mantraxl said:
That is very gracious of you to say that and also it gratifies me.
But now, are you going to build them?
mantraxl said:
Good question. Is the Elsinores the ultimate speaker? Can it be improved? Of course, anything can be improved.
Let's take the drivers: I think the Peerless HDS Nomex 830875 is a classic. In the motor department, as has been pointed out to me, the newer 830883 has been improved, but how much would this show up as a sonic improvement? I don't like its phase plug - if it was available without it, I would be sorely tempted in doing an upgrade using them. This driver would work in the same box but tuned slightly lower by about 2 Hertz. Under those conditions, the sub 100Hz response are virtually identical and so are the forces at work.
Beyond that I would look at the Scan-Speak as a team (yes, I have co-developers) we have experience with them. How would an Illuminator version of the Elsinore go? I hope it would be fantastic. But re Scan-Speak, we have compared/listened to speaker systems using SS drivers and found the Nomex drivers not inferior in any sense at all. They are remarkable in their own right.
Re Tweeter: Sorry, but I just love the new Peerless HDS 810921. Not only is it as good as tweeters several times the price but also they have one huge advantage: They are 8 Ohm. Most of its more expensive competitors are 4 Ohm (often really 3 Ohm like Vifa XT25). In speakers with higher sensitivities and using 1st order, the negative phase angle combined with Low Z (and no attenuation to keep sensitivity high) is really troublesome. I had this problem with the Mark 1 Elsinore and it was much easier to deal with when I went over to the HDS. Not to mention the HDS also sounds better, it is very versatile, and, to me this is important, the higher Z means the voice coil runs cooler - the dynamic compression is audibly very low. yes, there are other tweeters that I like but the HDS still comes up trump even if I wanted to spend more. Now if the new SS D30 (D3004/660000) was 8 Ohm - that would really tempt me. An 8 Ohm Seas Millennium too. But alas...
Finally the box. Yes, I would bevel the edges. Then model the crossover to match it diffraction. But the thing that I believe would improve the box most is the most simple (and yet difficult at the same time), take a look at the newer Dynaudio designs, that baffle of theirs made of high density fibre board. I have heard a pair of Lenehan ML-1 speakers in both standard and 'Signature' versions and this was the only difference. Make the front part of the box structure out of this material and I believe the improvement would be greater than anything I have covered so far, no kidding!
So there you are. Our little thought experiment, Gedankenexperiment, went well. What do you think?
Joe R.
rob323 said:
That is what Michael Lenehan of Lenehan Audio calls it, HD3.
But it is very hard to work with. He is soon getting a CNC machine to deal with the problem. He had his local wood supplier cut for him and had to pay for blades. The edges he showed were blackened by the saw. So for DIY purposes it is a difficult proposition. BUT if you know the right people with the right equipment, then it might be worth the effort. I would love to hear a pair of Elsinores done that way.
Joe R.
HD3 Alternative?
Hi Joe, all,
Here in NZ we have access to a product called "triboard". It is a wood composite material comprising outer layers of extremely hard, dense fibreboard sandwiching a much softer composite middle. I have built some mini monitor type speakers using this and the results are outstanding. A friend has built a magnificent pair of Tannoy Monitor Golds using this stuff and gave me the offcuts.
It is much stiffer than mdf and the outer layer is so hard it is not possible to dent it by hand using a screw tip or nail. It sounds completely different to mdf when tapped too; it has a much higher frequency sound as one might expect from its stiffness.
It may be available outside NZ as I believe it is used in the construction industry in Japan. It is manufactured by Juken Nissho a Japanese owned company with substantial forestry holdings and a factory here.
Rob.
Hi Joe, all,
Here in NZ we have access to a product called "triboard". It is a wood composite material comprising outer layers of extremely hard, dense fibreboard sandwiching a much softer composite middle. I have built some mini monitor type speakers using this and the results are outstanding. A friend has built a magnificent pair of Tannoy Monitor Golds using this stuff and gave me the offcuts.
It is much stiffer than mdf and the outer layer is so hard it is not possible to dent it by hand using a screw tip or nail. It sounds completely different to mdf when tapped too; it has a much higher frequency sound as one might expect from its stiffness.
It may be available outside NZ as I believe it is used in the construction industry in Japan. It is manufactured by Juken Nissho a Japanese owned company with substantial forestry holdings and a factory here.
Rob.
