I have an amplifier and Ive decided to connect a second loudspeaker in a distant room, pulling a wire about 10 meters long. However, even using boxes of the same type with the same speakers, the sound of the remote box is lower. What makes the sound come out the even?
What happens is that the speakers with low impedance, are sensitive to the resistance of the wires that connect them to the speakers. The greater is the length of the wire, the greater are the losses occurring in the signal. So a 10 meters wire, especially if it is thin, means a good loss signal which arrives weaker on the remote speaker. There are several possibilities to avoid losses in this case. The first is to use the thickest wire possible. Many use extensions with very thin wires producing large losses. Another solution is to work with a higher impedance. If the boxes are of 4 ohms, the losses will be much greater than in the case of 8 ohms boxes. Finally, there is the solution to work with a high impedance output which some amplifiers have, 600 ohms, in the case, pull the wire to the remote box and in it put a small transformer that lowers the 600 ohms to the housing impedance value . These transformers, called line transformers are used in sound distribution by many boxes like hotels, companies, etc.