[MidLife]

...newbie here, be gentle.

What are the settings for LFE, in db mean?. I understand that it can reduce distortion from very,very,very low frequencies that your speakers may not handle, but, The user guide doesn't explain the difference between the diff db settings, default being zero db. In which direction, db wise, does the suppresion increase??

 

[BGLeduc]

Most decoders that offer an LFE control allow the user to reduce the level of the LFE channel relative to the other channels. You normally can not increase it.


The default is normally 0dB, which means that the LFE is NOT attenuated. If you want to hear what is on the disc, leave it at 0dB. If for some reason you feel that there is too much bass, and you also feel it is because the LFE track was too loud, you may reduce it by up to -10 dB or so.


There may be some discs that record the bass as part of the main tracks, AND on the LFE. I have a Telarc DVD that implies in the DVD booklet that they do this. In that case, you may want to attenuate the LFE to avoid excessive bass (assuming your bass management is working correctly).


FWIW, this topic delves into the subject of bass management. You could spend weeks on just that subject! And you would probably end out with a major headache.


BGL

 

[Steve S]

One must also differentiate between LFE settings and Sub settings.


LFE settings adjust the level of the specifically encoded LFE track on a 5.1 or 6.1 source in relation to the other channels. This should be set a 0db for Dolby Digital, and +10db for DTS dvd. There are a few DTS audio CDs, and these should be set at 0db.


Sub level is for adjusting how loudly the sub plays when one or more other speakers are set to small. Setting one or more of the regular speakers to small diverts the bass that would normally be sent to that speaker to the sub. Since this bass is not encoded on the LFE track, but is being sent to the sub, the sub volume level must be adusted to match the other speakers.

 

[hwc]

Quote:

Originally posted by Steve S This should be set a 0db for Dolby Digital, and +10db for DTS dvd.

No way. The same setting is correct for both Dolby Digital and DTS DVD soundtracks.


There are only two reasons to ever change the level of the LFE channel.


a) The first reason is to correct for some of the early DTS audio CDs, where DTS screwed up the LFE channel and recorded it 10 dB too loud. Personally, I think a better approach to this problem would be to send the defective recordings back to DTS for a full refund, but that's just me. I don't have much patience with a company that can't even figure out their own recording system that they are trying to sell. Their little "snafu" has caused so much confusion. I feel the same way about Dolby's inability to get the DVD mastering labs to embed the proper flag on Dolby EX discs so they play properly on recievers for which consumers have paid good money in Dolby EX license fees.


b) If you have a system that simply cannot handle the output of the LFE channel, you could turn it down as a way of protecting your speakers. However, setting proper subwoofer levels and using the Dolby Digital dynamic range compensation feature are probably better ways of dealing with that problem.

 

[M Code]

Quote:

Originally posted by Steve S One must also differentiate between LFE settings and Sub settings. LFE settings adjust the level of the specifically encoded LFE track on a 5.1 or 6.1 source in relation to the other channels. This should be set a 0db for Dolby Digital, and +10db for DTS dvd. There are a few DTS audio CDs, and these should be set at 0db.

About 18 months back, the DTS certification standards had a mistake about LFE level it was 10dB low..... and certain AVRs were built with this error..

But..

recently built AVRs have corrected this like my new Harman/Kardon AVR 7200 so now the LFE should be set @ 0dB just like DD. However often U may want to go in tweak the level a couple of dB to suit whatever media U are playing to get the desired impact..

 

[hwc]

The default LFE levels are part of the chipset software. I am not aware of any receivers that have an error here for DTS DVD-V discs. This is an old, old problem with early DTS music CDs. Nobody who has bought a DTS receiver needs to worry about this issue. The same LFE setting is correct for both Dolby Digital and DTS DVD-Video soundtracks.


Tweaking the LFE level for "desired impact" indicates something out of whack in the overall system configuration. The proper adjustment is the subwoofer level trim that is part of the test tone procedure on most receivers. Once this is set properly, it should work for all sources: music and movies.

 

[Steve S]

About 18 months back, the DTS certification standards had a mistake about LFE level it was 10dB low..... and certain AVRs were built with this error..

But..

recently built AVRs have corrected this like my new Harman/Kardon AVR 7200 so now the LFE should be set @ 0dB just like DD. However often U may want to go in tweak the level a couple of dB to suit whatever media U are playing to get the desired impact.

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Thanks for the correction!!


My first DTS capable receiver, a Yamaha RXV-795 had separate DD and DTS LFE adjustments and in order to get enough LFE out of DTS I had to set it to +10db. I suspect this was one of those earlier dts capable receivers you're talking about.


My current receiver, a Pioneer VSX45TX has no LFE adjustments in it's setup menu, which had me worried as I could not set DTS LFE to +10, as I was mistakenly sure I would have to do. After listening to several dts discs and not having the low LFE I had experienced when played on the Yamaha with dts LFE at 0db, I quit worrying about it.