# Understand the difference between speaker impedance 4 ohm and 8 ohm in one article

Jan 07th, 2022 | by: Noob 7868
Category: Electronics
Views 60
Introduction to impedance
Impedance and resistance have the same unit, both are Ω. Resistance has an obstructive effect on current, and similarly, impedance has an obstructive effect on current.
Impedance can be any combination of resistance, capacitance, and inductance that hinders the current. Since the impedance of the capacitor to the direct current is infinite, and the impedance of the inductance to the direct current is zero, the impedance is more used to describe the obstructive effect of the current in the AC circuit.
High impedance refers to a large impedance value, and low impedance refers to a small impedance value.

What is a horn
The trumpet is divided into several different musical instruments, a kind of wind instrument, with thin upper part and thick lower part, mostly made of copper. The other is a modern electro-acoustic component, whose function is to convert electrical signals into sound, which is also called a speaker. It can also be used to describe someone who advocates and promotes for others.
A horn is actually a conversion device that converts electrical energy into sound. When different electronic energy is transmitted to the coil, the coil generates a kind of energy to interact with the magnetic field of the magnet. This interaction causes the paper plate to vibrate because the electronic energy changes at any time. The coil of the horn will move forward or backward, so the paper tray of the horn will move accordingly. This action changes the density of the air and produces sound.

Speaker impedance
In general audio equipment, the impedance of the speaker, the input impedance of the front and rear amplifiers, the output impedance of the front stage, (the latter is usually not called the output impedance, but the output internal resistance), the transmission of the signal line Impedance resistance (or characteristic impedance) and so on. Since the unit of impedance is still ohms, Ohm's law also applies, so in a nutshell, under the same voltage, the higher the impedance, the less current will flow, and the lower the impedance, the more current will flow. The most common horn impedance marked value is eight ohms, which means that when the pair of speakers is tested in the factory, when a 1KHz sine wave signal is input, its impedance value is eight ohms; or it is in the working frequency response of the speaker Within the range, an average impedance value.

It is not a fixed value, but varies with frequency. When the rear stage outputs a fixed voltage to the speaker, according to Ohm’s law, a four-ohm speaker will flow twice as much current as an eight-ohm speaker. When the four-ohm speaker is connected, it will automatically become 200 watts. When the impedance value of the speaker drops all the way, the subsequent stage outputs a fixed voltage, and the current flowing through it will become larger and larger. In the end, it is a bit like a direct short-circuit of the speaker wire, so the impedance value is sometimes as low as one ohm. Limit, beyond this range, the machine will burn. This is what most people often say: The power of the subsequent stage does not need to be large, but the output current seems to be large.

The difference between the speaker 4 ohm and 8 ohm is
1. The internal resistance of a 4 ohm speaker is 4Ω; the internal resistance of an 8 ohm speaker is 8Ω.
2, 4 ohm speakers, because of the small internal resistance, the voltage change will be more obvious than 8 ohms, so the sensitivity of the sound quality is higher than that of 8 ohms.
3, 8 ohm speakers, the power is relatively small, suitable for playing bass, appear more subdued, suitable for high-quality audio.