since common theatrical audience members rapidly adapt to and are readily trained to visually ignore the necessarily ever - present theatrical lights grouped around a stage , the present invention takes advantage of this easily trained human illusionary effect by creating a stage speaker system specifically adapted for camouflage among the theatrical stage lights . referring now to fig1 a , and 2 , in one embodiment of the present invention , a stage speaker system or device 1 includes a rear cover 3 , a body unit 2 ( alternatively speaker body unit 2 ), and a shield or guide unit 4 . rear cover 3 , body unit 2 , and shield or guide unit 4 are coaxial to a central axis a extending there through . speaker body unit 2 is a cylindraceous rigid member ( commonly metallic ) coaxially supporting a conventional tone generating circular speaker 2 a with a front screening member 22 at a first side ( both shown in shadow ). a second side of body unit 2 extends behind speaker 2 a defining a first generally circular opening . a bottom rim extends around the second side of body unit 2 to enable a clamping attachment to rear cover 3 , as will be explained . rear cover 3 is a rigid member ( in the present embodiment being , but not required to be , a cylindraceous rigid member ), generally bounding an inner volume and defining an opening coaxial to the central axis . in the present embodiment , a plurality of cooling members or fins 3 a ( also called heat radiating elements or heat radiators ) is arrayed about an outer perimeter of rear cover 3 . in an alternative embodiment , it is envisioned that cooling members 3 a may alternatively be understood as a single or multiple heat sink units and even a simple heat radiation coating ( including dark color paint ). it should be understood , that cooling members 3 a , of different types , may be used with or replace all or a plurality of cooling fins 3 a shown depending upon a user ” s desire to match the outward appearance of an existing speaker array or system . those skilled in the art of design will further understand that the heat radiating elements ( coating , cooling fins , heat sinks etc .) are selectable by a manufacturer or end user to match an existing or a preferred outward user - defined appearance and hence blend in with , compliment , or balance a speaker arrangement and / or lighting arrangement . it should be further understand that it is the outward audience - appearance ( as well as the speaker function ) of the combined unit that aids a user in blending the speaker into a pre - existing array of lighting units , namely , the speaker unit and any necessary electronic controls are internally mounted ( not easily visible ) with the “ lighting - body ” unit , while additionally providing for the benefits mentioned elsewhere ( acoustic remediation , easy user adaptability and control , easy computer and motion control , etc .). in an alternative embodiment , where speaker unit 2 a is self powered and may include a permanent or replaceable battery pack ( not shown ) or other electronic circuitry ( for example , positioning drive motors ) requiring or benefiting from actual thermal radiation to maintain an optimal temperature , then cooling members 3 a may operate to provide a practical cooling effect to the particular circuitry . as noted , cooling members 3 a are shown as cooling fins , but should be understood by those skilled in the art to include well known cooling members including radiating patent , heat sinks , cooling loops , electronic coolers etc . a watertight and / or a sound tight seal 7 is positioned about the circular opening in rear cover 3 . seal 7 enables the positioning of the unit in a weather - vulnerable position and minimizes the risk of sound radiation in an undesirable direction . a plurality of compression clamps 7 a is arrayed about the outer circumference of rear cover 3 . during an assembly with body unit 2 , clamps 7 a on rear cover extend to engage the bottom rim of body unit 2 and clamp body unit 2 to rear cover 3 , forming a water - tight and / or sound - tight junction with seal 7 . one or more edge gaskets may be used to increase sealing capacity of seal 7 , but are not necessary where substantial water / sound blocking surface contact exists . alternative types of joining methods , including threaded junctions , are also envisioned . prior to sealing , as needed , audio wire leads or other electronic circuitry ( not shown ) for speaker 2 a may be fed through a waterproof opening ( not shown ) on a rear surface of rear cover 3 opposite water tight seal 7 , and attached to speaker 2 a . in alternative embodiments , a wireless audio relay signal system and power supply system ( similar to those used in conventional wireless speaker systems and noted briefly above ) may be used to eliminate any need for audio wire and / or power wire leads that would limit unit movement . while the embodiment shown includes a separate rear cover 3 , it is envisioned that rear cover 3 may alternatively be formed integrally with body unit 2 depending upon a manufacturer ” s design preference . in this type of integral - formation , no seals or clamps would be necessary . a further embodiment may include a opening or hole in rear cover 3 ( not shown ) intentionally open to atmospheric pressure . defined openings of this type are commonly used to transmit long wavelength or base - note sounds in a manner similar to rectangular base - speaker unit . consequently , by either removing rear cover 3 completely , or by opening a section of rear cover 3 , the stage speaker 1 may transmit a broader range of audio and sub - audio wavelengths . alone or when joined with body unit 2 , rear cover 3 bounds a respective defined space enclosing a medium of electro - mechanical energy absorption such as air , a selected gas , a selected gas and foam combination , sound baffles , or a combination of all of the above as desired by a manufacturer . in use , as speaker 2 a operates , wavelengths of electro - mechanical energy are generated coaxially both toward rear cover 3 and shield or guide unit 4 . as will be described , shield or guide unit 4 , of a selected length , generally functions to emit the electro - mechanical wavelengths in a controlled manner and rear cover 3 functions generally restrain the wavelengths and to absorb or dampen any resulting vibration or reverberation from reaching a listener . in this manner , stage speaker device 1 may be used as a sound directional device positioned as desired by a user . alternatively , rear cover 3 may be open to the atmospheric air via a single large opening or a plurality of holes and thereby allow a sound uniformity as desired by an end user . an open access to rear cover 3 also provides for the release of any atmospheric moisture that may accumulate . of course , a closed and sealed cover would be beneficial in exterior water - exposed applications . it is noted that the rear cover unit need not provide a complete cover and need not be continuous and may be easily adapted to a user ” s needs . it is also noted that rear cover unit 3 may be formed integrally with the main body unit and , where needed , with a guide unit embodiment . in this manner , the present invention enables an inexpensive construction where desired by an end user or manufacturer . in alternative preferred embodiments , the defined space between body unit and rear cover 3 may be filled with simply atmospheric air during an assembly or maintenance . in other preferred embodiments ( as noted ), the defined space may be filled with a less dense , more readily compressed gas ( for example nitrogen or argon ) via a pressure purge / fill assembly ( not shown ), or a closed or open semi - rigid foam bounding gas bubbles containing a selected gas and able to absorb and limit maximum vibrations . shield or guide unit 4 is a cylindraceous rigid body defining a third opening end adjacent speaker 2 a and a fourth opening end opposite speaker 2 a , as shown . the third opening end is coaxial with and securely joined to body unit 2 at its first side . shield or guide unit 4 may be alternatively referred to by those skilled in the art of lighting design as a snoot or snout and is conventionally used as described below . it is also envisioned that the present embodiment may be operated effectively without the inclusion of a shield or guide unit 4 , particularly where an end user does not desire the complete benefits of the unit . in this circumstance , guide unit 4 may be removed after sale or not originally installed . in one of the preferred embodiments , a flange ( shown but not numbered ) extends from the third opening end of guide unit 4 and enables a plurality of screws or bolts ( shown ) to threadably join guide unit 4 to body unit 2 , providing a sound - tight ( and optionally for external use a second water - tight ) seal there - between . in this manner , guide unit 4 is able to receive and guide sound generated from speaker 2 a along its bounded length and out the fourth opening towards a desired target . while guide unit 4 is show with a length at least as long as a length of body unit 2 , guide unit 4 may be any suitable length selected by a manufacturer , sound engineer , or end user . other means may be used to join guide unit 4 to body unit 2 , including a magnetic seal , clamping means , threaded connections , adhesives , or other joining methods common in the theatrical arts , without passing beyond the spirit an scope of the present invention . as can be seen from fig1 a , the tonal directability provided by the present invention , having a predictable and directable projection width ( w ) and length ( l ), in combination with it ” s camouflage ability to hide in plain sight among a plurality of conventional stage lighting units , allows an operator of the present invention the benefit of using the device 1 to surgically project sound as needed . for example , to remediate poor acoustic design for a particular audience section or performer , or to provide a selectable and even movable zone of audible feed - back for a performer ( as will be described ), thereby allowing a performer to optionally step into and out of a defined audible feed - back zone or to be followed during performance movement by a movable audible feed - back . in the embodiment shown , a plurality of guide edges 11 and a pivot clamp 12 are arrayed about the fourth opening of guide unit 4 . guide edges 11 are formed from rigid angular metal and collectively form a receiving cavity perpendicular to the central axis . pivot clamp 12 is provided with a torsion spring ( not shown ) to generate an urging force to optionally retain a cover screen member 25 within edge guides 11 . in use , an operator may position ( singularly or jointly with modified guide edges 11 ) a plurality of cover screening members 25 in guide edges 11 , or may choose to operate the invention without a screening member 25 at all , depending upon operator preference . in operation , selectable cover screen members 25 are designed to function in predetermined and preselected manners to serve an operator ” s desire , i . e . to substantially block at least one of a visible wavelength entry and hence distracting audience reflection during use , to prevent a foreign object or moisture entry into shielding unit 4 , and to control a wavelength amplitude exit from shielding unit 4 ( sound dampening or focusing ), or other use , or a user - selected combination of all . it should be understood , that an operator ” s use of cover screen member 25 and the existence of guide edges 11 is optional depending upon a user ” s desires and a manufacturer ” s requirements . in many instances their incorporation is beneficial ( see below ) but it is also envisioned that uses without a cover screen and guide edges may be desirable to some end users . in use , screen members 25 may be a debris grill ( as shown ), some form of conventional manual or computer controllable aperture control ( not shown ) with linking circuitry , an audibly transparent visual - camouflage covering ( not shown ) for preventing an external viewer from viewing speaker 2 a or receiving unintended visible reflections therefrom , a water - proof - sound - transmitting covering ( alternatively camouflage ) for preventing entry of external moisture to shielding unit 4 and stage speaker device 1 while allowing sound transmission , or other form and thus enabling : ( a ) placement of the unit 1 in an external array of similarly shaped weather - protected lighting units , ( b ) expansion of available and usable weather - protected stage space ( previously used to house weather - vulnerable speakers ), and ( c ) easy operation with and incorporation into existing types of lighting arrays and computer control systems without expensive structural modifications . additionally referring not to fig3 , one embodiment of the present invention includes two bosses 20 positioned on an axis line perpendicular to the central axis on an outer diameter of rear cover 3 proximate water tight seal 7 . pivots 20 a fixably join bosses 20 to rear cover 3 , as shown . a yoke member 8 having two legs 8 a , 8 a , is pivotable about respective pivots 20 a , 20 a . bosses 20 , 20 are substantially circular and , at a position proximate an outer diameter of bosses 20 , 20 , a respective set of compression bolts 8 b , 8 b project opposite winged handles 21 , 21 . compression bolts 8 b , 8 b have projecting heads ( shown ) engaging the outer diameters of respective bosses 20 , 20 . during use and adjustment , as winged handles are 21 , 21 are tightened or loosened , and the projecting heads of bolts 20 , 20 engage respective bosses 20 , 20 and lock yoke member 8 relative to the pivot axis between bosses 20 , 20 on rear cover 3 . in this manner , bosses 20 , yoke member 8 and the additional elements noted form a single axis ( between bosses 20 , 20 ) means of adjusting or positioning in stage speaker device 1 . in use , yoke member 8 is commonly fixed to an external rigid fixing structure ( not shown ) such as a suspended grid positioned above , behind , or in front of a stage ; grids or support members positioned on either side of the stage ; or behind , on the sides of , or above an audience . in one preferred embodiment , an exterior surface 13 of stage speaker device 1 is painted a non - reflective color ( for example black ) selected to be similar to conventionally known stage lights and hence be visually indistinguishable and thereby visually ignored by the audience trained to ignore stage lighting fixtures through past visual experiences . alternatively preferred embodiments incorporate conventional single or multi - axis positioning systems to manually or electronically pan and tilt the device as required , programed or reprogrammed by an operator , or controlled by a robotic controller under computer supervision . it is the applicants present intention to show that the inventions contained herein are adaptable for use with conventional wireless or wired audio signal control systems and may be additionally controlled in a modified multiparameter computer programmable manner enabling specialty adaptation to a stage and incorporating complex audio control , synthesizer modulation or generation , robotic manipulation , and movement control parameters into known computer control lighting systems ( similar to those shown in the sugden ( reg . no . 5 , 406 , 176 ) and belliveau et all ( reg . no . 4 , 962 , 687 ) references above ). referring now to fig4 , a computer controlled stage system 100 includes a plurality of stage speaker devices 1 and conventional stage lighting units 54 mounted on rigid grids 53 , 52 ( or other track - type lighting and sound support structures ) positioned relative to a stage 40 and an audience 30 . a computer controlling system 50 communicates with individual stage speaker devices 1 and stage lighting units 54 via a wired or wireless communication link 51 , as shown . communication link 51 may be readily adapted to the multiple embodiments discussed herein and will be an integral part of any sound - action and lighting - sound control , management , and generation system . one benefit of the present invention is that units 54 and 1 are both out of the way , raised above the surface , thereby eliminating the tripping , sight - blocking hazards common in conventional stage - speaker designs and placements . in this manner those skilled in the art will understand that the present invention provides a substantial convenience benefit to users . in operation , stage system 100 may additionally include automatic positioning systems to drive pan / tilt / rotate motions of selected ones or all of the plurality of stage speaker devices 1 and stage lighting units 54 . stage system 100 , and computer controller system 50 may additionally include a transmission / reception system for transmitting wireless control signals to at least stage speaker devices 1 and for receiving confirming signals in return , or sound - action and sound - lighting timing controllers , sound generators and other electronic units as would be understood by one skilled in the art . it should be noted that the stage speaker devices 1 as shown may be alternatively positioned to project sound towards audience 30 , away from audience 30 , toward