41. In principle, any filter structure could be applied to impedance matching , but some will result in more practical designs than others. 42. There are a variety of devices used between a source of energy and a load that perform " impedance matching ". 43. Also, a folded horn with an exponential taper was constructed inside the cabinet to provide better impedance matching to the air. 44. Valve amplifiers have a tuned network that serves as both the low pass harmonic filter and impedance matching to the output load. 45. The Guanella transmission line transformer ( Guanella 1944 ) is often combined with a balun to act as an impedance matching transformer. 46. For instance, the matching network may be designed as a Chebyshev filter but is optimised for impedance matching instead of passband transmission. 47. However they are perhaps the least efficient in terms of power-loss ( aside from having no impedance matching at all ! ). 48. The horn also improves impedance matching between the voice and the air, which produces more acoustic power for a given speaker power. 49. A bridge tap has no hybrid coil or other impedance matching components, just a T ( or branch ) in the cable. 50. This gain is a form of impedance matching to match the soundwave travelling through air to that travelling in the fluid membrane system.
