I've located the sub direction in a blind test to 38 hz, under that I could not tell the direction anymore. That's why i laugh to the typical claims of 80 hz that "you can't tell where it's coming from". That's why I cross my mono sub around that 38 hz frequency. Sometimes I put it as high as 45. It ain't so bad yet.
That's a swell anecdote and truly up-ends what is likely a lot of lab research. But without being able to eyeball what is actually coming out of your sub at 39 Hz, hard to say what you are experiencing.
Even inputting pure sine waves, with the usual 10-20% THD below 40 Hz at loud volumes for the best subs, the Fletcher-Munson curves would predict you could locate the sub, assuming not playing music through all the speakers, just from the second and third harmonics.
BTW, just how did you do your blind experiment? Two or three other subs and had to guess which was playing and answered correctly most of the time? How did you test?
In my 52 years of using a sub with a 140 Hz XO playing music, I can't recall ever having that bad feeling that something is coming out from the sub over in the corner. Ever, that I can recall. But the research says that if I played a sine wave (or some trick wave) above maybe 80 Hz (but, of course, below 140 Hz), I might locate it.
B.
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well, you are localizing the high frequencies (harmonic distortion) coming from the cone.
Shorting rings help knock it down, maybe 150hz and up.
Wayne parnham show'd that.
see post 9
Push/Pull Subwoofer Theory? - AVS Forum | Home Theater Discussions And Reviews
But a push pull helps all the way down.
You can see that in m&k reviews.
But the drivers are a bit far apart to be 1/4 wavelength of upper harmonics (say 150hz).
push pull subwoofers are harder to localize, especially slot loaded.
Sort of like a friends car system, he went from a caprice to a hatchback.
The hatchback was "blurry".
That "blurry" sound was caused by the lack of the back seat filtering out harmonic distortion coming out of his subs, similar to the blurry noise you hear at best buy when someone tries to crank a sub in car audio when you are 1/2 way across the store.
velodynes sample driver motion, compare it to input, then cancels distortion back at the amplifier (feedback thing), nice, but expensive.
Shorting rings help knock it down, maybe 150hz and up.
Wayne parnham show'd that.
see post 9
Push/Pull Subwoofer Theory? - AVS Forum | Home Theater Discussions And Reviews
But a push pull helps all the way down.
You can see that in m&k reviews.
But the drivers are a bit far apart to be 1/4 wavelength of upper harmonics (say 150hz).
push pull subwoofers are harder to localize, especially slot loaded.
Sort of like a friends car system, he went from a caprice to a hatchback.
The hatchback was "blurry".
That "blurry" sound was caused by the lack of the back seat filtering out harmonic distortion coming out of his subs, similar to the blurry noise you hear at best buy when someone tries to crank a sub in car audio when you are 1/2 way across the store.
velodynes sample driver motion, compare it to input, then cancels distortion back at the amplifier (feedback thing), nice, but expensive.
Kreisel dxd12012
Push pull sub, ex m&k i guess.
KEN KREISEL DXD-12012 Dual 12" Push-Pull Subwoofer - HomeTheaterHifi.com
Push pull sub, ex m&k i guess.
KEN KREISEL DXD-12012 Dual 12" Push-Pull Subwoofer - HomeTheaterHifi.com
So what you are saying basically is that when people are testing in blind tests, their system is always so bad there are huge harmonics which easily reveal the location but when YOU play your material from your system, there are absolutely no harmonics and there is no way you can locate your sub woofer. Seems legit.
Ok maybe it's then easier that you give me the exact specs of the system that does not produce so much harmonics and then I will buy those and do the test again, and after that if I can locate the sub under 150hz, what do I win?
What if there is a low frequency material that is coming only from the sub? A brief moment where the stereo speakers are not doing the masking for you. Then you are losing that experience that was originally recorded, right? I don't want to lose anything since I have a choice.
Besides, I would not agree the stereo (or surround) speakers mask so much, every home that i have visited that has a separate sub that is crossed high as usual, I can hear it (locate it) at that particular corner. It's really annoying and does not feel like a high fidelity system. More like a bad compromise.
I remember when I was working for Nokia corporation in the early 2000. I went with audio engineer to their anechoic chamber where there was a big Velodyne sub. Right away when he turned it on, I asked "what is that hum coming from it, it's like a 50hz mains hum?"
the engineer who uses the system every day said, "ha, there is no hum, this is a Velodyne!" then I said, "There is a hum, put your ear to the speaker!" then he kneeled and said "oh, you were right, now I hear it, there is a hum! Never noticed that before!"
So I guess if I would buy a Velodyne you would say "well you just located it from the mains hum harmonics, you would not be able to locate it without it.."
Ok maybe it's then easier that you give me the exact specs of the system that does not produce so much harmonics and then I will buy those and do the test again, and after that if I can locate the sub under 150hz, what do I win?
What if there is a low frequency material that is coming only from the sub? A brief moment where the stereo speakers are not doing the masking for you. Then you are losing that experience that was originally recorded, right? I don't want to lose anything since I have a choice.
Besides, I would not agree the stereo (or surround) speakers mask so much, every home that i have visited that has a separate sub that is crossed high as usual, I can hear it (locate it) at that particular corner. It's really annoying and does not feel like a high fidelity system. More like a bad compromise.
I remember when I was working for Nokia corporation in the early 2000. I went with audio engineer to their anechoic chamber where there was a big Velodyne sub. Right away when he turned it on, I asked "what is that hum coming from it, it's like a 50hz mains hum?"
the engineer who uses the system every day said, "ha, there is no hum, this is a Velodyne!" then I said, "There is a hum, put your ear to the speaker!" then he kneeled and said "oh, you were right, now I hear it, there is a hum! Never noticed that before!"
So I guess if I would buy a Velodyne you would say "well you just located it from the mains hum harmonics, you would not be able to locate it without it.."
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I had two 15" woofers on a sealed box each side, 3m distance from me and 3m distance from each other. Then I had an assistant playing sine wave from each speaker in a random order and I would point where the sound is coming from. Then the assistant would write down the hz and the info was I right or not. Then going down and down in frequency when I at some point answered wrong, the assistant would start to repeat the frequency many times to see how good is the percentage. At 38 hz I started to give 50/50 right/wrong answers so we stopped there. Of course for example at 40 hz I was already making mistakes but not 50/50.
The volume was not loud, the 15" were really not moving almost at all. For example at 80 hz the distortion should be very low.
What are you saying? That's almost exactly the the frequency range where I could not anymore locate.
Agreed. Unlikely during most material but possible.
"I don't want to lose anything since I have a choice.
Besides, I would not agree the stereo (or surround) speakers mask so much, every home that i have visited that has a separate sub that is crossed high as usual, I can hear it (locate it) at that particular corner. It's really annoying and does not feel like a high fidelity system. More like a bad compromise."
I hate home systems crossed too high, like some shitty cinema system at 200Hz with super small stereo speakers guess it was a Bose.. OMG. I do no more want to think about that system...
I therefore consider ~70Hz appropriate for a HT system (of course with bigger stereo speakers).
Main reason why there isn't so many songs with low frequencies is that people have usually so shitty stereo system so they would not hear it, or might even break something.
When I built a sub to go really low, I also had to do some new mixes of some songs, so I would have material which to play
Which separates the boys from the men. It's such a joy when artists / producers throw in sub bass notes that make your system shine. I can't think of the track off the top of my head but in one hip hop track I played through my system he was referencing a low sub bass line and "how your system can't do this"
No no no.
The music delivered by the sound board of computers is converted from bits to a "conventional" analog signal by the DAC.
And if you use signal generation programs like Audacity, etc., it's exactly the same. They are sinusoidal signals. You can not hear "bits", they are zeros and ones.
This brings us to the famous and remanded discussion about the quality of this "conversion", the problems of "jitter", etc., etc.
The music delivered by the sound board of computers is converted from bits to a "conventional" analog signal by the DAC.
And if you use signal generation programs like Audacity, etc., it's exactly the same. They are sinusoidal signals. You can not hear "bits", they are zeros and ones.
This brings us to the famous and remanded discussion about the quality of this "conversion", the problems of "jitter", etc., etc.
Attachments
Yes, and ?
I do not understand your point, but leave it there, it has nothing to do with the thread anyway
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Hmm, some William orbit goes low. Same guy that mixed it did Madonna "ray of light cd", deep synthesizer stuff (I think).
But yes, when I had a 31 band spectrum analyzer (dod something), I was hard pressed to find much below 50hz (15 years ago). Below that seems to be what shakes the ceiling causing dust to rain down. But even rianaha gets pretty low now-a-days, let alone new Arianna grande.
I think if you can hit over 115db flat down to 27hz, that should be fine for anything.
And It won't cost an arm and a leg, or be a huge infinite baffle setup.
I assume soundtrack to "fight club" gets low, as does soundtack to newest "Ttron" (legacy ?).
I've seen spectrographs of movies and they seem to be doing the blow 10hz stuff.
Opening scene in attack of the clones (where ship blows up on the landing pad), and lord of the rings "return of the king" ch 28 where the chunk of cider block lands from the catapult.
Necessary ?
eh, up to you.
But more output and lower = more fun !!!!!!!!!!!!
But yes, when I had a 31 band spectrum analyzer (dod something), I was hard pressed to find much below 50hz (15 years ago). Below that seems to be what shakes the ceiling causing dust to rain down. But even rianaha gets pretty low now-a-days, let alone new Arianna grande.
I think if you can hit over 115db flat down to 27hz, that should be fine for anything.
And It won't cost an arm and a leg, or be a huge infinite baffle setup.
I assume soundtrack to "fight club" gets low, as does soundtack to newest "Ttron" (legacy ?).
I've seen spectrographs of movies and they seem to be doing the blow 10hz stuff.
Opening scene in attack of the clones (where ship blows up on the landing pad), and lord of the rings "return of the king" ch 28 where the chunk of cider block lands from the catapult.
Necessary ?
eh, up to you.
But more output and lower = more fun !!!!!!!!!!!!
Today I thought it's now time for another blind test of locating the bass, previous one was 10 or more years ago. Now, a different country, different amplifier, different woofers, different enclosure, different size room and shape and I got exactly the same results, around 40 hz the location starts to get real 'foggy' and 38 hz I can't locate it anymore, then it is truly omnidirectional.
I seriously doubt I am much better than others hearing the direction of the bass, so I guess others have not actually carefully tried it, instead they just think they know.
Also the fact is that some people say you can't locate sub below 100, then others say below 80, and some say below 60, is the best evidence that many people are simply wrong about the matter, since they all can't be right.
If there is interest, I could create a flac that alternates at 55 hz frequency between left and right channels. That should be easy enough for most people. And if many people locate that one, then they can believe that maybe it's possible to also hear 45 since 55 was also supposed to be completely impossible...
I seriously doubt I am much better than others hearing the direction of the bass, so I guess others have not actually carefully tried it, instead they just think they know.
Also the fact is that some people say you can't locate sub below 100, then others say below 80, and some say below 60, is the best evidence that many people are simply wrong about the matter, since they all can't be right.
If there is interest, I could create a flac that alternates at 55 hz frequency between left and right channels. That should be easy enough for most people. And if many people locate that one, then they can believe that maybe it's possible to also hear 45 since 55 was also supposed to be completely impossible...
"alternating" between left and right in case of "switching" will create a spectrum extending into midrange and even treble. Exactly that will make it "locate-able". In case of slow amplitude modulation between the two channels it will create sidebands next to the fundamental, each 1/(modulation time period) apart from fundamental. In that case, maybe a sine-type once-per-2-seconds amplitude modulation would be ok, in that sense that maybe a 40 Hz signal would be distributed between 39.5 and 40.5 Hz only....Today I thought it's now time for another blind test of locating the bass, previous one was 10 or more years ago. Now, a different country, different amplifier, different woofers, different enclosure, different size room and shape and I got exactly the same results, around 40 hz the location starts to get real 'foggy' and 38 hz I can't locate it anymore, then it is truly omnidirectional.
I seriously doubt I am much better than others hearing the direction of the bass, so I guess others have not actually carefully tried it, instead they just think they know.
Also the fact is that some people say you can't locate sub below 100, then others say below 80, and some say below 60, is the best evidence that many people are simply wrong about the matter, since they all can't be right.
If there is interest, I could create a flac that alternates at 55 hz frequency between left and right channels. That should be easy enough for most people. And if many people locate that one, then they can believe that maybe it's possible to also hear 45 since 55 was also supposed to be completely impossible...
To be clear, of course I'm not so simple that I would locate the sound based on some cracking sound at the moment of switch. That would indeed be pretty retarded.. The test sound was made so that there is no cracking sound, starting the wave at zero level smoothly.
I could also hear the direction still when the sine wave was ongoing, as a matter of fact, if the sound was extremely short it was harder for me to locate it near 40 hz.
I could also hear the direction still when the sine wave was ongoing, as a matter of fact, if the sound was extremely short it was harder for me to locate it near 40 hz.
I think it's best to first start from 75 hertz, since there are a lot of 80 hz believers.
I created the test sound in both flac and mp3.
http://penthouse.homelinux.net/diyaudio/75hz_alternating.flac
http://penthouse.homelinux.net/diyaudio/75hz_alternating.mp3
Notice that if your room happens to have a strong standing wave at that frequency it will make it seem more omni. In any case it's good to try to listen from different locations, since if the bass is truly omni, it's not possible to hear the direction from anywhere in the room.
Maybe it's obvious, but I will state it just in case, the test sound is meant for people with full range stereo speakers and not for those who have a mono sub woofer for sounds below 80hz.
I created the test sound in both flac and mp3.
http://penthouse.homelinux.net/diyaudio/75hz_alternating.flac
http://penthouse.homelinux.net/diyaudio/75hz_alternating.mp3
Notice that if your room happens to have a strong standing wave at that frequency it will make it seem more omni. In any case it's good to try to listen from different locations, since if the bass is truly omni, it's not possible to hear the direction from anywhere in the room.
Maybe it's obvious, but I will state it just in case, the test sound is meant for people with full range stereo speakers and not for those who have a mono sub woofer for sounds below 80hz.