LFE LPF vs Crossover Frequency

Pogre

Pogre

Audioholic Overlord
What it does not mention is any LFE signal getting mixed into the mains. My interpretation of that would be that no, the front channels do not get .1 in LFE+Main. If you have a dedicated sub enabled, then the LFE channel is directed just to the sub.
Yeah, I disagree. Subs + Mains is also called "Double Bass" on some models, and what it means is that both your main speakers and subwoofers are receiving bass frequencies, bypassing the crossover. "Double Bass". I would NOT recommend using LFE + mains unless you have true full range speakers and a very low LPF for your sub(s).

I will repeat, LFE + Mains or Double Bass sends LFE content to both your sub and mains and what you get is double bass, with main speakers and subs stepping on each other.
 
Pogre

Pogre

Audioholic Overlord
I have the crossovers for all my speakers manually adjusted to 80HZ, via the Denon AVR. Speakers are all on SMALL. It works well in my application and is suggested in some readings. The AVR is in complete control. I'm just suggesting if a little off topic. I use the "LFE" no LFE+Main.
That's what you want. LFE + Mains is rarely the way to go, unless you have true full range speakers, of which there are few.
 
Eppie

Eppie

Senior Audioholic
I was thinking some more about getting LFE to the mains and it's possible in theory.
Yeah, I disagree. Subs + Mains is also called "Double Bass" on some models, and what it means is that both your main speakers and subwoofers are receiving bass frequencies, bypassing the crossover. "Double Bass". I would NOT recommend using LFE + mains unless you have true full range speakers and a very low LPF for your sub(s).

I will repeat, LFE + Mains or Double Bass sends LFE content to both your sub and mains and what you get is double bass, with main speakers and subs stepping on each other.
I think you're confusing bass with LFE content. LFE content only gets sent to the mains when LFE is disabled. With LFE enabled, LFE content goes to the sub alone. The "double bass" refers to low bass content from the other non-LFE channels. So with mains set to large and LFE set to LFE+Main, the full singal (without LFE content) gets sent to the mains and bass below the crossover frequency gets mixed from the mains to the LFE channel, which is your double bass from non-LFE content.
 
Pogre

Pogre

Audioholic Overlord
I was thinking some more about getting LFE to the mains and it's possible in theory.

I think you're confusing bass with LFE content. LFE content only gets sent to the mains when LFE is disabled. With LFE enabled, LFE content goes to the sub alone. The "double bass" refers to low bass content from the other non-LFE channels. So with mains set to large and LFE set to LFE+Main, the full singal (without LFE content) gets sent to the mains and bass below the crossover frequency gets mixed from the mains to the LFE channel, which is your double bass from non-LFE content.
Okay, that you might be right about. I'm possibly confusing "LFE" with "Bass". You putting it this way I get what you're saying now. This deserves a little bit more homework on my end, but I think my point still stands in that LFE + Mains does send bass frequencies to both speakers and subs. LFE only keeps the crossover and your mains aren't playing any bass below the crossover, which is preferred for most most cases.
 
Eppie

Eppie

Senior Audioholic
Okay, that you might be right about. I'm possibly confusing "LFE" with "Bass". You putting it this way I get what you're saying now. This deserves a little bit more homework on my end, but I think my point still stands in that LFE + Mains does send bass frequencies to both speakers and subs. LFE only keeps the crossover and your mains aren't playing any bass below the crossover, which is preferred for most most cases.
It's a natural point of confusion for many because of the wording in manuals. For the Denon, there are two settings listed under the heading of Bass Settings. There is the LFE and LFE+Main option, and below that the LPF for LFE option with various frequencies. The LPF is the cut-off frequency for LFE content, but the LFE and LFE+Main setting controls the mixing of non-LFE content. A more logical pairing might be to have the LPF for LFE setting paired with the Subwoofer Yes/No setting under the Speaker Configuration since the LPF setting only gets used when the sub is enabled. The LFE / LFE+Main settings should be paired with the Crossover Frequency setting because they both control non-LFE content.
 
Trell

Trell

Audioholic Samurai
From a software/programming point of view all these options are very easily explainable and should after all these years be implemented the same among the various AVR manufacturers.

Perhaps I'll test this out the next time I drag out REW to do some measurements.
 
