Open Back
Designer:
Jeff S.
Project Category:
Loudspeakers/Cabinets
Project Level:
Advanced
Project Time:
20+ Hours
Project Cost:
$100-$500
Project Description:
Open Back
Design Goals:
Trying out old skool design with new technology parts
Driver Selection:
GW-212/4 Woofer
5SBM1-8. Midrange
T-34-02-306 Tweeter
Enclosure Design:
Open Back
Crossover Design:
3-Way 8 Ohm 800/4,500 Hz 200W, added 33uf across woofer out for 4 ohm 12dB
Tips & Tricks:
Lots of time.
Conclusion:
Works very good
About the Designer:
50 years building, repairing speakers.
At age 70 now
Project Parts List:
| Part# | Description | Qty. |
| 260-230 | Speaker Crossover 3-Way 8 Ohm 800/4,500 Hz 200W | 1 |
| 290-330 | Goldwood GW-212/4 12″ OEM Woofer 4 Ohm | 2 |
| 292-431 | GRS 5SBM1-8 5-1/4″ Sealed Back Midrange with 1″ Voice Coil 8 Ohm | 2 |
| N/A | T-34-02-306 Tweeter | 2 |
This does work very well and things you might want to try is swapping the midrange for another to change the results. Usually the tonal quality of a midrange is changed by trying different drivers. It’s the personal touch and application.
Jeff S
It seems pointless to have open back baffle when both midrange and tweeter have closed backs. 800 hz xo to woofer seems very high and could cause resonance in U-frame bass enclosure –unless added 33mF cap on woofer makes steeper xo so woofer doesn”t reach 800. The only thing that is “open back” is the woofer. I am suprised these work “very good”. One way to improve your design is to add extra rear-facing midrange and tweeter.