Re: HD3 Alternative?
Hi Rob
It looks like it is an NZ product and not so common here. But from what I've been able to see online, it looks like old fashioned chip board with an outer layer of MDF.
www.triboard.com/triboard.htm
But HD3 is so hard as to be described as rock like. BTW, as you have handled Triboard, what sort of weight does it have relative to a same size and thickness MDF piece? The picture in the above link, it looks like it is lighter and softer core. I like the sandwich idea though, but I would not like working with chip board. Joins would have to be V type and butt joint would be no good. Or am I making wrong conclusions.
Joe R.
Robert F said:
Hi Rob
It looks like it is an NZ product and not so common here. But from what I've been able to see online, it looks like old fashioned chip board with an outer layer of MDF.
www.triboard.com/triboard.htm
But HD3 is so hard as to be described as rock like. BTW, as you have handled Triboard, what sort of weight does it have relative to a same size and thickness MDF piece? The picture in the above link, it looks like it is lighter and softer core. I like the sandwich idea though, but I would not like working with chip board. Joins would have to be V type and butt joint would be no good. Or am I making wrong conclusions.
Joe R.
Hi Joe,
Triboard is described in the link as mdf outer layers and a chipboard centre. However when you are holding it in your hand you can see that the outer layers appear to be more like a strandboard than MDF in that the strands of wood are long and clearly visable on the surface. The outer layers are many times harder than any MDF product I have come accross.
Additionally it doesn't take paint as well as MDF as the surface is not as perfect so a good paint finish is harder to acheive.
You may be right about the joints. I used simple butt joints which is about the limit of my woodworking skills! It does cut and machine very well but it has a soft chipboard like core at least in the thinner 18mm panels I used. I recall that it seemed much lighter than MDF of the same thickness but to be sure I would need to weigh some samples. It certainly is many times stiffer.
Rob.
Triboard is described in the link as mdf outer layers and a chipboard centre. However when you are holding it in your hand you can see that the outer layers appear to be more like a strandboard than MDF in that the strands of wood are long and clearly visable on the surface. The outer layers are many times harder than any MDF product I have come accross.
Additionally it doesn't take paint as well as MDF as the surface is not as perfect so a good paint finish is harder to acheive.
You may be right about the joints. I used simple butt joints which is about the limit of my woodworking skills! It does cut and machine very well but it has a soft chipboard like core at least in the thinner 18mm panels I used. I recall that it seemed much lighter than MDF of the same thickness but to be sure I would need to weigh some samples. It certainly is many times stiffer.
Rob.
Joe,
Further to my earlier email I checked with the friend I mentioned who built the Tannoys. He says the thicker panels of triboard he used have a higher density core, more akin to mdf. These are also extremely heavy.
I checked out the JN website and note there are varying densities of this stuff. The 18mm board I used was clearly low density but this relates only to the core not the skin which is super hard and dense but quite thin.
Rob.
Further to my earlier email I checked with the friend I mentioned who built the Tannoys. He says the thicker panels of triboard he used have a higher density core, more akin to mdf. These are also extremely heavy.
I checked out the JN website and note there are varying densities of this stuff. The 18mm board I used was clearly low density but this relates only to the core not the skin which is super hard and dense but quite thin.
Rob.
Birch ply is vastly stiffer than MDF, oak ply even moreso. Aside from surface damage resistance, is there an advantage in HD3 over these more commonly available woods?
I read a few studies illustrating that there was greater antiresonance benefit in (solidly) bonding a more stiff material to a less stiff one (birch ply and mdf forinstance) as opposed to just using more of the stiffer material. The dissimilar vibrational frequencies of the two substances tend to damp one another, as opposed to just driving the harmonic freq higher, as with plain increased stiffness.
One could epoxy plate steel to MDF or wood, for further stiffness silliness. These are things I have contemplated, and still do.
In response to Joes question, yes, I definitely plan to build a set of Elsinores, though I am also working on a design of my own (well sort of my own) based on my understanding of the principles and methods laid out by Joe. I am trying to put my grasp of the ideas to the test and I suppose that we shall see how that works out. Regardless, I wouldnt think of missing out on joining the club of Elsinore builders and hearing the much-lauded results
I read a few studies illustrating that there was greater antiresonance benefit in (solidly) bonding a more stiff material to a less stiff one (birch ply and mdf forinstance) as opposed to just using more of the stiffer material. The dissimilar vibrational frequencies of the two substances tend to damp one another, as opposed to just driving the harmonic freq higher, as with plain increased stiffness.