actors or in other desirable directions for audio correction or compensation . consequently , it should be understood that the positions and directions shown for stage speaker devices 1 are not limiting and may be easily adapted according to a user ” s preference and need . in at least one selected embodiment , as briefly noted above , computer controller system 50 includes conventional microprocessors , memory devices , and input devices as needed allowing an operator to provide and program detail control to an individual or the plurality of stage speaker devices 1 while simultaneously controlling stage lighting units 54 . as also noted above , in another selected embodiment , computer controller 50 is understood to be a computer control system that may optionally include links with synthesizers ( s ) for engineering the transmitted sound , orchestra or band recording / transmitting loops to generate a sound in addition to an electronic recorded sound generation , with lighting systems of the types mentioned above , robot movement control systems for units 1 , and direct links with or integration with a theatrical light management system etc . in sum , those skilled in the art should recognize the easy adaptation of the present invention into a conventional theatrical control environment and incorporation with the previously known lighting and sound systems therein . as one benefit of the present invention , the normally large and bulky stage speakers are deceivingly repositioned among the plurality of conventional stage lights providing an easily missed illusion to an audience trained by experience to ignore stage lighting systems normally publically positioned to dissipate thermal energy . this same analysis would apply to movie theater lighting systems normally placed well above an audience along a darkened ceiling . since in normal use stage speakers are placed along the stage , in an immediate blocking view to the audience , and also occupy valuable stage space , there is an obviously desirable economy to enabling repositioning of the stage speakers in an assimilate - able matter to a plurality of stage lights . as another benefit of the present invention , individual or the plurality of stage speaker devices 1 may be initially positioned and then movably repositioned ( robotically or otherwise ) at selected , programmed , and synchronized stop points along a computer programmed entertainment time line . this ability , enabled by the present invention , allows a stage manager / controller to easily reproduce expensive sound - movement impressions ( by simply moving ( pan / tilt / rotate ) a speaker device 1 ) and to easily compensate for detrimental acoustics within a selected theatrical situation ( by repositioning or repointing the speaker device 1 as needed ). in another beneficial example provided by the present invention , during a moment of soft - tone / low volume dialog in a performance , normally difficult to hear by the upper seats or in seats selectively blocked by set design / structural members etc ., an operator can program movement of selected stage speaker devices to pivot and direct a channel of audible sound as desired to counteract these detriments and improve an audience ” s listening experience . in another example , an operator may direct a non - or barely - audible signal ( base sound ) against a reflecting and dispersing surface ( i . e . a wall or ceiling ) of a theater at one moment of drama ( thereby extracting a maximum audience impact ) and then reposition selected stage speaker devices to provide a general audible signal to the audience . the benefit of the rigid rear cover 3 filled with a medium of electro - mechanical absorption is clearly shown in this instance , since the device blocks wavelengths exiting the rear of the speaker device 1 ( i . e . substantially uni - directional ) and spoiling the benefit created . those skilled in the art should recognize that system 100 may be readily adapted to a circular or oddly shaped stage ( not shown ) or audience positions . alternative track designs , the selection of additional or different configurations ( for rear cover 3 , body unit 2 , cover 4 and other items ) enable the present system 100 to be positioned in diverse areas for diverse needs while still being controlled via controller system 50 . in another example of a benefit provided by the present invention , to mimic moving sound for a biaural audience , a sound designer may custom design a pivoting movement of selected stage speaker devices from stage left to stage right , thereby replicating a surround sound or moving or fading sound effect for reduce costs . in this manner , a wide plurality of audible effect can be easily generated by a sound engineer skilled in the art of audience sound engineering with a minimum or reduced number of stage speakers . finally , as noted above , an alternative benefit of the present invention is to serve as a redirectable feed - back speaker for a performer . in one example , since speaker device 1 is easily moved , a performer can receive continual microphone feed - back while moving about a stage , and since the feed - back speaker is suspended as an illusory conventional stage light , the audience easily ignore the slight movement of the unit . the noted opposite to this example is where a performer wishes to have a narrow fixed feed - back speaker zone ( for example , by using an elongated shielding unit 4 ) positioned for the performer ” s specific height . in this manner , a first performer may step into their selected narrow feed - back zone during their performance , and a different second performer may step into the same position and receive feed - back from their own differently - positioned feed - back speaker selectively