building one. If good, then I do have space on the floor and I can have 3 of these smaller subs (no room for my 10" Energy sub in storage). For just my desk area, the sub I made is all I'll ever need. In fact, on my second day of listening I kept turning it down. However, my imagination is on a binge and if I can put them away easily, then I have a recliner that faces a TV that you can see on the wall, and setting something up between the TV and the recliner so I can listen there, or even for a makeshift HT would be cool.
I did have a question: what do people think about these:
https://www.parts-express.com/GRS-PT6816-8-8-Planar-Slim-Tweeter-8-Ohm-272-128?quantity=1
I'm not bound to DML. I just thought it was a cool / cheap idea to experiment and it's lightweight stuff that I can manage in my space.
Doesn't have to be this brand, but would planer tweeters like this sound good from 2.5' away? would they be too much? I could try something like this for the build for the listening chair but wondering about mid-range; in addition to having subs, what else would you need to support these?
40 watts and it sounds pretty incredible at desk listening distance. Speakers are the 6$ exciters. The sub is the Goldwood 406D which is now 15$. I didn't mount the plate to it as I've heard some people have trouble with a good seal and also want the option to upgrade. Back can be opened to upgrade the woofer at some point also. It's reclaimed 3/4" hard maple. I didn't even know about these tiny amps. I recycled a great vintage Yamaha because I just don't have room plus the weight. If I knew about these little amps you can get, I might have started this project a few years ago. The aesthetics of this setup is the biggest issue. I had issues with my 1/4" round bit which I think would look better for the woofer and also it could use a couple padauk pinstripe inlays. The box on right should be unfolded to match the print of the box on the left.
So, version 1.1? I got the DAEX32 EP4 exciter, 40w, and mounted the first one to the typical pink insulation square; rounded corners, sanded. Haven't listened to it since gluing it on. In the press-against tests they sounded better with the squares than the cardboard towers; to me the little ones were better with cardboard. I'll get to a proper test in the next couple of days. Turns out I have a space on one wall I can make these work, I think. Not ideal listening position but...
I haven't thought about audio in so long I've forgotten just about everything. I have 2 studio monitors with 6.5" drivers -- they are heavy as sin and no way for me to use them in the space I have. However, they can be wired "bi-amp" so I should have tried using one of those as a sub before building one. If good, then I do have space on the floor and I can have 3 of these smaller subs (no room for my 10" Energy sub in storage). For just my desk area, the sub I made is all I'll ever need. In fact, on my second day of listening I kept turning it down. However, my imagination is on a binge and if I can put them away easily, then I have a recliner that faces a TV that you can see on the wall, and setting something up between the TV and the recliner so I can listen there, or even for a makeshift HT would be cool.
I did have a question: what do people think about these:
https://www.parts-express.com/GRS-PT6816-8-8-Planar-Slim-Tweeter-8-Ohm-272-128?quantity=1
I'm not bound to DML. I just thought it was a cool / cheap idea to experiment and it's lightweight stuff that I can manage in my space.
Doesn't have to be this brand, but would planer tweeters like this sound good from 2.5' away? would they be too much? I could try something like this for the build for the listening chair but wondering about mid-range; in addition to having subs, what else would you need to support these?
What does "DML" stand for?
I suspect that cardboard may be a good diaphragm material because it is lossy. Cardboard never rings.
Are the cones attached to the cardboard? The resonant frequency has to be low to get bass. I expect high frequencies to beam due to the large dimensions.
Ed
I suspect that cardboard may be a good diaphragm material because it is lossy. Cardboard never rings.
Are the cones attached to the cardboard? The resonant frequency has to be low to get bass. I expect high frequencies to beam due to the large dimensions.
Ed
What does "DML" stand for?
Anyone building "exotic" speakers out of scraps of household materials on forums like this in the last 3 years probably watched this Tech Ingredients video.
system 1.1 is the above, but swap out the boxes for the DAEX32 EP4 foam boards.
Tight space, but kind of out of the way. This is a quick and dirty hang job for now.
It took a few anxious minutes to get the sound right. I thought my little sub or the plate had an issue - no sound, but it turns out that the boards are substantially louder than the boxes and so the main volume wasn't high enough for the sub to come through at the old, "low" level.
The slight advantage with the boxes was I had them positioned equi-distance from each ear. But, the foam boards with larger exciter win by a lot. I only have 40w total power, and near full blast with a good orchestra and standing 6 feet back it's epic. And the boards fill the room unlike the boxes. I go to the door and it still sounds great. Even with the monitor obstructing.
Tight space, but kind of out of the way. This is a quick and dirty hang job for now.
It took a few anxious minutes to get the sound right. I thought my little sub or the plate had an issue - no sound, but it turns out that the boards are substantially louder than the boxes and so the main volume wasn't high enough for the sub to come through at the old, "low" level.
The slight advantage with the boxes was I had them positioned equi-distance from each ear. But, the foam boards with larger exciter win by a lot. I only have 40w total power, and near full blast with a good orchestra and standing 6 feet back it's epic. And the boards fill the room unlike the boxes. I go to the door and it still sounds great. Even with the monitor obstructing.
