Crossover setting on subwoofer

[JOHN FICKEL]

Thanks PENG. I have read that before. He does mention that wherever you set your sub levels, LFE will track automatically at 10 DB higher. So if you calibrate your subs at 85db, with LFE, subs will be at 95db.. with those certain scenes of movies

 

[lovinthehd]

Agree with the first part but not the last..For music there don't seem to be a need and in fact some, e.g. Telarc are using the .1 channel for height information.

Depends on the music you like I suppose. Why does music need height channels?

 

[PENG]

Thanks PENG. I have read that before. He does mention that wherever you set your sub levels, LFE will track automatically at 10 DB higher. So if you calibrate your subs at 85db, with LFE, subs will be at 95db.. with those certain scenes of movies

First all LFE and "sub" not the same, LFE is a discrete channel. Subout has to do with bass management. You seem ready to read 3 more, then we can talk some more.

http://www.dolby.com/uploadedFiles/Assets/US/Doc/Professional/38_LFE.pdf

http://www.soundstage.com/video/columns/200003_db_hometheaterbass.htm

http://www.beussery.com/pdf/beussery.dolby5.1.pdf

 

[PENG]

Depends on the music you like I suppose. Why does music need height channels?

Agree, and I didn't mean to say music recording would never need that channel as there are always exceptions/reasons. For one thing, music recording does not have to deal with the limit from the old 70mm tapes on the movies side.

 

[BlwnAway]

Thanks PENG. I have read that before. He does mention that wherever you set your sub levels, LFE will track automatically at 10 DB higher. So if you calibrate your subs at 85db, with LFE, subs will be at 95db.. with those certain scenes of movies

That's right, I guess that's was throwing me off, thinking about the -10db cut when manually level matching for reference.
Thanks.

 

[JOHN FICKEL]

First all LFE and "sub" not the same, LFE is a discrete channel. Subout has to do with bass management. You seem ready to read 3 more, then we can talk some more.

http://www.dolby.com/uploadedFiles/Assets/US/Doc/Professional/38_LFE.pdf

http://www.soundstage.com/video/columns/200003_db_hometheaterbass.htm

http://www.beussery.com/pdf/beussery.dolby5.1.pdf

I agree PENG, LFE is a discrete channel. I do understand. And sub out is for bass management. However, if you were to level your subs all at 80db, now during music your subs will be at 80db. Now watch a movie. That LFE channel in that movie will play through your subs at 10db higher than you leveled for ... Correct??

 

[PENG]

I agree PENG, LFE is a discrete channel. I do understand. And sub out is for bass management. However, if you were to level your subs all at 80db, now during music your subs will be at 80db. Now watch a movie. That LFE channel in that movie will play through your subs at 10db higher than you leveled for ... Correct??

Not exactly...
Did you read all 3 I linked especially the last one?

 

[JOHN FICKEL]

Not exactly...
Did you read all 3 I linked especially the last one?

Not yet. I will tho

 

[PENG]

LFE is purposely recorded at 10db higher.

In my previous response this part, that is definitely not correct. You can find related info in a couple of the articles I linked but I am still trying to find something that deal more directly with the points being discussed here. When I do I will post the link.

For now, I would just say LFE channel is actually supposed to be recorded with an -10 dB offset, i.e. 10 dB lower, than that for the main channel levels.

 

[JOHN FICKEL]

Yeah I can't believe that My Z9 gives me the capability of going from zero to -20 . If it's already at -10 why would one have to adjust it down further ? So you're saying when somebody levels their whole system including subs, the LFE is -10db lower? Article says wherever you calibrate.... ( LFE ) automatically tracks at 10 DB higher than the main channels

 

[JOHN FICKEL]

I will definitely reread all articles

 

[PENG]

Yeah I can't believe that My Z9 gives me the capability of going from zero to -20 . If it's already at -10 why would one have to adjust it down further ? So you're saying when somebody levels their whole system including subs, the LFE is -10db lower? Article says wherever you calibrate.... ( LFE ) automatically tracks at 10 DB higher than the main channels

Yes, that's done to bring it back to balance. That is, recorded 10 dB lower, but boosted 10 dB higher at play back just to match the main channel. The articles I linked deal with a lot more than the topic on hand, that's why I warned you to read the fine print.

 

[PENG]

John, the one linked below should clarify your doubt about the 10 dB offset. As I mentioned before, it is not about getting the LFE signal 10 dB louder, but about regaining balance with the other channels, while gaining 10 dB headroom in the LFE channel.

http://www.genelec.cn/faq/multichannel/subwoofer-level/

Edit: I referred only to the second Q (Headroom in the LFE channel) only. The rest of the Q&A may not be 100% correct though may be correct in general sense.

 

[JOHN FICKEL]

Ok thank you for clarifying all this

 

[PENG]

Ok thank you for clarifying all this

You are welcome, I know that article explained it much better than I could if I tried, that why I spent time searching it out. So now you know the 10 dB offset started during the recording process, and that it is actually a -10 dB offset in order to gain headroom in the LFE channel that movies such as Jurassic world might benefit from.

Obviously the AVR has to give it a +10 dB boost for play back to restore balance. To be clear, the AVR should boost only the LFE channel signal but not the redirected bass from the other channels.

All the time we are just talking about the reference levels, how loud the LFE gets during playback will depend on the movie contents, but you know that already.

 

[JOHN FICKEL]

So at the end of the day all is equal. LFE, Is equal output to all other channels Correct??

 

[JOHN FICKEL]

So when they say LFE tracks at 10db higher.. that is to bring it to balance to all the other channels. because it was recorded at -10 DB to begin with

 

[PENG]

So when they say LFE tracks at 10db higher.. that is to bring it to balance to all the other channels. because it was recorded at -10 DB to begin with

Yes, but whether the 10 dB boost is by default or by user adjustment may depend on the AVR/prepro. I know all my D&M AVR/prepro would do it by default though some of them do have provision for adjustment.

For example, below is copied/pasted from the AV7005 manual:

"LFE
Adjust the low-frequency
effects level (LFE).
–10dB – 0dB
For proper playback of the different sources, we recommend setting
to the values below.
• Dolby Digital sources : “0dB”
• DTS movie sources : “0dB”
• DTS music sources : “–10dB”"

Their higher end models (AV8801/8802/AVRX7200W) naturally provide even more adjustments.

You have the RX-Z9 but my guess is that if you go with the default setting you will get the +10 dB offset when playing DD/DTS 5.1/7.1 but to be sure, you should read the manual.

 

[PENG]

There are not a lot of info about how YPAO work but this one is quite good for those interested. According to this article, the older YPAO basic "measure the frequency response of your speakers and use a parametric equaliser (PEQ) to flatten the frequency response of the speakers/room in the frequency domain only (what it is doing really is match the timbre of the speakers to each others)"

The newer YPAO R.S.C. "will create filters that will modulate BOTH the phase and the frequency of the response."

 

[lovinthehd]

Yes but at what point does YPAO give up other than a level/delay setting for the sub? I've seen various suggestions but never sure just where it gives up, have assumed it was at best 30ish hertz but not sure if its more in the 60ish range. Certainly not as good as Audyssey....or is it?