I've been chasing infrasonic ranges in home audio for over 2 decades. You can't "detect" these frequencies in the normal way. You experience them by way of your physical environment being excited by them. Feeling pressure waves move through whatever you are standing/sitting on can add an entire new dimension to the experience.
I used to run experiments with friends and family using a 800L ported subwoofer tuned to ~13Hz with a 40Hz cutoff. Not one person would mistake it for being on vs off. Certain content makes these frequencies substantially more obvious. Classical music performed in large concert halls is one surprising candidate outside of Mission Impossible scenes. Being able to "feel" the original auditorium in your listening room is a very cool effect to me.
I'm perhaps dating myself a bit, but I remember being caught off guard the first time I walked onto the dancefloor at Fabric (a famous nightclub in London). They'd put mechanical transducers under the floorboards and hooked them up to the audio feed, effectively turning the entire dancefloor into one giant subwoofer. [1]
It was absolutely a gimmick, but a tremendously well-executed one. Being literally lifted a few millimeters into the air when the bass dropped was such a visceral experience that I'm still surprised it wasn't widely copied in other venues.
> I'm perhaps dating myself a bit, but I remember being caught off guard the first time I walked onto the dancefloor at Fabric (a famous nightclub in London). They'd put mechanical transducers under the floorboards and hooked them up to the audio feed, effectively turning the entire dancefloor into one giant subwoofer. [1]
I'm dating myself too by saying I always wanted to go to Plastic people back in those days and hear Youngsta dropping dubplates on SLs on a Funktion one system in such a tight room(s), but I had to settle for blowing out subs at 96kbps on pirate Radio (RinseFM) for many years until I finally got to seem him in the US with a Funktion One at Servante's and then the Blackbox in Denver, and a few more times at other venues on subpar sound-systems which didn't have the same effect.
Crazy stuff happened at Plastic People, so many crazy stories from residents to one-nighter bedroom DJ appearences made it sound like the holy grail of the Underground British Bass Music scene. That and I was still in my 20s, which will always add an extra glorified lens to anything.
I will definitely say something takes over at those sub-bass frequencies (20hrtz) on a proper system, it goes through your body and makes people go crazy on the dancefloor. Pinch articulated it best in my opinion [0]. I met him at a small venue in Hollywood where no one but me knew at the that hour know who he was and we had a really interesting about his label and music in general before his set along the lines of that interview around the same time, he is an incredibly smart person: he even dropped a dubplate (DS - Memory loss VIP) for me and was even kind enough to rewind as it went off!
Plastic People (Oxford Street or Shoreditch) was indeed an amazing experience. I went a lot. But its soundsystem was not quite on the same level as Fabric’s or The Ends - those two both seemed to have the sound system more integrated with the rooms design with huge reserves of power so everything was crystal clear and no ringing ears afterwards.
PP did have a better sound system than 99% of clubs I have been to around the world though - it was no slouch.
Tsunami is another good system in the US, unsure if they've been doing stuff since quarantine closed everything up. Analog in Brooklyn had a pretty wild SBS Slammer setup, but an ownership snafu caused that go away after only a couple years. Nowadays' indoors setup is the best in NYC for me – Randomer blows the lid off once or twice a year. This was him in 2019: https://imgur.com/a/ACocI87
> I enjoy seeing some heads on HN :) Hello from NYC! Had dreams of going to Plastic, RIP
Easy!
I think we all did back then, we were the outsiders looking in and that was Mecca; I started listening in 2006 when Youngsta's Dubstep All Stars came out so to us it was pretty rare thing that few out of LND had ever heard of, but we eventually had nights in CA. It was mainly brostep noise, with the occasional UK talent if you were willing to drive on a weekday to LA and drop lots of money, which I didn't have at all back then. But I saw Distance back in 2009 at the Roxy on a weekday and went to work and slept in the parking lot for a few hours after the rave just to see him, but I finally got to hear his remix of Changes and then Beyond on a decent rig and just went into some eyes down thing, and which made it all worth it.
