johnnog.
i took down my eps panel and replaced it with the 11x7inch crate panel, for comparison with the proplex panel.
the recording is of the left hand channel only playing through both speakers, to try and match them ?
the crate panels response drops off below 150hz but comes back strongly below 80hz.
so the crate panel does not sound as warm as the proplex , a sub is needed for that ?
mic distance 1m , they are about the same efficiency but the left mic is always louder ,so moved the mic to compensate ?
i have done nothing to either of these panels except glue on the exciters.
these were just thrown up and recorded , i hope the recording gives an idea of what to expect , sound wise, if using a small panel.
i believe if you are using a low frequency speaker ( karlsonator) below 300hz the small ply crate would work perfectly .
steve.
i took down my eps panel and replaced it with the 11x7inch crate panel, for comparison with the proplex panel.
the recording is of the left hand channel only playing through both speakers, to try and match them ?
the crate panels response drops off below 150hz but comes back strongly below 80hz.
so the crate panel does not sound as warm as the proplex , a sub is needed for that ?
mic distance 1m , they are about the same efficiency but the left mic is always louder ,so moved the mic to compensate ?
i have done nothing to either of these panels except glue on the exciters.
these were just thrown up and recorded , i hope the recording gives an idea of what to expect , sound wise, if using a small panel.
i believe if you are using a low frequency speaker ( karlsonator) below 300hz the small ply crate would work perfectly .
steve.
johnnoG.
i just did another recording but with the larger 17x14inch crate ply.
with a more similar response ,it is not as strong in the low end, but is there.
I could make an even larger crate ply panel, but i think we are going to need more crates
both panels need a little work to bring up the performance a bit more .
i have an idea how to do this with the ply panels but am not sure what can be done with the proplex , as i am not used to dealing with flutes ?
luckily the proplex is pretty good sounding, to start with, maybe a little too soft and warm sounding for me ,but i am sure many will like that ?
it is all a matter of taste.
the crate ply has a little of the EPS sound I like , which is what surprised me about this material.
steve.
i just did another recording but with the larger 17x14inch crate ply.
with a more similar response ,it is not as strong in the low end, but is there.
I could make an even larger crate ply panel, but i think we are going to need more crates
both panels need a little work to bring up the performance a bit more .
i have an idea how to do this with the ply panels but am not sure what can be done with the proplex , as i am not used to dealing with flutes ?
luckily the proplex is pretty good sounding, to start with, maybe a little too soft and warm sounding for me ,but i am sure many will like that ?
it is all a matter of taste.
the crate ply has a little of the EPS sound I like , which is what surprised me about this material.
steve.
Ordered amps and exciters for the panels, so no turning back now :\
Reading more about the Hypex fusion amps it seems like they might not be the best option, and I decided to go with Sanway, a Chinese supplier which builds line array systems as well as rack and plate amps for pro use. At least their regular amps seems to be considered decent. Double the power (although I guess the specs could be a bit inflated) but only a bit over 1/3 of the price compared to the fusion amps, and is made for pro audio with the usual connections for example.
Started designing the frames that will hold the panels. Since I'm aiming for making 16 plates in quite a short time, I want something cheap and quick to build. Plan is to use use wood ribs with 3d printed corners to hold the frames together and space them apart enough to press the plate between foam strips:
Also have to figure out a way to mount 4 plates together with amp, preferably on top of a pole screwed on the subwoofers, but will anyway make protection tents for the stacks so could possibly hang them as well.
Reading more about the Hypex fusion amps it seems like they might not be the best option, and I decided to go with Sanway, a Chinese supplier which builds line array systems as well as rack and plate amps for pro use. At least their regular amps seems to be considered decent. Double the power (although I guess the specs could be a bit inflated) but only a bit over 1/3 of the price compared to the fusion amps, and is made for pro audio with the usual connections for example.
Started designing the frames that will hold the panels. Since I'm aiming for making 16 plates in quite a short time, I want something cheap and quick to build. Plan is to use use wood ribs with 3d printed corners to hold the frames together and space them apart enough to press the plate between foam strips:
Also have to figure out a way to mount 4 plates together with amp, preferably on top of a pole screwed on the subwoofers, but will anyway make protection tents for the stacks so could possibly hang them as well.
Leob,
I like your design. I built something similar when I first started DML's and wanted to test a lot of different panel materials. The sandwich frame made that easier. I just used four screws to squeeze the sandwich.
Are you thinking that you will build the individual frame halves first, and that the corner pieces will simply serve to squeeze the sandwich together? Or are you thinking that the corner pieces can also serve to connect the 4 ribs of each of the two frames too, so that you don't even need to glue/or screw the ribs together at all?
My only suggestion for now is that you may want to run the exciter support spines in the opposite direction (i.e the short direction) so they will be effectively stiffer and perhaps less likely to resonate as much on thier own. But whether or not that works for you may depend on your exciter placement.
I'm eager to see your progress, especially when you start actually making plates!
Eric
Thanks Eric!
Yes, the idea is that the corner pieces should be tight enough to only need small screws to hold them in place. I'm at least hoping that the compliance of the foam in combination with sufficient precision will hold the plates in place without needing screws for tightening, but I realize that can be a bit optimistic. But I will give it a shot and add a way of clamping more if needed.
Good call on the direction of the exciter support! Stiffer, lighter and cheaper
With many plates, every bit counts. It doesn't seem so much with 4 stacks with 4 plates, but then for example you look at buying corner brackets and think €2 a piece is not that much...until you realize that with 8 per plate you will need 128 of them in total.
Leob, That's gonna' be kickin' man. Strategic dabs of super glue (or preferred glue) between your plate and the foam would work to ensure no plate slippage. I do this with my panels because it helps take weight off the exciter. Just a bit at every center point is what I would do. Good luck!Thanks Eric!
Yes, the idea is that the corner pieces should be tight enough to only need small screws to hold them in place. I'm at least hoping that the compliance of the foam in combination with sufficient precision will hold the plates in place without needing screws for tightening, but I realize that can be a bit optimistic. But I will give it a shot and add a way of clamping more if needed.
Good call on the direction of the exciter support! Stiffer, lighter and cheaper
With many plates, every bit counts. It doesn't seem so much with 4 stacks with 4 plates, but then for example you look at buying corner brackets and think €2 a piece is not that much...until you realize that with 8 per plate you will need 128 of them in total.
So I was thinkng that you could take 3 strips of foam per side and make a C channel for your plate to fit in for security.Thanks Eric!
Yes, the idea is that the corner pieces should be tight enough to only need small screws to hold them in place. I'm at least hoping that the compliance of the foam in combination with sufficient precision will hold the plates in place without needing screws for tightening, but I realize that can be a bit optimistic. But I will give it a shot and add a way of clamping more if needed.
Good call on the direction of the exciter support! Stiffer, lighter and cheaper
With many plates, every bit counts. It doesn't seem so much with 4 stacks with 4 plates, but then for example you look at buying corner brackets and think €2 a piece is not that much...until you realize that with 8 per plate you will need 128 of them in total.
Leob.
Your panel design does look very nice, but I would be very concerned about its rigidity.
for pro use, You are going to be putting a lot of energy into the exciter, panel and frame.
Any part of the frame and mounting that can vibrate , will vibrate.
Even the stand you mount the panels too, will vibrate if you are not careful.
I have problems putting 10watts into a panel , you will be using hundreds of watts.
Luckily I don't normally use frames (except for the canvas and rigid ply panels) but for pro use the exciter and panel need the protection and stability.
Your results will be very interesting.
Hopefully my thoughts are of some use.
Steve.
Your panel design does look very nice, but I would be very concerned about its rigidity.
for pro use, You are going to be putting a lot of energy into the exciter, panel and frame.
Any part of the frame and mounting that can vibrate , will vibrate.
Even the stand you mount the panels too, will vibrate if you are not careful.
I have problems putting 10watts into a panel , you will be using hundreds of watts.
Luckily I don't normally use frames (except for the canvas and rigid ply panels) but for pro use the exciter and panel need the protection and stability.
Your results will be very interesting.
Hopefully my thoughts are of some use.
Steve.
Thanks, another good idea! Not sure if it will be needed, the plates should be clamped hard enough, and if one makes the third strip a little bit too thick the damping effect will be reduced. But could definitely be worth exploring.
Yes, that is the major concern with how the design will hold up. I'm trying to find a good balance between weight, cost, speed of building, effect on sound and sturdiness. I should be getting machined parts really, even lasercut plywood would be a lot better, but that would become quite expensive. So a thin wood frame seems like the only reasonably easy and cheap option, and the printed corners should provide relatively good stability being very tightly fitted I hope.
And while it is for pro audio sound levels, it is not a system that will be used often for many years by different operators and has to hold up to that kind of stress, it will be only me carefully transporting and rigging.
I have just mounted the crate ply and taken some measurements.
There is a sound I am trying to get rid of.
I have tried different types of damping, but they alter the sound too much.
The closest I have so far got is with the arrangement in the picture.
This breaks up the early reflection from the two edges.
But as can be seen in the 30cm measurement ,the noise is still there with the peak at 630hz and 1.25k.
Pic 1. panel.
Pic 2. 3m.
Pic3. 30cm
Steve.
There is a sound I am trying to get rid of.
I have tried different types of damping, but they alter the sound too much.
The closest I have so far got is with the arrangement in the picture.
This breaks up the early reflection from the two edges.
But as can be seen in the 30cm measurement ,the noise is still there with the peak at 630hz and 1.25k.
Pic 1. panel.
Pic 2. 3m.
Pic3. 30cm
Steve.
Attachments
XRK.
I was going to explain more in my last post but I had to rush out.
The noise I believe is the exciter cavity problem, which is quite loud on this material.
I think I will have to use my fabric dome technique to stop this noise.
Or should I call it a dust cover ?
The main reason is to vent the coil cavity ,but it does also act as a tweeter to some extent , depending on the efficiency of the panel.
This should kill the noise at source ?
In the picture of the panel you can see a small blob of blu-tack in the centre of the coil area, in an attempt to dampen this noise.
Interestingly the 3m plot shows the peaks have dropped below the pink noise , but it can still be heard .
The idea of the strips of wood stuck to the panel edges at an angle was to deflect the reflection .
The left side reflects the the waves upwards and the right side downwards.
I will hopefully glue some angled ply strips on the side similar to other panels i have made, that is if I am still having problems ?
Even though the strips of wood are only stuck on with tape , the panel is sounding very nice, so it is promising.
Have you yourself tried that method of drilling holes in panel to stop reflections ?
How does it affect the panel response ? Sound ?
I have not cut off the handle part at the top of the panel yet as I am thinking of gluing 4 of these panels together at a later date when or if I get more crates ?
Steve.
I was going to explain more in my last post but I had to rush out.
The noise I believe is the exciter cavity problem, which is quite loud on this material.
I think I will have to use my fabric dome technique to stop this noise.
Or should I call it a dust cover ?
The main reason is to vent the coil cavity ,but it does also act as a tweeter to some extent , depending on the efficiency of the panel.
This should kill the noise at source ?
In the picture of the panel you can see a small blob of blu-tack in the centre of the coil area, in an attempt to dampen this noise.
Interestingly the 3m plot shows the peaks have dropped below the pink noise , but it can still be heard .
The idea of the strips of wood stuck to the panel edges at an angle was to deflect the reflection .
The left side reflects the the waves upwards and the right side downwards.
I will hopefully glue some angled ply strips on the side similar to other panels i have made, that is if I am still having problems ?
Even though the strips of wood are only stuck on with tape , the panel is sounding very nice, so it is promising.
Have you yourself tried that method of drilling holes in panel to stop reflections ?
How does it affect the panel response ? Sound ?
I have not cut off the handle part at the top of the panel yet as I am thinking of gluing 4 of these panels together at a later date when or if I get more crates ?
Steve.
Questions on Aesthetics/Finishing/Design
Looking through the DML posts I see a predominance of material experimentation and testing (which is in accordance with the topic of this thread), but relatively little of finished projects and it prompts me to ask the following questions:
1/ When considering and developing a project, how much of the thought process and effort is directed at producing a finished item with aesthetics and finish quality you would be pleased to display in a living room (whilst not compromising acoustic performance) ?
2/ If aesthetics and design are priority aims, to what extent, if any, do members feel limited by build experience, materials, and equipment/tools to achieve the desired ends?
3/ If limited in any of the above aspects, what, if any, practical things could possibly be done to assist/improve results?
4/ How many members have been satisfied/dissatisfied with finished projects from an aesthetic viewpoint ?
5/ How many don't care what a project looks like as long as it sounds great ?
Cheers
Eucy
Looking through the DML posts I see a predominance of material experimentation and testing (which is in accordance with the topic of this thread), but relatively little of finished projects and it prompts me to ask the following questions:
1/ When considering and developing a project, how much of the thought process and effort is directed at producing a finished item with aesthetics and finish quality you would be pleased to display in a living room (whilst not compromising acoustic performance) ?
2/ If aesthetics and design are priority aims, to what extent, if any, do members feel limited by build experience, materials, and equipment/tools to achieve the desired ends?
3/ If limited in any of the above aspects, what, if any, practical things could possibly be done to assist/improve results?
4/ How many members have been satisfied/dissatisfied with finished projects from an aesthetic viewpoint ?
5/ How many don't care what a project looks like as long as it sounds great ?
Cheers
Eucy
OK thanks XRK , maybe a future project , I will see how things go .
Eucy.
I'm definitely a number 5, I am only interested in the vibrating plate/panel , although I have thought of a few stand designs to support the panels.
But I have left that to the imagination of everyone else, to blend in with their own surroundings.
How much of a compromise putting the panel into a frame and mounting it , is up to you.
It can be as simple or as complicated as you like.
The art panel comes with its own frame for low frequencies, how you mount it determines its performance.
I would now recommend the crate ply(whatever that is) for this project , as it takes the performance to another level.
Steve.
Eucy.
I'm definitely a number 5, I am only interested in the vibrating plate/panel , although I have thought of a few stand designs to support the panels.
But I have left that to the imagination of everyone else, to blend in with their own surroundings.
How much of a compromise putting the panel into a frame and mounting it , is up to you.
It can be as simple or as complicated as you like.
The art panel comes with its own frame for low frequencies, how you mount it determines its performance.
I would now recommend the crate ply(whatever that is) for this project , as it takes the performance to another level.
Steve.
Hi Eucy
Thank you for your questions
Your point 5, is followed by point 2, challenging the esthetic based on results.
Eucy,
I am one that likes to be able to look at the finished product with pride. I did the art canvas panels and used thinned acrylic paint instead of pva/water. Although my brother is an internationally known artist, I did not get any of those genes. However, I was able to paint a solid color onto the canvases, which makes them aesthetically pleasing to me, and the cost and time to do so are essentially the same as pva.
I am one that likes to be able to look at the finished product with pride. I did the art canvas panels and used thinned acrylic paint instead of pva/water. Although my brother is an internationally known artist, I did not get any of those genes. However, I was able to paint a solid color onto the canvases, which makes them aesthetically pleasing to me, and the cost and time to do so are essentially the same as pva.
You might consider MakerBeam XL framing. It lets you make sturdy nice looking frames quickly. I use it to make amp chassis quickly. My griddle amp: