Bass management in home theater refers to the process of sending low-frequency audio signals (bass) from various audio channels (such as stereo or surround sound) to the subwoofer. This ensures that low-frequency sounds are reproduced accurately and effectively throughout the listening environment.
Why?
There are multiple reasons why you want to take advantage of bass management. The first one is that it removes the low-frequency load from the receiver and makes the subwoofer handle it instead. When you’re using bass management, you’re telling the receiver/processor that the speakers in your system should only play from frequency X and up, while the subwoofer handles the frequencies from X and down. The THX standard is 80Hz and is what we recommend for our 1723 series, but for a more detailed overview, you can look at this article: Recommended Crossover Points. By having the subwoofer handle these frequencies (which are the most taxing to reproduce), the receiver has more headroom to reproduce the rest of the frequency range more accurately. Since the subwoofer is better at reproducing these lower frequencies anyway, this is basically a win-win situation.
The same advantages as with the receiver can be achieved for all the crossed-over speakers.
Without the heavy bass load, they will have less distortion, and play much louder.
You will also hear much better clarity in the midrange as the sound is not masked or smeared by the bass they have to produce.
How?
This all sounds fantastic, “but how do I enable it?” you might ask. First of all, you need a receiver, processor, or integrated amp that has a dedicated subwoofer output, and the ability to set a crossover between the subwoofer(s) and the other channels. Basically, all receivers and processors have this option, but not all integrated amps. To enable it, you go into the setup menu of your unit, and set your speakers to “small”. On some receivers it might simply say “crossover”, but the result is the same. When they are set to large, they receive the full signal, and this can cause interference between the subwoofer and speaker in the overlap region if they’re both active. When you have selected small, you are prompted with a crossover number. Usually between ~40Hz and 150Hz. Which frequency will depend on your speakers, but also on your room: If you are limited in speaker and sub positions, and your front speakers always have a dip/null at 100Hz where your subwoofer doesn’t; it might make more sense to use a slightly higher crossover to avoid this null. Just keep in mind that the higher you set the crossover, the more you’re able to localize the sound, so it’s important to find a balance that suits your room and needs.