How do you get the best possible bass response in your room? Good bass is essential to an emotionally engaging music experience, as everyone knows. However, room resonances degrade the sound by amplifying some frequencies and cancelling out others. Traditional room correction systems attempt to address this through precise equalization of individual speakers. However, Dirac Active Room Treatment (ART) takes this several steps further by using all speakers together to actively cancel out room modes, thereby tightening up the bass in the time domain. The outcome is a significantly improved listening experience. As a Dirac R&D engineer, I’m fortunate to work closely with the very talented creators of Dirac ART, giving me insight into its inner workings. In this post, I will illustrate what Dirac ART does and even let you listen to an example.
Dirac ART is a comprehensive solution for advanced room correction, with features like multi-subwoofer bass management and customizable target curves. I will not go through all its capabilities here, but focus on illustrating how Dirac ART excels at sound field control in the bass. The core principle of the technology is to utilize all bass-capable speakers—whether full-range or subwoofers—to optimize the bass sound field. The speakers can be placed freely, and the Dirac ART algorithm aims to provide the best possible listening experience based on your specific setup and available equipment.
To understand how the sound field behaves in a room, let’s examine some simulations. Below I have simulated a shoe-box sized room using a standard image-source model. The simulated room has four subwoofer speakers, one in each corner of the room. For our test, we’ll feed all the subwoofers with a bass impulse. This impulse, shown below, has a uniform energy at all frequencies below 200 Hz:
In an ideal scenario, the listening position would receive a single, clear pulse that mirrors the input signal fed to the speakers. However, without any processing, this is not the case. The following videos illustrate the resulting sound field (image only, no sound):
Without sound field control, the sound pressure received at the listening position oscillates multiple times and doesn’t resemble the original single pulse fed to the speakers. Also notice that the sound lacks direction!
When Dirac Active Room Treatment (ART) is applied to optimize the speaker signals, the sound pressure at the listening position matches the original single pulse.
The pulse arrives from the direction of speaker 1, since Dirac ART is here configured to reproduce a left input channel from that position.
Next, I’ll provide some real sound examples from my own listening room. The setup includes two full-range monitor speakers positioned at the front (left and right channels) and two subwoofers located in the rear corners behind the listener.
The examples are binaural recordings of a brief bass sequence, captured at the listening position. These recordings were made using the microphone array shown in the photo above, following the method described in this post: link.
Please listen to all the samples below using headphones, and switch between them to experience and compare the sound differences.
Without any processing:
With Dirac Active Room Treatment (ART) activated:
With regular per-channel EQ of the speakers:
Here are a few key observations:
- Without processing, the sound is quite thin. Room correction is necessary with my speaker setup to add body to the sound.
- With regular EQ, the bass energy increases, but there is no improvement in the time-domain. The original rhythm of the bass line is muddled by the uncontrolled rumbling of the room reverberation.
- With Dirac ART, the bass is tight, dry and full-bodied, with greatly reduced impact of room resonances. The clarity of the bass is comparable to that of a high-quality outdoor PA system.
I hope you enjoyed this post and gained insight into how advanced room correction can dramatically improve bass response in a regular listening room!
