Can a Preamp Power Passive Speakers?

While passive speakers are very popular for various sound systems, they are also more complex than active speakers. Passive speakers need a power source, which is usually an amplifier of some kind. But could you use a preamplifier to power them just as well?

A preamp cannot power passive speakers; you need an actual amplifier. While they are similar devices, and you can use them together or an amplifier by itself, a preamp isn’t strong enough or designed to be used as a standalone amp with passive speakers.

To learn more about properly powering your passive speakers and why you shouldn’t use a preamp by itself to power them, keep reading. We’ll also cover the differences between preamps and regular amplifiers and how to find the right amp for your passive speakers.

Passive speakers

Do Passive Speakers Need a Preamplifier?

All speakers on the market today fall into one of two categories: passive or active. 

Active speakers are very popular because they typically have a built-in amplifier and power source. However, they don’t offer as much room for experimentation with different amps since they can’t be taken apart easily and have their components swapped.

Passive speakers, on the other hand, do not come with an amplifier or power source. You can’t plug them directly into your audio source. They need to first be connected to an amplifier to power them.

Preamps and amplifiers serve similar functions: They are both designed to boost the signals of whatever you’re listening to to make the resulting audio louder and sound clearer. 

Amplifiers, however, are a core piece of equipment needed for any audio setup, while a preamp helps to boost the power of the weakest signals before feeding them to the amplifier.

Preamps are also far weaker than amplifiers, so they aren’t meant to power passive speakers independently. They are designed to be used alongside an amplifier to make the weakest signals louder and stronger individually. This brings them up to line level before being sent to an amplifier, which boosts the entire collection of sounds coming from the speaker.

While you can certainly use a preamplifier and an amplifier with your passive speakers, you don’t want to use a preamp by itself. It isn’t strong enough by itself to power passive speakers, regardless of your personal setup. 

On the other hand, you can use an amplifier without a preamp for most passive speaker setups just fine without ever needing a preamp.

Some audiophiles might argue that a preamp with an amplifier is essential for the clearest and best all-around listening experience, but the difference is negligible for most situations.

Truthfully, the vast majority of casual setups will never need or even benefit from a preamp at all, as most passive speakers sound just fine with a decent amplifier. If you are going to use one, though, be sure to pair it with an amplifier rather than trying to use a preamp on its own as a substitute for an amplifier.

What’s the Difference Between Preamplifiers and Amplifiers?

As we briefly touched on above, an amplifier is necessary to power passive speakers since they aren’t designed to hold an amplifier inside them like active speakers. For any speaker, regardless of whether it’s passive or active, you’re going to need an amplifier.

Essentially, an amplifier is the primary power source for your speaker, whether it’s already assembled inside of the speaker like with active speakers or attached to it externally like with passive speakers. 

To sum it up as concisely as possible, an amplifier interprets the signals emitted by the speaker and boosts them so they can be heard and enjoyed by their user.

But a preamplifier is designed to function as a helper for a standard amplifier. It doesn’t boost all of the signals emitted by the source. A preamplifier only picks up the weakest signals and brings them up to the same level as the rest of the signals to create a clearer and more enjoyable listening experience.

If you’re using a passive speaker, an amplifier is externally connected directly to it rather than built into the device like an active speaker. 

You can optionally connect a preamp between your speaker and amplifier to boost weak signals, but it isn’t necessary unless you’re a particularly picky audiophile with some extra cash to spend on your audio system.

Can You Power Passive Speakers Without an Amplifier?

Technically, there is one way to power passive speakers without an amplifier. However, it isn’t recommended by most audio experts, and not all passive speakers will work with this method, and it can damage your speakers reasonably quickly.

You can theoretically connect certain passive speakers directly to your computer, as most (but not all) computers and even laptops have amplifiers built into them to boost audio coming from them. This comes with several caveats, though.

The reason why this method is not recommended is that it comes with a whole host of issues. 

The main problem is that the amplification system in most computers is not really designed to be used with passive speakers in this way, and the resulting audio will generally be of far worse quality than if you were to use an actual amplifier with your speakers. 

Unfortunately, the audio quality produced with this method tends to be relatively poor and not worth the effort you could be putting into a decent amplifier designed to be used with your passive speakers.

Additionally, you are likely to encounter problems and inconsistencies with connecting the speakers to your computer, and the overall volume of the audio will probably be disappointing and not nearly loud enough for even casual use.

But, in some cases, it totally is possible to connect passive speakers directly into your computer without using a standalone amplifier and still get decent results. Here is a video explaining a bit more:

What Kind of Amplifier Should You Use To Power Passive Speakers?

There are several different types of amplifiers you can use to power your passive speakers, and the exact one you’ll need depends heavily on many factors, including:

  • Your audio source: Are the speakers used for a personal computer, your television, or even a lavish home theater?
  • The kind of sounds you want to amplify: Is it music for personal listening, or is it for something larger in scale like a home theater system? If you’re using the passive speakers for music, what kind of music are you listening to? Do you want something like hip hop where you want to amplify the bass, or are you listening to something completely different, like classical music?
  • Your budget: Will you buy a preamp in addition to an amplifier? Just how loud do you want your amplifier to be? Generally, the larger the amp, the louder the sound, so if you want your speakers to be loud enough to fill your entire home, you’re going to need something a bit more pricey than if you were using your speakers for just a single room.
  • The overall size and scope of your setup: How long are you going to be using your speakers? Are they going to be reserved for specific situations, or are they going to be regularly used?

You have a choice of several different types of amplifiers. 

You might want to opt for an integrated amp, which has a preamp built into it. You’ll need to be sure to match your speaker’s impedance rating, or Ohm rating, to your amplifier’s impedance. For example, if your amplifier has an Ohm rating of 4 Ohms, your speaker should have the same value.

Conclusion

You don’t want to use a preamp alone to power your passive speakers; you need an actual amplifier. You can use a preamp with an amplifier or opt for an amplifier with a preamp built-in, but a preamp alone is not strong enough or designed to power your speakers by itself. 

There are ways to power passive speakers without an amp, but they put your equipment in jeopardy and result in poor audio quality that is too quiet and unreliable for practical use. For best results, you want to get an amplifier that matches your speaker’s impedance rating.