Omnidirectional Speakers

Omnidirectional Speakers

Coming up after the break we’ll be going from the traditional to the ultra-modern with omnidirectional speakers and trust me I’ve had some good feedback on this see you after the break welcome back choosing the right speakers for your sound system depends on how you prefer to hear music unidirectional speakers radiate sound in a single direction while omnidirectional speakers radiate in all directions bouncing the sound of ceilings and walls sounds good to me this omnidirectional speaker system has four towers – main system towers and two subwoofer towers the towers contain the drivers that radiate sound frequencies out of the speaker to start production a computer-guided mill shapes brass sheets into mounting plates for the main system towers each tower will contain six drivers two tweeters two mid ranges and two woofers each subwoofer tower also contains six drivers which will produce the lowest frequencies the surface of each brass mounting plate is ground smooth to prepare it for polishing and chrome plating the mill then shapes brass rings these are basis for the woofers which fit an opening in the mounting plate brass is the metal of choice for these parts due to its acoustic properties to improve their aesthetics the rings are painted black and the mounting.

Plates are electroplated with galvanized chrome next the tweeters for the main system towers are constructed the first step is to lay strips of resin impregnated carbon fiber into semicircular molds after removing the protective film that covers the carbon fiber foil strips are later each end these will direct heat from an oven to the carbon fiber strip and prevent the resin from leaking out the molds are now assembled and come sharp they’re placed in an oven for 45 minutes which cycles through a pre-programmed series of temperatures this heats the resin in the carbon fiber stiffening the strip’s and conforming them to the shape of the mold a punch press is used to cut each carbon fiber strip into several thinner strips each tweeter is made by gluing 24 of the thin strips to the tweeters voice coil a ring made of wound copper wire silicon is brushed between the strips before the entire surface is coated with more silicon and an aluminium cover plate is placed on top each mid-range driver is constructed in the same way but with carbon fiber strips that are thicker and stiffer these will radiate lower.

Frequencies better than the thinner more flexible tweeter strips tweezers and a toothpick are used to precisely align the strips a technique which requires a good eye dexterity and experience as with the tweeter the mid-range driver is placed in an oven for 45 minutes which again goes through a specific cycle of temperatures once the driver comes out of the oven and is cooled strips of sound dampening foam are glued to the inside sealing the gaps between the carbon fiber strips this prevents sound from radiating inwards rather than out of the speaker cables to transmit the electrical signals are now soldered in place these signals move the voice coil up while the drivers magnet moves it back down the repeated up and down motion flexes the carbon fiber strips radiating the sound frequencies a rod made of carbon is then installed before the hollow space inside the driver is filled with sound dampening wall this also prevents sound from reflecting into the driver rather than out of it lubricating oil is poured into a narrow gap in the drivers magnet before the voice coil is inserted into the gap the oil contains iron to conduct electrical signals to the coil an aluminium mounting plate is now screwed to the magnets posts before a desk of stiff sound dampening material is applied the tweeters.

Magnet is then installed on the mounting plate and the tweeters electrical cables are fed through the center rod these tweeters are now complete and it’s time to construct the woofers each melon shaped woofer is made out of 12 aluminium segments acoustic foam is glued to each of the segments and trimmed to the same shape the woofer is assembled upside down with the segment’s glued vertically between the woofers voice coil and a mounting plate at the center is a structural rod through which the cables for the speaker’s drivers will run once the segments are aligned and fixed in place the edges are coated with glue rubber gaskets are then glued between the segments to block the gaps and prevent air from escaping copper strips are seated in the segment’s grooves with their ends hooked into holes at the top and bottom the acoustic properties of the materials including brass aluminium and copper will combine to produce a natural sound balance the hollow interior space around the center rod is now filled with sound dampening material first synthetic insulating wool with long coarse.

Fibers is added a barrier of cotton insulating wool is then placed on top of this layer to prevent the coarse fibers from touching the voice coil the painted brass ring that was milled earlier is now installed which now has the woofers magnet fixed to it next a spacer and end piece are rounded to the center rod before the voice coils two cables are pulled through it the cables are then soldered together with the cables from the other drivers to a main cable that will plug into the speaker’s crossover the woofer is now turned right-side up and a liquid sound dampening compound is poured into the center rod this also secures and protects the cables now the speaker is ready for assembly first the mid-range and high frequency crossover cables are soldered to their respective driver cables the tweeter connection cables are then attached to the tweeter magnet installed earlier on top of the mid-range driver this unit is then mounted on top of the woofer the crossovers connectors are now installed the crossovers electrical components will separate the frequency ranges and send each one to the appropriate driver after sliding the crossover on to the speaker’s base the top is closed with the mounting plates between which a thick piece of wood has been sandwiched screw in stainless.

Steel support posts hold the assembly together and direct the weight down to the floor rather than into the speaker’s structure an aluminium crossbar is installed for structural support along with the second set of posts the ring at the base of the woofer slots into a hole in the mounting plate and is secured with screws the tweeters voice coil is then inserted into the tweeter magnet the cables are now soldered to the two connectors on the tweeter cover plate this completes the lower trio of drivers next an identical upper trio is installed upside down so that the two tweeters face each other in the middle of the tower the crossover for the upper trio is now mounted and the connector that joins the cables that supply the drivers is plugged in test tones are now run through the completed speakers a microphone positioned exactly one meter away picks up the emitted frequencies which a computer analyzes for accuracy once the speaker has passed inspection a decorative grille is installed over each woofer voice coil and with that the speakers are ready to radiate your music of choice although do try to make it a popular one or you could experience interference especially from your neighbor