It looks like they may have done this on a smaller model to get more surface area? I have some rectangular 1" XPS panels that I should try that shape on.
Conversely, it makes me wonder, on their largest model, if it is the optimum shape, would it be beneficial to scale it up larger for my own use, as many builders prefer 1 square meter or over?
Conversely, it makes me wonder, on their largest model, if it is the optimum shape, would it be beneficial to scale it up larger for my own use, as many builders prefer 1 square meter or over?
It is easier to make a large panel sound good than it is a small panel,large panels also have large scale and dynamics and lower frequencies.
Hopefully you won't suffer the droop in response in the 100 to 300hz area.
Cutting the shape is going to be the hardest part,that's a large template you'll have to make, and can also be messy if rounding the edges.
Hope it goes well.
Steve
Hopefully you won't suffer the droop in response in the 100 to 300hz area.
Cutting the shape is going to be the hardest part,that's a large template you'll have to make, and can also be messy if rounding the edges.
Hope it goes well.
Steve
Bradleypnw says the 100-200/300 droop is due to room acoustics. The Yamaha NS30 is baffled, with 14 inch deep sides. I don't know of any DML builds that are using a baffle of any depth. Would that be beneficial for bass, yet not negatively effect the rest of the range?
That depends on context. Let's say you have a panel that works down to 20Hz. When you place it in a small room you'll run into room modes that result in dips and peaks caused by long wave length sound waves interfering with each other as they bounce off walls, ceilings, and floors. It wouldn't be a drop in that case it would be interference. You generate the sound wave but it cancels itself out.
That means, in small rooms, you don't derive advantage from a DML that works at lower frequencies. Once you drop below the room transition frequency you might as well run normal subwoofers and use available low frequency design methods. Or, just use a single sub woofer with little control and call it a day.
All of our homes are small rooms unless they are 56 ft high, 56 ft long, and 56 ft wide or more. Or a backyard. OTOH, if you're in a backyard with no walls a DML doesn't supply advantage over cones because regular cone speakers aren't reflecting off walls or ceilings. Especially if your backyard is grass.
If your listening space is a small room the DML should help you with frequencies above the transition frequency. So design your DML for that range. Then do something different for the lower frequencies.
https://www.jdbsound.com/art/frequency wave length chart 2013.pdf
Attachments
Thanks for your response, Bradleypnw. Do not all speakers, more or less, suffer from room interaction, whether they are DML, open baffle or closed box cones? I have one IB sub that I am happy with 80 Hz and under. And I understand that multiple subs will smooth the response, but my question is what to do above 80 Hz? Open baffle cones with the DML panel? I was thinking that the Yamaha NS30 design (DML in a deep open baffle, maybe with a BMR) might get it done without the cones.
this is the same panel at 12FT into room ,showing dip between 80 and 300 HZ
These two pics are from my old gallery on audiocircle, one with and one without my transmission line speakers,which were rolling off above 300hz,microphone 12ft into the room.
I left the panels full range,no eq.
This cancelled the cancellations in the room and produced a very nice response, as can be seen.
Different panels will not necessarily have the same dip in the response in the same position when used on their own ,it varies for some reason?
But running the tls to cover this area always sorts out the problem ,sounds good too.
this is with the TLs turned on ,with no eq,at 12FT into room so can be improved, notice the ledge at 10K with this panel but the panel radiates this hf in all directions, could eq this but sounds natural to me ?
These two pics are from my old gallery on audiocircle, one with and one without my transmission line speakers,which were rolling off above 300hz,microphone 12ft into the room.
I left the panels full range,no eq.
This cancelled the cancellations in the room and produced a very nice response, as can be seen.
Different panels will not necessarily have the same dip in the response in the same position when used on their own ,it varies for some reason?
But running the tls to cover this area always sorts out the problem ,sounds good too.
this is with the TLs turned on ,with no eq,at 12FT into room so can be improved, notice the ledge at 10K with this panel but the panel radiates this hf in all directions, could eq this but sounds natural to me ?
Yes, all speakers suffer from small room interaction. That's the most important thing going on in home audio. DMLs offer a solution to the geometric acoustic region. Their room reflections aren't as highly correlated as cone speakers. They take advantage of your brain's inability to process a lot of "diffuse" uncorrelated reflections. As a result, your brain concentrates on what it can process so you interpret the direct sound and ignore the reflections.
Your room will probably be modal up to 200Hz. Another way of saying it -- maybe --is that modal behavior will dominate up to 200Hz then geometric behavior will dominate over 200Hz. If you use an online room mode calculator you'll see modes above 200Hz but those modes don't dominate your frequency response curve. In practical terms: modal below 200Hz, geometric above 200Hz.
In a way that really sucks because spoken voice is between 70Hz and 255Hz. Which means we have modal room problems in most of the spoken voice range. However, our brains do a lot of heavy lifting for us because our brains evolved to be really good at hearing spoken voice. That's why you can have a conversation with someone in in a tiny room and everything is ok.
You're dealing with a combination of the hard physics of sound waves and the soft way your brain interprets pleasing sound. Here's a video that makes a really good illustration of the way your brain will do a lot of heavy lifting for you with audio.
Green Needle or Brainstorm?🤔 What Do You Hear? - YouTube
What specifically should you do with the 80Hz to 200Hz range? I'd say treat it like the 20Hz to 80Hz range. Hand your DMLs off to cone speakers because the DMLs aren't taking advantage of your brain processing at that point.
Actually, maybe I can say it a better way. If you have trouble pushing your DMLs below 200Hz (or 150Hz, etc.) don't keep trying because it isn't going to help you. At that point be happy with your DMLs and use cone speakers below 200Hz.
I may have posted this a few months back...
If you want truly outstanding reference recordings for free here are 2 separate audiophile samplers Just click on the 2 "audiophiliac" labels in the center of the screen): Warning these are very large samples and can take a while to download)
Welcome to MA Recordings Online
They are absolutely stunning...simply recorded using a pair of mic's in an audio acoustic environment (cathedral, music hall, etc). These are not done in a studio. They are recorded uncompressed(!) and without any artificial reverb so watch out for your volume levels, the dynamic transients can be devastating. What you hear is the music as it was created in a fantastic acoustic space. Quite stunning in sound and should give your DML's a run for their money...or at least let you know if your going in the right direction.
geo
If you want truly outstanding reference recordings for free here are 2 separate audiophile samplers Just click on the 2 "audiophiliac" labels in the center of the screen): Warning these are very large samples and can take a while to download)
Welcome to MA Recordings Online
They are absolutely stunning...simply recorded using a pair of mic's in an audio acoustic environment (cathedral, music hall, etc). These are not done in a studio. They are recorded uncompressed(!) and without any artificial reverb so watch out for your volume levels, the dynamic transients can be devastating. What you hear is the music as it was created in a fantastic acoustic space. Quite stunning in sound and should give your DML's a run for their money...or at least let you know if your going in the right direction.
geo
You bet. Here's a Tectonics video that supplies additional explanation regarding the difference between DML vs cone speaker room reflections in the small room geometric frequency (200Hz up, normally) range.
DML vs Pistonic Behavior Part 2 - YouTube
geosand.
thanks for the link to MA ,I already have the cd MA on SA with some of these tracks on.
I bought it at an audio show some years ago MA were demonstrating their cd `s .
I liked this track from the download(had a lot of fun downloading and getting everything to play ok,but i got there).
this is another(oh no)recording of a couple of eps panels i have lying around,the left one is about 15x23inchesxhalf inch,the right is a 5ftx2ftx1inch,sanded but still not coated with pva.
hope it sounds ok.
funny thing was, the night before you posted the link i was recording one of the tracks that was on your link! but decided to use this one instead.
steve
thanks for the link to MA ,I already have the cd MA on SA with some of these tracks on.
I bought it at an audio show some years ago MA were demonstrating their cd `s .
I liked this track from the download(had a lot of fun downloading and getting everything to play ok,but i got there).
this is another(oh no)recording of a couple of eps panels i have lying around,the left one is about 15x23inchesxhalf inch,the right is a 5ftx2ftx1inch,sanded but still not coated with pva.
hope it sounds ok.
funny thing was, the night before you posted the link i was recording one of the tracks that was on your link! but decided to use this one instead.
steve
The sanded uncoated panel has a softer sound than I am used to,so will eventually be coated.
The smaller panel is a lower grade eps very light and quite soft (also a bit bashed about,I found it in a skip!)unexpectedly I do find myself liking the sound from this panel,I think this is to do with how light it is? and also maybe it does not have the harsher sounding skin of the higher grade eps?
They are both running full range with adjusted reflex loaded speakers rolling off at 300hz.
The in room volume was very loud ,I noticed in the recording in the second half(using my headphones)that the banging on the right channel moves physically closer to the microphone when loud and further away when played more gently,mmmm nice!
Thanks again geo ,I look forward to listening to the rest of these lovely recordings.
Steve
The smaller panel is a lower grade eps very light and quite soft (also a bit bashed about,I found it in a skip!)unexpectedly I do find myself liking the sound from this panel,I think this is to do with how light it is? and also maybe it does not have the harsher sounding skin of the higher grade eps?
They are both running full range with adjusted reflex loaded speakers rolling off at 300hz.
The in room volume was very loud ,I noticed in the recording in the second half(using my headphones)that the banging on the right channel moves physically closer to the microphone when loud and further away when played more gently,mmmm nice!
Thanks again geo ,I look forward to listening to the rest of these lovely recordings.
Steve
Also obviously,the original track is about 11minutes ,which is too long for posting,so I stopped recording at a handy pause in sound.
I do love recordings made in natural surroundings ,with natural ambiance.
Steve
I do love recordings made in natural surroundings ,with natural ambiance.
Steve
eps only
i thought I would try and record the eps panels only ,with no eq,I had to place some weights on the small panel to get the response to go below 100hz to try and match the large panels.
once again i would recommend using good headphones to get that being there feeling ,if played over speakers it sounds a bit odd and lacking in the low end ,which is down to the mic roll off and its position ,I think.
converted to mp4 using VLC.
steve.
i thought I would try and record the eps panels only ,with no eq,I had to place some weights on the small panel to get the response to go below 100hz to try and match the large panels.
once again i would recommend using good headphones to get that being there feeling ,if played over speakers it sounds a bit odd and lacking in the low end ,which is down to the mic roll off and its position ,I think.
converted to mp4 using VLC.
steve.
Those percussion strikes are incredibly clean and dynamic. I can't hear any distortion in the dynamic range using cheap earbuds...though possibly my hearing is permanently damaged now from cranking it, lol. Natural ambience in a recording is just so hard to achieve properly without electronic tom-foolery. And to think all that was needed was two simple mic's...the sound stage seems to go on forever. I've been playing with my cheap eps panels with a new amp/preamp (tubes) I purchased recently. I'm waiting for a few more new components to come in before I make a final sound judgement but I've already had Dave B. and Johnny C. and Chester/Lester stop by in my living room just to say hello play a few tunes...simply amazing what $1.50 worth of cheap eps can do...🙂 I should have the rest of my new gear in place in about 2 weeks. Right now I got my measurement mic and am trying to figure out REW. I'll be taking some pics and making graphs on it all soon and write it up here for you all, if it pans out.
$1.50 wow
Can you tell me the size ,the thickness and grade of eps you are using and exciter plus position?
Also treatment.
This will give me an idea of the sound you will have.
For me eps is a win win situation ,it only takes a few watts to produce room filling sound,my 10watt exciters hardly have to move to do this ,so no overheating,the 8watt digital amp isn't even ticking over.
The ability to let everyone hear the panels for themselves,rather than looking at graphs and reading patents,which doesn't give you any idea of how they sound or can sound,hopefully ,is a better way to promote dml?
The usual put down from people that do not understand what dml can do is that dml is a horrible cheap toy which uses cone breakup and distortion to produce sound,they need to move on,and the only way that can happen is if people can get a chance to listen to the excellent sound they produce.
Also I think that the fact that they can be made so cheaply(if you know what you are doing)is a bit of a problem for audiophiles,stick a few grand on the price and they may take some notice.
I feel NXT has a lot to do with all this,if they had put a high quality panel speaker into production to start with,instead of selling franchises it could have been a different story?
Sadly,it was left to peop!e like zigadr (RIP) (NXT RUBBISH THINK AGAIN)(and on diy audio)to push for nxt dml as a superior sounding technology.
Anyway that's as maybe.
Sorry for the rant.
Hopefully we are making a difference?
Steve.
Can you tell me the size ,the thickness and grade of eps you are using and exciter plus position?
Also treatment.
This will give me an idea of the sound you will have.
For me eps is a win win situation ,it only takes a few watts to produce room filling sound,my 10watt exciters hardly have to move to do this ,so no overheating,the 8watt digital amp isn't even ticking over.
The ability to let everyone hear the panels for themselves,rather than looking at graphs and reading patents,which doesn't give you any idea of how they sound or can sound,hopefully ,is a better way to promote dml?
The usual put down from people that do not understand what dml can do is that dml is a horrible cheap toy which uses cone breakup and distortion to produce sound,they need to move on,and the only way that can happen is if people can get a chance to listen to the excellent sound they produce.
Also I think that the fact that they can be made so cheaply(if you know what you are doing)is a bit of a problem for audiophiles,stick a few grand on the price and they may take some notice.
I feel NXT has a lot to do with all this,if they had put a high quality panel speaker into production to start with,instead of selling franchises it could have been a different story?
Sadly,it was left to peop!e like zigadr (RIP) (NXT RUBBISH THINK AGAIN)(and on diy audio)to push for nxt dml as a superior sounding technology.
Anyway that's as maybe.
Sorry for the rant.
Hopefully we are making a difference?
Steve.
Last edited:
Whew! I'm only up to post #711, but so far pretty much all the music I've heard people talk about listening to on their DML's is acoustic or at least somewhat laid back. I could see really enjoying some Neil Young or some Grateful Dead on them, but I can't help wonder how good they sound with more aggressive styles of music - distorted guitars, electronic, complex layering of many tracks, etc. Can anyone comment from experience?
OK So just the basics here without explanation of design decisions or pics...thats for later.
Using cheap EPS panels: https://www.homedepot.com/p/3-4-in-...-Insulation-Sheathing-6-Pack-150705/202090272
6 panels for less than $8.50. Each panel is 3/4" thick and 14.25" x 48" positioned vertically.
Using one exciter: Dayton Audio DAEX25Q-4 Quad Feet 25mm Exciter 20W 4 Ohm
No sanding or skin on the panel. However a wood glue pad the size of the exciter is used to mount the exciter (100% straight Elmers wood glue). The exciter positioned at 2/5, 3/5 position per Dayton Audio recommendations.
The rest will have to wait another couple weeks...
Last edited:
Thanks geo ,it says it is rigid eps but does not state which grade,should be interesting.
If the panel turns out to be too narrow you could always glue two panels together with pva ,for a full sized panel?
4evrplan.
I have posted some electric guitar tracks more recently ,somewhere on this site.
If the recording is good on the cd,then it should be good on the panels,badly mixed cds will sound badly mixed!
I did go down memory lane last night listening to my rock and electronic music cds to record for you,but got carried away and didn't get to bed till 2.30 am.
Some remixed ,remastered,cds are the worst culprits for bad sounding cds I'm afraid,!!!!!
Steve.
If the panel turns out to be too narrow you could always glue two panels together with pva ,for a full sized panel?
4evrplan.
I have posted some electric guitar tracks more recently ,somewhere on this site.
If the recording is good on the cd,then it should be good on the panels,badly mixed cds will sound badly mixed!
I did go down memory lane last night listening to my rock and electronic music cds to record for you,but got carried away and didn't get to bed till 2.30 am.
Some remixed ,remastered,cds are the worst culprits for bad sounding cds I'm afraid,!!!!!
Steve.