Will a 4 ohm amp work with a 8 ohm receiver?

Answer 1

Yes, if you use two 4 ohm speakers or or one 4 ohm resistor and a 4 ohm speaker to equal the 8 ohm resistance per channel. An important thing to note about this, is that you will need to make sure you get a resistor that can handle the current. You can go higher in resistance but not lower, it must be equal to or higher. Something important is added: The amplifier will have an output impedance of around 0.04 ohms. In hi-fi we have always impedance bridging. Zout << Zin. The damping factor DF = Zin / Zout tells you what Zout is. Zout = Zin/DF. If the damping factor DF = 200 and the loudspeaker impedance is Zin = 8 ohms, the output impedance of the amplifier is Zout = 8 / 200 = 0.04 ohms. You see, there is no "8 ohm amplifier" with a 8 ohm output. Scroll down to related links and look at "Voltage Bridging - Zout << Zin".

Answer 2

Yes, but:

1.) if the amplifier is not rated for 4 Ohms, it may become overloaded at moderate volumes, overheat, and burn out.

2.) A 4 Ohm speaker will draw twice as much power from a typical solid state amplifier as an 8 Ohm speaker. Therefore the volume will be incorrectly high.

3. ) If you must use the 4 Ohm speakers, put a 4 Ohm resistor in series with them to make a total of 8 ohms. The speakers will play at half power. The resistor must be rated for half the power of the audio output channel in question. It may become hot and should be mounted away from items that might burn or melt.

Answer 3

Amplifiers are rated to operate with certain speakers. Most speakers on the market have an 8 ohm impedance and many amplifiers are designed to drive 8 ohm speakers. In most cases, an amplifier will operate with a 4 ohm speaker but there is a possibility that as the output level increases, the amplifier may be damaged due to excess current being drawn by the speaker.

With all amplifiers, it is worth checking the manual to see what the manufacturer advises regarding lower impedance speakers.

As an additional note, it is worth mentioning that amplifiers have an output impedance that is far lower than the rated load impedance. Therefore, there is strictly no amplifier that has 8 ohm outputs. For more information on this aspect, see the link below.

Answer 4

There is really no amplifier with an output of 4 ohms. All loudspeaker amplifiers have an output impedance of 0.5 ohm or less. Scroll down to related links and look at "Voltage Bridging".

Answer 5

Sorry, there is no 4 ohm amplifier in the world. All loudspeaker amps have an output impedance of less than 0.5 Ohm.

Answer 6

Never heard of an amplifier with 4 ohms output impedance. It's always much less than 0.5 ohms. 4 ohms or 8 ohms amplifier are a myth.