One could epoxy plate steel to MDF or wood, for further stiffness silliness. These are things I have contemplated, and still do.
In response to Joes question, yes, I definitely plan to build a set of Elsinores, though I am also working on a design of my own (well sort of my own) based on my understanding of the principles and methods laid out by Joe. I am trying to put my grasp of the ideas to the test and I suppose that we shall see how that works out. Regardless, I wouldnt think of missing out on joining the club of Elsinore builders and hearing the much-lauded results
hello,
This is the layout of the crossover
http://img245.imageshack.us/img245/1393/im000072vl6.jpg
they are placed on 20cmx9,5cm mdf25mm
are the coils placed good to avoid magnetic interaction?
You've been a contortionist? woman must love you at bed
Anyway one of the side panel and the main brace isn't glued so it's not that difficult...
This is the layout of the crossover
http://img245.imageshack.us/img245/1393/im000072vl6.jpg
they are placed on 20cmx9,5cm mdf25mm
are the coils placed good to avoid magnetic interaction?
You've been a contortionist? woman must love you at bed
Anyway one of the side panel and the main brace isn't glued so it's not that difficult...
OK, here I go climbing my soap box again...
While there are elements of 'constrained layer' in the materials you guys are talking about, I do think that the most basic way at looking at damping and bracing enclosures, the target is to get the resonances as high as possible and then use mass. The higher we can force the resonances the smaller the amplitude and mass becomes more effective. The problem is that the Elsinores are a relative large speaker and the box I heard using HD3 were much smaller using the 5 1/4" Nomex and Peerless HDS. Small equals stiffness. There was a sense of very low noise floor and very good focus. Keep in mind the whole carcass was HD3.
In the Elsinores, I think it makes sense to concentrate on the Front Panel rather than the whole carcass. The Front Panel will always be the weakest panel - putting holes to mount drivers cannot help one bit. I see that Dynaudio makes the Front Panel very small even if box is large. I can see where they are coming from. Pretty sure this is HD3. The weakest part of the box also needs to be the strongest. The Front Panel needs our greatest focus and the rest of the box, don't ignore completely, use good strong construction and sound bracing techniques (I use longitudinal and asymmetric bracing techniques as much as possible).
Constrained layer or similar techniques work better with straight out panels. But the Front Panel is really not a panel in the full sense of the word. Sides, backs etc, yes. I think we need to think as the Front Panel as something that needs to be 'sculptured' for maximum strength, air flow behind the drivers. We know that 'shaping' an object changes its resonant modes. Take a cube of wood, even if not the tougest or highest density, and try make it 'vibrate.' Now slice the would into thinner sections and voila, it becomes much easier to excite.
For this reason I think that HD3 for the Front Panel, that can be CNC'd to good effect, would also be cost effective. The square driver cut-out (designed to be simple to do DIY wise) of the 25mm Sub Front Panel, the air flow and strength can both be improved by 'shaping'. I would also make both 18mm Front Panel (in two parts) as well as 25mm Sub Front Panel (1 piece) and the Tweeter Panel (1 piece). I would not be inclined to mix HD3 and something else.
I think this would make a very strong Front Panel - much improved. I would leave the rest of the box as is. But the rest of the box we could use Triboard or other some-such to could effect.
Think of photography: We know that even small amounts of camera shake can produce a blurry picture. Effectively it looks like lack of focus. It is not the scene that is moving but the camera. Now reverse that principle: When listening to a loudspeaker, it is not the listener that is moving. We are stationary. Unless the drivers in the box are also held stationary, the sonic images becomes blurry. Classic law of relativity. It is the noise generated by the Front Panel that causes this, not just vibrational modes of the box as a whole.
We need to keep those drivers locked in space. Like a vice!
Joe R.
While there are elements of 'constrained layer' in the materials you guys are talking about, I do think that the most basic way at looking at damping and bracing enclosures, the target is to get the resonances as high as possible and then use mass. The higher we can force the resonances the smaller the amplitude and mass becomes more effective. The problem is that the Elsinores are a relative large speaker and the box I heard using HD3 were much smaller using the 5 1/4" Nomex and Peerless HDS. Small equals stiffness. There was a sense of very low noise floor and very good focus. Keep in mind the whole carcass was HD3.
