Zaphaudio ZD5 wood options...

[pat00]

I finally have all the bits to make these.

Having trouble sourcing 19mm MDF, locally I have only found 18mm. Is this a problem?

Another though is I can also get Jarrah locally, I think boxes made out of that would look great. Is it OK to butt join 2-3 planks of hardwood together? It's usually only available in floorboard thicknesses.

[woof]

I would not butt joint the hardwood together. However, the 18 mm mdf would be great for an inner enclosure covered with the hardwood - the best of both.

[THORNSPAWN]

I have made enclosures using 18mm MDF covered in 12mm solid jarrah, it will work.

[pat00]

Would I get away with just 18mm MDF instead of 19mm?

[DIYNick]

Pat00, here in the UK the close MDF sizes are 15, 18, 22mm. The only 19mm MDF available is actually 18mm MDF sandwiched between two .5mm outside layers of veneer.

Do you think the plans you are following require pre veneered MDF? This is what PMC use, presumably it has different characteristics to plain MDF?

Hope this helps.

[giralfino]

In general, if you need/want to modify the box for an existing design, you should take the baffle as-is. This is also more true for a design like the ZD5 in which the placement of the drivers on the baffle is carefully selected.
So if you need to select a different MDF thickness, you should do a reverse job: the baffle stays as-is, but the internal surface would be different (less if you choose a more thick material, and more if you choose a less thick material). You then modify the depth of the box in order to match the volume of the design.
I would be very careful however in using a more thick MDF in the ZD5 (e.g. 22 mm), because the ZD5 design is very narrow, and IMHO with a 22 mm MDF you risk an insufficient airflow as the lateral panels will be very close to the driver. OTOH, if you veneer the box, then you will have 18 mm MDF + 0.5-1.0 mm veneer, so you are very close to the 19 mm of the design. Remember to take into account the veneer thickness in you design.
Here in Italy you can find also 10 mm MDF. You can also glue 2 panels together (MDF+MDF or MDF+hardwood), but I would not exceed a 20 mm total thickness.
Ralf

[perceptionchanges]

The answer is yes, use the 18mm. The volume difference is negligable.

[giralfino]

...mmm...
as designed: 13.97 x 30.48 x 58.42 = 24875.56 cubic cm = 24.9 L
with 18 mm MDF and same external dimensions: 14.17 x 30.68 x 58.62 = 25484.20 cubic cm = 25.5 L
So the difference is not negligible, but probably won't affect the tuning too much (and you can choose different tunings anyway).
But all this is probably only academic. I doubt that in this braced design a 1 mm difference in thickness would affect stability or the likes.
Ralf

[-B-]

Hi mate - I'm in Melbourne, same problem when sourcing MDF.

I'm building my ZD5's for the second time as we speak. Originally did in 18mm MDF sealed version, trying the ported version now in 18mm birch ply.

As giralfino says, it is critical that you don't chance the baffle size - zaph is very firm on the width, so you don't have many options with other materials. There simply isn't enough room inside if you go above the 19mm. It's alread pretty hard to get a nut on the back of driver bolts, let along airflow! Simply correct the internal volume by moving the shelf in the case of the ported, or perhaps depth in the sealed version, but leave front face the same. There is not much in it though, and in my first build I added some deadening material lining which probably negated my adjustments in any effect! Veneer is another option for you (pre or by yourself). Not sure how I will cover mine this time round, last time painted white gloss and they actually looked pretty good.

In terms of joins, I originally did 45 deg edges ... but I wasn't happy with my ability to get it accurate enough in the final assembly. This time around I am doing rebates, and also got the board pre-cut from the supplier - best thing I ever did, it is sub mm spot on in assembly.

If you want to compare notes or have questions just PM me