I'm interested in adding more power, but as little as possible. One aspect of the system I enjoy is there is no noise. Dipping into quite parts doesn't leave a hiss or hum from anything.
You might interested in this thread. https://www.diyaudio.com/community/threads/a-study-of-dmls-as-a-full-range-speaker.272576/
I can highly recommend these Ikea canvas based speakers. Just two pieces of 4 mm poplar plywood, some scrap wood for the spine and glue. Great sound for very little money. Perfect fot for the purpose of low level near field listening while working on the laptop.
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I pop in there occasionally. This thread is the low-IQ version of that one.You might interested in this thread
The exciter is DAEX30HESF-4, it is glued by construction glue to the spine (and with its self adhesive ring to the plywood board). It is important to have the spine just slightly higher than exciter back, the construction glue will fill the gap.
I created a spine for one of my 6$ Daytons, the same one as on the boxes in OP, glued a thin board to that, glued a 9 x 17 piece of cardboard to that, and then clamped down the spine. It sounded like an okay small speaker. disconnected it and connected one of the boxes above and it's not even close, the box destroys it. It sounded so good in comparison I had to do another listen test against the purple foam with the larger Dayton, and that showdown is much closer. The foam still wins overall. Guessing the small Dayton is just too small to get the mounting benefits. I could have done something wrong also, but it's hard to imagine I could have screwed up that dramatically. It sounds much like the experiments without the spine on smaller pieces of cardboard I did the first day, and again, with the little Daytons, it sound much better with the exciter facing you. I'll need to eventually try the spine with a larger exciter, don't have a spare one of those right now.
The spine is necessary for the canvas on frame construction. Or if the panel is held e.g. by foam tape in a frame. Clamping the spine to the same panel as the exciter is no good, since it reduces the energy transfer. When the panel is held on soft suspension, the spine makes sure the exciter is not moving and that the coil is not loaded by the weight of the exciter.
Oh, I see. I'll have to re-try this one. Now, given your exciters are a 40w version, have you tried the standard Tech Ingredients 24" x 24" foamboard version and if so, how does it compare?
I tried only a larger canvas before, which was too large and loose - so it had problems with bass. The new ones are built to fit the window and the canvas on these is tighter. I plan to make larger foam panels with 4 exciters later - similar to these: https://www.diyaudio.com/community/threads/dml-pa-systems.390363/
The canvas works more like a speaker surround, if I understand things well, it is actually the plywood that is the key thing.
The foam panels should be louder/more efficient.
I like these a lot - very detailed sound, nice stereo effect on my work table. I wanted to measure them and apply some EQ, but it is not really necessary. Some EQ would be needed for compensating the position - they sound better when further from wall. For higher levels, a bass unit/ subwoofer would be needed.
The canvas works more like a speaker surround, if I understand things well, it is actually the plywood that is the key thing.
The foam panels should be louder/more efficient.
I like these a lot - very detailed sound, nice stereo effect on my work table. I wanted to measure them and apply some EQ, but it is not really necessary. Some EQ would be needed for compensating the position - they sound better when further from wall. For higher levels, a bass unit/ subwoofer would be needed.
I'm slowly furthering the cause. The main blocker now is aesthetics. If you start with Home Depot boxes, and then move to foam, you might get compliments on how good the foam looks, but ultimately, the foam doesn't look good. Flat black or some other creative color would be better, and I'd prefer a different shape. But it's all about how much it will affect the sound. In the DML youtube videos I've watched, I've worried about paint because there seems to be a correlation between people painting their foam and then attaching tweeters. On the other hand, on some old Dayton-related threads, can't remember where they are, the Dayton guy says to treat the foam with a water / glue mix.
Anyway, I first tried covering with fabric. So I bought a yard of black fabric and did a trial cover of one speaker and I could hear enough of a difference
that I scrapped the idea -- maybe a different kind of fabric but I don't have any laying around so on to paint. I went with Liquitex craft spray paint from a Youtube recommendation, and they have it 2-day shipping on Amazon. Carbon black. I'm very impressed with the paint itself. I did several light coats with drying time in between. Probably could have used less, as sunlight is incredibly revealing. Attached a pic; I'd say it's one of those things tough to take a picture of and looks much better than in the picture. With a less beat-up foam board and some reshaping, aesthetics problem solved. But sound?
I listened to various clips over and over, connecting each to the same channel and it's a tough call. With a classical guitar, there is fret noise and nuance that comes through on the unpainted panel. It's brighter and airy. But the painted panel isn't dull, I definitely don't feel I need a tweeter for it. There's a tradeoff -- the painted panel sounds tamed. If the piece has reverb, crescendos get harsh with these speakers and replaying one of those spots over and over is definitely better on the painted. Prior to painting, I put a couple layers of thin insulation in the fabric I bought and pinned it to the wall behind the DMLs, hoping to ease the harshness -- I didn't do before and after tests as that's not easy to switch out. I think the paint is probably achieving what I was hoping with the fabric behind it. So the final evaluation for now is that without paint, there are passages that sound crisp and airy, adding a spark of magic the painted are missing, but other passages, with multiple instruments and things getting going, the unpainted can sound like it's in a bathroom compared to the painted, which sounds more controlled.
