subwoofer crossover hz / L.F.E. signals

[cornfedksboy]

wow, this is why i hate forums. Nothing but wrong information gets passed around. Set your sub crossover to 80Hz , frequencies roll off, so even though your set at 80hz the frequency band will roll off each side, so you will still produce 90 hz and above but it won't be as predominant as if you actually had the knob set at a 100 hz or a 110hz. Setting it at 80 ensures your subwoofer will reproduce the frequency below 80 hz and some of the mid range above80hz. If you set your sub at 120hz then your going to reproduce way to much mid range and its going to sound terrible. Stop thinking your going to miss something by not getting this setting right. Set your speakers to large and call it good, let them produce what they can produce. If you want to set your receiver crossover to anything then set it to 80hz and call it good. question 2) thats corect question 3) don't increase levels at all, set to it to zero question 4) thats because these yo yo's told you to set it at 120hz, set it at 80hz like i told you and tell me how much better it is for movies. question 5 ) if you set those rf 52s to small then your going to short yourself on the low range frequency, that speaker can reach as low as 36Hz, if you decide to set it to small then your telling that speaker "hey i want you to produce 60hz and above (not sure where small actually sets the crossover for that speaker but im sure its 60hz or above). so set it to large and call it good question 6) never heard of bass out, skip that until you know exactly what it does. Never hurts to call Yamaha directly and ask them. So in short , like this thread should have been. Set the sub to 80hz, set your crossover to 80hz or less (lowest i would set it would be 60hz), sit back, relax and enjoy the show

I was just reading through this thread. I kind of knew some of these things before, but think I understand them with more clarity after reading through this. Thanks for the discussion. A few things I'm wondering if I've got right...

1. Sounds like you always want to set the knob of your sub at 120hz or above, just so it can receive signals that high if they're coming from your LFE channel (or if you've set your crossover on your receiver higher). For example: if I have my crossover on my receiver set to 120hz, and my sub's knob set to 80hz... I'm effectively loosing everything in the 80hz - 120hz range? (Not that I would do that.)
2. I'm assuming that when I set my crossover on my receiver, that is ONLY effecting the frequencies going to my L/R/C/SL/SR that get sent to the sub and NOT capping the LFE frequency? So if my crossover on my receiver is at 80hz, my sub could still receiver 120hz signals from LFE during a movie?
3. My Yamaha receiver has a "level" for each channel, including the sub. Basically like a volume or output or gain or something. I'm assuming that effects ALL bass output to my sub, whether it's from LFE or taken from the other channels?
4. When I listen to movies it sounds like there's a lot more bass than when I listen to music. I'm constantly having to push up the aforementioned "level" of the sub around 5-10dB more when listening to music. I'm assuming that's because I get both low frequencies from L/R/C/SL/SR AND LFE in movies, and only low frequencies from L/R when listening to music? (Kind of annoying constantly having to adjust the bass.)
5. I have RF-52 IIs for my L/R (36Hz-24KHz), RC-52 II for my center (67Hz-24KHz), and RS-42 IIs for my SL/SR (62Hz-24KHz). Due to the range of all these, I'm assuming I need to set my receiver crossover at around 80hz. However, I'm wondering if I should set just my RF-52 IIs on "large" rather than "small" so they aren't effected by the crossover? Or is that not a good idea? In my head, even though they go a lot lower, seems like perhaps there's bass going to L/R channels that would probably be handled by my SUB-12 better, but wasn't sure.
6. My Yamaha receiver has a "BASS OUT" with options of Front, Sub, and Both. Anyone know what that's about? Does it effect only LFE, only channel crossover, or all bass output?

Any expert opinion on the above would be appreciated

Well, I can't say I totally appreciate the tone of the above post, but I will say this. The response to question #3 is absolutely wrong. Don't just "set it to zero." Zero might be the appropriate setting, but placement, room, speaker type/brand, frequency, etc, all play into how much power you want a paticular speaker to gain. A simple way of proving this is by running any number of calibration software. They will auto set the volume to each speaker so that the perceived volume at the MLP will be the same. If I were to run my subs at zero I would either have to turn the system volume all the way down such that the other speakers would be nearly inaudible, or I would knock all of the pictures off the wall just before my sub explodes.

[nightcabbage]

Rusty, please understand the setting I was talking about on point 1 was the physical knob on the back of my sub-12. I've heard many people all over different forums say to leave that physical sub knob on a higher setting and then let your receiver do the actual crossover. In other words: it doesn't matter that my sub knob's crossover would be set to 120hz or 150hz or 100hz if my receiver was set at 80hz. Basically the setting that mattered was the receiver, and I was told to just make sure my sub's knob didn't dip below the receiver's crossover setting otherwise there would be a small loss of range. That's how I've always understood it.

