And when the wavelengths in a room are long enough to sum as one?
Using multiple subs ontop. The advantage of "stereo" bass is what?
Thats how i read his comment at least. Near 100% summation at those frequencies.
How does the length of rooms have anything to do with wavelength summations? Summations, not formations from modes.
I think removing the idea of recordings predominantly are mono bass, is a first step in questioning how bass is heard in rooms.
I use my system for gaming and movies, not just music, and an accurate depiction of sub bass in the stereo field is important to me, but I am the minority...
I use my subwoofers a bit differently depending on the content.
For music, I run four subs in stereo bass mode. Placement is manual for smoothest response. No active delays.
For movies, I go all in with six subs non-stereo. Here DSP handles all the delays for smoothest and constructive interference.
I’ve found that setting the crossover around 60Hz hits the sweet spot subjectively.
One of the subwoofers is placed behind the setup, so it’s not visible in the picture.
For music, I run four subs in stereo bass mode. Placement is manual for smoothest response. No active delays.
For movies, I go all in with six subs non-stereo. Here DSP handles all the delays for smoothest and constructive interference.
I’ve found that setting the crossover around 60Hz hits the sweet spot subjectively.
One of the subwoofers is placed behind the setup, so it’s not visible in the picture.
Attachments
I use my system for everything, too. Having 4 subwoofers - 2 on the left and 2 on the right. I route the signal to the left subwoofers from the left main, and then the signal to the two right subwoofers from the main right. Mains are full-range, but fall off naturally, since we are talking about two WO24P in 75 liters closed.
Games are more fun with that deep firm bass, and I like movies to have full range none booming bass too - and this of course works great with music as well.
My situation is unique., I made my mains so big [2 15"s/2 18" each main] that I need no subwoofer.... Thus sub bass is covered by them, meaning All sound comes from my 2 way placed left and right, and lucky enough for the dimensions of the room to support corner loading.
My sub solution is two stacks of 4 BP subs almost up to the ceiling (8'). Placed at 1/4th and 3/4th of the width, against the front wall. time aligned with mains speaker, of which the fronts of the speakers are 2 meters/6,5' from the front wall and as close as possible to the side walls to avoid SBIR.
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I agree that later recordings done digitally would likely be in stereo (its easier.) But what I listen to almost exclusively are older recordings which are dominantly mono LF.
That said, perceptually I have trouble believing that it can make any difference. Only if one LF instrument was recorded uniquely in one channel and a separate/different LF source is uniquely on the other channel. Then there would be a strong perceptual difference between mono and stereo on playback. But if it is the same instrument is recorded on both channels, even if using separate mics for each channel, the recording channels will be highly correlated at LFs due to the extreme long wavelengths of the sound. Thus on playback the two different signals have to also be highly correlated thus not really yielding a pair of sources but one single source.
I am talking here about the speakers signals and not any spatial effects such as room placement. Room placement then does become the only independent parameter that we have to work with.
One could decorrelate the two LF channels in the recording and that would help, but I know of no one doing that. And, it would be just as effective to do the decorrelation at the speaker. An Ides that I have often proposed. This would be the best of all worlds - multiple decorrelated sources for the lowest possible FR variance.
Directional Subwoofer Mode
I recently bought an AV unit and it has two subwoofer modes: Standard (default), and Directional. I am wondering what advantage the latter touts.
The description in the manual says:
Standard: "All subwoofers output LFE signals and bass below the crossover frequency of all the speakers."
Directional: "All subwoofers output LFE signals. In addition, each subwoofer outputs bass below the crossover frequency of speakers that are placed near them."
My first thought was that Directional mode is only going to make the (Geddes-style) mode smoothing of a multi subwoofer setup less effective. In any case, all the bass above 80 Hz is already directional because it comes from the main speakers, and that is the bass that is localisable. I am starting to wonder if it is just a gimmick to appeal to stereo audiophiles who hate the idea of summing subwoofer frequencies on principle?
Do you have any thoughts on this?
I could not be definitive about my opinion not knowing how this is actually implemented but:
If the LF sources in the LR channels are uncorrelated, i.e. separate instruments, then adding just the LF from the nearest LF source would make some sense, but more fluff on the top than anything major. However if there is only one LF source in the recording then all channels are correlated anyways and act as I described above.