T

Trebdp83

Audioholic Field Marshall
I know this is well explained but for some reason, I still don't quite understand it. Which setting would you use to send LFE to both subs and mains? In my case, I want the mains to get full range and LFE. Also, I want the subs to get the same low-frequency signal and LFE from the other channels that are set to small. Is it possible to send the bass signal from all channels set to small to both the mains and subs?
The speakers set to small will have the signal below the crossover point sent to the sub if one is in use in the system. Check pic from manual above. Otherwise, the signal would go to the full range speakers. I keep mixing terminology based on manufacturer but I mean LARGE/FULL BAND when I use full range.

@Pogre isn't wrong about Onkyo's "Double Bass" setting and I don't like it because, unless "Double Bass" is ON when speakers are set to "Full Band," the subwoofer is cut off. Somebody thinks their speakers can handle low frequencies and drops the crossover all the way down to "Full Band". You'd think that means the full main signal would be output to the main speakers and any LFE in the LFE channel would continue to be output to the sub, but no, it gets nothing. Using the crossover at all effectively makes the speakers "small" and "Double Bass" CANNOT be activated at all unless at least the two front speakers are set to "Full Band."

Now, for somebody with a 2.1 system used only for music, "Full Band" with "Double Bass" isn't a big a deal. There might be a pair of really capable speakers in use there but the listener still wants added bass from a subwoofer. Try those settings with the "Aquaman" soundtrack using less than capable speakers and you just might have a problem. I know, I tried. Remember that guy who could make his eyes practically pop out of their sockets? Yeah, like that. :eek:

I guess I could power the little droid back up and tinker with it's "Extra Bass" feature but that little f#%ker might blow my speakers out just to spite me. Hey, it's not my fault Yamaha keeps dragging a$$ on those updates.:mad:
 
lovinthehd

lovinthehd

Audioholic Jedi
And for the really bass hungry why isn't there a setting that says fekk it all, just send the LFE channel everywhere and triple my bass! :)
 
S

sterling shoote

Audioholic Field Marshall
All I can say is experiment. My new 2.1 Parasound P6 Preamp is my first stereo amp in the last 35 years that has had enough bass management features to actually get a seamless crossover from mains to sub to fully appreciate what the sub brings to the performance.
 
lovinthehd

lovinthehd

Audioholic Jedi
All I can say is experiment. My new 2.1 Parasound P6 Preamp is my first stereo amp in the last 35 years that has had enough bass management features to actually get a seamless crossover from mains to sub to fully appreciate what the sub brings to the performance.
But has no LFE capabilities so not particularly germane in this thread.
 
William Lemmerhirt

William Lemmerhirt

Audioholic Warlord
In another thread they were discussing various sub-woofer settings. The comments on LFE LPF and crossover settings had me a bit confused. Why are there separate settings and how are they related? A little on-line research cleared the air. (I'll refer to the Denon manual as that is what I own.)
(Feel free to quote any errors below and I'll amend the post accordingly. This is my basic understanding of the topic and hopefully kept the explanation simple enough for beginners to understand.)

LFE, or low frequency effects, is part of the digital surround sound spec, or the 0.1 in the 5.1. There is a good explanation of its development in this article. I highly recommend this article if you want a deeper understanding of bass management in movie sound tracks.

This is a separate low frequency effects channel and while it's not considered part of the lower frequencies in, say, music, it can contain low frequency content from other channels so it is not an entirely separate channel in the strict sense. If that sounds confusing, read the above noted article. It's primarily the digital channel for your movie rumbles and explosions. When you set the LFE LPF (low pass filter), you are setting the highest bass frequencies that will be sent to your sub for effects. It's labeled as a low pass filter because there is a hard cutoff at 120Hz in the spec, but since most sound engineers roll off the effects at 80Hz, many AVRs default to a LPF setting of 80Hz. Since the LFE channel incorporates sounds from other channels, you can set the LPF to values higher than 120Hz but it is uncommon to use a higher setting.

Going over the Denon manual, setting the subwoofer mode to LFE passes the low frequency signals from all speakers set to "small" to the sub. Setting the mode to LFE+Main sends the low frequency signal from all channels to the sub, regardless of the size setting. The distinction is that if speakers are set to large, they still get the full range signal with the low pass filter also sending low frequencies to the sub (deep bass from both the sub and mains/speakers set to large). Using combinations of large / small and LFE / LFE+Main you can control where the bass effects are sent, although it is most common to set all speakers to small and let the sub handle bass effects (LFE setting). Technically, with all speakers set to small, LFE+Main should yield the same result.

