It's interesting that the standard spacing is around 1/4λ at 500Hz (17cm).
While I don't know much about it, I've read that it isn't based strictly on interaural spacing. I gather that spacing could be increased if wanted. However, I wonder whether bringing them closer together would diminish what natural capability our interaural spacing provides. I think of what Greisinger has found about perception transitions that can happen below 700Hz, keeping in mind this mic technique might be compact to allow mono compatibility, and maybe a bit of simplicity(?).
Of course and I hope to look at this in more detail this week. I will post my findings and test methods, of course.
We have to be care to look at what is, instead of what we think should be. That’s why it’s good to take random samples of a large data set.
The Beatles played on one channel and sang on the other. I guess that was groovy. Also, double basses in the orchestra are almost always on the right and sound like they are. This could be an illusion though. Much electronic music has low frequency sound left, right, and moving or ping ponging between channels. This is easy to see with power meters. With music like that I don’t get a good image from a mono sub, it also takes a fairly large room to hear it in stereo. Also, multi channel in movies has pretty good illusions of explosions happening in different places but the bass information comes from one mono LFE sub. The LFE sub disappears to me, the music sub does not. There is a lot going on with phase and dolby mixing.
The dual subs I have even out the bass frequencies a lot, they don’t do much for stereo bass at all. I don’t think I can get true stereo bass in my small listening room anyway.
The dual subs I have even out the bass frequencies a lot, they don’t do much for stereo bass at all. I don’t think I can get true stereo bass in my small listening room anyway.
My understanding is that with vinyl recordings, low frequencies had to be mixed mono to prevent the needle from jumping out of the groove. So yes, there is truth to the "all bass is mono" statement.
The first time I heard about "stereo subwoofers" was in the mid to late 2000's. I'm not sure when the audio community first learned about the benefits of multiple subwoofers and DSP tuning, but it must have been around the same time?
I feel like "audiophiles" discovered stereo subwoofers at around the same time home theater guys discovered multiple subwoofers. And the theory and technology behind home theater installations have gotten much more sophisticated since then as DSP processors have become readily available, but I think the audiophile space is still happy with stereo subs? Two subs is better than one, whether the source material is mono or stereo below 100hz.
I have multiple (i.e. 4) subs in stereo configuration, so best of both worlds?
This is a question I've wondered about! I have chosen to make my sub channels all summed, but I wasn't sure if left and right were already an identical signal.
I've been interested in what Dave Rat has to say about decorrelating left and right channels to reduce comb filtering, and it seems reasonable to me that in a multiple subwoofer system, we want the opposite. We want the same wave form coming from every subwoofer, because then we maximize the interaction between them.
I don't know for sure how to test this theory in practice, because an impulse measurement is always the same signal. I suppose someone would have to invent a way to send a decorrelated impulse to each subwoofer? I'll leave that one for someone else!
Small update, I've been looking at some recordings this morning and have found a mixed bag. A few have very little stereo content <100Hz, but many have as much and even more stereo content <100Hz as they have above that point. That was a surprise. Light My Fire by The Doors has very strong stereo under 100Hz.
Basically I look at the mid vs side levels above and below 100Hz, or the mono vs sides.
Basically I look at the mid vs side levels above and below 100Hz, or the mono vs sides.
Correct…..the wavelengths are just too long and the boundaries assure that you’re going to hear everything like a mixed bag of mono-ish sound. Engineers know this and behave accordingly.
Of course there are exceptions to the rule……but designing to accommodate those isn‘t feasible unless you have very limited genre interests.
Stereo was developed during the Beatles time. They always used the newest techniques (like multitrack). But stereo in the very early times was a radio with 2 speakers next to each other. So they did extreme mixing to hear at least some effect. When listened with headphones ... it's pretty extreme.
You don't locate the low frequencies of double bass - you locate all the other frequencies to the right! With a proper subwoofer setup you locate your double bass perfectly to the right, you locate bass instruments wherever they are panned to. It's just the very low frequencies plaid from the woofer, all important ranges for location come from your stereo speakers.
Can you name some?
To be honest - it appears to me that MOST people with subwoofers for music simply have a bad subwoofer setup! When you tune your woofer by ear it's 99% too loud. And you never get your phase perfect when tuning by ear - it's not possible, we are not sensitive enough for that.
Even when I tune by ear with plenty of experience it's most of the time too loud.
A "music sub" 100% disappears - otherwise the setup is not 100% right.
Let us not forget the low pass filter for a sub is usually not a brick wall and rolls off at a certain rate. This means there is still music coming out of the sub that is higher in frequency than the "set" cut off frequecncy.
Of course the higher frequency content is lower in volume, but it is still there and can be heard.
So the stereo sub issue is not only about what's below 100Hz. It largely depends on the filter order you have and its cut off setting.
Try this simple test..... play a tune with the main speakers off and only the subs on. You may be suprised what you hear. I was.
Of course the higher frequency content is lower in volume, but it is still there and can be heard.
So the stereo sub issue is not only about what's below 100Hz. It largely depends on the filter order you have and its cut off setting.
Try this simple test..... play a tune with the main speakers off and only the subs on. You may be suprised what you hear. I was.
That is not what I have found. It's a mixed bag, even across genres. See my thread here.
https://www.diyaudio.com/community/threads/is-there-in-bass-no-stereo.412211/latest
In college I had a neighbor who was setting up his stereo in the dorms. He had floor standing speakers and a subwoofer. He was turning the gain and asking me when I thought it sounded the best. I consistently thought that it sounded best when the sub was turned off...but I didn't know it was off.
His response was something like, "I have a subwoofer, so I should use the subwoofer."
I'm sure a lot of people feel like this. They buy a sub because they believe it will make everything sound better, and once they have one or more subs, they feel obligated to turn it up until they can feel it...or atleast see the drivers move. And this works fine for movies.
But what I'm wondering is how many people set up multiple subs for music and sound quality, rather than doing it because that is the current trend? And amongst those who are seeking sound quality, what configuration is the best subjective result. What details are you actually noticing that tell you if it is good?
I approach this as a learning experience. I don't think it is right to try to make music sound in some way how I want it to sound; I want to hear it as close to the artist's intention as possible. So just shoot for a relatively flat frequency response down to 20hz. I have a slight "house curve" right now, but I'm not sure I'll keep it. I see people arguing that this is the way music is suppose to be, but I'm pretty sure that studios shoot for perfectly flat impulse response to create a reliable reference.
Concussive comes from the bass matching with the upper frequencies. Kaboom in the real world comes from one source, kaboom in audio comes from ka from the midrange and boom from the subs. It’s almost always delayed.
This is difficult to reconcile since movies often have built in KA- Boom where the sound is separated for visual impact.
Check out cassandra wilson, blue light till dawn cd. Some recordings have alternate kettle drums left right.
I like to just talk frequencies, and skip the textual categories, so there's less confusion.
Also like to think in terms of subs, and mains.
In this thread, the idea I was trying to present with the "get the kick drum out of my butt" post, was that a sub has a directional concussive force, and multiple subs often lose that auditory and physical sensation.
For me, a sub typically handles 100Hz down. I use a linear-phase 96 dB/oct xover between sub and main,.
I am 100% certain, the bulk of concussive force like from a kick drum, comes from my sub(s).
I know like most of us, that transients including bass transients, are full range phenomena. But i also know, concussive kick is dominated by 100Hz down.
And often gets smeared as multiple subs are added.
It is very easy for me to mute any driver section, solo any driver section, solo any LCR speaker playing stereo summed to mono, play stereo, or matrixed LCR.
Each LCR speaker which are the same, also has the same sub underneath it.
So it's easy to discern things like a sub's concussive force alone, or whether multiples add for more force, or whether a track has mono sub or stereo sub content....etc.
Highly recommend a setup like this for sheer playing around/learning/experimenting..., my2c .
Also like to think in terms of subs, and mains.
In this thread, the idea I was trying to present with the "get the kick drum out of my butt" post, was that a sub has a directional concussive force, and multiple subs often lose that auditory and physical sensation.
For me, a sub typically handles 100Hz down. I use a linear-phase 96 dB/oct xover between sub and main,.
I am 100% certain, the bulk of concussive force like from a kick drum, comes from my sub(s).
I know like most of us, that transients including bass transients, are full range phenomena. But i also know, concussive kick is dominated by 100Hz down.
And often gets smeared as multiple subs are added.
It is very easy for me to mute any driver section, solo any driver section, solo any LCR speaker playing stereo summed to mono, play stereo, or matrixed LCR.
Each LCR speaker which are the same, also has the same sub underneath it.
So it's easy to discern things like a sub's concussive force alone, or whether multiples add for more force, or whether a track has mono sub or stereo sub content....etc.
Highly recommend a setup like this for sheer playing around/learning/experimenting..., my2c .
Interesting that chest thump is at 25, boom punch is at 125, and whack is at 1,250. I’ve always thought of those sounds as being part of a wideband sound. I’ll get some noisy recordings out today and listen through an equalizer.
Also, I think in contra bass, bass, tenor, contralto, alto, mezzo soprano, soprano, … Classically trained I guess.