If the LF sources in the LR channels are uncorrelated, i.e. separate instruments, then adding just the LF from the nearest LF source would make some sense, but more fluff on the top than anything major. However if there is only one LF source in the recording then all channels are correlated anyways and act as I described above.
Useful for setups where one uses tiny surround/mains speakers with cutoff above 100hz due to space constraints, budget, aesthetics WAF etc.
Regarding audiophile ears, even if you set the crossovers to 80hz there will be some midbass "leak" since crossovers are not ideal brickwall.
Hello, i've heard a lot of recordings that have bass and subass effect going right and left and recentely rediscovered them thanks to a coherent 20-20K rendering on each side, will you said that my music is BS ?
^ the point is that all instruments have harmonics and these higher tones yield probably 90% of the directionality of LF sources. The stuff that I am talking about is far lower in frequency than that - just the fundamental.
When I was experimenting with the flanking sub method I had one sub right between the mains playing mono to fill in a series of smaller dips. I found I could run that sub fairly straight up to around 1kHz, and I didn't notice it creating a stereo problem.
Not sure what precisely I can conclude but I think there are bigger priorities in this case.
Not sure what precisely I can conclude but I think there are bigger priorities in this case.
I'm still searching why i can localize the subbass sources at one meter of distance between the to sources on each sides , le loudspeaker units are extremely damped with heavy cones and no cabinets.
The open baffle situation isn't able to change the room pressure but i feel something, so the waves are strong enough to triggers significative gadients of pressure locally ?
Like an expolsion, the air can have a ballistic effect ?
The open baffle situation isn't able to change the room pressure but i feel something, so the waves are strong enough to triggers significative gadients of pressure locally ?
Like an expolsion, the air can have a ballistic effect ?
Even in most systems, and only playing single 30Hz sinus in either L or R, one would hear "direction" - this is not due to that one could actually detect the direction of the 30 Hz tone, but the fact that the speaker outputs so much 2nd, 3rd and 5th etc distortion that it is these component that reveal the source. If one can prove 0,1% THD - 30 Hz - 90 dB at listening position I dare one to point to the source location.
Still, I think there could be phase aspects / reverbs in say a church organ recording that might be possible to pick up by human hearing. I would not like to miss such events and therefore use my subs in stereo mode. My subjective experience makes me use stereo subs. It can be delusional - but as with any positive placebo - its nice, why skip it 😉
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Still, I think there could be phase aspects / reverbs in say a church organ recording that might be possible to pick up by human hearing. I would not like to miss such events and therefore use my subs in stereo mode. My subjective experience makes me use stereo subs. It can be delusional - but as with any positive placebo - its nice, why skip it 😉
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So, those who want to respect the norm of 20-20K on each sides are pointless and if you feel the "wind" of you loudspeakers cone movements it is because you listen them too loud.
I remember the impact of a bass drum at less than two meters
the waves were so powerfull that my whole body seems to be coupled with the membranes without any amplification, is it pontless to try to compendate the lack of pressure by a lot of heavy cone displacement ?
I remember the impact of a bass drum at less than two meters
We must be very careful when talking about the perception of LFs. That is because we feel them as well as hear them and it is almost impossible to tell which is which.
I am reminded of a couple of examples of this from my past:
When developing an audio system for a car-line we had a perceived boominess to the bass, but measurements didn't show anything out of the ordinary. We discovered that the seats had a resonance which when excited caused this perception - it was physical not airborne.
When we had a boominess in a sound room that we had constructed we found the same thing with the sofa. It resonated. Damping it out and reinforcing the structure solved the problem.
Tactile sensation of LFs is a critical part of our perception, but it can be structure-borne as well as airborne so the specifics of the situation are critical.
I am reminded of a couple of examples of this from my past:
When developing an audio system for a car-line we had a perceived boominess to the bass, but measurements didn't show anything out of the ordinary. We discovered that the seats had a resonance which when excited caused this perception - it was physical not airborne.
When we had a boominess in a sound room that we had constructed we found the same thing with the sofa. It resonated. Damping it out and reinforcing the structure solved the problem.
Tactile sensation of LFs is a critical part of our perception, but it can be structure-borne as well as airborne so the specifics of the situation are critical.
Dipoles cannot create a static pressure, but they certainly create pressures throughout the room above that. Monopoles are, of course, much more efficient at doing this at these VLF, and can create a static pressure change.