The thing that got me thinking after reading this particular thread was all that isn't exactly true... I started to surmise (still not sure rightly so?) that my receiver's crossover setting only effected ranges for my L/R/C/SL/SR channels and NOT the LFE channel, hence the sub actually COULD be receiving some higher frequencies if the sound engineers put them into the LFE channel. So in other words, if I did set my knob on my sub down lower to 80hz or 60hz or whatever, that's not necessarily taking full advantage of LFE channel signals. My concern was LFE since obviously I already handle my other bass crossover with my receiver setting

I get rolloff too but... sometimes when you're talking range settings it's just easier to forget about that Besides, speaking to the possible loss of range above: since both settings have rolloffs, you'd still have loss of range.

Also in regards to number 5: if I set those RF-52 IIs to "large" on my receiver then I would surmise I don't have ANY of the L/R channel bass put into the sub. I know those speakers can go down pretty low and have a better range, but they certainly don't produce bass as good as my sub-12. So while I may be slightly "cutting the speakers short" of what they can handle, aren't I certainly cutting myself short if I'm not using my sub for any of the range sent to my L/R channels? I suppose in a perfect world I would just set a lower crossover for those RF-52 II L/R speakers, but my receiver only has one crossover setting that seems to apply to all speakers set to "small". The way I understand it is I get one crossover setting, and then I choose to set my speakers to use it, or use no crossover at all. In this case, no crossover at all seems stupid. They aren't THAT good at handling bass.

[cornfedksboy]

Here's a great article that addresses all of the questions about LFE and Bass Management. It's 9 years old, but I think it still holds true. For anyone that thinks this article will tell you how to set-up your system, it won't, but it does tell you what compromises you make to your system by selecting different cross-overs, speaker size, etc.

http://www.hometheaterhifi.com/technical-articles/156--miscellaneous-ramblings-on-subwoofer-crossover-frequencies.html

[nightcabbage]

Here's a great article that addresses all of the questions about LFE and Bass Management. It's 9 years old, but I think it still holds true. For anyone that thinks this article will tell you how to set-up your system, it won't, but it does tell you what compromises you make to your system by selecting different cross-overs, speaker size, etc.

http://www.hometheaterhifi.com/technical-articles/156--miscellaneous-ramblings-on-subwoofer-crossover-frequencies.html

Reading now. Though some of it is a bit beyond my comprehension now, overall it's very helpful. THIS caught my attention:

"In the majority of surround sound processors and receivers, FULL RANGE copies of all channels set to "Small" are combined together with the LFE channel, and the sum is low-passed. Think about that. Strictly speaking, any* such processor with a sub/sat crossover frequency set lower than 120 Hz is "discarding" the upper end of the LFE channel. THX units are NOT exempt from this. With the standard THX 80 Hz 4th order crossover, the top of the LFE channel gets chucked.

Don't panic. This has been going on since day one, and virtually nobody has noticed . . . with good reason. I've said many times before, and I will say it again: THX did not pull their crossover out of thin air. It is the product of much development, and, when used in concert with THX speakers (or others which exhibit the correct roll-off), represents the best overall compromise of minimizing localization, extending dynamic range, and as it turns out, minimizing LFE truncation. When Dolby Digital was coming to the consumer marketplace, THX looked at an inordinate number of modern 5.1 soundtracks and guess what they found in the LFE channel: not much at all in the region of 80 Hz - 120 Hz, making their original choice of 80Hz rather fortuitous. Dolby Digital's LFE channel has a digital brick wall at 120 Hz, not a roll-off, so content creators almost always roll-off their stuff, usually somewhere around 80 Hz. Therefore, chucking the top band of the LFE is no big deal but the argument here is that a standard SSP crossover set much lower than 80Hz or so may actually be costing you bass content."

That's probably the most insightful look I've had into this entire topic yet! Makes perfect sense.

[cornfedksboy]

I was actually going to quote that, but I decided that there was too much good info in the article and just decided to paste the whole link. Also of note, Dolby's white paper on how to properly mix soundtracks states that a brick wall is to be placed on the low frequency channel at 120 Hz, but that it is recommended not to add much to the 80-120 Hz frequency as THX recommends a max of 80 Hz. It then states that; "The summation of the LFE and any other channels is low-pass filtered at the same frequency. If the crossover frequency is fixed at 80 Hz, as is standard in lower priced decoders, information in the LFE channel between 80 Hz and 120 Hz will be reproduced at a lower level than it is recorded at. To replicate what the consumer will hear, a third order 80 Hz filter in the LFE audio signal path to the recorder is recommended."

[nightcabbage]

Great stuff. I'm also going to quote the summary paragraph at the end here for all to read because I think it's extremely helpful in wrapping up why we do what we do with our crossover settings, because most people toss around the advice and don't really know why it's there in the first place.

"If you want consistent bass response from each channel of your 5.1 system, in our opinion, you're best to set all speakers to "Small", set them all to the same crossover point, and set that point no lower than what you are comfortable throwing away from the LFE channel. If your main left and right speakers are genuinely full range (be honest now!), then you are better off running them full range as opposed to high-passing them at a ridiculously low frequency. Short of that, high passing floor-standing speakers at 70 Hz is not "wasting" them in any way shape or form and in fact will more than likely extend their dynamic range thanks to the relief they'll be getting from the high-pass. Alternatively, setting center and surrounds as "Small", the mains as "Large", subwoofer as "None", and implementing an external two channel crossover to the subwoofer is a valid, and in some situations an advantageous way to go."

