Dome's Build Thread.

[joe58]

Last year I built some Zigmahornets and from then on I was hooked, now probably for life and I'm only 18. However being 5ft tall their not particuarly practical for University after the summer and therefore summets smaller was needed. Having seen the Ikea bowls I realised thats what I wanted to do, but still not the money for all 4 bowls. A little search and I found the Focal Domes and therefore decided to make some dome/ half-sphere shaped speakers. The little calculations I did are below as I don't have any software so I used online claculators: mh-audio.nl and linearteam.dk. Shown below are a few calculations I used from them. I know there won't be really any bass, but I do have a subwoofer to do that job, so thats sort of fine.



Colour scheme still to be decided on but I may go bright like the Focal's or keep the wood, have the mdf(shown later in build) painted silver and have a white grille, in a very minimalist way sort of like a Braun SK4. Shown below is a quick mock up on Sketch Up of what may happen, especially with the amp(Temple Audio Bantam), but dimensions will be refined and developed to be much more appealing.


If there are anysuggestions as I only have limited knowledge on in the propeties of speakers and how to make them sound better feel free to critisise and say how it is possible to make them better. The first parts of constrution will be shown in the post below as the first stages have been started.

[joe58]

Day One build. This will hopefully show construction much more easily than describing.
One Blanda 20cm Bowl and some very usefull brackets I found lying around which are screwed and glued in place. The circle was cut out by hand with a jigsaw by me, so is very round . Non of these laser cutters needed here.

Next was testing so see that it fitted when screwed on and a little sanding ajustment as the screws pulls the circle over a little. There will be some sort of gasket betwen bowl and mdf to mae a better seal.

Inserting the port, with another great find around the house being this thick card tube I found(budgets you see).

Day One completes with a quick test. To the right is a half built Fonken I will test them against hopefully when both are built.

[Dr.EM]

Interesting project. Are those Fostex drivers? It's a pity the build photos don't go any bigger, I can't see much detail.

I am also building small speakers for use at uni

[joe58]

Yes Fostex Fe103e. Sorry about the pictures. I'll try and change them. I realisied why there small, as I only copied the link from the smaller photobucket album section and not the one from the single puicture view like the first post pictures.

I've seen your wedges, going for summets completely different, but will probably sound much butter, but it's design design design with me, with the acceptence of slightly lesser sound. However when I tested them last night they sounded much better than I thought. All I wanted was them to sound like the Zigma's and I do think in my small room they are quite close.

What course, year, uni? I'm Coventry after the summer for Automotive Design.

[joe58]

Heres some better pictures. Shown here being tested, not ideal but just a test.

[Dr.EM]

These should sound good with a subwoofer, good drivers and no parallel surfaces inside the enclosure are plus points. A driver centered on a round baffle gives rise to a peaky baffle step response, placement near a wall may balance it out a little though.

Looks like a tidy build so far, look forward to seeing how it turns out

I'm goint to Solent to study Audio Technology in Sep

[enigmaticEntity.]

I like your "budget solutions". I have heaps of cardboard tubes from cling wrap products; some have thicker tubes than most - very nearly all cardboard ports you can buy, so essentially you have free ports with the limitation of diameter and the fact that you have to make your own flared ends. I assume Fostex drivers don't need flared ports due to their tiny excursion capabilities?

The enclosures look good on that chair, though making those curves would be difficult...

Plus, your feet look Hobbit-like in that photo with the bowl

[joe58]

You spotted the feet, that i nearly cropped off the photo, but hey ho everybody has them . Plus I'm on tiptoes. Yes the card tube was perfect, just merely lying around my house. I think mum was about to use it or bagsy'd it but a quick phone call to her at work secured the tube for me. I'm not sure about flaring the port. You won't see the fronts any way as i'm going to make another layer of mdf but in a ring form so I can wrap the speaker cloth around it and slot it on the front, with them grille fixing thingies like on the Wharfdale(bottom left).

[joe58]

Just a quick update. The stands have been started as shown in the photos. Bit of pine, but the base may end up being made from steel or a metal plate, but that will be worked out when done and if they don't work. They are/will be fully movable, but with a change of plan as the butterfly didnt hold them securley enough. Therefore they will pivot around the bolt and a series of holes will be drilled around the pivot areas and a thin pin will be inserted in any of thew holes through both parts of the wood at the pivot section in the desired postion. Slightly complicated but once done pretty simple.



Shown blow is the actual holder to be cut out in the "P" shape and will also be attached to the top using the pivot system and the ring will be used for the speaker to be sit in.

[joe58]

Just a quick update of how things will look when finished with stands. The stands will be sorted (ie holes filled form the many experiments and problems) and then primed and hopefully with a bit of sun to help get a good finish. While there drying the speaker grille rings(MDF) will be cut in hope of the speaker fabric(white-no black here-pure silver, white, light wood minimalism ) arriving on Monday and then can be ‘faffed’ around with to get them fitted/ finished to a high standard onto the MDF rings. I can hear the help of my Mum coming in here. Plus I’m hoping the circular MDF speaker holders that the speakers actually sit in will hold as I'm worried about the twist that I can sometimes see. But they are perfect as they allow the speakers to be directed in any way whatever. Up, right, left and down. Shame that the stands won't be movable, as my many experiments that I conducted didn't work as planned, due to mainly the softness of the pine. However experiment number 5,403 speaker stands will be built another time in the future, which will be hopefully fully movable and fully positionable.