Designer:
Dynamo

Project Category:
Bookshelf Speakers

Project Level:
Beginner

Project Time:
1-8 Hours

Project Cost:
$100 – $500

Project Description:
This is an easy 2-way bookshelf project using the prebuilt and finished BR-1 cabinet pair.

Design Goals:
The goal was to create a budget high-end pair of bookshelf speakers that did not require woodworking and incorporated drivers I have been wanting to build with.

Driver Selection:
XT25BG60-04 (264-1012) tweeter: This is a timeless tweeter family that sounds great and has been used in commercial high end speakers.

Dynavox LW6004PMR-N (295-620): I have been wanting to do a build with the Dynavox woofers for some time and this build was a perfect opportunity.

Enclosure Design:
Pretty simple since the cabinets are pre assembled and pre finished.

Enclosure Assembly:
Some easy mods are necessary. Center the tweeter in the opening and you get a gap between it and the recess. The woofer does not fit the recess, so it is surface mounted. The grills will no longer fit. Remove the protrusions of the grill grommets on the baffle and use craft foam sheet (whatever color pleases you) to cover the baffle. This will cover the tweeter gap and grommet holes. Use the same foam to make a woofer gasket. Adjust the port length in the box to 5 inches. Line the enclosure walls with polyester batting (glued on as to not fall on the crossover).

Crossover Design:
The crossover uses a 2nd order damped electrical filter and a notch on the woofer and 3rd order damped electrical filter and lpad on the tweeter. Resistors are 10w, except the woofer section should have 20w or doubled up 10w in parallel for best heat dissipation. Use NPE caps in the woofer section and the whole project including the foam, wire, and batting can come in under $300 for the pair.

Tips & Tricks:
Increase the resistor paralleling the tweeter to 20 ohms if the room used a lot of plush items (carpet, couches, curtains, etc) or if you otherwise desire a little more HF output.

Move them out into the room a bit if bass is heavy/boomy. They are best suited to be away from walls and on stands, not a table top.
Conclusion:
I was very pleased with the outcome of the project.

About the Designer:
Been designing speakers as a hobbyist for some time now and enjoy learning more with each project.

Project Parts List: