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Post by solidstate on Jul 17, 2014 0:55:28 GMT -5
Since we can't discern directionality in frequencies below ~80hz, the need for stereo bass is pretty much an academic (not real world) discussion. Cheers Gary If we're talking bass sounds that are from a single source (drums, organs, bass-guitars) then I agree with you. I do, however, have some electronic music that deliberately plays bass in one channel, then the other. It is perfectly clear on headphones. Since the bass sounds are not simultaneous, then there is, in fact, both right and left bass. With full-range speakers, the bass (below 80 Hz) is audibly directional - or not... Perhaps only the above-80 Hz. components with bass sounds make the source seem directional? Actually it's higher than 80Hz but generally that's the THX suggested xover point to use when your mains can't go low enough and you set your processor to "LFE+main" and set speaker to "small". |
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Post by Gary Cook on Jul 17, 2014 0:55:55 GMT -5
Sorry if this isn't making sense. I don't really understand how stereo subs work, and am very interested in getting a grasp on this. OK Pop, let me have one more go. I think we have covered the stereo subs for movies, if the track is 7.1, 5.1 or 9.1 that means mono LFE. Hence 1 mono sub covers it (or 2 subs mono, or 3 subs mono or 4 subs mono). Moving onto music, let's say I'm listening to a piano playing in stereo with the right hand playing the piano coming out of the right speaker and the left hand playing the piano coming out of the left speaker. High notes (high frequencies) right and low notes (low frequencies) left. As the music moves along the keyboard the sound moves from left to right or vice versa across the sound stage. Say I have a mono sub, crossed over at ~80 hz (forgetting about slope). Once the left hand plays notes below 80 hz the sound will stop coming from the left speaker and come from the sub. We know it doesn't matter where the sub is located as we can't tell directionality below 80 hz. But what we can tell, due to harmonics, is that it stopped coming from the left speaker. This is particularly noticeable to me if the sub is located off to one side. If I have stereo subs, located with their respective L&R speakers, then the transition (from left speaker to sub) isn't as noticeable. Personally I have always preferred a single sub, with a big driver, located between the L&R speakers, which eliminates (to my ears) the transition harmonics. Does that make sense? Cheers Gary |
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Post by solidstate on Jul 17, 2014 0:58:03 GMT -5
Sorry if this isn't making sense. I don't really understand how stereo subs work, and am very interested in getting a grasp on this. OK Pop, let me have one more go. I think we have covered the stereo subs for movies, if the track is 7.1, 5.1 or 9.1 that means mono LFE. Hence 1 mono sub covers it (or 2 subs mono, or 3 subs mono or 4 subs mono). Moving onto music, let's say I'm listening to a piano playing in stereo with the right hand playing the piano coming out of the right speaker and the left hand playing the piano coming out of the left speaker. High notes (high frequencies) right and low notes (low frequencies) left. As the music moves along the keyboard the sound moves from left to right or vice versa across the sound stage. Say I have a mono sub, crossed over at ~80 hz (forgetting about slope). Once the left hand plays notes below 80 hz the sound will stop coming from the left speaker and come from the sub. We know it doesn't matter where the sub is located as we can't tell directionality below 80 hz. But what we can tell, due to harmonics, is that it stopped coming from the left speaker. This is particularly noticeable to me if the sub is located off to one side. If I have stereo subs, located with their respective L&R speakers, then the transition (from left speaker to sub) isn't as noticeable. Personally I have always preferred a single sub, with a big driver, located between the L&R speakers, which eliminates (to my ears) the transition harmonics. Does that make sense? Cheers Gary "OK Pop, let me have one more go. I think we have covered the stereo subs for movies, if the track is 7.1, 5.1 or 9.1 that means mono LFE. Hence 1 mono sub covers it (or 2 subs mono, or 3 subs mono or 4 subs mono)." This isn't exactly true because in most instances signals originating from the LR has a low pass filter applied and that STEREO signal is then routed to the .1 LFE output. It would be interesting to understand how DIRAC handles this with the .2 output on the XMC-1 when you sub count is set to two in the UI. It might just very well take the two low pass signals from the mains LR and feed them discretely to each sub output IF you have a sub count of two and it's set as such in the UI. OR The second sub output could just be a clone from the converter of the first LFE signal. I have a feeling though the LR low pass signal is actually treated and processed in stereo if your sub count is two and it's set as such in the UI and your source is a stereo signal with the mains low pass filter applied. |
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Post by garbulky on Jul 17, 2014 1:03:42 GMT -5
Well I don't have stereo subs. But I do have the m80's which in my room are able to go deep and full range - in stereo. I would always want it to be stereo subwoofers. As for movies, I wouldn't know. There is a .1 channel in 5.1 and that is for the monosubwoofer Low frequency effects. But having said that all 5 channels can carry full range signals. But in reality most movies are center channel centric with the others used for panning effects etc. I think the emphasis becomes more important with music than with movies though. For instance, there's plenty of recordings where the singers voice comes through one speaker. The bass is thus reproduced in that channel only. Now one may think oh well we don't have to worry about bass as it's instruments that aren't reaching that low - but you would be surprised. There's all kinds of information that low. What about some beatles songs when drums richochet from left to right or simply play in one channel only. A piano will absolutely go very low and the recording is done in stereo. The pianist hits that low bass note it will be reproduced more on one side than the other. Same goes for other classical instruments in an orchestra. As for the mind filling in the blanks, below 80 hz being omnidirectional, I think your own experimentation with mono subs shows you how far that can take you. Which is to say pretty darn far!  I thought your sub gelled very well with the speaker and it wasn't easy to localize the subwoofer. Having said that I did wonder - is 80 hz really omnidirectional? Well I decided to test it. I played back this: This is an 80 hz test tone. I simply unplugged one speaker and played it full range so only one speaker was playing - no subwoofer. The answer surprised me mainly because is it was VERY obviously coming from one side. 80 hz is absolutely localizable. And I honestly don't know where people came up with that figure. You can try this too. (just make sure the subwoofer is turned off). Or simply turn off the amps and see whether you can tell which side the bass is coming from. www.audiocheck.net/audiotests_basslocalization.phpThis website goes one step further and does a left right split of bass notes and announces the frequency. This will also allows you to tell when the bass becomes omnidirectional. I tried a test this time with a little cheating. I used my HD600's to test the bass. And I simply took one earpad off. I used this: www.audiocheck.net/audiotests_frequencychecklow.php The answer was the bass was hilariously localizable all the way down to the point I started hearing the bass clearly which was around 20 hz - 25 hzish. And the brain wasn't fooled. It didn't make it come from all sides. It came from a single side which was the ear that was hearing it. So then I thought, okay, now how localizable is it if it is in room. Well I did just that. I found this bass sweep test that went from 10 to 200 hz and just used one speaker. www.audiocheck.net/audiotests_frequencychecklow.phpAnd here the result surprised me. I expected to hear the sound being omnidirectional at around 50 - 60 hz. But It wasn't. It was localizeable from the MOMENT I FIRST HEARD THE BASS which was around slightly below 40 hz, I would estimate about 35 hz. So make of that what you will. In real life music and movies we may not be able to localize the sound - as easily - but your ears and brain CAN hear the difference in an actual test tone. |
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Post by garbulky on Jul 17, 2014 1:06:21 GMT -5
I beg to differ with you. A recent airing of the movie Gravity distinctly proves that it IS recorded for stereo subs, myself and company have witnessed this event. I do think you have it backwards. I state this with all due respect. Nick Hi Nick, my Gravity blu ray (Zone B) is 5.1 not 5.2, hence mono LFE. So I'm with Chucky on this one; The harmonics above the 80Hz range are what allow you to locate the origin of the sound and those come thru the main speakers, unless you have the sub filter set too high (above 80Hz). Cheers Gary The .1 channel is indeed mono. But the other 5 or 7 channels are full range. So if the sound had low bass , and was played in any of the 5 channels you would get the bass in that way. For instance my blu ray player constantly refuses to downmix the 0.1 channel into the stereo downmix for my DAC. I know because when I run the test tones everything plays but the subwoofer channel. Having said that, there is no shortage of bass in movies which has to be coming from the 5 or 7 full range channels. |
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Post by Gary Cook on Jul 17, 2014 1:09:12 GMT -5
Hi Nick, my Gravity blu ray (Zone B) is 5.1 not 5.2, hence mono LFE. So I'm with Chucky on this one; You don't understand. No AV mux from any current transport supports two discrete LFE channels IE .2 The .2 means the unit has two sets of sub outputs that can be EQ'd via DSP engine separately but they are both producing the same .1 channel source/signal. Do you understand what I mean garycook? When Emo/Jade say the XMC-1 is 7.2 they are not saying the .2 is addressable via AV mux discretely. They are saying their room correction/DSP engine supports discretely EQ'ing and room correcting on those two outputs. Do you get it now bro? Perhaps DIRAC can process a 2 channel source and mix discretely the LFE info from the low pass on a discrete LR level and send it stereo down the two sub outputs but it's honestly pointless as these sound are mono in nature in your room anyway. I understand and I always had it bro, I just reused Gravity as being 5.1 for a singular example. It wasn't a general comment about all 5.1 movie tracks. I was also having a sly dig at the misnomer of 5.2, 7.2 or 9.2.  Cheers Gary |
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Post by solidstate on Jul 17, 2014 1:15:43 GMT -5
Hi Nick, my Gravity blu ray (Zone B) is 5.1 not 5.2, hence mono LFE. So I'm with Chucky on this one; Cheers Gary The .1 channel is indeed mono. But the other 5 or 7 channels are full range. So if the sound had low bass , and was played in any of the 5 channels you would get the bass in that way. For instance my blu ray player constantly refuses to downmix the 0.1 channel into the stereo downmix for my DAC. I know because when I run the test tones everything plays but the subwoofer channel. Having said that, there is no shortage of bass in movies which has to be coming from the 5 or 7 full range channels. "The .1 channel is indeed mono. But the other 5 or 7 channels are full range. So if the sound had low bass , and was played in any of the 5 channels you would get the bass in that way." Not if you have your AVR/Proc speakers set to "small" and you have LFE+main function turned on. This is how the majority of users should have their gear configured actually and you clearly don't with your DAC tests providing no signal to your LFE .1 output. Are you mains full range? If your player has any type of audio processing it should be TURNED OFF. Perhaps you are talking about using a 5.1 mix transport IE a movie and then using your DAC to a set of stereo speakers no 5.1 et al? If your bluray is playing a stereo source like CDDA and you don't hear sound out of your LFE channel on your AVR/proc you don't have the settings right in either in the bluray (xover turned on if it has stupid analog 7.1 out) or on your AVR/Proc. |
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Post by solidstate on Jul 17, 2014 1:31:36 GMT -5
Well I don't have stereo subs. But I do have the m80's which in my room are able to go deep and full range - in stereo. I would always want it to be stereo subwoofers. As for movies, I wouldn't know. There is a .1 channel in 5.1 and that is for the monosubwoofer Low frequency effects. But having said that all 5 channels can carry full range signals. But in reality most movies are center channel centric with the others used for panning effects etc. I think the emphasis becomes more important with music than with movies though. For instance, there's plenty of recordings where the singers voice comes through one speaker. The bass is thus reproduced in that channel only. Now one may think oh well we don't have to worry about bass as it's instruments that aren't reaching that low - but you would be surprised. There's all kinds of information that low. What about some beatles songs when drums richochet from left to right or simply play in one channel only. A piano will absolutely go very low and the recording is done in stereo. The pianist hits that low bass note it will be reproduced more on one side than the other. Same goes for other classical instruments in an orchestra. As for the mind filling in the blanks, below 80 hz being omnidirectional, I think your own experimentation with mono subs shows you how far that can take you. Which is to say pretty darn far! I thought your sub gelled very well with the speaker and it wasn't easy to localize the subwoofer. Having said that I did wonder - is 80 hz really omnidirectional? Well I decided to test it. I played back this: This is an 80 hz test tone. I simply unplugged one speaker and played it full range so only one speaker was playing - no subwoofer. The answer surprised me mainly because is it was VERY obviously coming from one side. 80 hz is absolutely localizable. And I honestly don't know where people came up with that figure. You can try this too. (just make sure the subwoofer is turned off). Or simply turn off the amps and see whether you can tell which side the bass is coming from. www.audiocheck.net/audiotests_basslocalization.phpThis website goes one step further and does a left right split of bass notes and announces the frequency. This will also allows you to tell when the bass becomes omnidirectional. I tried a test this time with a little cheating. I used my HD600's to test the bass. And I simply took one earpad off. I used this: www.audiocheck.net/audiotests_frequencychecklow.php The answer was the bass was hilariously localizable all the way down to the point I started hearing the bass clearly which was around 20 hz - 25 hzish. And the brain wasn't fooled. It didn't make it come from all sides. It came from a single side which was the ear that was hearing it. So then I thought, okay, now how localizable is it if it is in room. Well I did just that. I found this bass sweep test that went from 10 to 200 hz and just used one speaker. www.audiocheck.net/audiotests_frequencychecklow.phpAnd here the result surprised me. I expected to hear the sound being omnidirectional at around 50 - 60 hz. But It wasn't. It was localizeable from the MOMENT I FIRST HEARD THE BASS which was around slightly below 40 hz, I would estimate about 35 hz. So make of that what you will. In real life music and movies we may not be able to localize the sound - as easily - but your ears and brain CAN hear the difference in an actual test tone. You do realize when you used one speaker you cut your low frequency dB in HALF right and you've gone from two point sources to a single point source and the effect you are hearing is nothing more than ROOM RESPONSE. Just because you can localize it doesn't mean that those signals can be perceived of in STEREO if the same signal is sent to two point sources and orientated to the left and right of your ears. Do the same test to two speakers and cut the volume in HALF and note it still can't be perceived of in stereo though you might be less able to localize the source due to two point sources giving you better room response. This is the whole point of using multiple subs and achieving the same dB with half the output needed on each sub. Get it? You can get better room response and prevent standing waves etc whilst using half the power at each sub thus lowering the sub's distortion. The truth be told if you want even response in room for LFE you need two or MORE subs. |
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Post by garbulky on Jul 17, 2014 1:42:44 GMT -5
The .1 channel is indeed mono. But the other 5 or 7 channels are full range. So if the sound had low bass , and was played in any of the 5 channels you would get the bass in that way. For instance my blu ray player constantly refuses to downmix the 0.1 channel into the stereo downmix for my DAC. I know because when I run the test tones everything plays but the subwoofer channel. Having said that, there is no shortage of bass in movies which has to be coming from the 5 or 7 full range channels. "The .1 channel is indeed mono. But the other 5 or 7 channels are full range. So if the sound had low bass , and was played in any of the 5 channels you would get the bass in that way." Not if you have your AVR/Proc speakers set to "small" and you have LFE+main function turned on. This is how the majority of users should have their gear configured actually and you clearly don't with your DAC tests providing no signal to your LFE .1 output. Are you mains full range? If your player has any type of audio processing it should be TURNED OFF. Perhaps you are talking about using a 5.1 mix transport IE a movie and then using your DAC to a set of stereo speakers no 5.1 et al? If your bluray is playing a stereo source like CDDA and you don't hear sound out of your LFE channel on your AVR/proc you don't have the settings right in either in the bluray (xover turned on if it has stupid analog 7.1 out) or on your AVR/Proc. Hi Solidstate. Whew okay a bunch of questions. I think they would all be answered more easily this way. My setup is a Sony blu ray player to a DC-1 stereo DAC to a pair of axiom m80's. That's it. No subs, no surrounds etc. My only point in the post is that the other channels other than the .1 subwoofer channel ALSO carry bass and if your speakers are full rangers and are set accordingly you will get the bass out of those speakers. I guess I'm not sure what you mean here. I of course don't play sound in mono configuration in normal listening if that's what you mean. That was a test to see if I could localize the sound of low bass using test tones (and not real music) if I only played one channel. The reason for the test is that I've read that 80hz and below is omnidirectional THEREFORE a single subwoofer is all that's needed as the mind percieves bass as onmidirectional - or unlocalizable - so what's the point of using two subs. So I did that, essentially turning off one speaker and playing just one in a bass sweep test making it work essentially as a single sub to see if I could localize the sound. And the answer was I could localize it with just one speaker playing all the way down to where the speakers stopped producing sound (around 35 hz) and the same applied when it was just a headphone in one ear playing (no room involved). |
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Post by solidstate on Jul 17, 2014 1:48:34 GMT -5
"The .1 channel is indeed mono. But the other 5 or 7 channels are full range. So if the sound had low bass , and was played in any of the 5 channels you would get the bass in that way." Not if you have your AVR/Proc speakers set to "small" and you have LFE+main function turned on. This is how the majority of users should have their gear configured actually and you clearly don't with your DAC tests providing no signal to your LFE .1 output. Are you mains full range? If your player has any type of audio processing it should be TURNED OFF. Perhaps you are talking about using a 5.1 mix transport IE a movie and then using your DAC to a set of stereo speakers no 5.1 et al? If your bluray is playing a stereo source like CDDA and you don't hear sound out of your LFE channel on your AVR/proc you don't have the settings right in either in the bluray (xover turned on if it has stupid analog 7.1 out) or on your AVR/Proc. Hi Solidstate. Whew okay a bunch of questions. I think they would all be answered more easily this way. My setup is a Sony blu ray player to a DC-1 stereo DAC to a pair of axiom m80's. That's it. No subs, no surrounds etc. My only point in the post is that the other channels other than the .1 subwoofer channel ALSO carry bass and if your speakers are full rangers and are set accordingly you will get the bass out of those speakers. I guess I'm not sure what you mean here. I of course don't play sound in mono configuration in normal listening if that's what you mean. That was a test to see if I could localize the sound of low bass using test tones (and not real music) if I only played one channel. The reason for the test is that I've read that 80hz and below is omnidirectional THEREFORE a single subwoofer is all that's needed as the mind percieves bass as onmidirectional - or unlocalizable - so what's the point of using two subs. So I did that, essentially turning off one speaker and playing just one in a bass sweep test making it work essentially as a single sub to see if I could localize the sound. And the answer was I could localize it with just one speaker playing all the way down to where the speakers stopped producing sound (around 35 hz) and the same applied when it was just a headphone in one ear playing (no room involved). You can't compare a loudspeaker system in room to a set of headphones as a lot of other psycho-acoustic stuff and actual sound passing via your skull into your ear is going on. All I can tell you is you are localizing the sound due to the speaker's performance and the in room response. BTW do you know anyone that wants to buy a 5.1 set of those speakers? Cherry in the box with the protective plastic still over the fake veneer. Epic m80v2 master with the rear surround stands and everything... $1500 bucks and that's negotiable. Retail is more than double easy. PS you honestly should consider better designed loudspeakers if looking to improve your sound vs. buying amps DACs etc. PSS I hate to say it bro... in a whisper... dude... it's your SPEAKERS... |
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Post by garbulky on Jul 17, 2014 2:30:44 GMT -5
Hi Solidstate. Whew okay a bunch of questions. I think they would all be answered more easily this way. My setup is a Sony blu ray player to a DC-1 stereo DAC to a pair of axiom m80's. That's it. No subs, no surrounds etc. My only point in the post is that the other channels other than the .1 subwoofer channel ALSO carry bass and if your speakers are full rangers and are set accordingly you will get the bass out of those speakers. I guess I'm not sure what you mean here. I of course don't play sound in mono configuration in normal listening if that's what you mean. That was a test to see if I could localize the sound of low bass using test tones (and not real music) if I only played one channel. The reason for the test is that I've read that 80hz and below is omnidirectional THEREFORE a single subwoofer is all that's needed as the mind percieves bass as onmidirectional - or unlocalizable - so what's the point of using two subs. So I did that, essentially turning off one speaker and playing just one in a bass sweep test making it work essentially as a single sub to see if I could localize the sound. And the answer was I could localize it with just one speaker playing all the way down to where the speakers stopped producing sound (around 35 hz) and the same applied when it was just a headphone in one ear playing (no room involved). You can't compare a loudspeaker system in room to a set of headphones as a lot of other psycho-acoustic stuff and actual sound passing via your skull into your ear is going on. All I can tell you is you are localizing the sound due to the speaker's performance and the in room response. There's probably something I am missing here as the local consensus is 80 hz. So it is strange I'm hearing it all the way down..... I couldn't beging to speak knowledgeably on the speaker vs headphone vs room vs psycho-acoustic stuff. However I did test both speaker and room. Something tells me the sticking point in my test is that I used a test tone vs real music. Pssst....no, it's not  I remember we had a similar conversation. If I recall you are not too fond of the axioms  For me they are so far the best sound I have heard - which granted may not be saying much but it remains true - for me. Having said that......I have heard the axioms not do too well in certain situations. But I've also figured out what helps to make them sound better. A large room for the standalone version without sub does not really flatter it. Neither does certain types of amps. It also does better with a dedicated pre-amp than without. They are also very placement sensitive. A few inches here or there and you've lost it. What really helps it in large rooms - is a subwoofer. Good amps (the XPR-2 and the nakamichi stasis comes to mind) and a dedicated pre-amp. The best sound I have ever heard however is at my friend's house. THe first time I heard it it was an axiom m80 V4 supplemented by a powersound sub. It was driven by an XPR-2 connected to an XSP-1 (which made quite a bit of difference) and an oppo 105. And man the thing was FANTASTIC. He also tried the nakamichi stasis which was significantly lower powered class A amp and it managed to "light up" the midrange in a way that was really nice. Granted I'm not going to lie and say it's impossible for there to be better sound. Just that it really impressed me. If I could have that level of sound, I would honestly stop looking. |
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Post by Deleted on Jul 17, 2014 2:48:41 GMT -5
Garbulky, your are getting lots of bass out of your M80's because they are your only speakers. You still can't tell if any bass below 80Hz is coming from the L or R tower. You have no sub! I consider a high quality sub to be the correct type of speaker to be reproducing the sounds below 80Hz. Most towers are running out of gas below 80Hz and a high quality sub is dedicated to do this job better. This is not dissing the M80's, most towers are not that good at cleanly reproducing the 80Hz and down to 30Hz range in music (forget movies for awhile) The high quality sub simply does it better and many times with only one sub. Many folks ignore this or simply find the set up of a 2.1 system too confusing or difficult. We cross lower sounds from the tweeter to the mids and from the mids to the woofer. That used to be OK for most sources which were seldom below 50-60Hz. Now with better sources and even the low bass in movies, we need another level below the woofer, hence the subwoofer, and not the $200 ones with a big boom peak at 50-60Hz. The sub is not just for explosions in movies but modern lower bass music sources to be reproduced with low distortion, definition and high output down to 30Hz and some much lower. *** That one sub mated with your M80's, plays 80Hz and down and your M80's play the 80Hz and up. The bass below 80Hz is omnidirectional and you can have the sub in the center, to the left or to the right and not know the difference. The L&R M80's play the 80Hz (which is directional) and up and this is how you get the directional cues as to where the instrument was located in the recording . For example, a 50Hz tone from drum also might have a 100Hz overtone and was recorded in the left channel. If you were able to simply for a short time cut off the frequencies from that tone above 80Hz, you would here the 50Hz fundamental tone from the drum but not the 100Hz tone. You would now not be able detect the location of the drum. Now let's say you again allow the 100Hz overtone to be played you would now suddenly realize that the drum was located off to the left. In 2 channel music systems with a sub as well as multi-channel music/movie system with a sub, the location of the source of the frequencies below 80Hz is not identifiable. I think most folks will be much better off if they forget the idea of stereo subs or separating the LFE channel to its own sub. There are many good reasons for adding 2-3 extra subs to the single sub. However, the signal sent is to 1-4 subs is the same mono signal. The fact that one can hear separate low bass to the left or right or even rear channels is due to the tones and overtones above 80Hz as I explained above. I use 80Hz as the standard/general crossover frequency for my post example here. That's my 2 cents. *** (Whether one has one or two subs is a different question which many mistakenly think has to due with stereo/mono subs .......... all subs with playback below 80Hz are in effect mono, if the bass management is set up correctly ...... all bass below 80Hz re-directed from the other 5 channels and the LFE .1 signal should be combined and sent to any or all subs ..... any use of the LFE channel much above the 80Hz point (rolled of quickly from there up) or any LFE sound above 120Hz (the intended brick wall) is a misuse of the LFE channel's original purpose). |
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Post by garbulky on Jul 17, 2014 3:15:10 GMT -5
Garbulky, your are getting lots of bass out of your M80's because they are your only speakers. You still can't tell if any bass below 80Hz is coming from the L or R tower. You have no sub! I consider a high quality sub to be the correct type of speaker to be reproducing the sounds below 80Hz. Most towers are running out of gas below 80Hz and a high quality sub is dedicated to do this job better. This is not dissing the M80's, most towers are not that good at cleanly reproducing the 80Hz and down to 30Hz range in music (forget movies for awhile) The high quality sub simply does it better and many times with only one sub. Many folks ignore this or simply find the set up of a 2.1 system too confusing or difficult. We cross lower sounds from the tweeter to the mids and from the mids to the woofer. That used to be OK for most sources which were seldom below 50-60Hz. Now with better sources and even the low bass in movies, we need another level below the woofer, hence the subwoofer, and not the $200 ones with a big boom peak at 50-60Hz. The sub is not just for explosions in movies but modern lower bass music sources to be reproduced with low distortion, definition and high output down to 30Hz and some much lower. *** That one sub mated with your M80's, plays 80Hz and down and your M80's play the 80Hz and up. The bass below 80Hz is omnidirectional and you can have the sub in the center, to the left or to the right and not know the difference. The L&R M80's play the 80Hz (which is directional) and up and this is how you get the directional cues as to where the instrument was located in the recording . For example, a 50Hz tone from drum also might have a 100Hz overtone and was recorded in the left channel. If you were able to simply for a short time cut off the frequencies from that tone above 80Hz, you would here the 50Hz fundamental tone from the drum but not the 100Hz tone. You would now not be able detect the location of the drum. Now let's say you again allow the 100Hz overtone to be played you would now suddenly realize that the drum was located off to the left. In 2 channel music systems with a sub as well as multi-channel music/movie system with a sub, the location of the source of the frequencies below 80Hz is not identifiable. I think most folks will be much better off if they forget the idea of stereo subs or separating the LFE channel to its own sub. There are many good reasons for adding 2-3 extra subs to the single sub. However, the signal sent is to 1-4 subs is the same mono signal. The fact that one can hear separate low bass to the left or right or even rear channels is due to the tones and overtones above 80Hz as I explained above. I use 80Hz as the standard/general crossover