Here's a promising result.
I started dml experiments because I'm interested in dml for PA use. Mounting more drivers and keep the sound nice has been a challange for me however. So I changed direction and went for nice sound first.
In this one driver panel I seem to have stumbled upon a good compromise. It sounds really OK for music listening use.
It's a 3 mm nomex/paper skinned 60x40 cm panel with a Xcite driver mounted in the position of the Russian Sheet Control patent. I made a kind of rolled paper suspension with gaffer tape all around. A small whizzer is mounted a few cm from the driver for cheating a bit more top end.
Sounds pleasant, enough bass when it's on floor (coupling?), a little dip in the 150 Hz region (probably the standard low dip I see in all the measurements here online).
Works good for nice mono recordings like Chet Baker singing etc. You have te feeling of listening "through the panel".
I started dml experiments because I'm interested in dml for PA use. Mounting more drivers and keep the sound nice has been a challange for me however. So I changed direction and went for nice sound first.
In this one driver panel I seem to have stumbled upon a good compromise. It sounds really OK for music listening use.
It's a 3 mm nomex/paper skinned 60x40 cm panel with a Xcite driver mounted in the position of the Russian Sheet Control patent. I made a kind of rolled paper suspension with gaffer tape all around. A small whizzer is mounted a few cm from the driver for cheating a bit more top end.
Sounds pleasant, enough bass when it's on floor (coupling?), a little dip in the 150 Hz region (probably the standard low dip I see in all the measurements here online).
Works good for nice mono recordings like Chet Baker singing etc. You have te feeling of listening "through the panel".
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(Sorry the late reply, but PC problems)
Yes @Veleric , @Groundloops , @RMAM , I'ts equal to coroplast (brand), basicly Prolipropilene Plastic comunly used for advertizing panels
and problably by Tectonic DMLs like in the following photo ( Tectonic PL12), they seen to skin the surface with some kind of vinyl (not sure), but knocking on the surface sounds the same.
Those panels cross-over the DML section at 100Hz plus a ribbon at 7Khz and a sub at 100hz (they are used more on large instalations)
I really like the sound of PP panels BTW.
What a usualy do is : remove the 3M preinstalled tape ( the best way to do that is to use some drops of Zippo lighter fluid, it's like magic on most of labelling tapes and doesn't damage plastic surfaces, believe me ), then I install a large piece of another type of tape ( Double sided Mounting tape used for carpets ), it's very thin, so no damping at all.I to have wondered about the 'sticky tape' mounting of my 40 watt Daytons.
The tape is said to be a premium 3M product, but because I am using twin exciters > 80 watts
I am expecting quite a lot of panel movement at higher volume levels
I think I will start with the tape, and if need be, move on to 2 part epoxy.
PS.
Just a fun fact >
The 3M brand started out as: The Minnesota Mining & Manurfacturing Co.
I then use a large piece (if I'm trying surfaces), this way I can remove the driver without pulling on it, I pull the tape instead (more easy, but requires force nevertheless, ... or some drops of Zippo Lighter fluid). This way I'm more confident that I'm not damaging the driver.
... And another material comes to "play"
Yesterday I was taking my afternoon nap, when my daughter awaked me, she pranked me by jiggling a clear sheet of polypropylene (take from a large Ikea poster frame), it sounded like the end of the word (ahahh).
"Dad, do you want this to make some experiments ?", oh boy, Yes I do !
I slam one of this new wonderfull XCite drivers, and gave it a go. OMG !!!! It sounded amazing.
Some more testing next days, so, did anyone already tried this stuff ?
IKEA RIBBA frame ( just clear sheet of polypropylene ) about 1,5-2mm thin, size around 60x90cm, simply hanging from top with tape.
Yesterday I was taking my afternoon nap, when my daughter awaked me, she pranked me by jiggling a clear sheet of polypropylene (take from a large Ikea poster frame), it sounded like the end of the word (ahahh).
"Dad, do you want this to make some experiments ?", oh boy, Yes I do !
I slam one of this new wonderfull XCite drivers, and gave it a go. OMG !!!! It sounded amazing.
Some more testing next days, so, did anyone already tried this stuff ?
IKEA RIBBA frame ( just clear sheet of polypropylene ) about 1,5-2mm thin, size around 60x90cm, simply hanging from top with tape.
Hello Pviegas,
My last panels are made of a sheet of corrugated PPP (and are short in HF). The flutes are a bit like in cardboard : a wall perpendicular to the skins going all along a direction.
Tectonic from the documentation of the DML500 speaks about honeycomb carbon fiber so hexagonal cells.
How is your PPP sheet?
Christian
I checked quickly, PPP can be transluscent but seems not to be transparent. Transparent material are acrylic or I just learnt it : polystyrene. In its documentation, Ikea describes the front protection of the Ribba frame as polystyrene.
I used this kind of "glass" among the materials I tested to understand the drivers of the efficiency. It had the lowest efficiency of what I tested. You should get more feedback from other DIYer.
Christian
My PP material also have square flutes like yours. I've re-checked the video from tectonic and althought they look like square flutes running along the panel, that might have been for demo only (not to reveal the right stuff), so Yes
About the IKEA clear plastic sheet, sorry, it's polystyrene like you've corrected, thanks
I'm now playing around with some thin clear sheets of Plastic n.4 or LDPE (Low-Density Polyethylene), sound is super detailed with good HF.
I find the use of DML's for PA use quite interesting. ( little or never done before )
It makes sense to me that for PA use, multiple smaller panels with single exciters would be
far superior to large panels with multiple exciters. IE. 4 smaller panels would beat 1 large panel.
You not only get the shared power aspect, but also get the good "Synergy Effect" of multiple 'drivers'
Hello Mister Audio,
Here's the thread started by Leob that inspired me : https://www.diyaudio.com/community/threads/dml-pa-systems.390363/ I like his "can do" mentality a lot.
Tectonic (the former only PA DML manufacturer - they have now stopped selling the product.... ) claims that multiple exciters can be benificial because that way you will drive different spots on the panel so the modes are spaced more evenly.
It might not (yet?) work for me because I mount the drivers directly to the panel (no brace). Also my panel is quite light and not super stiff/hard, I'm not sure how much power I can use per panel.
I'll probably go for the "more low power panels" route, but there's a practical side to it : the general audience come to hear the artist, not look at a wall of panels. And the honeycomb material is relatively expensive.
Regards, Hans
Here's the thread started by Leob that inspired me : https://www.diyaudio.com/community/threads/dml-pa-systems.390363/ I like his "can do" mentality a lot.
Tectonic (the former only PA DML manufacturer - they have now stopped selling the product.... ) claims that multiple exciters can be benificial because that way you will drive different spots on the panel so the modes are spaced more evenly.
It might not (yet?) work for me because I mount the drivers directly to the panel (no brace). Also my panel is quite light and not super stiff/hard, I'm not sure how much power I can use per panel.
I'll probably go for the "more low power panels" route, but there's a practical side to it : the general audience come to hear the artist, not look at a wall of panels. And the honeycomb material is relatively expensive.
Regards, Hans
Problem is that you need a certain size to get good response down to where the subs take over. In my experience it has to be at least 300mm at the smallest dimension. This means that single exciter plates are not practical if you want to get a power handling and SPL to match typical PA subs. Full range exciters are max 40w each, and I have 4 per plate and need 16 plates to match the subs. With single exciter plates I would need 64 in total, and cannot size them down without sacrificing response, so it is just not practical for a PA.I find the use of DML's for PA use quite interesting. ( little or never done before )
It makes sense to me that for PA use, multiple smaller panels with single exciters would be
far superior to large panels with multiple exciters. IE. 4 smaller panels would beat 1 large panel.
You not only get the shared power aspect, but also get the good "Synergy Effect" of multiple 'drivers'
I have not managed to make any panel disintegrate by too much power so far
With laminated plates I might worry a bit about delamination, but otherwise I don't think you need to worry that if plates should hold up using for example 4x40w.
There is no need for bracing specifically if you have multiple exciters. I'm trying no brace now with 4 Xite X32-4 on plate since that is what the manufacturer recommends. We will see how it holds up for extended usage though.
I got around to trying out the UMM-6 and REW. So here's my historic first measurement (okay second, forgot to turn down the xover first time) of one of my XPS panels. Since this is a test and not a lot of time right now, I didn't do any setup. It's the full tower, 2 ~22x24x1 XPS panels stacked vertical, each with one Dayton thruster (in series) -- each panel has a different version of the thruster. It's hanging on the wall (I know, bad) and mic quite vertical on desk to record it.
I wouldn't say it's a huge surprise, with both the bass and highs dropping off. If I had to point to the worst part, it's the variance; the peaks and troughs over the meat of the frequencies have about a 10db spread.
But? I really don't know what to look for, I have zero experience here so any and all feedback is most welcome. This weekend I'm hoping to do some better tests, the mic might reach far enough to set up the speakers outside. I plan to test each thruster panel separately, integrate my DML tweeters, I also have the new dayton midbass i haven't heard yet, and another coin. Well, any guidance to make my testing more productive welcome.
I wouldn't say it's a huge surprise, with both the bass and highs dropping off. If I had to point to the worst part, it's the variance; the peaks and troughs over the meat of the frequencies have about a 10db spread.
But? I really don't know what to look for, I have zero experience here so any and all feedback is most welcome. This weekend I'm hoping to do some better tests, the mic might reach far enough to set up the speakers outside. I plan to test each thruster panel separately, integrate my DML tweeters, I also have the new dayton midbass i haven't heard yet, and another coin. Well, any guidance to make my testing more productive welcome.
They will sag the same as the Dayton's that went bad if the design is the same, simple as that.
If these are them, then yes, count on sag.... physics. https://www.xcite-audio.com/product/xt32-4/
Like I said, not according to the manufacturer and distributor, and the design doesn't provide any way to support them.
Are you sure that you really know better than Ben Stecker and soundimports specialist on exciters?
I'm not so sure about that, and like I mentioned before I prefer to keep warranty intact, which means following their recommendations.
Everything will sag with time, even a sheet of glass. Basic physics , but question is how quickly. Woofers sag as well, but good designs should not sag enough to start distorting within normal life time. Why would exciters be different?
Are you sure that you really know better than Ben Stecker and soundimports specialist on exciters?
I'm not so sure about that, and like I mentioned before I prefer to keep warranty intact, which means following their recommendations.
Everything will sag with time, even a sheet of glass. Basic physics , but question is how quickly. Woofers sag as well, but good designs should not sag enough to start distorting within normal life time. Why would exciters be different?
Three things >
*1. I guess I should clarify what I imagined as PA use. I was thinking of small Clubs & Bars for Duo's & Trio's
where excluding Kik & Vox. most of the sound comes direct from stage. Subs can easily be pushed up to 300Hz.
Backing-tracks could probably sound quite good using DML's, but for LOUD large-stage Rock bands, I don't think DML's
would be the way to go. There is sort of PA and PA.
*2. In the end analysis, all the frequency response charts we see have peaks & dips that appear to be inherent with DML's.
This is why I encourage all builders to incorporate EQ > even as simple as Graphic Equalizers, they are almost ideal.
*3. I once mentioned "semi-rigid bracing" of the exciter body. IF sag is in fact an inevitable outcome, just imagine how
an 'X style' flexible brace might greatly extend the expected life-span.
Strangely, I think of something like hose affixed using strong epoxy
*1. I guess I should clarify what I imagined as PA use. I was thinking of small Clubs & Bars for Duo's & Trio's
where excluding Kik & Vox. most of the sound comes direct from stage. Subs can easily be pushed up to 300Hz.
Backing-tracks could probably sound quite good using DML's, but for LOUD large-stage Rock bands, I don't think DML's
would be the way to go. There is sort of PA and PA.
*2. In the end analysis, all the frequency response charts we see have peaks & dips that appear to be inherent with DML's.
This is why I encourage all builders to incorporate EQ > even as simple as Graphic Equalizers, they are almost ideal.
*3. I once mentioned "semi-rigid bracing" of the exciter body. IF sag is in fact an inevitable outcome, just imagine how
an 'X style' flexible brace might greatly extend the expected life-span.
Strangely, I think of something like hose affixed using strong epoxy
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Having worked with the Bertagni folks, whose stuff was used by The Three Tenors (Placido Domingo was an investor in the company) I'd agree. For that vocal/orchestra music at not-insane SPL it was great. Someone like Motorhead would have destroyed that setup. And if we take "PA" to mean more like small DJ/club setups, no way enough SPL density versus driver array size.
I'm not aiming for super loud, but am more interested in the dipole and (claimed) diffuse nature of this speaker. I hope to get a more "natural" sound impression as opposed to a speaker that is screaming in your face.
I compared the panel in a bigger room (the theatre I work in), and it was ....interesting. The competition was quite stiff because I compared to a Meyer upq-1p (very expensive and high power active speaker). The panel was indeed a lot wider covering, and had less top end (but the meyer is quite extreme in that respect). The panel was sounding less direct/more difficult to pinpoint, but that could be mainly because of the dipole character.
The "natural sound" I am after might have too much downsides (too much room reverb). I'll have to built a few more panels first to really try it for live reinforcement.
My panel actually sounds quite good, but different (!). It is difficult to pinpoint what it is. It lacks in the 150-200 Hz region, but I only percieve that when comparing to other (floor monitor) speaker. When listening to music without comparing, it sounds good (to me). I have to test it singing through it. It may well be that the lack of midbass is awful/uncomfortable for PA use.
So for now the panel is great for listening music in a small room, but in a big room strange things happen.
BTW 1 I solved my problem of more drivers making the sound more fuzzy/indirect by using a dsp and x-over at about 630 Hz, and feeding the two drivers a different kind of the spectrum. That seem to work really well, but unfortunately extra complicated.
BTW 2 For the more technical minded : I'm loosely trying things and relying on my ears not because I think I have golden ears, but because it's just too complex for me. The differences I can hear are there because they are not subtle (else I would not percieve them). Then I try to solve the problems.
I tried in the centre like Tectonic, and for this panel in a line like in the Russian patent.
The setup that works best for me is also copied from the sheetcontrol monitors : 1 driver at the "best spot" and one in a corner opposite, with the low freq part going to the "best spot" driver and the rest to the upper corner.
Here's you can see the sheetcontrol setup that I copied :
I think for your kind of use my "problems" are a bit nitpicking.
I intend to use the speakers mainly for voice, and humans are trained a bit too well to pick up anythings that doesn't sound completely right in the human voice. Nobody knows how electronic music is supposed to sound exactly, so there's no comparing done. It has too sound good, not accurate per se.
Hans
The setup that works best for me is also copied from the sheetcontrol monitors : 1 driver at the "best spot" and one in a corner opposite, with the low freq part going to the "best spot" driver and the rest to the upper corner.
Here's you can see the sheetcontrol setup that I copied :
I think for your kind of use my "problems" are a bit nitpicking.
I intend to use the speakers mainly for voice, and humans are trained a bit too well to pick up anythings that doesn't sound completely right in the human voice. Nobody knows how electronic music is supposed to sound exactly, so there's no comparing done. It has too sound good, not accurate per se.
Hans
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