Jaxboy.
You seem to be a little concerned about the low frequency performance of the art panel,so I took some measurements of real music on peak hold to see the average responce.
Measurement at 3ft.
1 if it be your will,10db segments.
2 du hast,10db segments.
3 pink noise 20db segments ,ignore anything below the 40hz drop off,this is just road noise.
Notice no low end roll off until it reaches the 40hz or so drop off.
This fills all of the room with deep low frequencies down to the 40hz Mark,this is as loud as my IMF TLS at this frequency.
But the TLS goes all the way down to 20hz with the same power,which is nice
The patent mentioned going down to 20hz, but with no measurements to back this up ?
and I should mention that These measurements are all of one panel only!
It would be interesting to see if the 20hz can be reached with this type of panel.
If we take it that the response above say 500hz or whatever, is pretty much dictated by the ply panel response?
This then leaves the low end to be dictated by the canvas,so this must be optimised for the best performance,more powerful exciter? Size? Frame Rigidity? Correct tension,too much of too little?
This is where computer simulation is handy,it could take a long time to get it right otherwise.
I was just lucky with my size panel except for the CASCAMITE.
Although a little more rigidity in the canvas with some other substance could be an option?
Steve
You seem to be a little concerned about the low frequency performance of the art panel,so I took some measurements of real music on peak hold to see the average responce.
Measurement at 3ft.
1 if it be your will,10db segments.
2 du hast,10db segments.
3 pink noise 20db segments ,ignore anything below the 40hz drop off,this is just road noise.
Notice no low end roll off until it reaches the 40hz or so drop off.
This fills all of the room with deep low frequencies down to the 40hz Mark,this is as loud as my IMF TLS at this frequency.
But the TLS goes all the way down to 20hz with the same power,which is nice
The patent mentioned going down to 20hz, but with no measurements to back this up ?
and I should mention that These measurements are all of one panel only!
It would be interesting to see if the 20hz can be reached with this type of panel.
If we take it that the response above say 500hz or whatever, is pretty much dictated by the ply panel response?
This then leaves the low end to be dictated by the canvas,so this must be optimised for the best performance,more powerful exciter? Size? Frame Rigidity? Correct tension,too much of too little?
This is where computer simulation is handy,it could take a long time to get it right otherwise.
I was just lucky with my size panel except for the CASCAMITE.
Although a little more rigidity in the canvas with some other substance could be an option?
Steve
Attachments
Maybe I should have made measurements of the panel from the side or with the panel facing the wall to see how this would have affected the room response!
For flexibility I have two sets of low frequency drivers,plus I intend having three different sets of dml,1 eps 2 card 3 canvas or some others stretched material ?
Apart from my TLS the canvas panels will be the only other full range speakers.
But I will also have a choice of using the canvas panels as a low frequency driver for eps and the card panels for full range dml only
What fun!
Steve.
For flexibility I have two sets of low frequency drivers,plus I intend having three different sets of dml,1 eps 2 card 3 canvas or some others stretched material ?
Apart from my TLS the canvas panels will be the only other full range speakers.
But I will also have a choice of using the canvas panels as a low frequency driver for eps and the card panels for full range dml only
What fun!
Steve.
Wow! It looks like you have all the bases covered! I am excited about that low Hz response for the DML. I have 3 sets of full-range speaker boxes and a pretty good subwoofer. I am planning on running 1 set as TV speakers and 2 sets and the DML as my main stereo setup, backed up with the subwoofer. My exciters should be coming this weekend. As the room is only 10.5x12', I think that should more than cover it. If I could also run the subwoofer with the TV, that would be nice. I have a ground loop interrupter that I don't need any longer, as I found and corrected the reason for the hum. If I were to run the TV signal through that to the subwoofer, that should isolate it sufficiently from the stereo, shouldn't it? I would run both TV channels through 4k7 resistors before it to make the mono signal for the mono subwoofer.
mexjerry,
The reason I wanted to use the heat gun instead of the iron is because I would be drying the gesso with it at the same time I was trying to shrink the canvas. If I used an iron, it would get covered with the wet gesso, or if I turned the canvas over to iron the back side, I would either smear the gesso on my work surface, or if I held it vertically, it would be awkward to iron without pushing against the canvas too hard. The heat gun would allow me to rest the canvas on its back side and hold the heat source above the canvas without actually touching the canvas. Just a matter of convenience and ease of use. The heat gun is a light-weight 8" wand, and the iron weighs a lot more. Plus, and more importantly, SWMBO would have my head if I messed up her iron!
