Many of you, including music producers, audio enthusiasts, or a person who wants to rock out to your favorite tunes, want to add a subwoofer but do not know the correct pairing process.

Fear not, bass-hungry friend! In this guide, you will understand the difference between unbalanced (RCA, TS) and balanced (TRS, XLR) signals and how they affect cable selection. There is a theory of balance between unbalanced and balanced signals, which you must understand. 

I will go through simple steps and will cover selecting the right cables to connect them, and even throw in some pro tips to get the most out of your subwoofer setup, so read carefully. You can also check my guide for getting a good quality Underseat Subwoofer, check it as well!

The Audio Interface I used:

  • UA Volt 276 audio interface
  • M audio M track audio interface

Unbalanced Signals

Things Requires:

  • RCA output (from audio interface)
  • TS quarter-inch Jack (Tip and Sleeve)

To link a subwoofer to your audio interface via an unbalanced signal, connect the subwoofer’s RCA output to the interface’s unbalanced input using an RCA-to-TRS cable. Remember that, for unbalanced signals, you should not be a cable running 10 to 15 feet, and you may get some sort of noise and static interference. By using an RCA Or TS quarter-inch Jack, you should do short cable running.

Balanced Signal need for: If you need more than 10 to 15 Feet or you want premium quality for connecting your audio interface to your subwoofer and powered speakers. What is Requires: TRS quarter Inch Jack (that has Tip, Ring and Sleeve) Or XLR cable.

The common things regarding the audio interface: On the audio interface backside, you will find the left and right output of RCA or Quarter inch, and you will not find any separate subwoofer output. It does not mean that your audio interface is of low quality, as this is a common thing, so you don’t need to worry about that.

What is the Actual process? You will take left and right output from your audio interface (to feed the subwoofer), and this subwoofer will then send signals to monitors.

Out of the box subwoofer settings:

If there is a crossover selection option back to your subwoofer, you can choose between everything above 80 Hz to 120 Hz to send signals to your powered studio monitors. You can also select Bypass to send full signals to your studio monitors. Here is how you can install Powered subwoofer to Factory Stereo, read carefully!

Make connection by doing unbalanced RCA signal to connect your powered speakers:

  • Connection (Connect Subwoofer With RCA cables)
  • Take your Standard RCA cable, and you have to connect it to the back of your audio interface.
  • White (left) to white output.
  • Red (Right) to Red output.
  • Now connect the RCA cable to the IN of the Subwoofer.
  • Now you need to connect Out of the subwoofer (into your powered studio monitor)
  • Another RCA cable is required (to connect a subwoofer to the monitor)
  • Connect the RCA cable properly.
  • Now turn On both the Subwoofer and your Studio monitors.
  • Play Some Music and turn up the volume.

Balanced RCA signal to connect your powered speakers

Connect your Subwoofer With TRS and XLR cables. You need a quarter-inch Balanced TRS output of output 276 audio interface to connect your subwoofer!

Sometimes, your subwoofer may either contain balanced quarter-inch inputs and outputs, so my recommendation is to use a straight TRS cable (one with audio and the other with XLR input. Using a converting cable will convert balanced TRS outputs of your audio interface to Make XLR Jack. Simply, you have to connect this cable to universal audio volt 276 and a second end to the right output. For extending, you can use the XLR cable left output (Red to Red and White to White). You have to connect the left XLR input to the subwoofer’s back side. You have to use another white XLR cable to daisy chain the left output of your subwoofer. By using a RED XLR cable, you have to do the same and plug it into the right side.

Now play some music and test; if you have paired all wires correctly, then you will hear excellent audio quality, which is a positive sign that you have done well.

How can I connect subwoofer with audio interface for stereo mixing

If you want to listen to mixed stereo audio, then follow the mentioned step to pair the audio interface with the subwoofer and monitors properly:

Equipment you’ll need

  • Active subwoofer
  • Audio interface
  • Cables (TRS jack cables (balanced) or RCA cables (unbalanced)) 

Note: The cable selection depends upon your audio interface and subwoofer connection:

Connection Steps:

The cable identification is a very important part, and you have to check your interface and subwoofer for available input/output jack types. The most recommended is balanced TRS, which is for professional setup, and for unbalanced RCA cables, I will recommend RCA cables based on available options.

