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Post by ghstudio on Aug 12, 2010 7:01:16 GMT -5
This is another question, does the sub crossover setting on the UMC-1 pass anything higher back to the mains? I think it might. I noticed reading specs from my sub the other day that it really tops out at 90Hz (I had like you set the XO to 120 for the stated reason) so I switched it to 90Hz and now the mid-bass is much smoother and explosions etc. actually seem to have more slam. So I think the sub was rolling some stuff off and now it is coming out of the mains and is smoother/better. It most likely sounds cleaner because your sub can produce higher frequency sound but it's not clean. I don't think that frequencies above the sub crossover are sent anywhere...they just are cut off. If you set the mains to 120hz and the sub to 80hz, I would expect that you would not hear anything between 80 and 120hz, subject to crossover slopes, of course.
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Post by Nemesis.ie on Aug 12, 2010 8:29:28 GMT -5
So what does the sub x-over actually do then? Are you saying it is just a limiter?
It seems a little odd if so. I was hoping the idea would be that for recordings with higher frequencies on the .1 (and there was talk that the HD standards now specify a full range .1 channel) that it would redirect to your mains which likely will handle the higher frequencies better than your sub.
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Post by ghstudio on Aug 12, 2010 8:48:21 GMT -5
I've never seen a design like that....although it's an interesting idea....
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Post by Deleted on Aug 12, 2010 9:32:07 GMT -5
Bass is crossed over to the sub based on the crossover settting for each speaker....it has nothing to do with the sub crossover setting. LFE is supposed to have an upper limit of 120hz, however there are some recordings where it exceeds that, so setting the sub crossover to 120hz is to protect my speakers, just in case.l. Thanks for correcting my misstatement in the crossover setting. I always set the speaker crossover and sub crossover to the same frequency and thus my mental mistake. The sub crossover is of course a low pass filter and the speaker crossover is a high pass filter. However, the LFE channel is in fact limited to 120Hz and practically speaking 80Hz is an acceptable sub crossover setting. Here is a quote from the Secrets of Home Theater and High Fidelity's article on The Misunderstood 0.1 LFE Channel in 5.1 Digital Surround Sound by Brian Florian: "..........Dolby Digital's LFE channel carries additional bass information from 120 Hz on down. This is not a roll-off but a digital brick wall (i.e., no 121 Hz info), so the content is usually rolled off by the sound engineer starting around 80 Hz for a smoother blend...........To quote Miller & Kreisel, bosses of bass, “never send only the LFE to your subwoofer”...........One reason not to send a subwoofer the LFE channel alone is that there may not be anything on it or there may not be an LFE track at all..........." www.hometheaterhifi.com/technical-articles/163-the-misunderstood-01-lfe-channel-in-51-digital-surround-sound.htmlAgain, I would therefore set the sub crossover at 80Hz, since any LFE signal present in the soundtrack would almost always be set to roll off at 80Hz or lower. Setting the sub to 120Hz would mean that both the speakers and the sub would be duplicating the signals from 80-120Hz, not a good idea.
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Post by jmilton on Aug 12, 2010 9:51:03 GMT -5
"Make sure you disable the internal Low Pass Filter (LPF) of each of your subwoofers or set them to the highest frequency setting to avoid deleterious interactions with the bass management of your receiver/processor."- Gene Della Salla (Audioholics) This isssue is that 80Hz xover from the processor may not be the 80Hz xover on the sub...they could vary and create a gap/overlap. I put the xover on the sub all the way up and let the processor work without impedance from the sub. Further reading... www.audioholics.com/tweaks/get-good-bass/multiple-subwoofer-setup-calibration-1SECRETS is often full of mis....Oh! Wait a minute....they are actually a cornucopia of superlative information!
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Post by ghstudio on Aug 12, 2010 9:56:22 GMT -5
There is no duplication because there is no LFE in the soundtrack. If you don't have the sub, you don't hear the LFE....if you are listening to 5:1 sound.
The 120hz limit is used in recordings that meet dolby and dts specs....however the actual spec for the LFE channel is full range.....so using a limiter at 120 is wise because there will be some disk out there where the recording engineer forgot to limit the LFE track.
