What is the dustcap?
. [Top] What is impedance? When shopping for speakers, you will see figures stating the nominal impedance of a speaker (most speakers have a nominal impedance of between 4 and 8 ohms). This is the speaker’s average resistance to the flow of current through the circuit going from the amplifier into the speaker and back to the amplifier. However, this figure is only the average impedance rating across all frequencies into which the speaker produces output. In reality, the impedance may drop at some points to 2 or 3 ohms and may reach 40, 50 or even 60 ohms at other frequencies. A speaker with an 8 ohm nominal impedance will not generally have as low a minimum impedance as a speaker with a lower nominal impedance such as a 4 ohm speaker. Nominal impedance here refers to the impedance of the speaker at a defined low frequency in free air. The impedance will change with loading and frequency. The term nominal impedance has a number of different meanings. It refers to the approximate designe
