Lordtarquin.
Sorry everyone for posting this again 🙄
This is from my gallery on the NXT rubbish forum from about 10 years ago.
As it states no EQ at 12ft into the room with my TLS stopping at 300hz ,,that is how long I have been using this method .
.the panel is 5ft x 2ftx1inch ,apart from pva and being ut down the panel is straight from wickes .
As you can see the in room response is within plus and minus 3db up to 10k and then with a lower shelf still producing hf.
This is why I always seem a bit puzzled when even now days people are having to use vast amounts of dsp to drag the sound out of the depths of mordor.
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 ?
For domestic rooms there is no need to have such large panels, my small card or veneer panels can be swoped with them easily only with a slightly higher xo such as 150hz on the panels, but continuing with the 300hz on the TLS.
Steve.
Sorry everyone for posting this again 🙄
This is from my gallery on the NXT rubbish forum from about 10 years ago.
As it states no EQ at 12ft into the room with my TLS stopping at 300hz ,,that is how long I have been using this method .
.the panel is 5ft x 2ftx1inch ,apart from pva and being ut down the panel is straight from wickes .
As you can see the in room response is within plus and minus 3db up to 10k and then with a lower shelf still producing hf.
This is why I always seem a bit puzzled when even now days people are having to use vast amounts of dsp to drag the sound out of the depths of mordor.
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 ?
For domestic rooms there is no need to have such large panels, my small card or veneer panels can be swoped with them easily only with a slightly higher xo such as 150hz on the panels, but continuing with the 300hz on the TLS.
Steve.
aagas.
WrineX in the dml woofer questions you posted is the guy who made the dml panels I posted on YouTube on post 3546.
What are the chances.
Steve.
WrineX in the dml woofer questions you posted is the guy who made the dml panels I posted on YouTube on post 3546.
What are the chances.
Steve.
aagas.
Although it's not really a dml ,unless you attach an exciter ? ,I have liked the idea of this.
Fig 8
US20060159293A1 - Acoustic device
- Google Patents
But originally this.
US3164221A - Low frequency loudspeaker system
- Google Patents
This could be on a wall only a few inches thick of even two panels pulsating omnidirectional 😀
Steve.
Although it's not really a dml ,unless you attach an exciter ? ,I have liked the idea of this.
Fig 8
US20060159293A1 - Acoustic device
- Google Patents
But originally this.
US3164221A - Low frequency loudspeaker system
- Google Patents
This could be on a wall only a few inches thick of even two panels pulsating omnidirectional 😀
Steve.
Last edited:
Another WrineX video.
as much low as i can get out of 4 neodymium (DML) - YouTube
I was trying to find the EAR panel speaker by Tim da vinci,as this used a type of dml which used what looked like a cone driver filled with foam or eps ? And then stuck to a panel,this was used for the low end.
You could think of it as an extended B139 .
I was a little shocked to see a picture of him with 1945-2020 next to it !
If this is right ,it is a great loss.
I met him at audio shows sometimes,very passionate about his audio!
Steve
as much low as i can get out of 4 neodymium (DML) - YouTube
I was trying to find the EAR panel speaker by Tim da vinci,as this used a type of dml which used what looked like a cone driver filled with foam or eps ? And then stuck to a panel,this was used for the low end.
You could think of it as an extended B139 .
I was a little shocked to see a picture of him with 1945-2020 next to it !
If this is right ,it is a great loss.
I met him at audio shows sometimes,very passionate about his audio!
Steve
Last edited:
I'm wondering how this pvc / rice hull material would perform as PML panel. I see it can be hydroformed. There are a hanful of product videos on vimeo.
ACRE Sheets | Wood Sustainable Alternative
1/4" x 48" x 96" Natural ACRE™ PVC Composite Sheet | U.S. Plastic Corp.
Modern Mill
ACRE Sheets | Wood Sustainable Alternative
1/4" x 48" x 96" Natural ACRE™ PVC Composite Sheet | U.S. Plastic Corp.
Modern Mill
I wonder if one could purpose these things as exciters, see:
Moticont: Linear Voice Coil Motors
Lots of different sizes and specifications.
Moticont: Linear Voice Coil Motors
Lots of different sizes and specifications.
Attachments
aagas,
The Linear Voice Coil Motors are made for linear position systems and have a very limited band width. They could be used for the very bottom end say DC to 20 Hz but very expensive for just a band width of 20Hz. Again one has to consider the equation F=ma unfortunately that is the bitch kitty one always run into.
The Linear Voice Coil Motor likes a triangular wave form where one is generating a constant velocity.
The better Voice Coil Motor is a Sub Woofer...
Cheers
Steve
The Linear Voice Coil Motors are made for linear position systems and have a very limited band width. They could be used for the very bottom end say DC to 20 Hz but very expensive for just a band width of 20Hz. Again one has to consider the equation F=ma unfortunately that is the bitch kitty one always run into.
The Linear Voice Coil Motor likes a triangular wave form where one is generating a constant velocity.
