Perhaps you want to save money by using your old passive speakers instead of buying a new pair of active studio monitors. Or maybe you enjoy the sound of your passive speakers and still want to use it with your new audio interface.
Whatever your reason, is it possible to use passive speakers with an audio interface?
Passive speakers can be used with an audio interface, provided you use them with an external power amplifier. The audio interface’s line output will be sent to the amplifier’s input, and the speakers will be connected to the amplifier’s outputs. No sound will be produced through passive speakers when you connect them directly to an audio interface.
Passive speakers are more complex to set up because they do not include an amplifier, even if they don’t require a power cable. Instead, you have to select one after doing your own research with the appropriate specification.
Consequently, powered speakers may be a more convenient alternative, particularly for those without a degree in audio engineering.
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Can You Drive Passive Speakers With An Audio Interface?
You can’t drive passive speakers with an audio interface. And that’s because audio interfaces don’t have a power amplifier built into them. The outputs of audio interfaces are line outputs, and line outputs deliver line-level signals.
And just as we’ve explained many times on this blog, line-level signals cannot deliver enough power to speakers to drive them. As a result, the sound would be scarcely audible.
Most audio interfaces typically run on USB power, which is about 2.5-4.5 watts, and the line output wattage is considerably less.
Unfortunately, this is too low for loudspeakers, which typically require much more power. For example, your typical bookshelf-style loudspeakers will demand 50 to 100 watts.
In addition, the audio interface’s line-out circuit could be damaged. It’s built for use with equipment such as power amplifiers and active speakers that accept line-level signals.
These devices have line inputs that incur a high impedance (about 10000 Ohms), lowering the current and protecting the audio interface electronics. Impedance is essentially the alternating current equivalent of electrical resistance.
Passive speakers have audio inputs with a typical impedance of four to eight ohms, providing a much smaller resistance to current. Audio interfaces typically have protective components that limit the current to avoid accidentally bricking your audio interface. However, please do not abuse this, as it can cause damage over time.
What’s Needed To Use Passive Speakers With Audio Interfaces?
You’ll need a power amplifier that matches your passive speaker setup’s impedance and power requirements.
While a power amp is essentially all you need to drive passive speakers, I think it will be worth your money if you purchase a stereo receiver instead. That’s because receivers have an amplifier built into them, and they offer more functionality.
As an example, a simple receiver such as the Yamaha RS 220 Stereo Receiver (on Amazon) will function as your traditional power amp for your passive speakers. In addition, it has Bluetooth functionality and an FM/AM built into it as well.
Check how many channels you need or how many a given amplifier has. Having multiple speakers on one channel is possible, but you must calculate the speakers’ combined impedance and power requirement. I have an article on how to do that.
Doing so is considerably more complicated, involving the physical laws of circuits, so we’ll stick to the simple case of one speaker per channel.
Hooking up the audio interface to the amplifier is typically easier. Most Line Out ports on audio interfaces are ¼” ports. And most inputs on power amplifiers are RCA. So you’ll need a stereo ¼” to RCA audio cable such as these ones on Amazon.
Once you have connected your audio interface to the power amplifier, then you can connect your passive speakers to the amplifier using RCA or banana plugs, whichever ones your speakers come with.
How Do You Match Speakers And Amplifiers?
As I mentioned earlier, you need to find the right amplifier to match your passive speakers. An amplifier that matches well with your speakers is more efficient and will prevent any possible damage to your speakers.
But how exactly do you find the right amplifier for your speakers if you intend to use it with your audio interface? While that is way beyond the scope of this article, I’ll try and make it simple.
Firstly, your amplifier should be able to provide at least as much power as the continuous power usage. It’s recommended to find an amplifier that can deliver as much as twice the power requirement of your speakers. However, be careful, as overpowering the speakers can cause damage over time.
To make things simpler, check out this video on matching speakers to an amplifier.
Are Powered Speakers Better For Use With Audio Interface?
For those who don’t know what powered speakers are, these are simply speakers with a power amplifier built into them by the manufacturer. They are also known as active speakers.
And there are some benefits to choosing an active speaker to use with your audio interface. And these are
Whether you want to connect your audio interface directly to a speaker or have the choice of a powered speaker, you may want to consider the alternative. Powered (or “active”) speakers contain one or more amplifiers, thus needing a power cord. This combination has the following advantages:
- No external amplifier is required, and you don’t need to worry about finding the right amplifier that matches your speakers.
- It is easier to set an active speaker up with an audio interface. All you need to do is to connect the audio interface’s output directly to the speaker’s inputs.
- Most active speakers have internal limiters that prevent them from getting damaged.
- Many manufacturers rearrange specific components in their active speakers to improve efficiency and fidelity.
So if you want to simplify the setup process, I highly recommend you get active studio monitors or speakers instead of a passive one for your audio interface.
Conclusion
It is possible to indirectly connect a passive speaker to a computer’s audio jacks using an amplifier, allowing additional flexibility and control. However, powered speakers are probably the best choice for those unfamiliar with audio equipment or unwilling to maintain a complex signal-processing pipeline.
Hi, I’m Raymond. A keyboard player, music producer, and writer. And I’m also the founder of this blog. As someone who has been working with several audio and music equipment and different musicians for many years, my goal is to answer all your questions on music and equipment, as well as the latest music software and technology. For more info, check out my about me page