positioned for their second , without receiving conflicting feed - backit should be understood by those skilled in the art that the use of the phrase cylindraceous , as used herein , is particularly drawn to objects or shapes having generally cylindrical shapes / cross - sections , but may additionally be objects being ovoidal or geometric ( hex - octagon etc .) in shape / cross - section , may be a distorted or distended cylindrical , square , geometric , or ovidal shape are generally capable of having a mathematically definable radius function ( but not necessarily a smoothly continuously similar radius ) of any type about an type of regular or irregular circumference . cylindraceous should and can be additionally understood herein as a triangular , rectangular , and angularized geometric cross - section having rounded corners as this shape is capable of having a mathematically definable radius function . see webster ” s revised unabridged dictionary ( 1913 ed .). as noted throughout the description there are substantial utilitarian benefits from providing a stage speaker system easily used with an array or plurality of stage light . those noted earlier and cited herein include easy of adaptation to common stage lighting structures , systems , and computer control apparatus , the reduction in costs by employing fewer speakers and the benefit of increased space ( speakers not on stage ), directionality , and sound quality , and audio remediation of poorly designed and therefore acoustically deficient structures , and by being able to not employ costly and conventional heavy stage speakers . it should be further understood by those skilled in the art that the phrase “ axially - aligned ” should be understood as existing when individual components of the present invention are positioned generally in - line with or generally along a central axis of the overall cylindraceous shape of the stage speaker device , but there is no need to rigidly maintain a true central axis . when so aligned , the coaxial central axes of the individual rear cover , body unit , and guide or shielding unit extend ( generally aligned ) to form the long self - defined “ central axis ” of the resultant cylindraceous stage speaker device . see webster ” s revised unabridged dictionary ( 1913 ed .). it should be understood , that in an alternative embodiment , where a light ( not shown ) is combined with speaker 2 a within the same body housing 2 , that the general coaxial nature of the unit is maintained despite any axial displacement of the speaker . in this way , the present invention envisions close combination with adaptive lighting techniques within the same mechanical housing . it should be additionally understood by those skilled in the art that , where used , the phrase a medium of electro - mechanical energy absorption , may be any medium , or combination of mediums , capable of at least minutely reducing an energy state of a traveling electromechanical or sound wave . specifically , it is to be understood that such a medium includes atmospheric air ( non - vacuum state ), a particular selected gas or combination of gases ( for density change energy absorption ), a foam containing any gas or mixtures of gasses , and / or a mechanical energy absorbing means ( such as mechanical baffles ) all positioned within a substantially bounded space . another alternative embodiment envisioned positions the at least one speaker proximate the front opening or the rear portion of the speaker unit . where a speaker is positioned proximate the front opening the entire speaker unit may be shortened along it ” s central axis providing a more convenient shape . where a speaker is positioned proximate the rear portion of the speaker unit a similar shortening - benefit may result . in this manner , the present invention envisions an easy adaptation to a variety of manufacturer , set - design , and sound - architectural needs . it will be recognized by those skilled in the art that the present invention encompasses an alternative design enabling the transmission of high - frequency ( tweeter ) range sound waves from the face of a speaker to the front opening of the speaker without interference with the longer wave length mid - or - base range sound waves . such a design may include the use of a bounded sound directing channel member passing from a front face of the speaker to the front opening . while no particular design is required , the present invention envisions a horn - like bounded directional channel having a small end proximate the speaker face and a wider / larger end proximate the front opening of the unit . in the claims , meansor stepclauses are intended to cover the structures described or suggested herein as performing the recited function and not only structural equivalents but also equivalent structures . thus , for example , although a nail , a screw , and a bolt may not be structural equivalents in that a nail relies on friction between a wooden part and a cylindrical surface , a screw &# 39 ; s helical surface positively engages the wooden part , and a bolt ” s head and nut compress opposite sides of a wooden part , in the environment of fastening wooden parts , a nail , a screw , and a bolt may be readily understood by those skilled in the art as equivalent structures . having described at least one of the preferred embodiments of the present invention with reference to the accompanying drawings , it is to be understood that the invention is not limited to those precise embodiments , and that various changes , modifications , and adaptations may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims . accordingly , all such modifications are intended to be included within the spirit and scope of this invention as defined in the following claims .