HOW TO: Connect a Subwoofer to a 2-Channel System with and without Subwoofer Output

Connecting a subwoofer to a 2-channel audio system can significantly enhance your sound experience by adding depth and richness to music or home theater audio. Whether your equipment is basic or more advanced, this guide will help you connect a subwoofer in the most efficient way. We will explore two scenarios: one where your preamp includes a subwoofer output and another where it has no subwoofer output. By the end, you'll know how to connect a subwoofer in both situations confidently.

Understanding the Basics of Subwoofers and Their Importance

To appreciate why subwoofers are essential, it’s important to understand their role in audio systems. A subwoofer is designed to handle low-frequency sounds, typically between below 80-100 Hz, that standard speakers often struggle to reproduce. For example, when watching action movies, the deep sounds of explosions or musical bass lines are best delivered by a subwoofer. One excellent choice for filling out the low end in your audio system is the SDX12 subwoofer, which which we sell individually or in kits like the one linked. These are low distortion subwoofers with a huge amount of clean excursion to provide perfect reproduction of all the low end movie and music content.

According to a study published by the Audio Engineering Society, adding a subwoofer can provide up to 30% more clarity to low-frequency sounds compared to traditional speakers. For audiophiles and home theater enthusiasts, having a proper low-frequency setup makes a notable difference, allowing for a more balanced and immersive audio experience.

Scenario 1: Connecting a Subwoofer with a Preamp that has A Subwoofer Output

If your preamp (or integrated amp) features a dedicated subwoofer output, the process to connect a subwoofer is straightforward. This output will typically be labeled as "Sub Out" or "LFE Out," specially designed to send low-frequency audio signals to your subwoofer.

Steps to Connect:

1. Gather Your Equipment: You will need a subwoofer, an single channel RCA cable (sometimes listed as LFE or subwoofer cable), and your preamp.

   
   

2. Power Down Hardware: It’s always smart to turn off your preamp and subwoofer before connecting to prevent any damage.

   
   

3. Locate the Subwoofer Output: This output is usually at the back panel of the preamp.

   
   

4. Connect RCA Cable: Plug one end of the RCA cable into the “Sub Out” of the preamp and the other end into the subwoofer’s input.

   
   

   

   
   

5. Adjust Subwoofer Settings: Power on your system and set the crossover frequency and volume to your liking. A common crossover frequency is between 50-80 Hz for most setups. Use the gain adjustments on your preamp or subwoofer to control the subwoofer output.

   
   

6. Test the System: Play audio, like a favorite song or a movie scene with strong bass, to check the subwoofer's performance and integration. You can also measure using a USB or XLR style microphone to fine tune the adjustments if you have the capability.

   
   

Benefits of Connecting via Subwoofer Output

• Easier Setup: With a dedicated output, connecting your subwoofer requires fewer steps.

  
  

• Enhanced Sound Quality: The preamp optimally manages sound balancing, allowing clearer audio output and better integration with your main speakers.

  
  

Scenario 2: Connecting a Subwoofer to a Preamp without A Subwoofer Output

If your preamp lacks a dedicated subwoofer output, you can still connect the subwoofer through one of two methods: speaker-level connections or using a miniDSP device.

Option 1: Speaker-Level Connections

This method involves connecting the subwoofer using the same outputs that your main speakers use. In order to do this, you will need a subwoofer that has speaker level inputs. Not all subwoofers have this type of connection capability. If yours does not, you will need to use the previous method or option 2 below.

Steps to Connect:

1. Gather Your Equipment: You will need a subwoofer with speaker level inputs and speaker wire.

   
   

2. Power Down Hardware: Turn off both your preamp and subwoofer before making connections.

   
   

3. Access Speaker Outputs: Locate the positive and negative terminals at the back of your amplifier.

   
   

4. Connect Speaker Wire: Use appropriate gauge speaker wire to connect the output terminals from the amplifier to the speaker level inputs on the subwoofer.

   
   
   
   

   

5. Make Speaker Connections: Connect your main speakers to the speaker-level outputs on the subwoofer. NOTE: This often passes your main speakers through an internal highpass filter, whic sometimes causes peaking in the low end response of the main speakers.

   
   

6. Adjust Settings: After powering on your system, adjust the crossover frequency and gain settings on your subwoofer.

   
   

7. Test for Sound: Play audio with deep beats or bass-heavy content to test the subwoofer’s performance. You can also measure using a USB or XLR style microphone to fine tune the adjustments if you have the capability.

   
   

Pros and Cons of Speaker-Level Connections

• Pros: This option is straightforward and doesn't require extra devices or a sub level ouput on your preamp. It can function well with various configurations.

  
  

• Cons: Sound quality might not match that of subwoofer outputs. You may lack precise crossover control compared to dedicated outputs, especially for the main speakers.

  
  

Option 2: Using MiniDSP for Advanced Control

If you want more control over your audio setup, consider using a miniDSP or similar device. This device can help you manage multiple audio sources and finely tune your crossover settings and equalization.

Steps to Connect:

1. Gather Equipment: You will need a miniDSP device, subwoofer, and appropriate cables.

   
   

2. Install miniDSP: Connect the miniDSP before your preamp using RCA cables to split the audio signal before reaching the subwoofer and 2-channel preamp/amp.

   
   

3. Connect to Subwoofer and 2-channel Amplifier: Use RCA cables to run from the miniDSP output to the subwoofer’s input.

   
   

4. Set Up miniDSP Software: Download the miniDSP software on your computer to manage settings. Adjust crossover frequency and EQ for your space and speakers.

   
   

5. Testing: Similar to other methods, play different types of audio to ensure your setup works properly. You can also measure using a USB or XLR style microphone to fine tune the adjustments if you have the capability. This is where an active solution like this will provide more flexibility and fine tuning.

   
   

Benefits of Using MiniDSP

• Precise Control: This method lets you finely tune audio output to meet personal preferences and suit your environment. You can almost infinitely adjust crossover points, slopes, and gain, as well as get the ability to add parametric EQ, timing adjustments and more to help smooth out room mode issues and get the highest level of integration.

  
  

• Flexible Options: You can connect various audio sources and effectively manage them, rather than relying on your preamp alone.

  
  

Final Thoughts

Connecting a subwoofer to a 2-channel audio system can initially seem complex, especially if your preamp lacks a dedicated subwoofer output. However, it becomes manageable through the outlined methods, whether using a preamp with a subwoofer output or exploring speaker-level connections and advanced miniDSP setups.

Enhancing your audio experience with a subwoofer brings a richer, fuller sound that elevates music and movie enjoyment. Whether you are an audiophile or simply someone looking to improve sound quality, these methods will guide you toward a better listening experience. Enjoy the improved sound quality and happy listening!