Connect interface to subwoofer:

Direct connection (common method)

  • First, connect the left audio interface output to the left subwoofer input.
  • Second, Connect the right audio interface output to the right subwoofer input.

Subwoofer output connection (2.1 setup)

If your subwoofer offers L/R outputs, then you can connect the main outputs of your interface to your subwoofer input, and after that, you have to connect your subwoofer output to your subwoofer monitors. You now have a subwoofer connected to your audio interface, enhancing the low-frequency sounds.

Set the subwoofer settings as follows

Crossover frequency: By setting the crossover point on your subwoofer (which means frequencies it handles like 80Hz and onward), your studio monitor can handle mid and high frequencies, while your subwoofer handles bass.

Volume level: You now have to adjust the volume of your subwoofer so that it blends seamlessly with your studio monitors.

Additional Tips: Now I will tell you some additional tips to increase audio quality, so check below:

Subwoofer placement: The first recommendation is subwoofer positions, which you have to try and experiment with differently in your room to get the right bass response.

Phase adjustment (experiment if needed): To adjust the phase switch on your subwoofer, you need to play music at first, and then adjust it until you get a full-sounding bass.

Monitor volume calibration: If you have a meter, you can use it to calibrate your monitors and subwoofer to ensure accurate levels.

In A Nutshell

I hope you have learned properly about connecting your audio interface to the subwoofer with my guide. I have mentioned two methods, including balanced and unbalanced methods, and tips for the best subwoofer settings. You can also read the FAQ section below for more technical information. I hope this helps!

Frequently Asked Questions

Can you run four studio monitors in parallel connected to the same Subwoofer? One pair connected via RCA and the other via XLR?

Running four studio monitors in parallel with a single subwoofer is a bit tricky, but it can be done. You can use both RCA and XLR connections, which introduces some complexities. To start, you have to first ensure the Subwoofer has multiple outputs (for each pair of monitors). You’ll need a subwoofer with dedicated outputs (for both RCA and XLR), and additionally, you have to check the impedance matching of all components (It will avoid amplifier overloading). You can use a high-quality splitter or a distribution amplifier (for both RCA and XLR signals), so it will help maintain signal integrity. Because of the unbalanced (RCA) and balanced (XLR) connections, how loud each monitor is may differ from the other. You must have to monitor and adjust the levels to achieve a balanced sound. You have to use the right equipment and pay attention to successfully run four studio monitors in parallel.

What do you do with a subwoofer that has only inputs, not outputs? (like Magnat Alpha RS8)?

Here, one approach is to use the subwoofer in a stereo configuration, connecting it between your audio source (e.g., audio interface or mixer), and I will recommend you use an audio interface with four outputs then. It is a straightforward process; you would run the audio source output to your subwoofer input and then connect your subwoofer output to the input of the monitor controller; it can also connect directly to your main studio monitors as well.

My audio interface has TRS output, and my subwoofer has RCA. What do I do?

When your audio interface has TRS (Tip-Ring-Sleeve) outputs, and your subwoofer has RCA inputs, I recommend you use a TRS to RCA cable. Well, the only option you have is using 1/4" TS to RCA cable (not balanced) as your subwoofer is unbalanced. It has a TRS connector on one end and RCA connectors on the other.

Basit
Meet Basit, your guide through the symphony of music production and technology. He has been writing about tech and audio production for many years, and with a passion for the perfect blend of beats and bytes, he dives deep into the intersection of musical creativity and cutting-edge technology. From testing Audio interface to synthesizers reviews to production techniques, join Basit on a harmonious journey, unlocking the secrets of the ever-evolving world where music and tech collide. (Email: basit@fabaudiovisual.com)