September 16, 2011
A 1×12 comboAs guitar speakers are different, so their cabinets are different. The box design is acoustically less critical than that for hi-fi or PA systems, but proper construction is essential.
Primarily, the cabinet is a convenient way of housing the speaker, so it should be solidly built to ensure no joint vibration (unpleasant buzzing), and be strong enough to withstand hard use. After all guitar speakers are quite heavy and amplifiers that sit on top of guitar cabs are even heavier.
Guitar cabs aren’t built to provide bass extension like a PA box might, but they do perform an “acoustic” function. If the driver were used without any cabinet at all, the sound coming from the rear of the unit would cancel out some of the sound coming frm the front, thereby reducing the amount of bass heard. Enclosing the the speaker inside a cabinet reduces this effect resulting in a truer bass performance that is neither enhanced nor attenuated.
For illustrative purposes, a basic design for a 2×10 or 1×12 open back cabinet is shown here. To build a cabinet like this we would recommended the use of 15mm plywood with number 10 screws positioned no more than 150mm (6″) apart.
Panel joints can be simple butt-joints, screwed and glued, with reinforcing battens (you can use more sophisticated joints if your woodworking skills are up to it!) Whatever joint type you use, it is important that the whole thing is both airtight and secure.
The drivers can be mounted to the front or the back of the baffle. Front mounting makes a very simple job of dropping the speaker in or out of the cabinet. In either case it’s preferable to use mounting bolts and T-nuts to fix the driver to the baffle.
There is a wide range of speaker cabinet accessories available from specialist suppliers. Fitted carefully so as not to weaken the box or create air leaks; wheels, handles, grilles and corners all add to convenience and durability.