A Study of DML's as a Full Range Speaker

I have no experience with either of these but I have read of issues with the frog-leg types so I'd stick with the second one as a starting point. Be aware though that there are higher quality units available (at correspondingly higher prices).

Best Wishes
Eucy
+ @sarathssca
I read the same about legs but not experienced. I remember posts saying to remove those legs and the plastic around the exciter.
As mentioned before, one my criteria is the inductance as low as possible. The last exchanges seem to say it is a not too bad choice. The DAEX25fhe is better on that and it reaches more than 10k in my canvas.
 
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Hi Steve
Thank You for making the time for the New Trials that are being carried out.
I hope the lighter material remains one of interest.

I have had a listen to the latest supplied recording through the Laptop, and it is quite impressive, these recordings being made, do make the Laptop Speakers sound improved, so an added bonus.

I am looking at the return to discussing Exciters and will hopefully be purchasing some in the not too distant future.

In relation to creating a adhesion that is reliable, there is usually a few pre-adhesion application processes that are the required disciplines to follow.
Due to implications that can develop through my work, I usually have to produce Task Briefings for adhesive and sealant applications to be applied to Powder Coated Surfaces, Glass, Plastics and Polished Metals.

The following is a guideline if there has been a difficulty in creating a reliable adhesion for an attached part to a Panel.

In general dowsing a material is to be avoided, adding a small amount to a Lint Free Towelling or Paper Wipe is usually the guideline.

Usually a manufacturers product data for the adhesive/sealant materials being used, will suggest a suitable primer is used as the base material for the adhesive/sealant to bond to.

The Primer data will suggest when there are smooth or oily surfaces needing a treatment, prior to the Primer being applied, surfaces are to be abraded and thoroughly degreased with a suitable Degreasant.

A Degreasant will usually have a period of exposure to the ambient environment that is temperature related for the dry time, the dry time is essential to be followed prior to any other application being applied.

Avoiding Cross contamination is critical, so the advice is to use a different towelling/paper wipe for each of the applications.

The Link is to a Primer that was found after a short search that is compatible with Plastics.

https://altaengineering.uk/product/...MIzvuwg8Pe9wIVF4BQBh26ZQUeEAQYASABEgIz4fD_BwE
 
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JohnnoG.
I always recommend using a decent pair of headphones for listening to my recordings, this gives a better impression of being there.
the pva is still stuck to the panel,so far, and I am testing gluing some wood to the thicker panel to see how easy it is to pull off.
my first attempt was not that great, as the wood snapped off quite easily with pressure.
Yesterday I played some very quiet and gentle music but turned the volume up so as to be immersed in the sound, which was lovely, but I fell asleep (it was so nice) and when I woke up the CD was nearly finished,but the music was a lot louder.
I quickly stopped the CD and rushed over to feel the exciters, the heavier panel exciter was very hot , but the new lighter panel exciter was ok.
Disaster averted ! But it was close .
Steve.
 
Hi Steve
I am not too far away from hearing these speakers in the Flesh.
It is just the Exciter Purchase now to be considered.
Your report on the extended use of a Exciter on a certain panel material having been a cause for concern, has got my attention, is there a particular methodology on how to use the Panels.
Even though the following is different to my my initial use for this speaker design, I am keen to learn about the best usage of them in all circumstances.
For instance when using a Vinyl Source, I am always in attendance. When using a CD Source, I am quite happy to vacate the room for a short duration. The use of Valve Amp's such a Phonostage and Power Amp's as well a Valve DAC does require a need to stay close to the system during a replay.

What risks are there to be concerned about for the Exciters, through usage on the DML Panel?
 
+ @sarathssca
I read the same about legs but not experienced. I remember posts saying to remove those legs and the plastic around the exciter.
As mentioned before, one my criteria is the inductance as low as possible. The last exchanges seem to say it is a not too bad choice. The DAEX25fhe is better on that and it reaches more than 10k in my canvas.
Hi homeswinghome,
does DAEX25FHE needs any support to reach 20KHz with canvas.
do we miss any treble with it or it sounds well regarding the high frequencies.
 

spedge

Member
2009-09-03 3:41 pm
JohnnoG.
I can fall asleep listening to vinyl or CD , I've had many years of practice 😴.
usually at audio shows, when I close my eyes to listen to the music , this usually ends in snoring 😂 .

If using these panels full range , a more powerful exciter than mine is needed.
and a method of bracing the exciter to prevent exciter wobble with low frequencies.
both these problems can damage exciters.
If not using the exciters below say , 100hz or so, this should help prevent most of the overheating and wobble.
Although you will still probably have a room suck out somewhere in the 100hz to 300hz area ?
If playing old LPs , panels are not very forgiving of poorly produced recordings, and show up all the problems .
Too much use of the echo machine and noises produced by the machines are easily heard(tape joins and distortions).
You can hear the noises disappearing into the distance !
You can also hear everything going on in the recording studio.
This is also the same for CD obviously.
I'd always keep my TL speakers for those recordings ,as they was the type of speaker they were listened to during the recording sessions.
Steve.
 

spedge

Member
2009-09-03 3:41 pm
Sarathssca.
From experience , I have found that gluing the exciter firmly to the panel gives a higher hf response (no damping layer between the exciter foot and the panel).
I think that the exciter manufacturers use the tape as a way of damping some of the exciter noises that can be set off through the panels ?
Using a brace as far as I know does not affect the hf response, only the low frequencies and exciter wobble.
It does not matter if the panel cannot produce a 20hz signal, the exciter will still try and produce it,which can be destructive to the sound as well as the exciter !
I can always tell if the exciter is coming loose for some reason , as the hf will start to droop above 10k (I have the RTA running all the time), this is before any audible noises and distortions set in.
Steve.
 
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Hi Steve
I will learn the best methods to mount a Exciter and the methods used to control the level of Low Frequency Cut Off nearer the time I produce a Pane.
The idea of wart's and all replay is for myself with an appeal, It will certainly be a 'honest rendition', I have an album where the entry into the recording booth is detected as their is a ambient noise and I assume as the door closes, the ambient noise instantly disappears, I like at times to detect such information in a recording.


A little way off topic, but it might be off interest.

'The Audio Consultants will be hosting a Musical Event at the Crowne Plaza Hotel, Reading East at Winnersh Triangle.
This will be on Saturday 21 and Sunday 22 May 2022 in the Sandhurst Suite between 10am and 5pm.This will feature similar systems to that we had an exceptional response to at the UK Audio Show 2021 last October. This quality venue will allow for a more comfortable and controlled listening experience for our visitors.
Centred on AVM and Luxman amplification coupled with Eggleston Works and Kudos loudspeakers, the sources will be the excellent Aqua La Diva/La Scala combination and Luxman D-10X CD players, with the Innuos Statement for streaming'.
 

spedge

Member
2009-09-03 3:41 pm
JohnnoG.
One of the first things I noticed about dml panels was how well they played natural sounds , such as trickling water , the clarity and realism was amazing.
I find it a different experience to listening to speaker.
I must admit that since discovering dml I have not paid much attention the high end ? Audio scene.
I looked at some of the prices on the audio consultants site , pretty eye watering to say the least .
I'm probably not the best person to go to a high end audio session ,as over the years I can't say I have been very impressed with what I have heard in the past ?
I did check with my wife ,and it seems I'm seeing friends over that weekend, which is a pity as the demonstration is only a few minutes down the road .
They say they will be holding one later on in the year ,so maybe I will get to that one ?
But hopefully I should make it to some of the usual audio shows , if they are on ?
Steve.
 
Hi Steve
I have been letting my local HiFi Group know of my keenness to get the DML Panel produced, and to give them a demonstration.
I am very confident the demonstration will prove to be a great stimulation, and the Groups resident Speaker Builder will have a go, he already has OB's on a Cardboard Baffle as a speaker demonstration.

I will need to get my WAD K5881 Valve Power Amp running as the Amp to drive these, as my 845's are not friendly for logistics and the Amp's used within the Group are of a rare vintage type or quite expensive modern designs, it would be a fright if these were attached to such equipment as an introduction to the design.

The K5881 Power Amp has been maintained since built in the late 90's and was superseded in the early 00's by the 845's, I always had a second system in mind for the K5881, but that was a pipe dream, with less family at home and potentially more space to become available, the idea can realise for the not too distant future.
I would also be very keen to listen to the DML used with a DIY Built Neurochrome Amp that one of the HiFi Group Members has built, this is a Amp I have heard in differing models and all have been very impressive when encountered.

When the Mobile Home is finally here and moved into, there will be no Valves in use, all devices used for music will be Solid State and most likely the music will be from a Computer as the Source Material.

As for a HiFi Show/Event, I have many visited over the years, but today I am more into meeting like minded enthusiasts with different levels of skill sets for being creative with HiFi, this is commonly a home visit, but we also arrange to meet at a event.
In the most recent years I have visited the Owston Show where Speaker Building is quite prominent but all HiFi is on the presentation and many DIY Projects, on a few other occasions I have visited The Wam Show and have also exhibited my system there as well.
I feel sure the DML Panel would receive a lot of attention at The Wam Show.
I can't recall the last time I was involved with anybody from the retail side making an inquiry as a customer, I would assume as far back as 2006, when I purchased a system for my son.
 
Hi homeswinghome,
does DAEX25FHE needs any support to reach 20KHz with canvas.
do we miss any treble with it or it sounds well regarding the high frequencies.
Hi Sarathssca
The DAEX25FHE in the canvas I built keeps a quite good level at 20kHz (see the different FR below : different conditions/locations, distance from 1.5m to 2.5. red curve is in my garden. blue and green in different rooms).
1652632373152.png
 
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spedge

Member
2009-09-03 3:41 pm
Christian.
It is interesting to see your plots have an upwards trend at 20k.
the three plots have the peak at about 10k ,with the dips (cancellations) before and after, this I believe is caused by the exciter coil area, which I am always banging on about 😁
Which no one seems to pay any attention too ?
what is also interesting is the hump in the response in the 2k and 3k area , this I believe is the exciter noise being reflected back from the walls, which is not in the red outside plot .
this happens in various degrees and frequencies depending on panel materials ?
Personally I would bring in my TLS at the 300hz point ,producing a slow roll off similar to the room response idea ?
I would roll off the panel at about 100hz or so depending on listening tests ?
I would also recommend using a material similar to the cheap crate material, as this is a performance changer !
Steve.
 
JohnnoG.
Snap !
Mine has been sitting here for some years now gathering dust, waiting for me to alter it back to its original state.
I made alterations to try to improve things ,but have come to the conclusion, I was wasting my time !
The little box on the right is the digital amp I have been using for some years now.
I turn the amps off and on all the time testing panels ,which is not good for valve amps.
The only thing I miss is the warm glow of the valves at night , before I nodd off 😴 😁
Steve.
 

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JohnnoG.
Years ago I did think about taking my large EPS panels to a wam show but as usual I never got around to it.
Having to fit everything into my car without damage was a problem.
I suppose the smaller panels I use now days are easier to move around?
But there is no way I'm lugging my TLS around, in their present condition.
I don't know what the Owston show is ?
Below is a picture of a old mullard 5_10 my friend gave me yesterday, he has had it in his garden shed for over 15 years, ever since he bought a new valve amp.
I have various old valve gear around the house including radios.
I must stop collecting them .
Steve.
 

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johnnoG.
i was watching a documentary on tv last night about .the moody blues .
so today i have been going down memory lane and listening to ,in search of the lost chord.
thought id share the experience .
headphones please, there are quite a few odd sounds on this, LP , cd ?
this album has always had a warm sound ,to me.
steve.
 

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Hi Steve, Christian,

thanks for the inputs.. finally ordered a couple of DAEX25FHE exciters from soundimports.eu :) .
Already brought a couple of stretched canvas of size 16 x 12 inch.
So once we receive the exciters, the next steps would be like:
1. apply diluted PVA (50% PVA 50% water) solution on both sides of the canvas.
2. attach plywood board at the center of the back side of the canvas.
3. attach exciter at the center of the plywood board.

Could you please suggest:
1. what size of plywood board would be good.. whether to use 6 x 4 inch & 2 or 3 mm thick , or do we need to use bigger board for using as full range ?
2. do we need to glue the plywood to canvas back or can we use double sided tape, so that we can remove it if we need to change the size of plywood board.
3. how do we need to attach the exciter to the plywood board
- whether to use the given double sided tape
- or do we need to use PVA or other glue
- or can we glue the exciter to a small thin plywood piece and put holes in the center of the canvas+plywood board and using a washer (thin plywood or metal washer) and screws attach the "exciter+thin plywood", so that we can easily unmount it if we need to use it on different DML panel, without effecting the exciter or the current panel.
 
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Hi Steve
Another very impressive recording, I putting the files onto a USB Stick, a friend is to play them through their streamer when I get the chance to do this.

The following images are from The Owston Show, which nr Doncaster, plenty going on at this to keep a DIY minded individual interest attuned, the event has been good to me over the years, I even met the foundation members of my local hifi group here :cool: .

The Bottom Image with the Quad ESL 57's encroaching the image, is the Home System exhibited at The Wam Show.
I met so many people on that weekend, I was overwhelmed by the interest being shown in the system, I did not see the exhibition room developing into the place of interest that it did (y).
.
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Christian.
It is interesting to see your plots have an upwards trend at 20k.
the three plots have the peak at about 10k ,with the dips (cancellations) before and after, this I believe is caused by the exciter coil area, which I am always banging on about 😁
Which no one seems to pay any attention too ?
what is also interesting is the hump in the response in the 2k and 3k area , this I believe is the exciter noise being reflected back from the walls, which is not in the red outside plot .
this happens in various degrees and frequencies depending on panel materials ?
Personally I would bring in my TLS at the 300hz point ,producing a slow roll off similar to the room response idea ?
I would roll off the panel at about 100hz or so depending on listening tests ?
I would also recommend using a material similar to the cheap crate material, as this is a performance changer !
Steve.
Thank you for your feedback Steve
  • The 20k upwards trend is "unusual". Only seen on this panel in what I built. The explanation might be this panel is able to produce 20k which is reflected. You will see on the spectrogram below the delayed energy which enter in the FR of the previous post. The last FR here is the same records but with a frequency dependent window that rejects the reflections.
  • The 10k is the hump seen on many realization and as you suggest probably coming from the coil area (see discussion before on the possible countermeasures : add mass, hole, dome...)
  • For the 2k to 3k area, the causes seem different in the 2 FR. In the blue curve, it is a reflection from the rear wall (see the spectrogram below at 1.8ms which is 30cm, the distance of the rear wall in this case). For the green one (second spectrogram) , no reflection delayed so is it an effect of the distance (1m)? the floor? I change I made and I don't remember?
  • Your suggestion of filter sounds good. I have in preparation an amplifier with a filter for such test but this project is going to be delayed...
  • Crate material was in my scope when I did this canvas because it is an easy way to get light plywood but I was afraid by the weight and reading your post about balsa plywood (you remember the plywood from Amazon which is not balsa?) I did it with real balsa. As everything is glued... that's too late for this one.
Christian

1652716560873.png

1652716620955.png

1652716798978.png
 
Hi Steve, Christian,

thanks for the inputs.. finally ordered a couple of DAEX25FHE exciters from soundimports.eu :) .
Already brought a couple of stretched canvas of size 16 x 12 inch.
So once we receive the exciters, the next steps would be like:
1. apply diluted PVA (50% PVA 50% water) solution on both sides of the canvas.
2. attach plywood board at the center of the back side of the canvas.
3. attach exciter at the center of the plywood board.

Could you please suggest:
1. what size of plywood board would be good.. whether to use 6 x 4 inch & 2 or 3 mm thick , or do we need to use bigger board for using as full range ?
2. do we need to glue the plywood to canvas back or can we use double sided tape, so that we can remove it if we need to change the size of plywood board.
3. how do we need to attach the exciter to the plywood board
- whether to use the given double sided tape
- or do we need to use PVA or other glue
- or can we glue the exciter to a small thin plywood piece and put holes in the center of the canvas+plywood board and using a washer (thin plywood or metal washer) and screws attach the "exciter+thin plywood", so that we can easily unmount it if we need to use it on different DML panel, without effecting the exciter or the current panel.
Sarasthssca,
Here is what I did... but as there no "deposit" plan, it is possible I introduced some difference from other realizations...
16x12inch canvas => mine is 41x33cm so close
1. apply diluted PVA (50% PVA 50% water) solution on both sides of the canvas. => I applied diluted PVA only on the rear side of the canvas, not on the front one
2. attach plywood board at the center of the back side of the canvas. => yes
3. attach exciter at the center of the plywood board. => yes

1. what size of plywood board would be good.. whether to use 6 x 4 inch & 2 or 3 mm thick , or do we need to use bigger board for using as full range ? => 10x15cm which is about 4x6inch in 2mm thick. no idea of what is the result with a bigger size
2. do we need to glue the plywood to canvas back or can we use double sided tape, so that we can remove it if we need to change the size of plywood board. => mine is glued. I won't be confident with tape... but not experienced.
3. how do we need to attach the exciter to the plywood board
- whether to use the given double sided tape => in my experience there is no reason not to use the provided tape for a first test. the question will come in a second time if you think about possible improvement or want to reuse the exciter on an other panel. In my case, the plywood panels work with the provided tape, the canvas with epoxy as it is a second used of the exciter and I was not aware of the PVA possibility.
- or do we need to use PVA or other glue => in a second time, see just before
- or can we glue the exciter to a small thin plywood piece and put holes in the center of the canvas+plywood board and using a washer (thin plywood or metal washer) and screws attach the "exciter+thin plywood", so that we can easily unmount it if we need to use it on different DML panel, without effecting the exciter or the current panel. => my few experiences of some interface part lead to a lack of HF or some resonances that are visible on a spectrogram. Not sure of the impact but as there is no evidence of the performances, I'd don't go that way.
Christian
 
JohnnoG.
I can't remember the last time I heard the old quads.
I used to like them if I remember correctly they needed space and beamed a little ?
My friend who has a couple of pairs (he collects vast amounts of audio) cleaned them once , after draining them ,he thought, he ended up flying across the room 😳
He lived to tell the tale.
I have heard the new quads ,but must admit to being very disappointed, is it just me ?
He has just posted me a picture of his latest purchase, a shanling mc30 1watt cd tuner ?
He is in love again 😍
Steve.