Designer:

The Zard

Project Category:
Portable Speakers

Project Level:
Beginner

Project Time:

1-8 Hours

Project Cost:

Under $100

Project Description:

A women I know contacted me and told me how she blew the speakers in her bumpboxx ultra blasting it non stop and since it was several years old it had no warranty and she did not want to have to send it cross country to them to get fixed and pay out a bunch of money.
Many electronic devices will say ‘ no user serviceable parts inside ‘ but that is not always true depending on your skill level and ingenuity.
So I told her I would check it out to see what could be done.

First thing I checked was the amps output using a bookshelf speaker and it was fine, bump boxxs except for the new one, all run mixed mono as their made to be portable guitar amps.
The bump Boxx ultra runs 8 ohm speakers in parallel, the woofers are not crossed over but each tweeter has a cap on it.
The lead to the speakers from the amps output is run to the first woofer then parallel to the first tweeter and parallel to the second woofer then parallel to the second tweeter. see diagram.
the tweeters measures 5.1 and the woofers 5.4 Ohms on a multimeter.
I decided to use cerwin vega XED car tweeters [ their 4 ohm ] as their the exact same size as the existing tweeter hole in the box, I had a new unused set with a value of $15, I took a picture of the cap in the CV crossover looked up the frequency at 4 ohm and the same x over freq. for 2 ohm and ran them in parallel, and soldered some caps together to get the correct value.
The woofers I took from a used set of KLH bookshelf speakers, their also 8 ohm like the ones out of the bump boxx and fit no problem.

2 months later it is still working great, and cost less then $20 in parts to fix.

Design Goals:

I wrote this to help people who are considering weather or not to try to repair a boom box them self’s

Driver Selection:

2 cerwin vega XED car tweeters
2 KLH 5.52 woofers

Enclosure Design:

N/A

Crossover Design:

N/A

Tips & Tricks:

N/A

Conclusion:

Many electronic devices will say ‘ no user serviceable parts inside ‘ but that is not always true depending on your skill level and ingenuity.

About the Designer:

i design and repair boom boxs.

Project Parts List: