Hi Steve
The Links will show some materials available today with varying degrees of flexion offered through the design for the materials used.
I can not find a flexible MDF with less than a 6mm (1/4") Thickness.
The Laminates shown in the Creffields Product Range may create a interest as well, these share similarities in the description for their manufacture that resembles that of Densified Wood such as a Panzerholz.
https://www.creffields.co.uk/products/flexible/flexible-mdf/
https://www.barbourproductsearch.info/Flexible Panels Product Guide - Nov 2018-file090955.pdf
The Links will show some materials available today with varying degrees of flexion offered through the design for the materials used.
I can not find a flexible MDF with less than a 6mm (1/4") Thickness.
The Laminates shown in the Creffields Product Range may create a interest as well, these share similarities in the description for their manufacture that resembles that of Densified Wood such as a Panzerholz.
https://www.creffields.co.uk/products/flexible/flexible-mdf/
https://www.barbourproductsearch.info/Flexible Panels Product Guide - Nov 2018-file090955.pdf
For reference and available for shipping in the USA
https://www.mcmaster.com/products/laminates/shape~sheet-and-bar/
Specs are shown with highlight of product number
https://www.mcmaster.com/products/laminates/shape~sheet-and-bar/
Specs are shown with highlight of product number
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JohnnoG.
When I get around to it, I intend to do a recording on YouTube of the two 6ft 3mm ply and MDF panels.
I will also hopefully make a recording of me changing the response of a small panel using my fingers.
I will do this in real time using pink noise, so that everyone can see and hear the vast changes this makes.
I will somehow have to suspend the panel next to the RTA, with me laying on the floor 🙄
I'm getting too old for this 🥴
I may have to ask my wife to give me a hand 😱
Steve.
When I get around to it, I intend to do a recording on YouTube of the two 6ft 3mm ply and MDF panels.
I will also hopefully make a recording of me changing the response of a small panel using my fingers.
I will do this in real time using pink noise, so that everyone can see and hear the vast changes this makes.
I will somehow have to suspend the panel next to the RTA, with me laying on the floor 🙄
I'm getting too old for this 🥴
I may have to ask my wife to give me a hand 😱
Steve.
Don't pay too much attention to those curves on the Dayton specifications. The 1/2" foam-core board that they use for their tests shows similar peaks and dips for all of their drivers. And they all have a drop-off at higher frequencies.
Hello
New step: the 2 channels are wired with the crossovers including the tweeters (FT17H). 1st tests were today. Amazing. Even after more than 2 years (3?), DML continue to surprise me...in a good way, even if the test was in my kitchen.
The most important is the listening :
So this pair is better than expected for its purpose.
I understand @Leob how was the surprise for your party!
Next step is it to work around some EQ to get a cleaner sound.
In the mean time, I got my wife's approval for the use of this pair and to continue for a pair for home.
From design point of view :
Here are the FR
And the IR
Last the FR to show what the tweeter adds
New step: the 2 channels are wired with the crossovers including the tweeters (FT17H). 1st tests were today. Amazing. Even after more than 2 years (3?), DML continue to surprise me...in a good way, even if the test was in my kitchen.
The most important is the listening :
- The bass are to "boomy", not dry enough. It was expected due to the compact design of the bass cabinet. Part of the balance was corrected with the simple EQ of the audio player which in my computer. A more sophisticated is needed.
- The energy, the "slam effect", the energy and clarity is great.
- The canvas panels have the spaciousness of the DML, the wide range
- The large plywood have more energy, life. A good balance, more life. A good scene.
- This pair adds punch.
So this pair is better than expected for its purpose.
I understand @Leob how was the surprise for your party!
Next step is it to work around some EQ to get a cleaner sound.
In the mean time, I got my wife's approval for the use of this pair and to continue for a pair for home.
From design point of view :
- the installation today was not good enough to appreciate the sound scene but the DML working with a tweeter seems a good option
- in the good option, the large relative area of the DML (similar to the 15" below) gives a great impulse to the air.
Here are the FR
And the IR
Last the FR to show what the tweeter adds
Hello Audiofrenzy,
Interesting and good findings.
Those exciters are low mass and low inductance.
If DaytonAudio use the same material for all the specifications, which it is written, then as you do, the FR can be compared. The humps pointing by André being here in all the cases. Those FR don't say what will be the result with an other material but the potential of the exciter.
Reverse side of the coin, those exciters seem to be low force factor and low power handling so limitation in efficiency and power.
For a home use it shouldn't be a problem as we have already the experience from Steve with 10W exciters.
Are they the exciters in your DMLs?
Christian
It is a shame that Drayton use such an inferior material ( unless used with a fairly rigid skin,like epoxy) to use for their frequency measurements.
I just had a quick look at various exciter measurements and found the measurements vastly different?
Some had a good frequency up to 10k and some have a very poor response, some rolling off at 1k and down 15db at 2k 😱 and 25db at 20k 😱😱
If all the conditions are supposed to be the same ? Why are the frequency responses so different .
I would definitely pay attention to this ?
Wouldn't you ?
Steve.
I suspect that some of the amateurs might misunderstand what I'm saying here. That's OK because such misunderstanding is a recurring problem...et al ad nauseum...
The thing is that the word "similar" is quite different to the word "identical".
Q. E. D.
Here they say that only the short sides of the panel need to be fixed:https://patents.google.com/patent/US20090028368A1/en?oq=US4480155
Been both a bit exhausted and busy after the party, and is preparing for road trip to Hungary with the family for a festival gig next month, so just a quick report for now...
Party was a big success this year as well! We had a fair bit or rain the second night during my set, but dancefloor kept going and nothing got damaged
Plates had to work hard though....this time I was running one plate per amp channel with 900w @ 4 ohm instead of the rated 160w
According to some quick tests comparing 2 plates in 8 ohm and 500w with single plate at 900w, output seemed similar, but at the party I found that ideally I wanted to push the amps close to max to keep up with only one plate per 18" sub (Yamaha DSX18). I upped the XO from 100hz to 120hz to take some load of them, and was mainly nervous about the exciters becoming unglued since I did not notice any heat buildup.
Unfortunately some of the plates used a little bit different preparation with a larger area covered by glue, and a couple had extra shellac to fortify the mounting area. One exciter unmounted from one of those plates early on, but I could get it out of the way so it didn't cause any distortion.
They blasted on nicely during the night and I constantly checked temp, but after changing DJ in the morning I suddenly noticed some exciters was getting very warm. I pulled down the volume, but damage was already done to the panels using the extra shellac fortification where now several exciters had become loose.
By the end it was running with 5 panels instead of 8...I would have liked it a bit louder, but they kept up fine and everyone was happy with the sound.
Two plates per sub would be a more sensible setup to leave some margin, but can't make an omelette without breaking some eggs
What I found very interesting was how the extra shellac fortification affected the heat buildup. It did reduce efficiency a bit, hence I decided against it, and obviously the energy has to go somewhere so it results in not only less output for the panel, but also means that the exciter can handle less power. I guess that a panel that is 3dB less efficient would not only need double the power for the same output, but would also be able to handle something like half the power before exciter overheats, resulting in a 6dB actual difference in what it can produce.
It does seem like the last batch of plates I made have a good balance between secure mounting, good HF reproduction and efficiency. I do hope to get some time this year to experiment with composites and see if that can make an improvement, but at least now I feel I have a decent idea about the limits of EPS/GPS plates.
Will get back next month with some clips of the dancefloor and pics of melted GPS
Party was a big success this year as well! We had a fair bit or rain the second night during my set, but dancefloor kept going and nothing got damaged
Plates had to work hard though....this time I was running one plate per amp channel with 900w @ 4 ohm instead of the rated 160w
According to some quick tests comparing 2 plates in 8 ohm and 500w with single plate at 900w, output seemed similar, but at the party I found that ideally I wanted to push the amps close to max to keep up with only one plate per 18" sub (Yamaha DSX18). I upped the XO from 100hz to 120hz to take some load of them, and was mainly nervous about the exciters becoming unglued since I did not notice any heat buildup.
Unfortunately some of the plates used a little bit different preparation with a larger area covered by glue, and a couple had extra shellac to fortify the mounting area. One exciter unmounted from one of those plates early on, but I could get it out of the way so it didn't cause any distortion.
They blasted on nicely during the night and I constantly checked temp, but after changing DJ in the morning I suddenly noticed some exciters was getting very warm. I pulled down the volume, but damage was already done to the panels using the extra shellac fortification where now several exciters had become loose.
By the end it was running with 5 panels instead of 8...I would have liked it a bit louder, but they kept up fine and everyone was happy with the sound.
Two plates per sub would be a more sensible setup to leave some margin, but can't make an omelette without breaking some eggs
What I found very interesting was how the extra shellac fortification affected the heat buildup. It did reduce efficiency a bit, hence I decided against it, and obviously the energy has to go somewhere so it results in not only less output for the panel, but also means that the exciter can handle less power. I guess that a panel that is 3dB less efficient would not only need double the power for the same output, but would also be able to handle something like half the power before exciter overheats, resulting in a 6dB actual difference in what it can produce.
It does seem like the last batch of plates I made have a good balance between secure mounting, good HF reproduction and efficiency. I do hope to get some time this year to experiment with composites and see if that can make an improvement, but at least now I feel I have a decent idea about the limits of EPS/GPS plates.
Will get back next month with some clips of the dancefloor and pics of melted GPS
How to suspend the plate really depends on plate dimensions, compliance of the clamping mechanism, plate material, etc.
I guess that for a reasonably sized plate slightly clamping short sides is ideal from efficiency perspective since a completely free plate will cancel itself a bit from residual vibrations. Usually the plates are very strong around the first modes in the low mid and I suspect that might become an issue if I would reduce clamping even more, but will give it a try to clamp short sides only.
Leob.
I look forward to listening to your videos.
I had a large 1cm xps panel with a coating of cement.
I was doing some frequency testing, when I received a phone call, I thought I had put the test CD on pause.
I was upstairs and could hear all these noises coming from what I thought was outside ?
When I finally realised that it was the test CD going through all the torture tests at very high volume, I ran downstairs.
But I was too late and all the XPS had melted away in-between the cement, the cement was still in place but it was now hollow 🫣
Especially on low efficiency panels I always constantly feel the temperature of the exciter to make sure they are not heating up.
I don't normally have trouble with eps as it is far too loud in my room before it warms up, and that is with a 10watt exciter 😃
Steve.
I look forward to listening to your videos.
I had a large 1cm xps panel with a coating of cement.
I was doing some frequency testing, when I received a phone call, I thought I had put the test CD on pause.
I was upstairs and could hear all these noises coming from what I thought was outside ?
When I finally realised that it was the test CD going through all the torture tests at very high volume, I ran downstairs.
But I was too late and all the XPS had melted away in-between the cement, the cement was still in place but it was now hollow 🫣
Especially on low efficiency panels I always constantly feel the temperature of the exciter to make sure they are not heating up.
I don't normally have trouble with eps as it is far too loud in my room before it warms up, and that is with a 10watt exciter 😃
Steve.
Hi Audiofrenzy.
I could only access the first link in your last post and I could not access any of your posted links on this page ?
Sorry I should have mentioned this earlier.
The exciter in you last post says it is a mid bass, but the bass seems to roll off heavily below 100hz?
It says that it has dual suspension for low frequency excursions?
It also has the large puck for removable mounting.
I did not look at this one when looking at frequency responses.
Others seem to have a far better performance in the low end ,if the tests are identical , as they say ?
I agree with you that it would be good idea to design an exciter to operate over certain frequencies, rather than try to cover from 20hz to 20k.
My exciters are certainly not designed to go down to 20hz , although they can on certain materials, as long as you do not push them too hard.
I prefer to keep all frequencies below 100hz ,well away from my exciters, on most panel materials.
Steve.
I could only access the first link in your last post and I could not access any of your posted links on this page ?
Sorry I should have mentioned this earlier.
The exciter in you last post says it is a mid bass, but the bass seems to roll off heavily below 100hz?
It says that it has dual suspension for low frequency excursions?
It also has the large puck for removable mounting.
I did not look at this one when looking at frequency responses.
Others seem to have a far better performance in the low end ,if the tests are identical , as they say ?
I agree with you that it would be good idea to design an exciter to operate over certain frequencies, rather than try to cover from 20hz to 20k.
My exciters are certainly not designed to go down to 20hz , although they can on certain materials, as long as you do not push them too hard.
I prefer to keep all frequencies below 100hz ,well away from my exciters, on most panel materials.
Steve.
Connect the voice coil with screws like in my previous test
But my voice coil is just a spider web
So the board needs to be balanced
Dear DML players, don’t just play DAYTON anymore
Any voice coil can play DML
let's use our imagination
Have fun
This is a test when I first started playing
The location of this exciter is not good
At the beginning, I didn't know that I needed to find a more balanced position
But in the bass part, I still think that the sense of space is better when using speakers with boxes
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Sorry to correct my words
Maybe the DML is good with bass on a large panel?
Sorry because I haven't heard the large DML
But the above statement is based on the general room space
Speakers with boxes are usually smaller and can have good efficiency
I mean the bass part
Usually take up too much space and will be disliked by family members
So I still prefer to have a box for the bass part.
Of course, I also want to play large-scale DML when conditions permit.
Have fun
Sorry to let me add again
Because i like to do it myself
Regardless of the result, the process of DIY is a kind of joy
But we can see more of DAYTON's exciter
They always have a lot of new ideas to refer to
They are the pioneers of the industry
Like sharing this above I found that there are many innovations to refer to
Forgot to thank @Audiofrenzy for sharing this exciter
Good luck for DML players and have fun
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Hello
This is the DAEX25 shared some posts ago
This is the DAEX25SHF-4
Can we conclude the DAEX25SHF-4 has a better efficiency (higher BL even if 20db difference in the charts is strange), a better Xmax (not specified) but a lower HF capability? The difference in the mids are strange, this area being more driven by the material and the geometry than the exciter. In the LF, the roll off comes most probably from the panel material and dimensions.
Can you explain what you mean here by "going into pistonic mode"? As far as I know, exciters function virtually only in pistonic mode. Except at very high frequencies (say over 10 kHz), where the voice coil can go into breakup (like a conventional speaker cone). But other than such very high frequencies, exciters themselves are pretty purely pistonic. It's correct that panels (or cones) driven by pistonic exciters may be pistonic or modal, depending on their stiffness and areal mass, and the frequency at which they are driven, however, the exciters themselves are basically the definition of pistonic motion.
Eric