The reason I wanted to use the heat gun instead of the iron is because I would be drying the gesso with it at the same time I was trying to shrink the canvas. If I used an iron, it would get covered with the wet gesso, or if I turned the canvas over to iron the back side, I would either smear the gesso on my work surface, or if I held it vertically, it would be awkward to iron without pushing against the canvas too hard. The heat gun would allow me to rest the canvas on its back side and hold the heat source above the canvas without actually touching the canvas. Just a matter of convenience and ease of use. The heat gun is a light-weight 8" wand, and the iron weighs a lot more. Plus, and more importantly, SWMBO would have my head if I messed up her iron!
Jaxboy.
I sometimes use my wife's hair dryer to help dry the pva.
I have to use a low setting and constantly move the hair dryer around.
If you use too high a setting the pva will start to bubble.
If as you say gesso has pva in it ,it might be wise to ease off on the heat?
Yesterday I was playing around trying to tighten the art panel and my round crochet ring ,this had the affect of raising the the low end frequencies ,which is what you would expect from tightening a drum !
So maybe it is just a question of tuning the canvas like a drum to the desired low frequency ?
It would be very handy to be able to dial in and adjust this frequency as desired especially if using a sub.
Or for loss of tension over time of varying temperatures ?
These tests were me just fiddling around so don't take them too seriously,but tensioning the canvas did seem to increase the output higher up in frequency?
I suppose we are dealing with some sort of damped drum ,the damping being the ply ?
It's just a thought ?
Steve.
I sometimes use my wife's hair dryer to help dry the pva.
I have to use a low setting and constantly move the hair dryer around.
If you use too high a setting the pva will start to bubble.
If as you say gesso has pva in it ,it might be wise to ease off on the heat?
Yesterday I was playing around trying to tighten the art panel and my round crochet ring ,this had the affect of raising the the low end frequencies ,which is what you would expect from tightening a drum !
So maybe it is just a question of tuning the canvas like a drum to the desired low frequency ?
It would be very handy to be able to dial in and adjust this frequency as desired especially if using a sub.
Or for loss of tension over time of varying temperatures ?
These tests were me just fiddling around so don't take them too seriously,but tensioning the canvas did seem to increase the output higher up in frequency?
I suppose we are dealing with some sort of damped drum ,the damping being the ply ?
It's just a thought ?
Steve.
Jaxboy.
Basically yes.
Tightening a canvas panel would be similar to tightening a drum or guitar string.
A small drum would not be able to go down as low as a large drum.
But there must be a compromise there somewhere ?
The weight of the exciter and ply must be helping to lower the frequency obtainable from my art panel.
But my 12inch card crochet panel is too small or too light to get much below 100hz ,so far ?
This is all guess work ?
If the expanse of canvas gets too large I would think that the canvas would start to become uncontrollable (as I havery found with polythene in the past) and act like a big drum,not what we want ,I think ?
Tensioning to aircraft standards night be OK for lower midrange up, but I'm not sure about the low end ?
If anyone has a spare first ww aircraft lying around and would like to make some test measurements, that would be a great help
Steve.
Basically yes.
Tightening a canvas panel would be similar to tightening a drum or guitar string.
A small drum would not be able to go down as low as a large drum.
But there must be a compromise there somewhere ?
The weight of the exciter and ply must be helping to lower the frequency obtainable from my art panel.
But my 12inch card crochet panel is too small or too light to get much below 100hz ,so far ?
This is all guess work ?
If the expanse of canvas gets too large I would think that the canvas would start to become uncontrollable (as I havery found with polythene in the past) and act like a big drum,not what we want ,I think ?
Tensioning to aircraft standards night be OK for lower midrange up, but I'm not sure about the low end ?
If anyone has a spare first ww aircraft lying around and would like to make some test measurements, that would be a great help
Steve.
I have poly-fiber coming, and an idea for the frame, but sourcing poly-brush, poly-fiber, here in Mexico, maybe problematic, shipping would be horrendous.
In the mean time, for testing I will thickness plane some knot free pine, somewhere in the width of 8-10 inches, I think I'll start testing the sound at about 1/2 inch thick, depending on what I hear, continue to plane, until it sounds to my liking, then move on to rosewood, rinse and repeat.
In the mean time, for testing I will thickness plane some knot free pine, somewhere in the width of 8-10 inches, I think I'll start testing the sound at about 1/2 inch thick, depending on what I hear, continue to plane, until it sounds to my liking, then move on to rosewood, rinse and repeat.
Hey all- new to the forums and new to DMLs but pretty excited by both. After seeing the apparently formative Tech Ingredients videos and some of the experiments people are doing with different materials, dampening, etc, I decided to try to build my own but haven't come close to reproducing the results other people seem to get. In particular, I first tried some plywood panels (just some birch I had available; ended up doing 24"x18") with one DAEX32QMB-4 per each (I tried centered, 2/5 and 3/5, and 2/5 from top while centered L/R and also later tried with only the center attached and not the 4 extra arms) and the results were fairly hollow sounding and definitely not full range.
Next I tried to follow the 2'x2'x1" foamular design from the tech ingredients video (additionally I followed this video in case I missed anything from the TI video) and ended up with nearly identical looking panels buuut the sound, although much more efficient than the plywood, had a much more noticeable echo and was again not anything close to full range.
I have a few DAEX25VT-4's on the way (why did everything have to go out of stock just now lol) to try both panel types with not just a different exciter but also multi-exciter placements. Until then though I was hoping to get some hints from the pros in this wild thread:
1) Is the DAEX32QMB-4 exciter just not appropriate for the panel types? I've seen some posts about how matching the exciter to panel is key but the results I had were so horrible I thought there must be some other issue. Having also seen the cat food can DIY exciters I sort of also doubted that my exciter was the issue.
2) For the foam panels, how important is sealing/coating? I saw a few posts/videos about a 50/50 water and glue coating (which I tried to seemingly no effect) and other coatings but neither the TI video nor the other linked video treat the panel in this way.
3) For mounting exciters to foam panels, how important is attaching a more rigid material to distribute movement into the foam? I haven't noticed any give/springiness in the foam I'm using + neither video used a hybrid material panel. I did try a square of plywood between the foam and exciter and it sounded interesting, but I didn't glue it down as to not destroy the foam panel if it didn't work.
4) How important is the surface finish? The TI video encouraged sanding off the shiny film and breaking the edges, which I've done, but my panels also came fresh with some smaller dings/marks from home depot which I though might impact the sound but really just seem cosmetic.
5) Are there any other should-be-obvious mistakes in my process that jump out to anyone who has successfully built similar panels? At this point, bar having a different model exciter, I can't spot the difference between mine and those in the videos (new exciters get here sometime in the next 4 days to try).
Sorry for the longer post! Those who know me know I tend to get too deep into things too quickly and I'm definitely invested in trying to get these to work lol. I actually did like the sound when I paired the plywood with my monitors + sub but they just don't sound good at all paired just with the sub and I know I can do better. I have looked at the FR for my monitor/sub setup but haven't bothered for either panel yet as the results were.. obviously not good haha
Side notes about the setup/trials: For both panels I tried a wall mount (which was just outright terrible and not what I described above, at least without any damping behind it) and a standing mount. For both, the actual mount was not rigidly attached to the panels and just provided some thin cord the panels were suspended on. The plywood panels were suspended about 6" in from either side on the back via frame wall hooks glued to some leftover high density acoustic foam chunks. The foam panels were attached via two small glued-in-place hook screws which I tried both attaching at a similar spot on the back (although 9" from the side as they were wider) as well as from the top. Both panels were tested on both an sx-10ae receiver as well as an older dayton 50 wpc amp. Both panels were tested in a room approx. 15'x24'.
Next I tried to follow the 2'x2'x1" foamular design from the tech ingredients video (additionally I followed this video in case I missed anything from the TI video) and ended up with nearly identical looking panels buuut the sound, although much more efficient than the plywood, had a much more noticeable echo and was again not anything close to full range.
I have a few DAEX25VT-4's on the way (why did everything have to go out of stock just now lol) to try both panel types with not just a different exciter but also multi-exciter placements. Until then though I was hoping to get some hints from the pros in this wild thread:
1) Is the DAEX32QMB-4 exciter just not appropriate for the panel types? I've seen some posts about how matching the exciter to panel is key but the results I had were so horrible I thought there must be some other issue. Having also seen the cat food can DIY exciters I sort of also doubted that my exciter was the issue.
2) For the foam panels, how important is sealing/coating? I saw a few posts/videos about a 50/50 water and glue coating (which I tried to seemingly no effect) and other coatings but neither the TI video nor the other linked video treat the panel in this way.
3) For mounting exciters to foam panels, how important is attaching a more rigid material to distribute movement into the foam? I haven't noticed any give/springiness in the foam I'm using + neither video used a hybrid material panel. I did try a square of plywood between the foam and exciter and it sounded interesting, but I didn't glue it down as to not destroy the foam panel if it didn't work.
4) How important is the surface finish? The TI video encouraged sanding off the shiny film and breaking the edges, which I've done, but my panels also came fresh with some smaller dings/marks from home depot which I though might impact the sound but really just seem cosmetic.
5) Are there any other should-be-obvious mistakes in my process that jump out to anyone who has successfully built similar panels? At this point, bar having a different model exciter, I can't spot the difference between mine and those in the videos (new exciters get here sometime in the next 4 days to try).
Sorry for the longer post! Those who know me know I tend to get too deep into things too quickly and I'm definitely invested in trying to get these to work lol. I actually did like the sound when I paired the plywood with my monitors + sub but they just don't sound good at all paired just with the sub and I know I can do better. I have looked at the FR for my monitor/sub setup but haven't bothered for either panel yet as the results were.. obviously not good haha
Side notes about the setup/trials: For both panels I tried a wall mount (which was just outright terrible and not what I described above, at least without any damping behind it) and a standing mount. For both, the actual mount was not rigidly attached to the panels and just provided some thin cord the panels were suspended on. The plywood panels were suspended about 6" in from either side on the back via frame wall hooks glued to some leftover high density acoustic foam chunks. The foam panels were attached via two small glued-in-place hook screws which I tried both attaching at a similar spot on the back (although 9" from the side as they were wider) as well as from the top. Both panels were tested on both an sx-10ae receiver as well as an older dayton 50 wpc amp. Both panels were tested in a room approx. 15'x24'.
habeeb,
Welcome! How long have you played the exciters? They may need to be broken in. That is a common complaint I have seen frequently on this and other forums. Don't be too quick to dismiss them until they have been played up to a week, and some have even said that exciters need warming up on each playing!
Welcome! How long have you played the exciters? They may need to be broken in. That is a common complaint I have seen frequently on this and other forums. Don't be too quick to dismiss them until they have been played up to a week, and some have even said that exciters need warming up on each playing!
Just thinking...
SilveRboard.
$15 for a 1/2" x 4' x 8' sheet
faced with...
Aluminum flashing: Thickness: 0.0092 in.
$58 for a roll 20" x 50'
Anyone have an idea of how thin one can get aluminum without it being "foil"?
This would give something very rigid for its weight.
SilveRboard.
$15 for a 1/2" x 4' x 8' sheet
faced with...
Aluminum flashing: Thickness: 0.0092 in.
$58 for a roll 20" x 50'
Anyone have an idea of how thin one can get aluminum without it being "foil"?
This would give something very rigid for its weight.
Attachments
https://www.amazon.com/M-D-Building...eywords=aluminum+sheets&qid=1622918938&sr=8-3
M-D Building Products 56064 1-Feet by 2-Feet .019-Inch Thick Plain Aluminum Sheet
M-D Building Products 56064 1-Feet by 2-Feet .019-Inch Thick Plain Aluminum Sheet
Habeeb.
Hi welcome.
The closest I have to 1inch xps panels are my 5mm xps,these have been hiding behind some curtains in my front room for a few years now ,and it looks like someone has got a little over excited with the Hoover and broken off about 6inches off of the bottom
Anyway,here is a picture of the panel and some responses.
This is a 30db window.
The first pic is the response at one ft.
The second is about 3mtrs into the room.
The third is the sorry looking panels with missing bits .
At one foot the low end looks pretty good but as you move away to about 10feet you can see the large hole in the response which can appear anywhere between about 100hz to 400hz.
This can give a strange hollow sound ,this is not a full range panel.
This panel is coated in pva and a few coats of vinyl silk paint.
They were test panels and I just kept coating them until it was too much.
So I would regard them as over damped.
I have done a recording with the panels full range but with TLS rolling off at 300hz,so the panels and the sub are running in tandem below 300hz to fill the hole in the room response.
Steve.
Hi welcome.
The closest I have to 1inch xps panels are my 5mm xps,these have been hiding behind some curtains in my front room for a few years now ,and it looks like someone has got a little over excited with the Hoover and broken off about 6inches off of the bottom
Anyway,here is a picture of the panel and some responses.
This is a 30db window.
The first pic is the response at one ft.
The second is about 3mtrs into the room.
The third is the sorry looking panels with missing bits .
At one foot the low end looks pretty good but as you move away to about 10feet you can see the large hole in the response which can appear anywhere between about 100hz to 400hz.
This can give a strange hollow sound ,this is not a full range panel.
This panel is coated in pva and a few coats of vinyl silk paint.
They were test panels and I just kept coating them until it was too much.
So I would regard them as over damped.
I have done a recording with the panels full range but with TLS rolling off at 300hz,so the panels and the sub are running in tandem below 300hz to fill the hole in the room response.
Steve.
Attachments
Normal click should bring up that option.
Attachments
Thanks for the tips + info jax and spedge! I had only put maybe a few hours into the exciters in various configurations so I could definitely believe more time would help. That said, the improvement I've noticed in the past from burn in/breaking in wouldn't make up for the hollowness I was hearing (which I assume is the same that spedge mentions). I didn't have enough time to test this today but sometime I'll try curving the front plane (I believe TI tries this in one video and didn't note a significant difference but we already have different results lol) in case that parallel surface is contributing to the echo. It's unfortunate as they're super efficient compared to the plywood, so I'm curious about getting them working.
I did get the 4 new exciters in the mail today and spent most of my free time wiring up and trying a 2x and 4x per panel harness, both of which actually sounded great on the plywood (even before deciding on an arrangement and attaching them). Once I test a bit more with the foam panels I'll lock in on a design and do a sort of head-to-head with my current monitors.
I did get the 4 new exciters in the mail today and spent most of my free time wiring up and trying a 2x and 4x per panel harness, both of which actually sounded great on the plywood (even before deciding on an arrangement and attaching them
). Once I test a bit more with the foam panels I'll lock in on a design and do a sort of head-to-head with my current monitors.5mm eps recordings
habeeb.
That should read 5mm XPS recordings !!!!
one with the sub and one without the sub.
not sure if this was the best track to test but it is only 2mins long .
not sure if this is one of the causes of your sound problems?
do you recognise any sounds in the recording that you are having problems with?
Please listen using headphones.
steve.
habeeb.
That should read 5mm XPS recordings !!!!
one with the sub and one without the sub.
not sure if this was the best track to test but it is only 2mins long .
not sure if this is one of the causes of your sound problems?
do you recognise any sounds in the recording that you are having problems with?
Please listen using headphones.
steve.
Last edited:
I've started to get a bit carried away again
I've just added a second dome tweeter to the right panel the glue is still drying from the one I did yesterday but the hf is slowly getting much better.
The right panel tweeter is still pretty wet only about an hour after being glued,but with a little help from a hair dryer.
By tomorrow the wet tweeter should come up to the performance of the dryer tweeter,hopefully the dryer tweeter might be performing better tomorrow as well ?
The first pic is of the new domes after cutting a hole in the centre of the coil area with a Stanley knife and gluing on the domes.
Normally I'd glue the domes on to the coil foot ,but this is another one of my bodge jobs,as the panels have just about had there last tests ,I think?
Second pic is the dryer tweeter,notice the better hf.
Third is the wet tweeter.
I intend again to do a recording to show how this improves the harsh noise on vocals,and generally clean up the sound and also hopefully this will be more obvious ?
Steve
I've just added a second dome tweeter to the right panel the glue is still drying from the one I did yesterday but the hf is slowly getting much better.
The right panel tweeter is still pretty wet only about an hour after being glued,but with a little help from a hair dryer.
By tomorrow the wet tweeter should come up to the performance of the dryer tweeter,hopefully the dryer tweeter might be performing better tomorrow as well ?
The first pic is of the new domes after cutting a hole in the centre of the coil area with a Stanley knife and gluing on the domes.
Normally I'd glue the domes on to the coil foot ,but this is another one of my bodge jobs,as the panels have just about had there last tests ,I think?
Second pic is the dryer tweeter,notice the better hf.
Third is the wet tweeter.
I intend again to do a recording to show how this improves the harsh noise on vocals,and generally clean up the sound and also hopefully this will be more obvious ?
Steve
