Paul Carmondi's ZX Spectrum - First Build (pics)

[zxgravediggerxz]

Hi all,
This is a continuation of a previous thread where I was asking for info on my first speaker build and it can be found here.

First Build-selecting drivers.

I have settled on building the ZX Spectrum by Paul Carmody

Woofer HiVi M6a
Tweeted Neo3-PDRW



Here are my cutout diagrams by using a 3/4" thick 48"x96" peace of MDF





Here are all the cutouts I had to make.



[IMG]http://i.imgur.com/lmwWwh.jpg[/IMG
Rounded edge braces. I didnt take too much care here. I used the jigsaw and than rounded the hard edges.


Glued together cabinets so far.










Just finished flush trim for the back and top of the cabinets.





Removable bottom feature for access to the crossover. I will use 8x screws to secure the bottom plate and than flush trim it. I used small grooves so I can remove the plate if need be.






I plan on gluing the front baffle and that's why i have the removable bottom





I got SoniCaps for the series caps, Mills Resistors, Jentzen Inductors, and a Dayton polypropalyne for the shunt cap






This is what I have so far..... and it has taken forever!!!!

Album

I have all the parts but i am yet to build the crossover and test the speakers. No I do not have microphone test equipment :/

I do have a couple of questions tho.....


There were small gaps on my braces with the walls :/ so I decided to use Polyurethane adhesive Loctite PL Premium. It actually expands as it dries and I figured that I would do good in flling the gaps.
I mostly used so far Titebond II wood glue.

I am thinking of using the Polyurethane for the baffles as well since the edges are not exactly straight. They are maybe a degree or two off because i forgot to straighten them with the router :/
there are also two gaps that will happen on the braces of one of the speakers :/ so I either need to fill that now with something or use a glob of polyurethane and let it do it's magic.... what do you think?

I am not sure how much it matters but I have a couple of chouses for wiring. I have some Belden Video cable that i got on sale with some real heavy insulation and looks pretty damn pro and I am thinking of stripping the cable and using the conductors inside (which are also shielded) for the wiring. I also have VampireWire speaker cable that has I believe teflon coating and a braided shield. Both wires are low gauge maybe around 12-16, which one should I use?

[Helmuth]

Hi Paul,

To get a nice finish it help to glue a thin MDF-plate(3mm) on the top and back to disguise the joints.

Because when it is sanded down to flat and than painted it will later show due the movement in wood. With a thin layer on top this problem can be solved. Success with your build looks nice.

[zxgravediggerxz]

Originally Posted by Helmuth

Hi Paul,

To get a nice finish it help to glue a thin MDF-plate(3mm) on the top and back to disguise the joints.

Because when it is sanded down to flat and than painted it will later show due the movement in wood. With a thin layer on top this problem can be solved. Success with your build looks nice.

Helmuth,
I'm Ivan, it is Paul Carmondi's design

That is a really good tip!
I will try and see if i can do it for the back and top of the speaker box, It can save me some major sanding and leveling time. Do you sand extensively and than seal/prime before you put on the 3mm MDF-plate?
Hopefully I can find it in the local store.

I did plan on doing a 15degree chanfer that will actually hide the butt to butt joints because of that particular swelling problem but it will help if i only have to do the chamfer only for the front baffle

[Helmuth]

Originally Posted by zxgravediggerxz

Helmuth,
I'm Ivan, it is Paul Carmondi's design

That is a really good tip!
I will try and see if i can do it for the back and top of the speaker box, It can save me some major sanding and leveling time. Do you sand extensively and than seal/prime before you put on the 3mm MDF-plate?
Hopefully I can find it in the local store.

I did plan on doing a 15degree chanfer that will actually hide the butt to butt joints because of that particular swelling problem but it will help if i only have to do the chamfer only for the front baffle

It easy to sand MDF only it shows later though the paint, when covert with a thin plate the problem disappears. I would sand it to have a good and easy fit.

[zxgravediggerxz]

Originally Posted by Helmuth

It easy to sand MDF only it shows later though the paint, when covert with a thin plate the problem disappears. I would sand it to have a good and easy fit.

I did a quick search and I couldnt find a an MDF plate of 3mm... do you have a picture or can show me a link that I can see what you are talking about?

[Helmuth]

Originally Posted by zxgravediggerxz

I did a quick search and I couldnt find a an MDF plate of 3mm... do you have a picture or can show me a link that I can see what you are talking about?

Here I just googled I can buy 1.8 -6mm MDF in the Netherlands.

Its Dutch but you can read it talks about mdf and the sizes (dun =thin and Dik=thick). So you have to search a bit in your region.

Houtdatabase

[zxgravediggerxz]

Originally Posted by Helmuth

Here I just googled I can buy 1.8 -6mm MDF in the Netherlands.

Its Dutch but you can read it talks about mdf and the sizes (dun =thin and Dik=thick). So you have to search a bit in your region.

Houtdatabase

nope :/ looks like here in the US we don't have 2-6mm mdf plates or boards... all i get is UK and Australian sites lol. I'll keep on looking I guess

[lduarte1973]

a piece of acrylic wont do the same job ?

[DrDyna]

I'd probably just sand it smooth and use a good glue-on laminate, that seems to be the typical thing that most folks do.

Looking good so far!

[Helmuth]

I did a speaker set speakers in 2010 using baltic Brich and glued on a layer of triplex Birch as a kind of veneer. Work very good and it let sand it down fine to get a smooth fit.

In the picture the top layer and the back side are a triplex layer.