With most AVRs, if the subwoofer channel is enabled, you can set the crossover point for all speakers or individually set the crossover point for each pair of speakers (channel: front, center, surround, back, etc.). The Denon manual states that the low frequencies will be output to the subwoofer if enabled. The LFE LPF and crossover frequencies both default to 80Hz, but potentially they can be different. The crossover setting covers content not delivered to the LFE channel as part of bass effects. The above article implies that there is some overlap here, so there is some magic in the surround spec with multi-channel bass management, but this primarily covers 2 channel content and the rest of the bass in multi-channel content. Offloading the deep bass to the subwoofer has certain benefits but I won't go into details here.

Why the two settings? Many people will likely opt to have the LPF and crossover set to the same frequency in the 80Hz to 100Hz range. While deep base has the property of not sounding directional, those with speakers capable of going very deep might opt to have the LPF higher for movies but prefer a lower crossover point for music to keep most of the sound emanating from the front stage. Others may prefer a high crossover point to clean up the main speakers. Others may use different frequencies to fine tune a system to match a room's acoustics. It's about flexibility and personal preference. The two settings are there because modern AVRs have the subwoofer doing double duty, playing both surround effects and deep bass content.
Could be too late at night, but I missed an answer before this went into the weeds about lfe+mains lol.
The .1 is ONLY related to 5.1 soundtracks in films. Redirected bass from speakers set to small is NOT incorporated into the LFE(.1) channel.
Redirected bass IS sent to the subwoofer but is not related to LFE(.1). Music(some multichannel notwithstanding) does not have .1
So listening to music on a system with a subwoofer, the subwoofer only gets redirected bass below XO.
Watching movies on the same system, the subwoofer gets all of the redirected bass PLUS the lfe(.1) channel from the soundtrack. To be clear, the redirected bass is not part of the lfe channel, but is sent to the subwoofer. The LPF of LFE had zero effect on music, or content without an actual.1 channel.
So why the lpf setting? Good question. IMO, it’s about localization, which can be a thing with any content above 60-80hz. AFAIK, not too many mixes use the LFE channel very high in frequency range, but it can definitely be there.
It’s just a way to tailor the effects channel, since the crossover won’t affect the LFE on the soundtrack channel whatsoever.
 
Last edited:
Teetertotter?

Teetertotter?

Audioholic
Well, for me, my Denon is set on LFE and speakers are set to small. Sub and all 5 speakers are set at 80HZ. Do you think I am missing something??? I watch DD movies
 
William Lemmerhirt

William Lemmerhirt

Audioholic Warlord
Well, for me, my Denon is set on LFE and speakers are set to small. Sub and all 5 speakers are set at 80HZ. Do you think I am missing something??? I watch DD movies
I don’t know why you would be... what is the LPF of LFE set to?
 
T

Trebdp83

Audioholic Field Marshall
I think, perhaps, he meant the LPF is set at 80hz as well as the crossovers for the mains.
 
Pogre

Pogre

Audioholic Overlord
Just when I think I have it figured out... lol
Redirected bass IS sent to the subwoofer but is not related to LFE(.1). Music(some multichannel notwithstanding) does not have .1
So listening to music on a system with a subwoofer, the subwoofer only gets redirected bass below XO.
Watching movies on the same system, the subwoofer gets all of the redirected bass PLUS the lfe(.1) channel from the soundtrack. To be clear, the redirected bass is not part of the lfe channel, but is sent to the subwoofer.
Okay, so for stereo music. Does LFE + Mains or "Double Bass" mean that your main speakers receive a full range signal (bypassing the crossover) along with the subs playing bass redirected below the crossover at the same time? That's how I currently understand it. I think...

Then for 5.1 content. Do the mains get a full range signal bypassing the crossover while the rest of the speakers remain high passed and the sub plays only LFE?

My god man. It seems so simple to explain but it's not. It took me 15 minutes tryna figure out how to even word my questions...
 
flyboylr45

flyboylr45

Full Audioholic
So, is there a setting that plays the LFE content on both the sub and mains set to large?? Is that LFE+Mains?

Sent from my SM-N975U using Tapatalk
 

Latest posts


newsletter
  • RBHsound.com
  • BlueJeansCable.com
  • SVS Sound Subwoofers
  • Experience the Martin Logan Montis
Top