Designer:

Michael Larson

Project Category:

Guitar and Bass Speakers

Project Level:

Beginner

Project Time:

1-8 Hours

Project Cost:

$100-$500

Project Description:

This is a battery-powered PA speaker that allows me to play my bass guitar from anywhere. Besides the guitar input, there are also inputs for 2 microphones, and you can choose Bluetooth, RCA, microSD, or USB for backing tracks. While the website for the plate amplifier doesn’t advertise it, the microphone inputs have worked for another guitarist to play with me.

Design Goals:

I wanted an active speaker that I would be able to carry and use with my bass guitar, regardless of access to wall power. Since I play a 5-string bass, I wanted to achieve a low-end extension of around 60Hz (-3db). This is just below the second harmonic of the lowest note on a 5-string bass.

Driver Selection:

I chose a woofer that could get good low-end extension in a package small enough to wear on my back as a backpack. Once I chose the woofer, I found a tweeter that allowed for a good crossover point, and had a similar sensitivity to the woofer.

Woofer: Goldwood GW-S650/4 (PN 290-308)
Tweeter: Dayton Audio ND25TA-4 (PN 275-057)

Enclosure Design:

Since I wanted to be able to wear this on my back, I wanted something relatively slim, but width and height were not as strict, especially when I have plenty of width and height myself. It turned out that 1 cubic foot was a nice number that I could make in a satisfactory shape.

The dimensions are 14″x8″x20″ (WxDxH).

Crossover Design:

N/A

Tips & Tricks:

N/A

Conclusion:

I’m genuinely surprised by the performance of this project. I wouldn’t consider is Hi-Fi, but the purpose is to be able to play bass/guitar in places without wall power, and it absolutely delivers. Even when just using it as a Bluetooth speaker, it sounds incredible.

The only disappointment I have is that the USB port on the plate amplifier is not air-tight, so there is some rattling/chuffing from that when playing at high volumes. It also takes a while to turn on, but it lasts forever when it is on.

About the Designer:

I’m Michael Larson. I am currently a Computer Engineering student who has been building speakers since senior year of high school. What I lack in terms of tools and experience, I believe I make up in terms of passion for the hobby.

Project Parts List: