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Discussion Starter #21
Regarding the LFE bandwidth, just because you set your subwoofer crossover at 80hz doesn't mean your sub automatically isn't still getting the full LFE channel. Processors with a richer feature set usually give you fine control over the LFE channel, and by default, they tend to feed the sub the full signal regardless of your redirected bass crossover point. You can reduce the bandwidth of the LFE channel if you desire in stated processors, but why would you?

There can be quite a bit of bass in the LFE channel from 80-120hz assuming the scene calls for it.
I suppose some may use the LFE LPF to eliminate the potential of localizing bass above 80Hz. I don't really know any other reason for it, but some processors put it there... I suppose thinking some might find a reason for it. :huh:

For me... I am not worried about bass localization because I have subs all around me... creating much less sense of localization.


If you can find my old disk it has the LFE from 1-20Hz in one hertz increments, and then 25-120Hz in five hertz stops. All other 5. channels are 20-120hz in five hertz stops.

I have popped out custom test signals in raw ac3 for computer playback with multi-tracked tones, but I don't have any links.

I could run you some myself, if I ever get that computer back up and running again. Anyone with a old spare ATI 9800 Pro 256MB, or better AGP x8 card laying around unused? :D
I am looking... maybe I can find a solution.
 

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Good questions... and your answer may be the most beneficial reason for using the LPF.

I am not sure of what the trend is with limiting frequencies of encoding LFE, but it might answer some questions.
I cant say I have ever noticed hum, or hum that is cured by altering the LPF, that is Onkyos thing, but the localization would make sense. FWIW, when I had dual subs I set the LFP to 120hz and left it there to see if it made a real difference. I couldnt tell, and the benefits of dual subs in the end made me forget about it, and thats probably one reason Ive never thought of what actually happens to 80-120 hz, its never been an issue.

I think one problem is that research is ongoing all the time. Ideas change and can drift one way or the other for periods over time. A manufacturer of processors might get an idea, or a movie publisher decide to try something for a while, and these sometime stick and sometimes dont. Things like this come up all the time and something like the LPF of LFE is probably neither here nor there in the grand scheme of things, and pretty inconsequential.
 

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I suppose some may use the LFE LPF to eliminate the potential of localizing bass above 80Hz

For me... I am not worried about bass localization because I have subs all around me... creating much less sense of localization.
Perhaps, but the LFE channel doesn't have a discrete intended location aside from the subwoofer, so it's not like we should be hearing it from our rear left and instead it's coming from the sub - it should be coming from the sub. As you say, multiple subs would tend to eliminate any localization to begin with.
 

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Discussion Starter #26
It is for a review of a piece of equipment. I have been unable to find discrete .1 LFE tones, so I may forgo the testing of it. It has become irrelevant considering how the equalization system is flawed, so it will not be a big deal.
 

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Discussion Starter #27
It might still be nice to have the LFE test tones so that I can test anyway... for those who do run their entire system full range and have no redirected bass.

I was looking at AVIA Pro ... but I won't be spending that much on a test disc. If I were a full time reviewer, it might be worth it, but I ain't.
 

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I never saw this thread before but I was doing a google search for the same thing and this thread popped up.

Do you have a test cd with stereo tracks?
...about 30 minutes ago I read another post suggesting to put the AVR in FULL MONO or ALL CH STEREO mode. It will put out the test tones to all speakers connected. If you only want to test the sub (LFE ch), disconnect all other speakers.

I just tried it, and it works. I'm so excited, but my wife isn't because it's the middle of the night. oops!
 

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Perhaps, but the LFE channel doesn't have a discrete intended location aside from the subwoofer, so it's not like we should be hearing it from our rear left and instead it's coming from the sub - it should be coming from the sub.
But if there is content in the LFE above 80hz, you will be able to localize that sound, whether intended or not.
Example:
You're watching a movie, say there is an explosion way off to the left side, much of the sound should be coming from the left speakers so you hear it from that direction. But what if your sub is directly to the right of your seating area. If the sub is producing part of the explosion sound and it contains info above 80hz, then you will hear the explosion on the right side and the left side.
 
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