In the Elsinores, I think it makes sense to concentrate on the Front Panel rather than the whole carcass. The Front Panel will always be the weakest panel - putting holes to mount drivers cannot help one bit. I see that Dynaudio makes the Front Panel very small even if box is large. I can see where they are coming from. Pretty sure this is HD3. The weakest part of the box also needs to be the strongest. The Front Panel needs our greatest focus and the rest of the box, don't ignore completely, use good strong construction and sound bracing techniques (I use longitudinal and asymmetric bracing techniques as much as possible).
Constrained layer or similar techniques work better with straight out panels. But the Front Panel is really not a panel in the full sense of the word. Sides, backs etc, yes. I think we need to think as the Front Panel as something that needs to be 'sculptured' for maximum strength, air flow behind the drivers. We know that 'shaping' an object changes its resonant modes. Take a cube of wood, even if not the tougest or highest density, and try make it 'vibrate.' Now slice the would into thinner sections and voila, it becomes much easier to excite.
For this reason I think that HD3 for the Front Panel, that can be CNC'd to good effect, would also be cost effective. The square driver cut-out (designed to be simple to do DIY wise) of the 25mm Sub Front Panel, the air flow and strength can both be improved by 'shaping'. I would also make both 18mm Front Panel (in two parts) as well as 25mm Sub Front Panel (1 piece) and the Tweeter Panel (1 piece). I would not be inclined to mix HD3 and something else.
I think this would make a very strong Front Panel - much improved. I would leave the rest of the box as is. But the rest of the box we could use Triboard or other some-such to could effect.
Think of photography: We know that even small amounts of camera shake can produce a blurry picture. Effectively it looks like lack of focus. It is not the scene that is moving but the camera. Now reverse that principle: When listening to a loudspeaker, it is not the listener that is moving. We are stationary. Unless the drivers in the box are also held stationary, the sonic images becomes blurry. Classic law of relativity. It is the noise generated by the Front Panel that causes this, not just vibrational modes of the box as a whole.
We need to keep those drivers locked in space. Like a vice!
Joe R.
Peter N said:
If you saw my silhouette, the joke would be even more obvious!
In the members profile it asks for "Occupation", so I put Contortionist and nobody so far has noticed.
www.diyaudio.com/forums/member.php?s=&action=getinfo&userid=4828
Joe R.
Finally I finished the elsinores! For my first laudspeaker it wasn't easy at some point, especially cuts and crossover.
Great dynimic and it's well under control.
Great soundstage, it's really good.
It has really a good sensivity, I'm using little power.
The only thing sometime I don't like are the highs, for me sometime are too laud. On some cd the voices sound a little harsh.
Maybe I did something wrong in the crossover?
The first time I had connected 3 one ohm resistor in parallel then I heard something wasn't right and I connected them in series. maybe I burned a resistor?
A mistake I did is on tweeters. They're not aligned from the center by 2-3mm.
I have not yet honed the edges, I don't understood if I have to do it.
Great dynimic and it's well under control.
Great soundstage, it's really good.
It has really a good sensivity, I'm using little power.
The only thing sometime I don't like are the highs, for me sometime are too laud. On some cd the voices sound a little harsh.
Maybe I did something wrong in the crossover?
The first time I had connected 3 one ohm resistor in parallel then I heard something wasn't right and I connected them in series. maybe I burned a resistor?
A mistake I did is on tweeters. They're not aligned from the center by 2-3mm.
I have not yet honed the edges, I don't understood if I have to do it.
Peter N said:
Good on you!
Check the crossover and wiring over and over again. This is where mistakes are most likely. This includes getting the right phase. Keep checking until you are absolutely sure.
Just ask Rob, he has a similar problem and it turned out that his tweeter's phase wasn't right. It is VERY easy to make a mistake, so don't feel a fool if you find something. Happens to the best of us.
Peter N said:
Not sure what you mean by that.
Joe R.
The symptoms I had were a treble that was very shouty and fatiging, an image that would wander as the frequency increased, and all imaging just about totally disappeared unless you sat dead central in the sweet spot.
The cure for all the above was to reverse the phase to both tweeters.
Edit - Oh, and don't listen to them without the felt around the tweeter, it makes a huge difference.
The cure for all the above was to reverse the phase to both tweeters.
Edit - Oh, and don't listen to them without the felt around the tweeter, it makes a huge difference.