Introduction: Amplifier and Speaker DIY

This is final stage of amplifier DIY project by adding speakers to the previous outputs from the following instructables.


- PC speaker amplifier introduced in Dec 27th, 2020

- Arduino Audio Sound Level Meter published in Dec 30th, 2020


The Amplifier and Sound level meter circuits are already completed and fully functional as shown in the previous instructable..

Therefore, self-sufficient operation shall be possible as complete audio amplifier system when if speaker is included.

That’s why this instructable written.

Let’s add DIY speaker to the amplifier as an icing on the cake.

Step 1: Schematics, Soldering and Wiring

Differ from the other instructables, any complex schematics or drawing is not necessary.

Just connecting two wires of speaker cable from binding terminal to the speaker input connector is the all necessary work.

Speaker binding terminal is attached to the backside of the amplifier box.

Step 2: Parts

The most important part is Pioneer TS-879 speakers which are usually used for car audio system.

It is sold as speaker unit only form and without enclosure.

Therefore, any kind of chassis, box or enclosure which can mount and fix speaker unit should be made.

As I don’t have proper equipments to make air-dynamic feature supporting professional speaker enclosure, only acrylic box is designed and assembled as shown in the picture above.

The technical specification of Pioneer speaker unit is as follows.


- 3 and 1/2 Inch 2-Way Speakers

- Carbon-graphite blended IMPP composite cone woofer

- 60 Hz to 28 kHz frequency response; 88 dB sensitivity

- 40 watts maximum power handling (10 watts nominal)

- Weight 1.9 Pounds


Now the 40Watt version (TS-879) is already obsolete.

I had received this speaker about 15 years ago from my friend.

High pitch audio sound seems to come out from the central part (Possibly tweeter is located there) and middle-range/Bass sound is produced by the bigger cone behind central part.

Step 3: Assembling

For assembling acrylic boards and mounting speaker unit, M3 (3.5mm) bolts and nuts are used.

As big circular hole is necessary for the front acryl panel to mount speaker unit, the part was outsourced to the internet part supplier who has laser acryl cutting device.

Beside front panel, all other parts are cut and assembled together with “L” shaped mounting brackets, bolts and nuts.

Except transparent front and bottom acryl panels (4mm thickness), cloudy white side and top panel’s thickness is 2mm.

Actually box shaped structure is not contribute to the sound quality such as controlling air-dynamic flow or support any acoustic functions.

The plastic box structure is made to prevent electric shocks by covering contacts (Speaker +/- terminals and other exposed metal parts) where high current can flow.

Step 4: Finishing and Music Playing

As the speaker unit’s power is 40W and

tweeter & woofer is integrated into the single unit, sound depth and dynamic feature can be a little bit limited.

But still it can playback significant sound volume as you can check in the video below.

*** <Video link>


In the Youtube video above, Sara Bareilles is singing her song “Brave” with orchestra.

As the audio is recorded by smart-phone, sound quality is not much great.

But still you can hear not flattened sound and a little bit dynamic rhythm of speaker sound.

Thanks for reading.