1. Field of the Invention
This invention relates generally to speaker systems, and more particularly, to an improved speaker system which produces superior harmonic sound through the addition of an open tube arranged to work in conjunction with a single or double closed tube.
2. Prior Art
Speaker systems now in commercial use fall into one of five categories; ie. closed box systems with variations, ported box systems with variations and/or ducts, labyrinth systems with variations, horns and variations thereof, and flat baffles with variations.
In the closed box speaker system (ie single closed tube), the speaker itself serves as a shallow disk closed pipe which emits frontal primary sound. The enclosed cabinet behind the speaker serves as a resonator, air spring, and a secondary closed system. While this system is generally considered to be a single closed tube system, it may in effect be considered as comprising two closed tube systems working in conjunction with each other.
In the ported box speaker system (ie double closed tube back-to-back system), the speaker itself serves as a closed tube sound emitter which operates in conjunction with a vented cabinet which also serves as a closed tube and resonator which may be tuned. This closed tube system (ie the vented cabinet) operates from the rear of the speaker.
Labyrinth box speaker systems (also double closed tube systems back to back) are constructed to consist of two closed tube systems arranged back to back. The speaker is the primary closed tube sound generator and the labyrinth case construction operates from the rear of the speaker as the secondary closed tube system.
Both the labyrinth and ported tube systems can operate in conjunction with a ducted tube port; however, both of these continue to structually represent only a primary and secondary closed tube system operating back to back and in conjunction with each other.
Horns act as accoustical transformers having flared sides so as to permit sound wave expansion at a constant rate. However, since it may be necessary to provide a horn of up to 30 feet in length, horns are folded for use in stereos. Essentially, the horn (and straight sided megaphone) is simple an extension of a closed tube system.
In addition to the above, another commercial speaker arrangement consists of a tube having a speaker inserted therein. It should be clear that this merely represents a double closed tube system. The tube in front of the speaker is only an extension of the closed tube speaker while the tube behind the speaker is only a secondary closed tube system.