Anyway, I first tried covering with fabric. So I bought a yard of black fabric and did a trial cover of one speaker and I could hear enough of a difference
that I scrapped the idea -- maybe a different kind of fabric but I don't have any laying around so on to paint. I went with Liquitex craft spray paint from a Youtube recommendation, and they have it 2-day shipping on Amazon. Carbon black. I'm very impressed with the paint itself. I did several light coats with drying time in between. Probably could have used less, as sunlight is incredibly revealing. Attached a pic; I'd say it's one of those things tough to take a picture of and looks much better than in the picture. With a less beat-up foam board and some reshaping, aesthetics problem solved. But sound?
I listened to various clips over and over, connecting each to the same channel and it's a tough call. With a classical guitar, there is fret noise and nuance that comes through on the unpainted panel. It's brighter and airy. But the painted panel isn't dull, I definitely don't feel I need a tweeter for it. There's a tradeoff -- the painted panel sounds tamed. If the piece has reverb, crescendos get harsh with these speakers and replaying one of those spots over and over is definitely better on the painted. Prior to painting, I put a couple layers of thin insulation in the fabric I bought and pinned it to the wall behind the DMLs, hoping to ease the harshness -- I didn't do before and after tests as that's not easy to switch out. I think the paint is probably achieving what I was hoping with the fabric behind it. So the final evaluation for now is that without paint, there are passages that sound crisp and airy, adding a spark of magic the painted are missing, but other passages, with multiple instruments and things getting going, the unpainted can sound like it's in a bathroom compared to the painted, which sounds more controlled.
"if I understand things well, it is actually the plywood that is the key thing."
Yeah. I've tried a variety of tweaks since I posted last time, and the one thing that makes a huge difference is a frame. For bass. It's night and day. That got me motivated because with a frame the options for mounting these are so much better. Today was a huge effort to make progress and I got all 4 panels mounted to frames. I'm just gluing them with wood glue. I will have to trim because of space so 4 22" x 24" xps panels with the Dayton thrusters.
I assume it's due to construction demand, but Home Depot 1/2" sanded plywood while way more expensive than it used to be, is cheaper than the junk stuff. So it was cheaper than I expected.
Yeah. I've tried a variety of tweaks since I posted last time, and the one thing that makes a huge difference is a frame. For bass. It's night and day. That got me motivated because with a frame the options for mounting these are so much better. Today was a huge effort to make progress and I got all 4 panels mounted to frames. I'm just gluing them with wood glue. I will have to trim because of space so 4 22" x 24" xps panels with the Dayton thrusters.
I assume it's due to construction demand, but Home Depot 1/2" sanded plywood while way more expensive than it used to be, is cheaper than the junk stuff. So it was cheaper than I expected.
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Got a little bit done this morning. I cut the excess foam off on the table saw. cuts really nicely but I will say be prepared for the worst dust you've ever seen, worse than MDF. The part I've had a mental block on is rounding the edges. My go-to router canister broke, and my little Makita's template is too small for the 1/2" roundover. I bought a new bit and the size was mis-advertised. I sighed, and detached my 1/2" router from the table, I've never actually used it by hand it and it's too massive for the spongy xps; can't control it. So made a custom template for the little Makita that's big enough for the bit, plus it's much larger than the stock template for better control, because this stuff is so bouncy. It ended up working great. I should have smoothed the template though as it scratched the xps surface a little but I just have so little patience sometimes.
It's worth mentioning all of this just because I think people ought to consider routing their DML edges. I don't like making bailing-wire-and-tape recommendations when it comes to power tools for safety reasons, but in this case I never felt the cutting was the least bit unsafe, it's just really easy to damage. Anyway, a light router with a large template seems to be the solution. I highly recommend having some sacrificial foam to practice with.
Almost starting to look like a real speaker. Would look even better if I taped off the wood and stained it or used hardwood plywood. But I think the biggest thing DML speakers have going against them is they generally look ridiculous, nobody except the most pragmatic left-brained engineers at least wants to have pink or green insulation hanging from the ceiling on a wire. Even after getting them to look decent, durability is going to be an issue, I'm sure.
It's worth mentioning all of this just because I think people ought to consider routing their DML edges. I don't like making bailing-wire-and-tape recommendations when it comes to power tools for safety reasons, but in this case I never felt the cutting was the least bit unsafe, it's just really easy to damage. Anyway, a light router with a large template seems to be the solution. I highly recommend having some sacrificial foam to practice with.
Almost starting to look like a real speaker. Would look even better if I taped off the wood and stained it or used hardwood plywood. But I think the biggest thing DML speakers have going against them is they generally look ridiculous, nobody except the most pragmatic left-brained engineers at least wants to have pink or green insulation hanging from the ceiling on a wire. Even after getting them to look decent, durability is going to be an issue, I'm sure.
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