# LFE filtered by Xover Setting?



## bgarcia17 (Jan 8, 2007)

So I learned recently that Pioneer receivers actually filter the LFE channel based on Xover settings. I tested my receiver and confirmed, after which I posted this...

"Well,, this is disappointing. Now I gotta go back and rewatch all of my movies. I did confirm what was stated here recently by a few fellers, not that I questioned their knowledge. Just wanted to see with my own eyes. The LFE signal is indeed filtered by the xover setting. I had mine set to 100Hz (and earlier at 80Hz). I could see that the 150Hz-20Hz sweep was coming in differently based on xover setting. Only the 150Hz and 200Hz setting showed the topend of the sweep. The 50Hz setting had the worst effect as expected. I cannot believe Pioneer does such a thing! FWIW, I also set the fronts to large to see if the topend was routed to them, and it did not. Did not check to see if a large center got the missing freqeuncies, cuz that's not a setup I would ever have anyway. All these years I thought the LFE was untouched and send straight to the sub output (or large fronts if there was no sub). And that the xover setting was simply for small speakers/sub bass management.

My test setup for those interested...Pioneer Elite VSX-03tx, laptop running REW (RTA), PS3 playing Ultimate DVD, discrete LFE rattle track repeatedly (DD bitstream).

Guess I have another reason to try a new receiver brand."

Is this normal, and have I had it wrong all this time? Or is this something unique to Pioneer? Unfortunately, I don't have another receiver brand in-house that I can test quickly. And I have my eye on a deal for a Yamaha RX-A820 that expires today. So any feedback real quick would be greatly appreciated.


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## fitzwaddle (Aug 25, 2010)

Maybe I'm misunderstanding, but as written, that's what I expect a crossover network to do - to implement a low pass filter with a given rolloff to the sub, and a high pass filter with a given rolloff to the mains, both centered around the same crossover frequency, so that when summed, you end up with a flat(tish) frequency response. What am I missing?


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## bgarcia17 (Jan 8, 2007)

The distinction here is for the dedicated LFE channel. Why would the LFE need to be split? I understand having to send bass frequencies to the sub when one has smaller speakers in their setup, from their respective channels. But the LFE content is intended to go to a sub, so if you have one in your system, shouldn't it receive the whole signal?

I just setup a Denon, and it at least offers a user-selectable xover for the LFE content. I guess in case someone doesn't like the idea of sending the higher, potentially localizable frequencies to their sub. I haven't tested to see if the frequencies above this xover point are redirected.

Pioneers however don't offer this LFE xover. Thier xover setting appears to be universal. No big deal, except that it appears to discard any LFE content above the xover setting.


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## bgarcia17 (Jan 8, 2007)

Just as a follow-up: It has been confirmed that Pioneer simply filters out any LFE content, if your bass management xover is set lower than 120Hz. Content between your xover point and the top end of the LFE is NOT rerouted to other channels. Remember, LFE content is filtered above 120Hz per spec, although some folks claim that there is not much LFE content above 80Hz (no idea the basis for their claim). Funny thing, Pioneer's xover settings go from 100Hz to 150Hz, so if you're like me, you are stuck with a pretty high xover point if you want to make sure you get all LFE content. 

Denon appears to provide a seperate LFE xover point, apart from the normal bass management xover. Have not tested to see if content is split to other channels, or simply filtered away. My hunch is that it's not rerouted, just filtered away.

Yamaha tech support claims that their LFE is unfiltered, simply sent to sub preout or to large speakers if no sub is present. Xover setting affects only bass management, small speakers/sub and such. So they appear to be the only manufacturer that employs the whole sub signal management system as I thought all were doing.

For whatever it's worth to those who care.


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## primetimeguy (Jun 3, 2006)

Onkyo receivers have an LFE low pass filter that is separate from the speaker crossovers.


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## bgarcia17 (Jan 8, 2007)

Thanks for providing this info. Been years since I've owned an Onkyo, and I wondered about them.


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## mlundy57 (May 21, 2013)

Neither my Matantz SR5007 nor my NAD T748 AVRs have a separate selectable crossover setting for the LFE channel. Both of these AVR's send the full signal recorded on the LFE track to the sub plus any signals below the crossover point you select for the seven amplified channels. It is then up to the sub's inputs and setup which frequencies will actually be played.


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## bgarcia17 (Jan 8, 2007)

Good info, thanks. Another pair of manufacturers that setup up bass management and LFE the way I always assumed it to be. Did you verify this in any way, or are you going by their documentation?


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## mlundy57 (May 21, 2013)

A combination actually. Documentation for the Marantz is more extensive than for the NAD and inquiries to NAD's tech support. 

I can also tell you for the NAD the crossover filters (for the seven amplified channels) use a first order (6dB/octave) slope. Don't know about the Marantz, I didn't ask them. Don't assume it's the same though different manufacturers use different slopes. As an example, the Outlaw 975 uses filters with different slopes on different channels.


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## andy_c (Aug 8, 2006)

The Marantz SR5007 has selectable "LPF for LFE" (page 122 of manual, bottom left). It can be set to 80, 90, 100, 110, 120, 150, 200 and 250 Hz independent of the LPF of the conventional crossover.


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## mlundy57 (May 21, 2013)

Don't know how I missed that but I did, thanks. I wonder what the slope of that filter is? 

Now I have to find out how to set this for my sub. I have a Rythmik F12 which, as I understand it, is not designed for a crossover setting above 90 Hz. The downside here will be losing the LFE content above 90 Hz.


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## bgarcia17 (Jan 8, 2007)

I don't know how they align with Denon models, but I'd imagine they would share some hardware/features to be cost-effective. And I don't know either line too well at all. I'm glad users are reporting what they know, so those who care about such details may find answers here or elsewhere.


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## mlundy57 (May 21, 2013)

I have a Marantz (SR5007)and two Denon's (AVR 391 & 1912). The 391 now sits in a closet. It was replaced by a NAD T748. The Marantz replaced the 1912 which has been relegated to the guest room. I prefer the Marantz to the Denon. Granted, the 5007 cost about 30% more than the 1912 but even at equal price points (or a slightly more expensive Denon) I prefer the Marantz.


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## bgarcia17 (Jan 8, 2007)

Just curious, but is this seperate LFE crossover setting available in even your lower Denon (391)?

And fwiw, I have set my Pioneer's bass management xover to 150Hz, just for evaluation. And I have to admit that I think my system actually sounds better. Not that I was losing LFE, but that my center channel (Klipsch with two 5.25" woofers) didn't have the ability to render the full range of dialogue. Voices (and overall audio) now sounds much fuller, and it isn't distracting as some might fear due to 'directional bass'. Non-Directional sounds are all still firmly centered on the screen as they should be. May be due to me having my speakers in my wall unit, but for whatever reason, my system sounds better with the higher xover setting. So I'm happy again.


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## mlundy57 (May 21, 2013)

Yes, the crossover frequency can be set for the LFE channel as well as the amplified channels on the Denon 391.


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## primetimeguy (Jun 3, 2006)

Technically it is a LPF (low pass filter) rather than a crossover for LFE.


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