Speakers and amplifiers go hand in hand. Speakers produce sound, and amplifiers make speakers sound. In short, all speakers depend on amplifiers in order to work.
With the craze for acquiring and experimenting with new gadgets and devices, some music enthusiasts have been asking, “can headphone amps be used to power speakers?”
Reading: Speaker and headphone amp
Headphone amps cannot power speakers. speakers require a relatively large amount of power to drive them, but headphone amps generate significantly less than 1 watt of power. this is not enough to drive the speakers.
As you may already know, speakers require a power amplifier to work. most consumer speakers these days usually have a built in power amplifier. however, for normal passive speakers, you need to purchase a separate power amplifier.
but how is a power amp different from a headphone amp? Well, that’s what we’re going to see next. and then I’ll move on to all the reasons headphone amps can’t power speakers.
headphone amps vs power amps
In terms of functionality, headphone amps and power amps work on the same principle. Their basic design may also be similar, but honestly, the only thing headphone amps and power amps have in common is that they both amplify audio signals and drive voice coils to produce sound. however, this is what makes them different.
Headphone amps, as the name implies, are made to drive headphones. in fact, every device that allows you to connect a headphone has a built-in headphone amplifier. however, most of the time, these built-in headphone amplifiers are not powerful enough, especially for high-end headphones. that’s why external headphone amplifiers were made. that’s how they work.
all headphones have an important feature known as a voice coil. although there is more, you can think of a voice coil as a copper wire that has been wound around. keep this in mind.
Voice coils are an essential component in a headphone because they make it sound. but how do you do that?
The voice coils receive audio signals from whatever device the headphones are connected to, in the form of electrical currents. when this current (or audio signal) passes through the voice coil, it instantly converts it into an electromagnet. I’m sure you’re familiar with this concept if you remember physics from elementary or high school.
Once the voice coil becomes an electromagnet, it begins to repel and attract the permanent magnets in the headphones. this causes the headphone drivers to move back and forth to produce sounds. If you’ve read our article on how bass damages headphones, I’m sure you’re familiar with how voice coils work.
Essentially what a headphone amplifier does is boost or “amplify” any audio signal before it is sent to the headphones or voice coil. the power (or electrical current) that will be sent to the headphones will be much higher than without them. this will result in higher volume, fuller sound, and sometimes improved signal clarity.
Now let’s briefly talk about loudspeakers and power amplifiers.
Speakers and headphones are very similar in how they work. Speakers also have a voice coil that causes them to produce sound when they receive an audio signal (or electrical current) from an amplifier.
however, speakers are designed to play much louder than headphones. all the components inside a speaker are much larger compared to a headphone. for this reason, they require a lot of power to run, much more power than headphones require.
Power amplifiers are designed to supply the necessary power to speakers to operate efficiently.
Essentially all I’m trying to say is that speakers require a lot more power to run than headphones. headphone amps are designed to power headphones that require much less power than speakers. power amplifiers are designed to provide speakers with enough power to drive them.
This is the simplest difference between a headphone amp and a power amp. but for my audience that is a bit technical and knows a bit about electricity here is the difference between a headphone amp and a power amp.
headphone amp vs power amp: impedance
the big difference is that; They are designed to handle different resistance loads. power amplifiers are designed to drive a load impedance of 4 to 16 ohms. on the other hand, headphone amplifiers have been designed to drive a load impedance in the range of 16 to 600 ohms.
As I said before, loads with low impedances require a lot of energy to drive them. this means that headphone amps are designed for loads that don’t require a lot of power.
headphone amp vs power amp: power, current and voltage
The difference in impedances between headphone amplifiers and power amplifiers affects all other electrical properties associated with these amplifiers. therefore, headphone and power amplifiers also differ in terms of power demand, current, and voltage.
why headphone amps can’t power speakers
As mentioned above, in theory, headphone amps and power amps don’t differ. they work the same way. but headphone amps simply can’t supply enough power to the speakers to make them work. that’s the main reason headphone amps can’t power speakers. however, there are more reasons why they are not ideal for speakers.
here are a couple more reasons not to power your speakers with headphone amps
1. no speaker jacks on headphone amps
one of the problems with headphone amps is that they don’t even have slots where you can attach the connectors for the speaker cables. For you to have a headphone amp that has a slot where speaker cables can be plugged in, you would need DIY.
Honestly, the time and effort it takes to build a headphone amp that requires speaker wires would be better spent buying a power amp.
2. low output voltage
Headphone amplifiers are generally rated by the amount of output voltage they can deliver.
Headphone amplifiers are designed to handle very small voltage signals, sometimes measuring a few nanovolts. unfortunately, these voltages are not strong enough to drive speakers.
3. the high output impedance of headphone amps will alter the frequency response
many headphone amps have an output impedance in the range of 0.5 to 50 ohms. speakers, on the other hand, have an input impedance of 4 to 12 ohms.
Ideally, the output impedance of an amplifier should be eight times less than the input impedance of the loudspeaker. for example, if you are using a speaker with an input impedance of 8 ohms, the output impedance of the amplifier must be 1 ohm or less.
If that is not the case, it will affect the frequency response of the audio signal being sent to the headphones. Simply put, the headphone amplifier will not send accurate audio to the speaker and this will affect the sound quality.
Most headphone amplifiers have an output impedance that is generally higher than the input impedance of a loudspeaker. so even if the headphone amp can supply the necessary power to the speakers, they won’t sound very good.
4. the headphone amplifier may be damaged due to heat
Theoretically, there are high expectations that some headphone amplifiers can be used to drive speakers successfully. even if this is achieved, the headphone amplifier will be forced to overwork to meet the speaker’s power requirements. this will cause the amplifier to overheat as it is not designed to power such speakers.
how to properly power a speaker
At this point, I’m sure we’ve established the fact that headphone amps can’t power a speaker. the only way to drive a loudspeaker is with a power amp.
You need to find the right power amplifier for your speakers to make them work efficiently. but how do you find the right power amp for your speakers? this is where the combination of speakers and amplifiers comes into play.
Amplifier speaker matching is a process of finding the right power rated amplifier for your speakers. uniquesquared made an excellent video explaining how this is done. If you have plans to buy an amplifier for your speaker, you should definitely check it out.
In short, headphone amps can’t provide the large amount of power a loudspeaker needs to run. this means they cannot power or control the speakers.
Ultimately, when it comes to speakers and amplifiers, it’s important to take note of their maximum drive capabilities. it’s best to get an amp that’s a little more powerful than your speaker’s ratings. this will help ensure that only clean, undistorted power reaches your speakers.