'2×12 Cabinet v2'
This cab started life as a Marshall MX212AR with Celestion Seventy80 speakers.
It is a MDF cab by Marshall, which results in sub optimal resonance, and heavy weight.
Also being an angled, smaller cab, it has less depth than the typical Marshall 4x12, and accordingly lacks bass.
To address the lack of bass issue, I decided to try a design approach used by Mesa / Boogie in the 1980s, the 'Split Back' approach. Essentially dividing the speakers into a sealed, and unsealed chamber. My hope was, the combination of both a free air speaker, and the tightly sealed speaker may produce more low end resonance than the original design.
To do this, the grill cloth had to be removed, to allow the lower speaker in the sealed chamber to be front-loaded into it's sealed portion. The top speaker was left rear-loaded. The cab was braced with 1" ply strips, the rear panel changed to 1/2" plywood, and both chambers were created.
The result, was more low end. However, in playing, the standing waves inside the lower chamber seemed to build and essentially fold on themselves during sustained leves of low frequency.
In the end, I ended up converting the cab back to a modified version of it's single chamber form.
To address the lack of bass issue, I decided to try a design approach used by Mesa / Boogie in the 1980s, the 'Split Back' approach. Essentially dividing the speakers into a sealed, and unsealed chamber. My hope was, the combination of both a free air speaker, and the tightly sealed speaker may produce more low end resonance than the original design.
To do this, the grill cloth had to be removed, to allow the lower speaker in the sealed chamber to be front-loaded into it's sealed portion. The top speaker was left rear-loaded. The cab was braced with 1" ply strips, the rear panel changed to 1/2" plywood, and both chambers were created.
The result, was more low end. However, in playing, the standing waves inside the lower chamber seemed to build and essentially fold on themselves during sustained leves of low frequency.
In the end, I ended up converting the cab back to a modified version of it's single chamber form.