Quote:
Originally Posted by craig john 
Examine this graph closely:
The blue trace is the old, "brickwall" filter that was used in the pre-lossless codec's during the recording/encoding process. Note that there is almost no content above 120 Hz present. The pre-lossless codecs did not need an LPF of LFE because they were filtered during the recording process and there could not be any content above 120 Hz in the LFE channel.
Now look at the red trace, the 80 Hz LPF. Remembering that the LFE channel in the lossless codecs is a "full range channel" and that it gets filtered on playback, note how little content gets through above 120 Hz. Content at 120 Hz is down about 15 dB.
Now look at the blue trace, the 120 Hz LPF. Content at 120 Hz is only down about 4 dB, and there is a lot more content above 120 Hz that is at audible levels.
If there is content above 120 Hz in the LFE channel, it's very likely that it was mistakenly put there by the recording engineer. This is especially true on MC music. An 80 Hz setting of the LPF of LFE will better eliminate the >120 Hz content that could possible get into the LFE channel.
Nonetheless, what we are discussing here amounts to minutiae. On 99.9% of content, you won't hear any difference between an 80 Hz setting of the LPF of LFE and a 120 Hz setting. Try it for yourself and see if you ever hear any difference.
Craig
Examine this graph closely:
The blue trace is the old, "brickwall" filter that was used in the pre-lossless codec's during the recording/encoding process. Note that there is almost no content above 120 Hz present. The pre-lossless codecs did not need an LPF of LFE because they were filtered during the recording process and there could not be any content above 120 Hz in the LFE channel.
Now look at the red trace, the 80 Hz LPF. Remembering that the LFE channel in the lossless codecs is a "full range channel" and that it gets filtered on playback, note how little content gets through above 120 Hz. Content at 120 Hz is down about 15 dB.
Now look at the blue trace, the 120 Hz LPF. Content at 120 Hz is only down about 4 dB, and there is a lot more content above 120 Hz that is at audible levels.
If there is content above 120 Hz in the LFE channel, it's very likely that it was mistakenly put there by the recording engineer. This is especially true on MC music. An 80 Hz setting of the LPF of LFE will better eliminate the >120 Hz content that could possible get into the LFE channel.
Nonetheless, what we are discussing here amounts to minutiae. On 99.9% of content, you won't hear any difference between an 80 Hz setting of the LPF of LFE and a 120 Hz setting. Try it for yourself and see if you ever hear any difference.
Craig
Good stuff, I'll try setting the lfe lpf and see how that goes. Doubt I'll hear a difference in my untreated room but hey tweaking settings is always fun!
