This is really what I tried to describe running a mono signal to two speakers, there are nodes that you can hear from which direction a tone comes. Also keep in mind I only listened to below 80Hz that all of the high frequency cues regarding direction is removed. If I put the high frequency portion of the signal back then they are the direction of sound and woofer placement has virtually no bearing on position, it becomes a LF enforcement.
My observation could be that if there is only low frequency tones available you can detect its source and probably due to our flight or fight instinct. However, once the sound becomes complex and contains higher frequency (300 to 3000Hz) content this could be the direction identifying factor.
I tried another test that probably has no real value, but I have a second system consisting of two L3/5 speakers and a B139 sub placed behind a large easy chair. When I play the system normally there is no way I can find the direction of the woofer, but if I play the woofer on its own you can tell which direction it comes from. The direct wave is much higher level than any of the reflections.
Kindhorn. I dunno. I've run test of steeply filtered noise panning back and forth. Yes, it gets harder as the frequency drops, but I can still hear the pan. Some people claim that it's box and port noise, harmonics, whatever. Maybe I need to measure how much of that there is. My guess is - not much.
I've run similar tests in large spaces and I can point pretty accurately to where to the sound is (blind). Most of the guys I work with are far less accurate. I've also been able to point to the direction of earthquakes. I do not know why that is. But it might be worth someone studying differing abilities in different people. My simple tests seem to indicate a difference in abilities.
Listening to classical music with a mono bass is OK, but I don't find it as real as stereo subs. Mono subs sound less realistic to me. But for a lot of recordings and tastes, you can get away with mono subs just fine. I really don't have to worry about it, as my woofers cover from the 30s up to 700Hz. For me, it's not a problem.
I've run similar tests in large spaces and I can point pretty accurately to where to the sound is (blind). Most of the guys I work with are far less accurate. I've also been able to point to the direction of earthquakes. I do not know why that is. But it might be worth someone studying differing abilities in different people. My simple tests seem to indicate a difference in abilities.
Listening to classical music with a mono bass is OK, but I don't find it as real as stereo subs. Mono subs sound less realistic to me. But for a lot of recordings and tastes, you can get away with mono subs just fine. I really don't have to worry about it, as my woofers cover from the 30s up to 700Hz. For me, it's not a problem.
Thanks Nico and Pano for your answers.
I guess you must be pointing at California for those earthquakes! Not sure I could point in a particular direction when that low rumble happens, but you do know that one is coming.
It would be interesting to see what the frequency response of the ports are when producing those low signals, there may be a much higher harmonic being produced in the port giving away the directionality.
Like you Pano I don't really think about it as my two way monitor is going down to 35hz so it is in phase and from the same space as everything else. I don't see much point in separating the sub from the rest of the sound system if you don't have to do that. Unless you are one who wants to use the corner loading to excite the entire room.
I guess you must be pointing at California for those earthquakes! Not sure I could point in a particular direction when that low rumble happens, but you do know that one is coming.
It would be interesting to see what the frequency response of the ports are when producing those low signals, there may be a much higher harmonic being produced in the port giving away the directionality.
Like you Pano I don't really think about it as my two way monitor is going down to 35hz so it is in phase and from the same space as everything else. I don't see much point in separating the sub from the rest of the sound system if you don't have to do that. Unless you are one who wants to use the corner loading to excite the entire room.
Room issues
Given that two sources cannot occupy the same location, and that most rooms have no mirror symmetry, it would seem to me that subs in different locations in a room pump the modes differently; hence some clues as to their location are unavoidable without "smoke and mirrors", even if just level effects (as Kindhornman alludes to)
Actually, I feel (and have used for 15 years or so) the multi sub approach kind of uses this to advantage
John L.
Given that two sources cannot occupy the same location, and that most rooms have no mirror symmetry, it would seem to me that subs in different locations in a room pump the modes differently; hence some clues as to their location are unavoidable without "smoke and mirrors", even if just level effects (as Kindhornman alludes to)
Actually, I feel (and have used for 15 years or so) the multi sub approach kind of uses this to advantage
John L.
I'm currently using corner loading, which gives me a little too much low end gain. I turn it down in the EQ. Don't know if it makes it any smoother.
In the warehouse, which is about 135x100 feet, I don't know how much room nodes play a part in localization.
I dunno, seems like either I am talking to myself or else no one quite grasps the crux of the things I've been saying... seems to me you guys are going round and round with the same things and missing the crux.
The whole thing revolves around *maximal focus* in terms of spatial resolution, not tonal fidelity. You want dead flat response for tonal fidelity, but that may or may not yield spatial resolution at the same time - depending on how that flatness is achieved.
I'd opt for better spatial resolution - instruments and voices materializing in space - over flatness in the lower region, given the choice/tradeoff. The idea, if it isn't clear, is better spatial resolution is the same as saying "less confusion" and "a clearer picture", overall.
If you start with a dead accurate main speaker system, and then add in a sub that is acoustically remote or removed from the main speaker you introduce a sort of confusion and make the image less clear - despite the inherent clarity of the mains.
The original cues from the mains remain, but there is the added incorrectly timed cues from the bottom end. I hear that, especially when it's not even close. But even when it is close, whenever I have take the time to try to get the best relationship between the stereo subs and the mains, I find that there is a point where usually the total image "snaps" into place and what is going on in the sound stage becomes much clearer and obvious. Obvious is a key idea here.
I guess this is an aspect of setting up speakers that either hasn't gotten a lot of attention or else simply hasn't been generally recognized as important, maybe not even as audible.
_-_-
The whole thing revolves around *maximal focus* in terms of spatial resolution, not tonal fidelity. You want dead flat response for tonal fidelity, but that may or may not yield spatial resolution at the same time - depending on how that flatness is achieved.
I'd opt for better spatial resolution - instruments and voices materializing in space - over flatness in the lower region, given the choice/tradeoff. The idea, if it isn't clear, is better spatial resolution is the same as saying "less confusion" and "a clearer picture", overall.
If you start with a dead accurate main speaker system, and then add in a sub that is acoustically remote or removed from the main speaker you introduce a sort of confusion and make the image less clear - despite the inherent clarity of the mains.
The original cues from the mains remain, but there is the added incorrectly timed cues from the bottom end. I hear that, especially when it's not even close. But even when it is close, whenever I have take the time to try to get the best relationship between the stereo subs and the mains, I find that there is a point where usually the total image "snaps" into place and what is going on in the sound stage becomes much clearer and obvious. Obvious is a key idea here.
I guess this is an aspect of setting up speakers that either hasn't gotten a lot of attention or else simply hasn't been generally recognized as important, maybe not even as audible.
_-_-
I disagree. A number of us here are on the same page. I've been saying that for years - or at least I think I have. Maybe I'm not getting across either.
Perhaps it starts from a flawed premise. "Bass is omni-directional." If people believe that, then the will find all sorts of excuses for mono bass. And why not? It's one of those things you can get away with. It doesn't make it better, just a generally acceptable compromise. If you haven't heard good stereo bass, you might be inclined to believe the flawed premise.
Is there a point where everyone can agree that stereo bass is no better than mono bass? 80 Hz? 60 Hz? 40 Hz?
Depends on room size but I'd say a crossover no higher than 80Hz is desirable. I'm currently running my nearfield sub up to 150Hz which makes it more localizable but flat frequency response wins hands down over "stereo bass".
I also don't think there's a thing like "stereo bass". There's more or less spaciousness caused by room effects >100Hz but as research has shown this is best reproduced by surround speakers (just like higher frequency reflections for increased ASW). It's a perception that is caused by sound arriving after a substantial delay. Toole is talking about >80ms. Nothing our rather small listening rooms can provide.
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In my mind "dead flat response for tonal fidelity" and "spatial resolution" is the same thing when we're talking about stereo reproduction. Stereo is listening within an interference field. That interference field is distorted by differences in the in-room response of the left and right speaker.
Can human beings localize the colour red? 😉
Anyhow Bear might be accurate in saying a that flat frequency for tonal fidelity and spatial resolution are not exclusive to each other.
A tone is defined by it's duration, pitch and intensity. You could have an accurate tone reproduction without necessarily having dimensional information.
The same way an image can have good colour and not be 3-dimensional.
Anyhow Bear might be accurate in saying a that flat frequency for tonal fidelity and spatial resolution are not exclusive to each other.
A tone is defined by it's duration, pitch and intensity. You could have an accurate tone reproduction without necessarily having dimensional information.
The same way an image can have good colour and not be 3-dimensional.
I doubt there is a point where everyone can agree. Seems many people simply don't hear bass location, others do. So stereo bass will be important to one group, but not the other.
80Hz is the low pass for 5.1 LFE, isn't it? Sort of a de facto standard. Me - I'd probably build a mono subwoofer if running under 40Hz. For the simple trade off of return vs cost and space.
See, I just can't agree with Toole on this at all. IF that is what he has said.
In fact I don't seem to fall in line with a whole lot that he/they put out. Up to a point Toole's work seems to be reasonable.
Bass *radiates* omnidirectionally. That's all.
There is clearly "stereo bass", whether or not it is used in recordings is another question. I have recordings with stereo bass - where the left and right bass tracks are different.
Here's yet another example of something that *can* be recorded involving stereo bass. IF I do an "out of phase" trick, like for example Hendrix employed in Electric Ladyland, which forces the apparent source of the sound *outside* the left/right plane of the speakers, and I have a MONO subwoofer, the LF information stays centered, while the rest pans wildly... with a stereo sub set up, everything moves together.
Together or not together, I vote for together = stereo bass, time "aligned".
If you think that you get "flat bass" in your room, I think that this is a funny idea, unless you happen to have a warehouse like Pano to play in (and even then I dunno).
Probably Dr. Geddes approach of multiple subs in a typical room is about the best you can do to overcome the inevitable nodes and anti-nodes. But to me that is akin to putting a gourmet meal into a blender. Ok, a bit strong of a comment but hyperbole helps to nail the idea.
A duel then? Tweeters at 10 paces? 😛
_-_-
In fact I don't seem to fall in line with a whole lot that he/they put out. Up to a point Toole's work seems to be reasonable.
Bass *radiates* omnidirectionally. That's all.
There is clearly "stereo bass", whether or not it is used in recordings is another question. I have recordings with stereo bass - where the left and right bass tracks are different.
Here's yet another example of something that *can* be recorded involving stereo bass. IF I do an "out of phase" trick, like for example Hendrix employed in Electric Ladyland, which forces the apparent source of the sound *outside* the left/right plane of the speakers, and I have a MONO subwoofer, the LF information stays centered, while the rest pans wildly... with a stereo sub set up, everything moves together.
Together or not together, I vote for together = stereo bass, time "aligned".
If you think that you get "flat bass" in your room, I think that this is a funny idea, unless you happen to have a warehouse like Pano to play in (and even then I dunno).
Probably Dr. Geddes approach of multiple subs in a typical room is about the best you can do to overcome the inevitable nodes and anti-nodes. But to me that is akin to putting a gourmet meal into a blender. Ok, a bit strong of a comment but hyperbole helps to nail the idea.
A duel then? Tweeters at 10 paces? 😛
_-_-
If you have been following the thread, I think that you will see
Myth: All Recordings are mixed to Mono in the Bass.
That would be 120Hz. In newer formats LFE has become a full range channel for whatever reason but is still used for low frequency content only.
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