I don't know what "full range" is, but I don't think it's quite my RF-52IIs. This also makes ryanrusty's advice seem rather short sighted, and I understand why now. (Not that I'm knocking you for giving advice rusty, but I think you should read the article too).

[Heritage_Head]

There just isn’t a lot low content in most of the 5 channels other than the fronts when watching movies. Bass management has more advantage for 5 channel stereo music than 5.1 movies. The idea that we don’t over work the smaller speakers by sending the low content to subs is a popular argument made by many articles. It’s just not as relevant as it may seem. If there’s no low content going to most of the speakers anyways what are we really crossing over to the subs (other than the front channels)? And if there isn’t much information from 80-120 Hz in the lfe channel. Why would it matter if we set the subs to 120? I swear there are a thousand different opinions on this topic by audio gurus and they all make sense. It’s so far apart that audioholics has one article that says 120 Hz isn’t directional and another article written by gene who says based on a blind test they did anything over 60 Hz is. Lol and they are connected but written by two different people.

[cornfedksboy]

Other things that shouldn't be ignored are the power of your amp and efficiency of your speakers. The more gain you have there, the lower you can go without putting the "undue stress" on your speakers.

[Brunt]

There just isn’t a lot low content in most of the 5 channels other than the fronts when watching movies. Bass management has more advantage for 5 channel stereo music than 5.1 movies. The idea that we don’t over work the smaller speakers by sending the low content to subs is a popular argument made by many articles. It’s just not as relevant as it may seem. If there’s no low content going to most of the speakers anyways what are we really crossing over to the subs (other than the front channels)? And if there isn’t much information from 80-120 Hz in the lfe channel. Why would it matter if we set the subs to 120? I swear there are a thousand different opinions on this topic by audio gurus and they all make sense. It’s so far apart that audioholics has one article that says 120 Hz isn’t directional and another article written by gene who says based on a blind test they did anything over 60 Hz is. Lol and they are connected but written by two different people.

This is what I thought...when using LFE output/input I thought you would bypass the subs crossover anyway?! The reason for turning subs crossover to 120hz or higher was if it didn't have an LFE input, it would be open to accepting all signals (thus cranking subs crossover all the way up) that were sent to it from the AVR's crossover. Elemental Designs recommends doing just this, cranking crossover all the way up because they lack a dedicated LFE input. That way (as explained to me by an employee there) the sub will play everything the AVR's LFE output is giving it.

[Heritage_Head]

There just isn’t a lot low content in most of the 5 channels other than the fronts when watching movies. Bass management has more advantage for 5 channel stereo music than 5.1 movies. The idea that we don’t over work the smaller speakers by sending the low content to subs is a popular argument made by many articles. It’s just not as relevant as it may seem. If there’s no low content going to most of the speakers anyways what are we really crossing over to the subs (other than the front channels)? And if there isn’t much information from 80-120 Hz in the lfe channel. Why would it matter if we set the subs to 120? I swear there are a thousand different opinions on this topic by audio gurus and they all make sense. It’s so far apart that audioholics has one article that says 120 Hz isn’t directional and another article written by gene who says based on a blind test they did anything over 60 Hz is. Lol and they are connected but written by two different people.

This is what I thought...when using LFE output/input I thought you would bypass the subs crossover anyway?! The reason for turning subs crossover to 120hz or higher was if it didn't have an LFE input, it would be open to accepting all signals (thus cranking subs crossover all the way up) that were sent to it from the AVR's crossover. Elemental Designs recommends doing just this, cranking crossover all the way up because they lack a dedicated LFE input. That way (as explained to me by an employee there) the sub will play everything the AVR's LFE output is giving it.

Yes Svs and Epik both recommend running the subs full range (120). (def tec does to but I haven’t talked to them on the phone like I have with svs and epic). Svs told me that movie content for the most part is already crossed over to the sub. Even though the fronts have bass content the other speakers just don’t have much information below 80 Hz anyways so crossing them over in svs words is almost pointless. But bass management is needed with all channel music or really small speakers like bose cubes or something. But any full range speaker that can handle bass below 50 Hz with ease is perfectly safe handling full range movie content as surrounds or even the center speaker. The most common thing I read is set everything to 80 Hz and be done but. Per svs and epik yes that works but it’s not always optimal by any means.

[Heritage_Head]

Keep in mind these are suggested setting for ht listing not necessarily other sources. []

[nightcabbage]

More good points in these followup posts. Thanks guys.

[A1UC]

I have my fronts a t 60hz center and surrounds at 80hz

used a spl and set all speakers at 80db and its sounds great

used audyssey setup and did not like what it did