The better Voice Coil Motor is a Sub Woofer...
Cheers
Steve
Surround speakers test.
I replaced the left and right speakers on my cheap and old surround system.
I'd already modified the satellite speakers for a fairly decent sound,but wondered how the panels would sound ?
There was a bit of a gap between the sub and the panels responseat about 150 hz.
So I stuffed some foam in the port to damp the peak and raised the sub volume, which gave a little needed warmth to the vocals, but now the bass is too strong, I have no eq ,so it will have to do for these tests.
The picture is of the sub response after port damping, I tried to extend the low end a little but I think it has electronic roll off? Bass and treble.
I thought I'd do two recordings to show the problem.
These are old bashed around panels about 7inces in odd sized shapes, I should have taken photos 😀
Steve.
I replaced the left and right speakers on my cheap and old surround system.
I'd already modified the satellite speakers for a fairly decent sound,but wondered how the panels would sound ?
There was a bit of a gap between the sub and the panels responseat about 150 hz.
So I stuffed some foam in the port to damp the peak and raised the sub volume, which gave a little needed warmth to the vocals, but now the bass is too strong, I have no eq ,so it will have to do for these tests.
The picture is of the sub response after port damping, I tried to extend the low end a little but I think it has electronic roll off? Bass and treble.
I thought I'd do two recordings to show the problem.
These are old bashed around panels about 7inces in odd sized shapes, I should have taken photos 😀
Steve.
Attachments
I must apologise for the noise of all the clocks ticking away in the background,and the left panel was damaged somehow so was distorting rather badly.
The sub is behind the tv in the corner so is not setup for sound quality.
The dav 5500 is only a 10watt max ,if that, output ,heavily restricted.
Steve.
The sub is behind the tv in the corner so is not setup for sound quality.
The dav 5500 is only a 10watt max ,if that, output ,heavily restricted.
Steve.
Attachments
Last edited:
What difficulty are you talking about? What about this one?
AIYIMA Mini Audio Portable Speaker Column 44/50MM Full Range Vibration Speaker Altavoz Portatil Resonance Speakers For Computer|vibration speaker|portable speakerresonance speaker - AliExpress
Progress, of sorts.
With my one remaining exciter (before the Monacors arrive), I've been playing with a revised OB bass setup and also trying EPS instead of the ply I've been using.
It appears that the weird drop off in frequency is down to the Dayton Audio exciter. However, the EPS is much easier to correct in the 10hkz region.
Attached are a couple of results. The first is showing with and without EQ plots from the DA exciter. Mic was positioned near field about 40cm from the panel. The panel is free floating - attached only to the exciter. It may be the double sided stick stuff used to attach the exciter to the panel is resulting in the dramatic mid and high falloff.
The second shows the revised OB bass and aforementioned EPS playing together. The mic was again about 40cm from the speaker at ear height. Apart from a little trough around 5khz, its running at about 40-20,000hz +/- 3db.
With my one remaining exciter (before the Monacors arrive), I've been playing with a revised OB bass setup and also trying EPS instead of the ply I've been using.
It appears that the weird drop off in frequency is down to the Dayton Audio exciter. However, the EPS is much easier to correct in the 10hkz region.
Attached are a couple of results. The first is showing with and without EQ plots from the DA exciter. Mic was positioned near field about 40cm from the panel. The panel is free floating - attached only to the exciter. It may be the double sided stick stuff used to attach the exciter to the panel is resulting in the dramatic mid and high falloff.
The second shows the revised OB bass and aforementioned EPS playing together. The mic was again about 40cm from the speaker at ear height. Apart from a little trough around 5khz, its running at about 40-20,000hz +/- 3db.
Attachments
"Improved Directivity of Flat Panel Loudspeakers by Minimizing the Off-Axis Radiation below Coincidence"
- (PDF) Improved Directivity of Flat Panel Loudspeakers by Minimizing the Off-Axis Radiation below Coincidence
- (PDF) Improved Directivity of Flat Panel Loudspeakers by Minimizing the Off-Axis Radiation below Coincidence
Fascinating!
I've only just skimmed the paper, but the conclusion that edge damping is desirable is an interesting one.
I've only just skimmed the paper, but the conclusion that edge damping is desirable is an interesting one.
Lordtarquin.
That is a massive drop from 2.5k to 5k ,15db ,something odd is going on there?
Although it is good that you can eq the problem.
Can you take a measurement at about 2inches in front of the exciter ? Just for curiosity.
And maybe 2inches from the back of the panel and exciter Area.
I find, and this could just be me of course, that I prefer the response to roll off slightly above the 300hz point, similar to the room curve.
Although this sound is very similar to the headphones, which some may not like?
The reason for me to do this is that the panels always seem to sound louder ,so much more energy and detail.
You might find you need a strong powerful sounding sub to match the panel
I tried once to make my panels sound similar to my full range TLS , and kept reducing the volume until I got them close.
I'd practically turned off the eps panel by the time I had a close match
Steve.
