Designer:

Taylor Hansen

Project Category:

Bookshelf Speakers

Project Level:

Intermediate

Project Time:

20+ Hours

Project Cost:

Under $100

Project Description:

Built on the frame of the Kenwood LS-622R and SW-38HT, nearly every aspect of these bookshelf loudspeakers and subwoofer combo has been completely overhauled – all on a shoestring budget.

Design Goals:

After sitting in a garage for nearly 20 years, I wanted to breathe new life into these old loudspeakers. This project was an exercise in squeezing every drop of performance out of cheap commercial drivers, all while looking their best.

Driver Selection:

OEM Kenwood 1″ silk dome tweeters
OEM Kenwood 5-1/2″ woofers (reconed)
OEM Kenwood 6-1/2″ subwoofer (repainted frame)

Enclosure Design:

The OEM ported bookshelf enclosures were tuned way too high and had some pretty substantial resonances. Bracing, polyfill, and port plugs were implemented to better shape the bass alignment. Final design was a sealed 0.5 cubic foot enclosure with an F3 of 80Hz.

The OEM Subwoofer enclosure was in rough shape, and needed a complete rebuild. The cabinet was constructed out of 3/4″ MDF, and featured a tunable port and isolated amplifier chamber. Final design was also 0.5 cubic feet tuned to 50Hz with an F3 of 43Hz.

Crossover Design:

A 3rd order HPF on the tweeter and a damped second order LPF on the woofer allowed for smooth driver integration and phase alignment. Minimum impedance of 6 ohms.

Tips & Tricks:

While not always practical, allowing pine to fully dry before working with it significantly reduces the risk of it warping on you.

Conclusion:

Cheap commercial drivers will only get you so far, but massive improvements were made to their aesthetics and overall tonal balance. I’m pleased with how they came out, and they will be loved by a family for many more years to come.

About the Designer:

Taylor Hansen is an electrical engineer specialized in power electronics for the aerospace industry. He has found that speaker building is a great way to couple his professional skills with his many hobbies such as fine woodworking, home theater, and live sound reinforcement. When not tinkering with electronics in the lab or sanding MDF in the shop, he can often be found serving as a pianist for his local church in Fort Wayne, Indiana. But perhaps most importantly, Taylor finds fulfillment in his wife and son, who serve as constant sources of motivation and love.

Project Parts List: