Loudspeaker cabinet incorporating curved vents
A loudspeaker cabinet designed for bass guitar amplification and performance, with long and curved, side-ported vents that reproduce and distribute low frequencies at up to 6 db greater loudness to the sides, where fellow musicians will commonly perform on stage. The vents also function as cross-bracing to stiffen the cabinet for better low frequency response. The vents tune the cabinet to the lowest possible frequency that will not induce driver voice coil excursions beyond mechanical limits. In addition, the vents are of sufficient cross-sectional area to prevent port air speed from exceeding a defined limit, such as 25 meters/second, which would otherwise result in destructive and non-musical port noise called “chuffing”. A variety of vent and port geometries are possible within these design constraints.
1 . A loudspeaker cabinet apparatus comprising:
a generally rectangular housing having a height, width, and depth;
one or more drivers;
two or more curved vents disposed within the housing, each vent having a defined cross section, and each vent having a gentle C-shape along an axis perpendicular to the defined cross section, and each vent being longer than any of the height, width or depth of the housing;
wherein the vents are further:
configured to channel backwave energy from the one or more drivers;
disposed adjacent to one another and mutually self-supporting; and
coupled to respective side ports that are located on opposite faces of the housing.
2 . The apparatus of claim 1 additionally comprising:
wherein the vents are further configured to tune the cabinet to a lowest usable frequency for a selected one of the one or more drivers at full rated power.
3 . The apparatus of claim 1 wherein the defined cross-section of each of the two or curved vents is chosen to restrict port exit speed to below 25 meters per second or less at full rated power.
4 . The apparatus of claim 1 wherein the vents and ports are rectangular in cross-section.
5 . The apparatus of claim 1 wherein the vents and ports are non-rectangular in cross-section.
6 . The apparatus of claim 1 wherein the housing includes curvilinear sections or constructions, or faces that include other than two planar faces in 180° opposition.
7 . The apparatus of claim 1 wherein the one or more drivers are located in acoustically separated spaces within the cabinet.
8 . The apparatus of claim 1 wherein the one or more drivers are configured for delivering low end frequencies of bass guitars and/or acoustic basses.
9 . The apparatus of claim 1 further comprising:
additional drivers disposed within the housing, the additional drivers being configured to produce higher frequencies; and
crossover electronics, housed in isolated interior housings within the cabinet.
10 . The apparatus of claim 9 wherein the additional drivers comprise:
midrange drivers, tweeters, or mid-bass drivers.
11 . The apparatus of claim 9 wherein the crossover electronics are configured to attenuate distortion introduced by the additional drivers.
12 . The apparatus of claim 9 wherein the crossover electronics are configured to:
(a) split frequency content to a low frequency driver and one or more of a mid-range driver and a high frequency driver; and
(b) attenuate distortion inherent in the low frequency driver.
13 . The apparatus of claim 9 wherein the crossover electronics are configured to:
(a) split frequency content to a low frequency driver and one or more of a mid-range driver and a high frequency driver; and
(b) attenuate distortion inherent in the low frequency driver to produce a more accurate harmonic output.
14 . The apparatus of claim 1 further comprising:
additional drivers, configured to produce higher frequencies disposed along with crossover electronics in a separate enclosure from the housing.
15 . The apparatus of claim 1 additionally comprising:
one or more shims disposed between at least two of the vents.
16 . The apparatus of claim 1 additionally comprising:
a shim disposed between at least a selected one of the vents and a selected wall of the housing, the selected wall being opposite the wall having the side port to which the selected one of the vents is coupled.