That is a massive drop from 2.5k to 5k ,15db ,something odd is going on there?
Although it is good that you can eq the problem.
Can you take a measurement at about 2inches in front of the exciter ? Just for curiosity.
And maybe 2inches from the back of the panel and exciter Area.
I find, and this could just be me of course, that I prefer the response to roll off slightly above the 300hz point, similar to the room curve.
Although this sound is very similar to the headphones, which some may not like?
The reason for me to do this is that the panels always seem to sound louder ,so much more energy and detail.
You might find you need a strong powerful sounding sub to match the panel
I tried once to make my panels sound similar to my full range TLS , and kept reducing the volume until I got them close.
I'd practically turned off the eps panel by the time I had a close match
Steve.
A recording from the movie blade Runner.
I did it in stereo as I don't have the centre channel set up ,I use the TV for that.
So I muted the TV ,but it sounds odd without the center chanel ,even in stereo.
I tried to move the microphone back to minimise the sub sounds, but the microphone still seems to pick it up, as well as the dog? And clock's.
Steve
I did it in stereo as I don't have the centre channel set up ,I use the TV for that.
So I muted the TV ,but it sounds odd without the center chanel ,even in stereo.
I tried to move the microphone back to minimise the sub sounds, but the microphone still seems to pick it up, as well as the dog? And clock's.
Steve
aagas,
You should check this paper out to make exciters from linear solenoid Solenoid actuator for loudspeaker application - ScienceDirect
One could use 4 solenoids at each corner to make a sub woofer.
Cheers
Steve
You should check this paper out to make exciters from linear solenoid Solenoid actuator for loudspeaker application - ScienceDirect
One could use 4 solenoids at each corner to make a sub woofer.
Cheers
Steve
Steve
Here are a couple of response curves. The red one is from a couple of inches from the front of the panel near the exciter. The green one is from a similar position, but the back of the panel. Still the same big dip centered around 6khz and a general fall-off from 1000hz. I tend to try to aim for a 3db droop over the full frequency range.
I'm beginning to suspect the double sided gluey stuff I'm using for attachment of the exciter to the panel. With only one exciter and only a couple of EPS panels to play with, I'm going to have to save gluing the exciter to the panel when I can afford to sacrifice one. I need to try a reduced panel size first. 350x400mm positioned in landscape mode would be a nice fit with the OB bass unit. Those dimensions are also very close to the so-called golden ratio, not that I'm convinced it matters hugely.
Simon.
Here are a couple of response curves. The red one is from a couple of inches from the front of the panel near the exciter. The green one is from a similar position, but the back of the panel. Still the same big dip centered around 6khz and a general fall-off from 1000hz. I tend to try to aim for a 3db droop over the full frequency range.
I'm beginning to suspect the double sided gluey stuff I'm using for attachment of the exciter to the panel. With only one exciter and only a couple of EPS panels to play with, I'm going to have to save gluing the exciter to the panel when I can afford to sacrifice one. I need to try a reduced panel size first. 350x400mm positioned in landscape mode would be a nice fit with the OB bass unit. Those dimensions are also very close to the so-called golden ratio, not that I'm convinced it matters hugely.
Simon.
Attachments
carlmart —
I’ve typically worked with various exciters from Parts Express and have had success with several versions. Unfortunately all the ones of interest to me have gone on back order.
Have you tried the AIYIMAs? I’ve seen them mentioned but don’t remember reports of how they worked.
tagis —
Thanks I’ll check it out.
Andreas
I’ve typically worked with various exciters from Parts Express and have had success with several versions. Unfortunately all the ones of interest to me have gone on back order.
Have you tried the AIYIMAs? I’ve seen them mentioned but don’t remember reports of how they worked.
tagis —
Thanks I’ll check it out.
Andreas
Lordtarquin.
Thank you for the plots.
Yes something odd definitely going on there😕
Can you possibly do two more plots please ?
One at some point maybe halfway on the long axis from the exciter and the edge.
And one within the exciter coil area again, but this time with a small pea sized piece of bluetak in the middle of the coil area , this could be chewing gum or something similar if you have no bluetak.
I've used bog standard double sided tape for testing purposes on various types of panel materials , the excites will eventually peel off , but has always givend a pretty good response up to at least 10k.
The excites could already be coming loose of course, but I feel the problem is elsewhere, as you yourself have said the manufacturer plot are also bad?
Steve.
Thank you for the plots.
Yes something odd definitely going on there😕
Can you possibly do two more plots please ?
One at some point maybe halfway on the long axis from the exciter and the edge.
And one within the exciter coil area again, but this time with a small pea sized piece of bluetak in the middle of the coil area , this could be chewing gum or something similar if you have no bluetak.
I've used bog standard double sided tape for testing purposes on various types of panel materials , the excites will eventually peel off , but has always givend a pretty good response up to at least 10k.
The excites could already be coming loose of course, but I feel the problem is elsewhere, as you yourself have said the manufacturer plot are also bad?
Steve.