You most likely listen to music every day on your commute to school, work or while driving to places. But have you ever wondered what is inside the device that makes possible for us listen to music?
A speaker driver is an individual transducer that converts electrical energy to sound waves, typically as part of a loudspeaker of car audio speaker or even of a tiny speaker inside your headphone. Attached to the apex of a loudspeaker cone you find a voice coil (consisting of a former, collar, and winding). When it comes to winding, the actual wire employed in voice coil winding is almost always copper (95 percent), with an electrical insulation coating, and in some cases, an adhesive overcoat.
Copper wire provides an easily manufactured, general purpose voice coil, at a reasonable cost. Where maximum sensitivity or extended high frequency response is required from a loudspeaker, aluminum wire may be substituted, to reduce the moving mass of the coil.
While rather delicate in a manufacturing environment, aluminum wire has about one third of the mass of the equivalent gauge of copper wire, and has about two-thirds of the electrical conductivity. Copper-clad aluminum wire is occasionally used (in 5 percent of voice oil winding), allowing easier winding, along with a useful reduction in coil mass compared to copper.
Some system designs may benefit from the longer Xmax if the system uses extremely long excursions, as may the case be competition vehicles making high distortion 2 second SPL runs. The longer coil windings keep more turns of wire in the magnet gap at high excursion.
The aluminum wire, with its larger cross section area, is not as efficient as copper. A copper wire coil will pack more turns of wire into the magnet gap and results in higher energy over the operating Xmax of the coil. Well designed enclosures usually give better performance with the more efficient copper windings in both sound quality and output.
The power handling differences between copper and aluminum are negligible IF both wires are using the same coatings and same adhesives systems. Aluminum will have more surface area to dissipate heat, but takes more power to reach the higher efficiency of the copper coil, in subwoofer applications. In midrange/tweeter applications, the lighter aluminum wire can have significant impact on high frequency performance where moving mass dominates.
Debates on whether use copper or aluminum has been ongoing for decades; we posted an article explaining the debate here.
Shanghai Metal Corporation is leader in Ultra Fine Rectangular Enameled Copper Wire which widely used in voice coils, moving coils, printer coils etc. We pride ourselves in excellent quality products with competitive pricing and prompt delivery. We also offer alcohol soluble enameled flat copper wire and alcohol soluble Enameled copper-clad-aluminum round and flat wire. For our full list of products that we offer check out our website here. Be sure to join the conversation in our LinkedIn group, Facebook, Twitter and Instagram. Try also our new mobile application by scanning the QR code below.
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Source: soundqubed.com, wikipedia
Pictures: audiowork.wordpress.com, electronicsforevery1.blogspot.com
Camilla G.//SMC Editor