Computer Speaker W4F

This is a simple, but functional loudspeaker enclosure for TB W4-1320SIF driver. Inner volume is ~3 liters and reflex port is tuned to ~65 Hz. I use these speakers personally in my work for Teams meetings and background music. They should be better than almost any integrated TV speakers. These are not as good as MDF (or wooden) cabinets, but they are considerably cheaper and all you need to do is print.

In addition to the prints you will need the drivers, screws, nuts or heat-set inserts, internal wiring and binding posts. Soldering of wires is highly recommended, but depending on the binding posts, crimping with Abiko connectors is also possible. Paint work not necessary. I used heat-set inserts for M5 machine screws for attaching the driver, the model has appropriate holes for such heat-set inserts. You can blend in or heat-insert a nut if you know how. You will need an amplifier just like with any passive speaker.

Required minimum print area is (X, Y, Height) 160 x 180 x 175 mm.

NB. Before printing make sure your screws fit the drivers screw holes and you got the correct type of nuts or inserts at hand.

Printing and Building

I recommend printing in 3 pieces, each STL file. Material should be mechanically strong and not flexible, I used PLA. I used 10 % gyroid infill, but if you got time, use higher percentage. Use ~2 mm wall thickness. I recommend printing the faceplate piece visible side upwards, so that the print lines come cleaner. If you print faceplate down, you can add the slot in the same print, but it might be uglier. I used butyl damping mat with alu coating (car sound proofing material) on the inner walls (optional). Glue together with any glue that works with prints (super glue?). The cabinet should be made air tight, except the slot opening, so use a lot of glue and press together tightly.

NB. The air volume inside the enclosure and the slot are critical for the bass reflex to work as designed. Do not change dimensions of the model and do not fill the enclosure with hard objects. You can use light soft stuffing (polyester) to cover the ball shapes inside the cabinet, but do not cover the slot. The slot must be able the breathe freely.

Photos are my personal items that have been printed with Prusa MK3 with upgrade kit towards MK4. Painted and lacquered. The frequency response and distortion graph is attached. Expected power handling 50 Watts. The bass and midrange of these is very good considering size and total price.

Painting

Painting 3D printed parts is tricky. I'm sure you can find good instructions for different print materials, but I'll share my experience with these. Avoid paints with solvents when painting PLA. Plastic primers will not help. Solvents will make PLA soft and it will remain that way even years after painting. So if you paint, water based paints only and with those you might see problems with the paint sticking to the plastic.

You can paint (spray works) and color screws with permanent markers (like Sharpies), but the screws will need to uncoated, plain steel. If the screws are galvanized or zinc coated, the paint will fall off and look ugly. Best results can be achieved if you get screws that are already anodized or chemically blackened at the factory.

Compatibility With Other Drivers

I went through many specsheets of the same size drivers from Tang Band brand. The specsheets can sometimes contain small errors or outdated info about physical driver dimensions, so if you get one of these alternatives, measure it before printing.

My enclosure has a 104 mm diameter hole and a 127 mm diameter, 2 mm step for driver flange. The screw holes are placed 4x115, that is 4 evenly spaced screws, centered on 115 mm diameter circle. Basically any driver that can fit into these dimensions can be placed into the enclosure. However, you cannot place any driver into any size enclosure with any sized reflex port. That's why the enclosure needs to be simulated to find best match drivers. Comments below. I found the following drivers to fit the enclosure and match the screw placing.

FITS and SIMULATES WELL (Best Match)

All these drivers should be fully compatible with the enclosure and you can basically choose by the looks.

• W4-1320SIF (my choice)

• W4-1320SI

• W4-1320SMF

• W4-1320SJ, cut flange

• W4-1320SJF, cut flange

• W4-1337SDF

• W4-657D, some screw hole dimensions are different, check before printing.

• W4-2356 Because of the weird shape, this driver may be too wide basket/magnet, may not fit though the hole as-is. I cannot fully confirm because of the shape. Bass-heavy.

• W4-2142

• W4-1720

• W4-1337SD

• W4-1757SB, cut flange, wider basket, may not fit though the hole as-is with thick wiring. Slightly bass-heavy.

FITS, but does not simulate well

The following drivers fit physically into the enclosure, but the simulation for bass response is ugly. These are not recommended.

• W4-1879, screw holes are different size, check before printing. Bass heavy.

• W4-1129E, incompatible with this enclosure.

SHOULD FIT, but…

• W4-1749S (coax). Some dimensions are different, check before printing. Coax driver, needs a crossover (I cannot help at this time, sorry). There seems to be an error in the specsheet, so I cannot confirm bass response. Otherwise simulates nicely though.