Audio and speakers
LFE channel
The Low Frequency Effects channel, the '.1' in 5.1, a dedicated bass-only track with 10 dB of extra headroom that feeds the subwoofer.
The LFE channel is a separate, band-limited track reserved for very low frequency effects such as explosions and rumbles. It is not the same as bass from the main channels; the subwoofer plays the LFE track plus bass redirected from speakers set to small.
The channel is mixed 10 dB hotter than the others to give bass more dynamic range, and the receiver applies that gain on playback. An undersized or misconfigured subwoofer clips on exactly the moments the channel was made for.
LFE is limited to 120 Hz, and reference playback puts it at 115 dB peak versus 105 dB for the main channels. Leave the receiver's LFE low-pass at 120 Hz so no content is discarded, and set speaker crossovers separately.
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