frequency for my post example here. That's my 2 cents. *** (Whether one has one or two subs is a different question which many mistakenly think has to due with stereo/mono subs .......... all subs with playback below 80Hz are in effect mono, if the bass management is set up correctly ...... all bass below 80Hz re-directed from the other 5 channels and the LFE .1 signal should be combined and sent to any or all subs ..... any use of the LFE channel much above the 80Hz point (rolled of quickly from there up) or any LFE sound above 120Hz (the intended brick wall) is a misuse of the LFE channel's original purpose). This is confusing the issue. It appears that the subtle implication is that when playing an 80 hz (and below) test tone my m80's are distorting so badly that I'm hearing the harmonics of the 80 hz tones? And therefore that is what is localizable? This is simply not true. It's easy to discount a finding by saying the speakers are distorting, but I am listening to these tones and they are not doing that. Also the bass is localizable all the way down to where the speakers simply stop responding. The bass is clear. I'm hearing it and I'm localizing it. And that is what is happening. The axioms have four 6 1/2 inch aluminium drivers just for the bass a pair.  In a larger room, I would agree with you about them running out of gas but not here. It's got plenty. Now what is true is that at B'zilla's setup, with his axiom's and power sound sub I can't clearly localize the 80 hz cross over with music playing. And with a subwoofer in my system, I wouldn't be able to clearly localize the sub. I'll grant that. The brain cannot differentiate. But it CAN differentiate if there's less information - at least that's how I interpret the result. Edit: Reading this post made me realize other than me saying "nuh uh!", it doesn't actually move the conversation forward So, I suggest you try it. You use a sub. Turn off your speakers. www.audiocheck.net/audiotests_frequencychecklow.php Play the frequency test. I assume your sub is in the middle of the room. Move well to the side of your room i.e. a place where the sub isn't. Tell me if you have any kind of idea where the bass below 80 hz is coming from - at least a general direction towards the sub. Then move to the other side and repeat. Let me know. If you can place the general direction where the sub is then that means somehow the bass is localizable below 80 hz. |
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Post by Deleted on Jul 17, 2014 4:26:28 GMT -5
Sorry Garbulky but you completely misunderstood my post. Now perhaps on the other hand if I misunderstood your previous post, then I apologize. Quickly, I had two points. One was that a quality sub has less distortion than most towers below 80Hz. All speakers have distortion but many times the sub's distortion in the 80Hz and down range is lower. Thus my suggestion for improved full range sound by adding a sub and going 2.1 versus 2.0. I thought you implied that you were running the M80's full range without a sub. Sorry, if I was wrong there. My point then was that a sub taking over at perhaps 80Hz (slightly lower is fine) would have lower distortion and perhaps better low bass FR. I see the graph you posted here. Note these FR graphs do not tell us anything about the distortion levels. That is a fine FR very flat down to about 70Hz, off some to about 50Hz and then fairly flat again and then a sharp drop off below 30Hz. That is a very respectable performance and very similar to other towers in the same class. I only suggest the sub as not only for HT but an improvement to an already nice speaker at full range. Here is a graph from the SVS PB-2000 sub. Note the very flat response from 100Hz down to 20Hz and obviously below (actually –3dB point is at 18 Hz!). Again this is not to dis your M80's, but to show here for example a sub that appears to be an excellent match with a very flat bass right thru 30Hz and down to 18Hz, outstanding performance!. The main reason for my post was because I thought you were confused about the points in the lower frequency spectrum at which bass tones become omnidirectional. Plus the fact that a single tone from a low bass instrument can consist of both fundamental frequencies that are below 80Hz and thus not location identifiable, but also the higher overtones that add the location of the instrument. Harmonics are part of all tones and are what allow us to distinguish for example the exact same note is played by either a trumpet or a trombone. It had nothing to do with my supposedly implying that your M80's were producing harmonics because they had high distortion (in fact I was not implying that). You say: Also the bass is localizable all the way down to where the speakers simply stop responding. I'm really sorry but that is simply not true. One cannot usually locate the source if the bass is below about 80Hz. You are in fact localizing the overtones of the fundamental bass tone. For example, with a 50Hz fundametnal tone you will hear a 100Hz tone, That 100Hz tone is the source of your localization cue. I'll move on here but was only trying to help with a sub suggestion and a clarification of the bass localization question.  |
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Post by Boomzilla on Jul 17, 2014 4:42:23 GMT -5
Thank you, solidstate - THAT explains what the equipment ".2" designation is for. The source (soundtrack) ".2" does not exist. All movie source material is ".1" as you say.
Garbulky - I agree with you that if only a single speaker is playing in a room, then yes, you can identify which one is playing the bass. However, if you were to use an 80 Hz crossover, and then send the >80 Hz signal to one speaker and the <80 Hz. to the other, you may not so much notice the transition. If you had pure tones, only, then you might be able to localize the shift as the frequency dropped, but many (many) tests over time have shown that on wide-band program, the ear cannot localize sounds lower than 80 Hz. Remember, also, that no crossover is a brick wall. At 12 dB per octave (a common crossover slope), when using an 80 Hz crossover, the high-pass side is only 12 dB lower at 40 Hz. than the low-pass side. Also, the converse is true - the subwoofer still has some audible output at 160 Hz (EASILY localizable). This is an artifact of the crossover, not the acuity of the ear.
Boom
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Post by garbulky on Jul 17, 2014 5:29:38 GMT -5
@chuckienut
I guess I tend to ramble So let me delete my previous post and post this instead.
If you turn off your speakers. Cross your sub at whatever point you deem it to be not localizable and play a bass note - a test tone - below 80 hz. Can you locate it?
If you can - harmonics or not. The single mono sub is playing a localizable note - that the ear can hear.
Yet the suggestion is that
1. These low notes from the subwoofer are not localizable.
2. The single sub - which plays localizable bass should be used in a stereo 2.1 system as it isn't localizable (except it is).
That's my issue.
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Post by Boomzilla on Jul 17, 2014 5:36:16 GMT -5
I'm ahead of you, Gar - I've played the bass sweep (and music) with the sub on but the speakers off. Yes, the sub IS localizable with music - I can even discern voices from the sub. I'm sure this is an artifact of the 12 dB/octave crossover.
As the frequencies descend with test tones, though, localization becomes far harder. I'll try the sweep again to see if I can localize 80 Hz.
Using a single sub, hard left in my room, though, I can't localize the sub with stereo music using an 80 Hz. crossover. When a drum is in the right channel, the sound seems to emanate from the right speaker only, despite the fact that all <80 Hz. info is in the sub only.
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Post by pop on Jul 17, 2014 9:16:18 GMT -5
If your sub is easier to localize typically that means it is in the wrong position in your room. I would experiment with different locations. Ok so last night I did a 80hz and lower sweep on the subs and had Jessica turn one on at a time (Blind testing) Here is a picture of my subs and their locations  IMG_0135 by Austin Contemporary Dance, on Flickr I was wrong 5 out of 6 times. She picked which sub would be on and she started the sweep. I literally took a wild guess at what sub was on. This test proves at least to me that 80hz and below is harder to localize. I thought as the sweep started that I was locating the sub at 80hz, so generally that was the one I picked. Mostly, I was wrong. |
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Post by monkumonku on Jul 17, 2014 9:23:37 GMT -5
monkumonkuExactly. My mind is perceiving emphasis from the location. I should elaborate a bit - the mind is responsible for how we perceive things but in my example about directionality I didn't mean that in a case where a car is going from left to right but the speakers are hooked up incorrectly so the sound goes from right to left that your mind is going to make you think the sound actually matches the cars. I'm talking about where there is an absence of obvious cues to work with. Also, even though low frequency sounds are difficult to localize, they often generate other sounds at higher frequencies that aid in determining where they are. For example, someone plucking an upright bass. The frequency of the finger plucking the bass can be localized through the main speakers, at which point the mind may then tell you the sound is coming from that same side. But something like a low rumble in which the entire sound is low frequency, will make you look around the room wondering where it is coming from if you don't have a visual cue on the screen. |
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Post by pop on Jul 17, 2014 9:26:11 GMT -5
monkumonkuExactly. My mind is perceiving emphasis from the location. I should elaborate a bit - the mind is responsible for how we perceive things but in my example about directionality I didn't mean that in a case where a car is going from left to right but the speakers are hooked up incorrectly so the sound goes from right to left that your mind is going to make you think the sound actually matches the cars. I'm talking about where there is an absence of obvious cues to work with. Also, even though low frequency sounds are difficult to localize, they often generate other sounds at higher frequencies that aid in determining where they are. For example, someone plucking an upright bass. The frequency of the finger plucking the bass can be localized through the main speakers, at which point the mind may then tell you the sound is coming from that same side. But something like a low rumble in which the entire sound is low frequency, will make you look around the room wondering where it is coming from if you don't have a visual cue on the screen. I understood, We are on the same page Rickie. |
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I thought your sub gelled very well with the speaker and it wasn't easy to localize the subwoofer. 
For me they are so far the best sound I have heard - which granted may not be saying much but it remains true - for me.
