Designer:
JBass 212×5

Project Category:
Guitar and Bass Speakers

Project Level:
Intermediate

Project Time:
8-20 Hours

Project Cost:
$100 – $500

Project Description:
The JBass 212×5 is a 2way bass guitar cabinet using dual 12″ woofers and 5″ midrange intended for power levels up to 400w.

Design Goals:
A better alternative to commercial offerings that do not account for cone breakup and distortion of larger drivers and cannot accurately reproduce the range of a bass guitar

Driver Selection:
Eminence S2012 woofers and PRO5MRN-8 midrange

Enclosure Design:
Ported enclosure, 6 cu ft ported via twin 4″ ports for an Fb of 40hz and f3 of 50

Enclosure Assembly:
Butt joint construction, braced between baffle and rear wall. Baffle is inset 1.25″ to account for the PE preformed mesh grill. Enclosure measures 31.5w 24h 17.75d.

Crossover Design:
The crossover uses 2nd order electrical filters on each side with the woofer using a damped circuit. Resulting crossover point is 2khz.

Tips & Tricks:
To inset the baffle, I mounted strips of hardwood on the inside perimeter. This allowed for additional glue surface. Additional strips were applied to the baffle with 1/8″ clearance to capture the preformed grill for a pressure fit.

Conclusion:
The project is a definite success. The response transitions wonderfully between the drivers and gives a very clean presentation. In testing, I used an Adcom GFA555 (350W@4) and had no problems driving this to the amps limit. Punchy, smooth, with great sensitivity.

About the Designer:
I am an advanced designer of 10+ years.

Project Parts List: