Briefcase speaker (parametrizable)

This is a design for a battery-powered amplified speaker in the size of a (small) briefcase. It is intended to be used with a musical instrument, such as an electric guitar; suitable for practice or small-scale performances. One feature are the fold-out supports (or "legs") that give stability to the speaker when it stands on the floor.

The speaker is designed for the VISATON "FR 12" driver (but this can be adjusted). There is little else in it: an on/off switch (preferably with LED), a volume control, an input jack and the battery holder.

The design is in OpenSCAD, and most dimensions and options can be adjusted with the OpenSCAD Customizer. As-is, I made it to contain four drivers. In configuring it, you can also disable options. For example, if you do not want the fold-out legs, you can set its size to zero, and they won't be created at all. Likewise, you can omit the volume control or the on/off switch (or both), or the battery holder, or the input jack.

That said, the current configuration is the only one that has been tested, so far. Also, when you want to add options (e.g. tone control, or wall mount support), you will have to dive into the OpenSCAD script itself. The battery holder was difficult to create a generic parametrizable model for, so if you want to use a different battery holder, you will likely also have to modify the OpenSCAD source.

A number of additional items are needed for this design, listed below (again, this refers to the default design, you can change the number of speaker drivers and many other options):

Printing tips

I used PLA for the entire design. The back and frame are in a light colour (Prusament rPLA Risotto). The front panel is printed in black, so that even with a sheer grill cloth, the  drivers won't stand out.

Unless you have a very large printer, at least the front and back panels must be split in several parts for printing. I used the cut tool in the slicer, and glued the parts together with epoxy.

The back panel requires supports for the carrying handle. There are also countersunk holes in the back panel that do not need supports (the hole for the recessed nut for the input jack in also does not require supports), but the default algorithm will add these anyway. Therefore, I recommend to add a "support enforcer" below the handle, and set the slicer option for supports to "for enforcers only".

The frame is already split in four parts in the design. These parts fit on a Prusa XL; I have not checked other printers. Among the STL files is also a full frame, which you can cut in appropriate parts with the slicer. I printed the frame parts so that the inside surface is on the print sheet, but whichever orientation you choose, these parts need supports. The default algorithm for supports ("from sheet surface only") is fine.

Construction notes

The spacers (of which you need 16) are glued to the front panel, and have a threaded insert at the other end. The back panel is screwed onto these spacers. I prefer a flush appearance of the back, so there are also little plastic disks that you can push over the screws. These "caps" are supposed to be press-fit, not glued. This allows you to still open the speaker afterwards. It is quite possible that you won't be able to remove the caps without damaging them, but the goal is, of course, that I will only rarely need to open the speaker.

There are small holes in the legs and in the frame to glue magnets in. The magnets serve to "snap" the legs in "folded in" or "folded out" positions. The magnets can be disabled by setting their size to 0. If you omit the magnets, a spring washer (for controlled friction) is recommended.

In the design of the frame in four parts, these parts are fit together with "finger joints" for extra strength and aesthetics. When you use the "full frame" STL file, to cut it with the slicer, you can use the slicer's options for pins or dovetails for joints.

I have experienced that the parts for the sides (the "frame") may warp a little (especially the top and bottom sides, which are the longest). This is why I added a few rectangular "alignment pins" on the frame and corresponding slots on the back panel.

The grill cloth is probably most easy to fix with staples. Make sure that you use staples with a height of 6 mm maximum (the thickness of the front panel).

As you may have noticed, I have not specified which amplifier module to use. The reason is that I used left-over components from a product that my company no longer manufactures. So you will have to find your own. The battery holder that I chose for this speaker holds four AA batteries, so that gives you 6 V for Alkaline or Lithium batteries and 4.8 V for NiMH. With this voltage levels, power output of this speaker will obviously be modest: about 2.5 Watts per channel is the maximum that you can expect (I am reaching 8 Watts, my amplifier module has four channels and provides 2 Watt per channel).

I did not include a DC power connector in my design, because I plan to use this speaker powered by (rechargeable) batteries. However, an option for a DC connector (e.g. CLIFF FC681473) is already in the script, and you can enable it with the OpenSCAD customizer.

Miscellaneous

I have not uploaded any variants (different sizes, different drivers, etc.) because I consider that installing OpenSCAD is light and simple (and then you can change every parameter to your liking). If you'd like to use a customized design, but cannot install/use OpenSCAD, leave a comment and I'll see whether I can upload a custom model.