Wonderful in presentation
Uniquely understated in design
Fun in the making

These entries are dedicated to my 1st DIY Project - WUF #1

full range speaker

2 way cross-over

TMM drivers

The story goes like this,… the recent 3 years I dabbled deeper into high-end AV. I liked what I see but not the high price that came with it. After several upgrades, the speaker became the weakest link. The commercial option would set me back sgd12K. Unwilling to pay the high premium the legal alternatives is DIY. .

Months of reserach follows and finally I proceeded with Project WUF#1.

Arrival of Drivers
14 March 2005:: Yes! The drivers finally arrived. They are gorgeous, especially the mid-bass. The tweeter is nowhere as sexy as the higher ‘radiator’ model. But the sound is sweet as honey. Diminishing marginal return law dictates the 2x price increase of the radiator model.

I was apprehensive about buying as there is zero support in terms of warranty - just old fashion good faith. Thus, I anxiously fixed up the crossover to test them just in case there’s a problem. Thankfully, there were none.

The crossover actually turned out pretty good/better than expected. Did I mention that only a pair of the mid-bass were in stock. I have to wait another 2 months for new stock to arrive. As is, the tweeter output is abt 4-5dB louder when partner with the single mid-bass. As a temp measure, I bought a cheap 2Ω/5w resistor to tame it down. The result is surprisingly good. Here are the pix.

Enclosure Contruction
I managed to locate a local supply who is willing to take my small order. They will precut the MDF boards to dimension according to the provided drawings. Cutting the holes is the costliest - $3-4 per holes. The material cost plus cutting only add up to $140 compared to $300+ for just one driver.

The main challenge here is routing the depression for flush mounting the drivers. It took almost 36hrs of effort, routing 2mm per pass. I am lucky that I did not make any major mistake… the pieces fall into place with 1-2mm tolerance. A lot of sanding was involved.

I was undecided on how to make the curvature of the front baffle… routing was not an option as my rotary tool can only rout 2-3mm radius which is not sufficient. In the end I manually sand using the rotary tool a chamfer of 12-15mm. After which, I use a strip of sandpaper and sand by hand to evenout the edges and get a smooth curve.

I spent quite a bit of time figuring out the construction sequence, as the glueing the pieces together is not an easy thing. The worse thing that can happen is the pieces run and the box dimensions get distorted. If that happen, there will be gaps all over the place and the subsequent pieces will not fit!

10 April 2005
The 1st box is all sealed up and ready to rock.
I’ve mounted the drivers and fixed up the xover for an initial test drive…. good, but one problem. There is a box resonance at a low-mid/high-bass region… I would need to tame this down if I were ever to get a good all round result. On most material, this ‘defect’ does not show itself… but on some, it can be very annoying.

22 April 2005
Progress on the 2nd box is impeded due to non-availability of “wood glue”, however managed to fix-up stiffener to increase rigidity of the side and back panels. Also grabbed more foam for cabinet stuffing.. these are packing support foams used for server hard disk. Hope this will help tame the box resonance.

09 May 2005
The 2nd pair of mid-bass drivers are finally here. I immediately complete the 2nd xover and hook them up. My god, the mids are really gooooood! The bass would need further tuning though, I still detect a tinge of boxiness and resonance hum at certain frequencies. I am torn between extended listening as it is and taking it apart to finish-up on the enclosure! Likely I’ll perform an extensive listening before I progress further into the final cosmetic which will definitely take a month (if I’m not too lazy) at a min or maybe 3 months. There’s a lot of surface leveling to be done since the glueing resulted in 1-2mm differences.