High-end 3 way dáppolito with aluminiumcone

[Helmuth]

Hi I am new here so a introduction is necessary.

I am Helmuth.Lageschaar from de Netherlands.
I work as assistant at engineering department of a manufacturer from electronic ballast. I do stuff as UL approval and prototype building.

The start of my electronic career was triggered by my the hobby of my father and my fascination for audio equipment.

And then the focus on speakers and amplifiers. I often design virtual speakers when I got a idea. Now I have got a college how is interested in a quality speaker designed by me.
I want to post the evolution of this project.

His request was a bass reflex and attractive design by using aluminium cone speakers.

My goal to make the best possible design for a low budget price with professional appearance.

I started al ready but register on DIY today so here the design.


This drawing is already modified but good for to get a impression.

[tinitus]

Seems ok...sure hope thats a 12" woofer

btw, I would make a seperate room behind the mids to house the xo

As fore the matrix stucture in the midrange...much better to make round holes in the structure instead of squared holes

I reckon you are aware that MTM deappolito asks fore small mids and low xo point...theoretically

[dublin78]

http://www.audiocomponents.nl/speake...erence_eng.htm

See Maxima at the bottom. Not aluminium though, at least someone else has had the same idea.


http://www.audiocomponents.nl/speake...g/Maxima_1.htm

[el`Ol]

Alcone drivers?

[Helmuth]

@tinitus

I understand your comment (round holes). But with the wave length of the sub this is no point.
The tip for creating a room for de XO I will implement good idea.

It is a 10"woofer here the predicted response. -3dB 26Hz



The pipe will be place 15cm from the ground and there by lift the level round from 18-35Hz. So -3db would be a possibility when the prediction is correct.
Impedance and cone extrusion.



I have used core plywood. This is the most cost effective way to create a professional finish.

Because you don't have to paint.
The part were saw form one plate to maintain the wood structure.



See the line's in the wood.



Used glue red dry transparent the green one is super strong and foams up used inside the box.



To mount them perfect use tape.



Then turn the part 90 degrees and put on the red glue.
fold the part to gather to get a perfect fit use the back plane without glue to fix the 3 parts.



hold it with two clamps to dry.

[litezoner]

I love your design, great professional quality work, it begs the question, Why are some of the X-over componants mounted outside the inclosure? Just curious. still very very nice.

I just noticed that may not be your work as I clicked the link just below your first post. Sorry about that

[Helmuth]

Originally posted by dublin78
http://www.audiocomponents.nl/speake...erence_eng.htm

See Maxima at the bottom. Not aluminium though, at least someone else has had the same idea.


http://www.audiocomponents.nl/speake...g/Maxima_1.htm

This setup is not new see visaton vox visaton voxexist for about 10 year now. Price kit 1600euro.

I will make a same quality speaker for 700-1000 euro.

The example with active sub that you have posted will also be more expensive. Than the passive version I design. A good alternative for active layout is adding a Bi-wiring connector

Alcone drivers?

Alcone has great drivers and nice price.
But still more expensive then necessary and to early breakup around 5000Hz like almost al aluminium mid drivers.




The glue is dry



now I will glue the backplane. To get a good contact with the Formica first sand it.



here you see the foam off the bizon construction gleu.



The excess glue can by scraped with a paint remover tool.



Dry result. This perfect finish can only be archived with care full sawing the parts. So look for a good hobby market with professional saw machine.
Then in two day's you have this result.



close look

I love your design, great professional quality work, it begs the question, Why are some of the X-over componants mounted outside the inclosure? Just curious. still very very nice.

When you mount them outside the box it is easy to tweak the part great for hobby. Not useful for normal users.

Graetz Helmuth

[tinitus]

man, that was fast

[Helmuth]

man, that was fast

This is the result of the last two weeks so not this weekend


Now the bracing.

The parts are made out of 12mm MDF. This will form the bracing off the top part of the box.








These excess strips are great for bracing the box behind the woofer.






The bottom part will be accessible by removing the cover, mounted with m5 bolds and nuts how can be hammered in I have also glued them.

[Nanook]

but I do have a few comments, and they are my standard ones:

minuses:

• enclosure is made with what we in Canada call "chip board", only used in the lowest quality anything here
• the panels most likely will resonate
• both the interior and exterior should use the same finish. Eg: if polyurethane top coat on the outside, do the same on the inside
• MDF does not have the stiffness of solid lumber in the longitudinal (with the grain) direction. I would have made the bracing out of solid wood or plywood rather than MDF

some pluses:

• energy storage will not be much of an issue.
• another possible plus in your construction: the finish layer laminated to the core should be well bonded and stop typical MDF air losses
• they look very good thus far

Because I am not completely aware of what may be available to you for materials, I am trying not to be typically me and be overly critical. I understand that many build with what they know or what they have available to them. As I noted above, they do look very good. I hope you and your client love the sound.

Ken Lyons, the maker of the Neuance shelving suggested that the British brand "Target"(makers of hi-fi racks and stands) uses a similar material that you used for your enclosure for their shelves and that the shelves are fairly good anti-resonant wise and in terms of energy dissipation.

And you have done all of this in a very short period of time. For that I am impressed (and I can't build anything anyways, I have two left hands...)

for some interesting projects from the Netherlands one might look here:

• Tony Gee
• BD designs

Regardless, you are doing what we all state we do--DIY, and that is worth the voyage in and of itself.


stew