Bass management
Encyclopedia
The fundamental principle of bass management (also called LFE Crossover) in surround sound
replay systems is that bass content in the incoming signal, irrespective of channel, should be directed only to loudspeakers capable of handling it, whether the latter are the main system loudspeakers or one or more special low-frequency speakers (subwoofer
s). There are notation differences between the pre-bass-managed signal and once it has passed through bass manager. For example, when using 5.1 surround sound
:
As the table shows, the bass manager directs bass frequencies from all channels to one or more subwoofers, not just the content of the LFE channel. However, when there is no subwoofer, the bass manager would direct the LFE channel to the main speakers. This is the only time the LFE channel would not be sent to the subwoofer.
The key concept is that the LFE channel is not the "subwoofer channel".
Surround sound
Surround sound encompasses a range of techniques such as for enriching the sound reproduction quality of an audio source with audio channels reproduced via additional, discrete speakers. Surround sound is characterized by a listener location or sweet spot where the audio effects work best, and...
replay systems is that bass content in the incoming signal, irrespective of channel, should be directed only to loudspeakers capable of handling it, whether the latter are the main system loudspeakers or one or more special low-frequency speakers (subwoofer
Subwoofer
A subwoofer is a woofer, or a complete loudspeaker, which is dedicated to the reproduction of low-pitched audio frequencies known as the "bass". The typical frequency range for a subwoofer is about 20–200 Hz for consumer products, below 100 Hz for professional live sound, and below...
s). There are notation differences between the pre-bass-managed signal and once it has passed through bass manager. For example, when using 5.1 surround sound
5.1 surround sound
5.1 is the common name for six channel surround sound multichannel audio systems. 5.1 is now the most commonly used layout in both commercial cinemas and home theaters. It uses five full bandwidth channels and one low frequency enhancement channel . Dolby Digital, Dolby Pro Logic II, DTS, and...
:
| 5.1 channels | |
|---|---|
| Before bass management | After bass management |
| L - Left | L - Left |
| R - Right | R - Right |
| C - Center | C - Center |
| SL - Surround Left | SL - Surround Left |
| SR - Surround Right | SR - Surround Right |
| LFE - Low Frequency Effects | N/A (incorporated into Sub) |
| N/A (bass can be in any channel) | Sub - Subwoofer |
As the table shows, the bass manager directs bass frequencies from all channels to one or more subwoofers, not just the content of the LFE channel. However, when there is no subwoofer, the bass manager would direct the LFE channel to the main speakers. This is the only time the LFE channel would not be sent to the subwoofer.
The key concept is that the LFE channel is not the "subwoofer channel".