Jackson Ampworks paid very close attention to detail with the 1x12 Open Back cabinet. The size of the cabinet as well as the ratio of the height, width and depth. All of these factors work together to shape the final tone and resonant frequency produced by the cabinet and they've designed a cabinet that actually has the low end of the Dual Ported cabinets but still retains the signature highs and airiness of an open back cabinet.
One of the critical components of any speaker cabinet, and certainly so with the an open back speaker cabinet design, is the baffle that the speaker physically mounts to. This piece of the cabinet is not only what the speaker mounts to but also how the vibrations from the speakers are transferred into the rest of the speaker cabinet. Too thick of a speaker baffle and the cabinet can sound stiff and restricted; too thin of a speaker baffle and the low-end will suffer.
The most famous open back cabinets ever made, were made not to reproduce a certain tone, but were instead designed for economy and speed of manufacture. While it is very inexpensive to manufacture these cabinets, the side effect of cutting corners is a dramatic loss of low-end content. So much so that the maker of these cabinets would have to increase low-end focus on the amplifiers in order to compensate for the lack of low-end response in their cabinets. Try this! Take an American styled amp from the 60’s, disconnect the speaker lead from the combo and plug it into a well made speaker cabinet – either open back or closed back. There’s a good chance you’ll find that you have WAY too much bass in your tone and will have to turn the Bass control either way down or almost completely off. This is because the standard speaker baffle design that has been used for years is extremely ineffective.
There is a more costly downside to this oversight other than just having to adjust the Bass control on the amp. It takes power to reproduce low end. That is why you’ll seldom see a bass amp less than 60W any many times you’ll see solid state amps producing 1000W or more. The reason is that it takes a lot of power to reproduce low end cleanly. When your cabinet design is inefficient, you have to generate more low end in the amplifier which means that for a given volume your tone will be more overdriven that you may like. In short, it means you have to make compromises in the amplifier design to maintain low end, and the more low end you push from the amp, the more headroom you lose. Conversely it means that if you design the cabinet correctly, and it will accurately deliver the low end that is sent to it, you can remove some low end from the amplifier circuit and the amp will remain cleaner longer than it normally would with a poor speaker baffle design.
In order to mount the speaker baffle into the cabinet so that it would be mechanically secure (no rattles or buzzing!) and acoustically efficient, they chose to dado the entire speaker baffle along all four sides of the cabinet. As the cabinet is being assembled, three of the four sides of the cabinet are assembled using their dovetail joints and once they are together, the dado is filled with glue and the speaker baffle is installed. Once the speaker baffle is mounted into the cabinet, the 4th side of the cabinet is installed thus trapping the speaker baffle into position and supporting it on all four sides. Once the cabinet is dried, the speaker baffle is now part of the cabinet as a whole and cannot be removed. This construction method is more time consuming and costly than traditional methods, but the results speak for themselves.
Final tuning of the cabinet was done using the port located on the back panel of the cabinet. Again every little thing matters including the size of an opening on the back of a speaker cabinet. Jackson Ampworks also found that the location of the speaker on the speaker baffle made a huge difference in tone.
Very seldom are well designed products as simple as they appear. In fact that is one of the hallmarks of a well designed product. It looks simple. There is usually a lot of experimenting and study involved until the desired result is achieved and the speaker cabinets are no different. Every little thing matters and everything we do has a specific reason and I can’t imagine doing it any other way.
All Open Back Cabinets are constructed using 13-ply Baltic Birch and feature Dovetail joints for unparalleled strength, rigidity and tone. Also included is a steel strap handle, a genuine Switchcraft jack for reliable operation and 12AWG speaker wire for unrestricted tone and performance.