LFE split between mains and sub?

[pultzar]

Question about how the crossover works on recent Emotiva processors (XMC-1 and future RMC-1). Say I have main speakers and the subwoofer with a crossover point of 60hz. I understand how the low frequency content of the main channels will get routed to the subs. What I'm wondering is what about the .1 LFE channel? Is 100% of that signal sent to to the subs or is it split between the mains and the subs based on the crossover frequency?

[knucklehead]

DVD/BR discs have .1 LFE encoded info that goes only to the sub(s). I can't see how that would end up playing over your mains, especially if you're crossed over at 60hz, there is zero chance of hearing LFE in your mains.

[DYohn]

While I don't know how the signal routing works in the XMC-1, Dolby LFE information can go up to 120Hz, so it is possible the processor adds information from the LFE channel above the Xover to your mains. Many processors handle the main Xover and the LFE channel separately, however.

[pultzar]

Mar 10, 2018 15:17:26 GMT -5 DYohn said:

While I don't know how the signal routing works in the XMC-1, Dolby LFE information can go up to 120Hz, so it is possible the processor adds information from the LFE channel above the Xover to your mains. Many processors handle the main Xover and the LFE channel separately, however.

My subs aren't designed to play much above 80z so ideally I could have the LFE routed to the mains above the crossover frequency. I suppose one route would be to implement my own crossover, but I'd rather have the processor do it

[DYohn]

Reading the XMC -1 owner's manual from the Emotiva web site, it appears to function in a standard HT processor manner most of the time: All LFE information regardless of frequency is sent to the subs, and information below the mains Xover setting is sent to the subs. In "Enhanced Bass" mode, it seems the sub Xover is fixed at 80Hz for speakers designated as "small" and if the mains are designated as "Large," then information below 80Hz is routed to both the mains and the subs.

At least that is how I read it with a cursory look. Read it yourself here: cdn.shopify.com/s/files/1/2572/6926/files/XMC_user_v30_manual.pdf?9161570434650216536

[Gary Cook]

LFE is a track, it's encoded on the disc, everything that the movie sound mixer/engineer put in the LFE track goes to the LFE channel, if there is an LFE channel (ie; we have a sub woofer/s connected) then everything encoded in the LFE channel is sent to the sub woofer, regardless of frequency. If we don't have a subwoofer/s and tell the processor that, then it decides where to send the LFE sound to. If you set the other speakers cross over to 60 Hz in the processor then the processors "shouldn't" send any of the LFE sound below that ie; it's not sent anywhere.

Cheers
Gary

[KeithL]

The way it's all SUPPOSED to work is as follows (this is the general standard):

The LFE channel is a separate channel... and it gets sent straight to the subwoofer (or to both if there are two).

For any other speaker that is set to LARGE..
- all of the content for that channel is sent directly to that channel's speaker.
For any other speaker that is set to SMALL...
- all of the content for that channel above the crossover frequency is sent to that channel's speaker.
- all of the content for that channel below the crossover frequency is sent to the subwoofer
     (if you have stereo subs, then content below the crossover frequency is sent to the sub for the appropriate side).

There if a non-standard extra option called "enhanced bass".
Enhanced bass allows bass that is routed to the subs to ALSO be reproduced by your main speakers.
Exactly how this works is slightly different between our different models (and other folks).
Either way, enhanced bass is not the "correct" way to do things, and is generally less accurate, so it is not usually recommended.
(This option is for people who have large main speakers and a sub and are determined to "have all their woofers playing".
In general, it creates more complications that it's worth, due to all the interactions, and the differing performance of the various speakers.)

If you DO NOT HAVE A SUBWOOFER, then the LFE channel will be routed to your other speakers that are set to LARGE.

If you DO NOT HAVE A SUBWOOFER, and all your other speakers are set to SMALL, then you have created a sort of paradox (the low bass has no place to go).
This may produce unexpected results, and may work differently on different units.... so don't do it.
(You are expected to have at least a sub or one pair of speakers capable of reproducing the full frequency range.)

There is a low pass filter option for the subwoofer on some of our units.
This filter is intended as a sort of "junk catcher" for the subwoofer.
Even though the LFE channel is intended for low frequency effects, it is actually a full-range channel, so there can be high-frequency noise on it.
On some of our units, the subwoofer low pass filter can be adjusted; on others it is fixed.
On units where it is adjustable, you should NOT set it below the crossover frequencies on your other channels.
(Doing so may create a "gap" where certain frequencies have nowhere to go.... again, don't do it.)

[pultzar]

Thank you everybody!

If the subwoofer low pass filter is enabled, where do the frequencies above the cutoff get routed? Or are they dumped?