The safest settings, which work in almost every case (but may not be optimal) are using 80 hz crossovers on all speakers and limiting your sub to 120hz.
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Post by Nemesis.ie on Aug 12, 2010 9:58:14 GMT -5
GH, out of curiosity (you have no sig) what sub are you running?
Thanks.
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Post by ghstudio on Aug 12, 2010 10:09:13 GMT -5
GH, out of curiosity (you have no sig) what sub are you running? Thanks. James EMB-1200
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Post by Deleted on Aug 12, 2010 11:33:21 GMT -5
There is no duplication because there is no LFE in the soundtrack. If you don't have the sub, you don't hear the LFE....if you are listening to 5:1 sound. The 120hz limit is used in recordings that meet dolby and dts specs....however the actual spec for the LFE channel is full range.....so using a limiter at 120 is wise because there will be some disk out there where the recording engineer forgot to limit the LFE track. The safest settings, which work in almost every case (but may not be optimal) are using 80 hz crossovers on all speakers and limiting your sub to 120hz. I think you are not following the flow here. The LFE is part of the soundtrack, it is the .1 of the 5.1 soundtrack. When you set the sub crossover to 120Hz you are including the low bass of the 5.0 channels from 80Hz up to 120Hz in addition to the .1 signal that is combined with it. So when I mention duplicating the signal, I'm not talking about the LFE signal but the bass from the 5 channels at 80-120Hz that is being reproduced by the 5 speakers as well as the sub. Yes the sub is reproducing the LFE signal, but there is in effect almost no LFE signal from 80-120Hz. The problem is that both the 5 speakers and the sub are doubling up by both reproducing the bass from the regular 5 channels. Hope that is more clear now. Sorry, but the LFE channel is not full range but limited to an absolute maximum of 120Hz. "..........5.1-channel audio consists of five discrete, full range main channels (Left, Center, Right, Left Surround, and Right Surround) plus an optional band-limited Low- Frequency Effects (LFE) channel. In contrast to the main channels, the LFE channel delivers bass-only information (<120 Hz) and has no direct effect on the perceived directionality of the reproduced soundtrack..........." Quote form Dolby Labs www.dolby.com/uploadedFiles/zz-_Shared_Assets/English_PDFs/Professional/38_LFE.pdf
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Post by Nemesis.ie on Aug 12, 2010 11:47:59 GMT -5
So CN, you are saying that the sub crossover is not a limiter for the LFE range, but is in fact a "summing limiter" for the other channels? That Dolby thing linked is from 2000. There was talk that with the new HD codecs, the .1 was possibly full range now? Maybe Lonnie needs to come in and explain this - of course it should be written clearly in the manual as to what the control does.
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tubby
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Post by tubby on Aug 12, 2010 11:50:58 GMT -5
I believe he is refering to the High res format spec, which allows full bandwidth on all channels.
Chuckie you are confusing the LFE low pass with the low pass on the mains. hey are 2 seperate things.
When you sent you mains to crossover at 80hz there is a high and low pass on the main channel material at 80hz. The LFE lowpass only affects the .1 lfe Material which could be full range depensing on the spec and implementation of the sound engineer. There would be no duplication of bass routed from the mains.
BTW the sub (LFE) cossover goes up to 250hz I have mine set at this setting just to see what would happen and so far I have not noticed anything different then when it was lower with my old receiver. Which tells me there is probably not much upper level bass in the LFE.
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Post by Deleted on Aug 12, 2010 12:31:14 GMT -5
So CN, you are saying that the sub crossover is not a limiter for the LFE range, but is in fact a "summing limiter" for the other channels? It is a low pass limiter for both the LFE signal and the low frequency of the other 5 channels, combined. There is a lot of confusion about the LFE channel/signal. It is not even necessary for home theater 5 channel sound but was included because it was originally designed for movie theater use to provide the loud reproduction of low bass special effects using several 18" pro subs. Many think the sound coming thru the sub is only the LFE channel. Many subs mistakenly label the sub line in RCA/LXR jack as LFE. What the sub reproduces is actually a combination of the special .1 LFE channel (remember in some cases their is actually no LFE signal at all) and the re-directed and low bass form the 5 speakers low passed below the sub crossover setting. Again, there is virtually no significant LFE signal above 80Hz and not necessary to low pass the LFE at 120Hz. Even if the LFE signal is not combined with the low bass signal to the sub it is not a worry because of its natural roll off way before 120Hz. In other words, for practical purposes, you can completely ignore the LFE channel when setting the sub crossover. Forget the LFE for a second. If I set the crossovers so that the speakers play down to 80 Hz and the sub plays from 80Hz down I have an excellent bass management system similar to the THX guidelines. I have reproduction where the sub has taken over with its dedicated amp the low bass that it can reproduce much better than the sub. That is the purpose of the sub and in my opinion playing the sub so that it reproduces up to 120Hz when the speaker reproduce down to 80Hz is doubling this frequency range. I must add here that I do not have a new pre-pro. However, my very sophisticated Sony has separate crossover controls for all 5 speakers and the sub. Therefore the sub crossover determines the low pass frequency for both the low bass from the speakers combined with the LFE signal. I have not read the UMC-1 manual so if it has separate sub crossover setting for the low bass thru the sub and LFE channel then I apologize for being out of date. All my comments above are based on the presumption that if the LFE channel is low passed at 120Hz then the 5 channels low bass also low passed at 120Hz and hence the problem. There is no reason the LFE channel would be full range. Its sole purpose is to reproduce "low frequency effects" at 10dB's above the other channels, thus the "LFE."
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Post by Deleted on Aug 12, 2010 12:40:07 GMT -5
BTW the sub (LFE) crossover goes up to 250Hz I have mine set at this setting just to see what would happen and so far I have not noticed anything different then when it was lower with my old receiver. Which tells me there is probably not much upper level bass in the LFE. What you see on the back of your sub is not a LFE crossover but the sub crossover which includes the sub signal derived form the 5 main channels and combined with the LFE signal. The LFE signal is zero at 121Hz and above. You could bring bass at up to 250Hz to your sub but that would be silly. Most subs have a max setting of about 150Hz on that dial. You should never use the crossover in on the back of the sub in modern setups (it is for a different purpose, when you don't have the bass management controls on your processor). You bypass it if there is a bypass switch on your sub (otherwise leave it to the max setting) and use only the sub crossover controls on your pre-pro or receiver.
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Post by tubby on Aug 12, 2010 13:04:19 GMT -5
BTW the sub (LFE) crossover goes up to 250Hz I have mine set at this setting just to see what would happen and so far I have not noticed anything different then when it was lower with my old receiver. Which tells me there is probably not much upper level bass in the LFE. What you see on the back of your sub is not a LFE crossover but the sub crossover which includes the sub signal derived form the 5 main channels and combined with the LFE signal. The LFE signal is zero at 121Hz and above. You could bring bass at up to 250Hz to your sub but that would be silly. Most subs have a max setting of about 150Hz on that dial. You should never use the crossover in on the back of the sub in modern setups (it is for a different purpose, when you don't have the bass management controls on your processor). You bypass it if there is a bypass switch on your sub (otherwise leave it to the max setting) and use only the sub crossover controls on your pre-pro or receiver. I am not talking about the dial on the sub. I am talking about the setting of the sub cossover in the UMC-1. The UMC has 5 lowpasses. One for L&R, one for Centre, one for surround, one for back and one for LFE. It is misslabled as subwoofer and should be called LFE. Setting a crossover to you mains at 80 will lowpass the L&R and sent below 80 to the sub. Setting a subwoofer (LFE) crossover at 80 will lowpass the LFE channel only and send that to your sub. Setting this at 120 or 250 or whatever will not take any additional information from the L&R signal. Conversly setting it below 80 will not affect the lowpassed info from your mains. It affects the LFE signal only.
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Post by Deleted on Aug 12, 2010 13:22:13 GMT -5
Sorry Tubby for my misunderstanding.
I guess I need to read the UMC-1 manual. So it appears there are separate filters for the LFE channel and for the low bass that is re-directed from the other channels. Apparently this is to keep out any LFE high frequency signals to the sub in the case the soundtrack included some full range LFE signals (which it is not supposed to). Thanks for the info and setting me straight on the UMC-1.
