Small Stereo Speakers

This build was originally done in July 2003 and used on BBQ days with fellow student friends during my second and third years of university. I still have these speakers in 2020 so re-took some better photos. These days they are kept for sentimental value, although they work, I've better alternatives now (see PAM8403 speakers with bass boost).

I decided that I need a system that can do stereo and go quite loud with better sound quality than my small TDA7052 system. I noticed that my local retailer, Maplin, have extended their low-cost speaker range. See their site here. These speakers are small in diameter and height and have notably good quality for their size, and handle around 3W. Unlike other speakers at their size, these speakers have higher power handling and a rubber surround and look and feel a lot heavier than most other cheaper versions, i.e. ones found in small TV's and clock radios. With these two of speakers, two cases and a TDA2822M amp on one PCB, I have made quite an impressive system that is small in size.

The picture above is an original showing the two speakers complete, the box on the right contains the amplifier and the controls. The box on the left is just another speaker and a set of 4 AA batteries. You can see from the front view that their is a power switch, a power LED and a volume control - again minimal controls as nothing else is really needed and just takes up space. You can also see that I gave up on the idea of drilling lots of holes for the sound to escape and have instead cut a large hole using a holesaw and used speaker grill instead, which actually looks quite nice.

The speakers again in June 2020.

The picture above shows the amplifier speaker with the cover removed. You can see how the amplifier is slotted into the space above the speaker using the grooves the box already has inside. The PCB is again one of my home-made ones that was designed and etched by myself and works well. You can also see the back of the speaker; the size of the magnet gives you an idea of the quality of these speakers compared to others at their size.

This is a picture of the PCB taken out of the box, you can just see that there is a TDA2822M chip with 5 electrolytic capacitors, and 2 mylar capacitors. Other components include two 3.5mm PCB jack sockets, one is the line input, the other is a speaker out for the other box. There is 2.1mm PCB power plug socket too for the power, one dual gang volume control as there are two channels to adjust the volume of (stereo), a power LED and its resistor and a power switch which is a PCB toggle switch.

This is the underside of the board showing the drawn layout. Feel free to copy that, or adjust to suit. The board was designed with the exact height and width to fit into the ABS box grooves so may not be the ideal size for your own project.

The only wires leaving the board are for the speaker that is inside the same box. You can also see various jump wires as I needed to keep the board size small.

The rear of the amplifier speaker has the three sockets needed for power, line in, and output (mono) to the second speaker.

The second speaker holds the batteries. I have placed a battery holder that holds 4AA batteries, giving me 6V. It "just" about fits in the area above the speaker, which is convenient.

As you may have spotted, both speakers are filled with a fibre wool which is to remove the hollow sound from the box and help tame the midrange a little (at this size it does not make much difference though).

Performance is good indeed. The volume is more than acceptable at the size these speakers are (that being 100 x 76 x 41mm).