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Post by Topend on Aug 12, 2010 14:20:27 GMT -5
With all this talk on crossovers I thought I would clear the air on some terminology.
The crossover for the mains, center and surround speakers is a high pass filter (HPF).
The crossover for the sub as it is in the UMC is a low pass filter (LPF).
The HPF allows highs to get through and the LPF allows lows to get through.
If the mains are set to 80hz, then the HPF will filter any sound below this freq and redirect it to the sub.
If the sub is set to 120hz, then the LPF will filter any sound above this freq. I don't know if this sound (if there is any) gets redirected or discarded.
Dave.
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Post by topcat on Aug 12, 2010 14:33:24 GMT -5
I simply don't like what I'm reading lately on this thread with regards to the base management for the XMC-1. I'm not a tecchie. I'm not even a diehard audiophile (based on the original meaning of being a subjectivist). I'm a guy who loves music and can greatly appreciate music played from a well tuned system. I don't have unlimited space in my theater rack either to accommodate the many bass paraphernalia that would be needed in order to guarantee good, accurate bass! I was sincerely hoping that the XMC-1, would be a one box solution that would have base management and auto room correction a la audyssey, only done Emo style, and with most of the other features listed in this thread that would make it usable/current for at least the next 3 years. My one hope now is this: Some one had earlier mentioned that the XMC-1 was going to be THX certified, and that would make the base management issue moot. Is that true? If the XMC-1 does not have effective room correction & base management, HD Radio tuner & active HDMI, then I will just have to live with the UMC-1 until another pre/pro turns me on! jamrock jamrock, this response is to you and others that are assuming that the XMC-1 will have THX certification. A search of the Emotiva forum has shown me this: 1. Under the heading of "Processors" go to "XMC-1 Redux" on page 19 started by Lonnie.Enter XMC-1 Redux. Once there go to page 4, reply #68 dated 14 Nov 2009. Big Dan asked out opinion on including THX for the XMC-1. Following this there is quite some discussion on the subject. Then finally on page #18 reply #351 on 19 Nov 2009 Lonnie indicated the majority opinion as stated below> Re: XMC-1 Redux! « Reply #351 on Nov 19, 2009, 7:47pm »
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Post by moodyman on Aug 12, 2010 15:27:52 GMT -5
With all this talk on crossovers I thought I would clear the air on some terminology. The crossover for the mains, center and surround speakers is a high pass filter (HPF). The crossover for the sub as it is in the UMC is a low pass filter (LPF). The HPF allows highs to get through and the LPF allows lows to get through. If the mains are set to 80hz, then the HPF will filter any sound below this freq and redirect it to the sub. If the sub is set to 120hz, then the LPF will filter any sound above this freq. I don't know if this sound (if there is any) gets redirected or discarded. Dave. The LPF in the UMC is stricltly for the LFE channel...
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Post by Topend on Aug 12, 2010 15:45:16 GMT -5
With all this talk on crossovers I thought I would clear the air on some terminology. The crossover for the mains, center and surround speakers is a high pass filter (HPF). The crossover for the sub as it is in the UMC is a low pass filter (LPF). The HPF allows highs to get through and the LPF allows lows to get through. If the mains are set to 80hz, then the HPF will filter any sound below this freq and redirect it to the sub. If the sub is set to 120hz, then the LPF will filter any sound above this freq. I don't know if this sound (if there is any) gets redirected or discarded. Dave. The LPF in the UMC is stricltly for the LFE channel... Yes it is.
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Post by Erwin.BE on Aug 12, 2010 16:53:50 GMT -5
"In contrast to the main channels, the LFE channel delivers bass-only information (<120 Hz) and has no direct effect on the perceived directionality of the reproduced soundtrack..........."
Guys, unless you have a SW for every main speaker plus each SW placed in the same respective position as their speaker or have miniature speakers, use the darn 80 Hz setting on the processor or AVR and select the "small" setting. From 80 Hz and above, the content becomes directional sensitive. I am sure in this case it does not matter if the SW is set to 120 Hz or not because he ain't getting anything above 80 Hz from the AVR...
No?
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