So, when that wasn't possible I stuck to pissing off my neighbors with my paltry bedroom DJ antics on vinyl I had shipped from Redeye every 2 months from London and listening to RinseFM to fill the void.
NYC? Isn't Joe Nice still doing/running things out there?
I know the Dub Warz nights were the US' version of DMZ for a while, and was sort of a soundclash [1] theme to it, right? I saw some footage of Kahn at one and the dubplates he was pulling out during his set were insane.
I've been out of the scene for a while now, last event was before COVID (late 2018 or early 2019) where I was convincing Youngsta to get SP:MC to Denver since Nicole repped'd so much talent and SP;MC is badman (MC/DJ/Producer), which he did later in the year but I couldn't make it out.
I still can't believe Toast bigged me up at a rave ahead of Leon Switch's set when I told him I was part of the original Thursday night 'brandy and bass' crew as he was walking up to the stage and I was talking to Leon, which for those of who listened from the US back then seemed impossible but they were just normal lads happy to see people came. I asked him if he could drop The Fifth VIP, and when it dropped I ran up to the booth from the dance floor trigger fingers in the air and we both had smiles ear to ear (reminding me of this [0]).
Apparently he started including that track in his sets from then on.
Good times!
I'll send you pic of my signed copy Surge/Cold Blooded when I get back to the US. I got it when I met Youngsta a few years after it got pressed. I used to hang it on my wall above my decks, you're probably the only one HN that would even know who that is let alone appreciate the golden era we were going through back then--talent from DnB and Dubstep were crossing over so much back then and that was the when the genre felt so free and open to explore what it wanted to be.
Leaving you with this one, as I just fired up the sub and will be signing out with this [2] tonight with a spliff.
Safe, those were fun times, but if you really want a step back into time check this one out [0], all that talent in the BBC studio with MAH was in insane. I remember that picture they took floating around back on DSF, too!
I bagged a few Loxy and Resound VIPs on wax last night (CLS001/INV:LOS) as I was having such a good time remembering all those nights. I'm glad to see others enjoyed those days, too. I tend to forget how much Stella sessions influenced my mixing until I remember what Skream used to sound like back then, I learned how to vary up my track selection and mix down-transition not from Distance or Youngsta (both were way too talented for me) but from Skream which is way more raw.
Something about hearing Mud into Ruffage (with the crowd shelling) makes me feel like I'm back in those dark rooms; Skream and Distance look so young in that video it almost makes you think in there right mind gave them that can of red stripe! And since I'm about the same age as Skream, it makes it even more nostalgic.
I remembered that a kid from Scandinavia (Sarsy) who was too young to be there back then but loved those days searched all over the internet and pieced together a bunch of Kryptic Minds dubplates from radio shows or otu at clubs on ableton on uploaded them over the years on soundcloud [1], now that was dedication!
This one's a favorite of mine, thank for the reminder. Also, you know what brings me back? There's an old computer music production video with El-B Ghost showing off his setup and breaking down his production notes on a track [0]. It's amazing how someone who's not big on computer and technology can figure out everything they need through sheer intellectual brute force and determination.
For a minute there I could not get enough Skream, Loefah, Caspa, Appleblim, Boxcutter. I still listen to them, but it's hard to reconcile that a lot of the original pioneers have moved on. There's a new sound now, more of a wobble - check out mixes from JVIZ and his podcast called JVIZ Presents: Earthquake Weather. It's still new generation dubstep, but it's more roots oriented, and has a fresh out the basement feel to it. [1]
> I still listen to them, but it's hard to reconcile that a lot of the original pioneers have moved on. There's a new sound now, more of a wobble - check out mixes from JVIZ and his podcast called JVIZ Presents: Earthquake Weather. It's still new generation dubstep, but it's more roots oriented, and has a fresh out the basement feel to it. [1]
I guess it really depends where you are in the US, because when I'm in the US I'm mainly in CO and this kind of set happens (Kahn and Neek) in Denver on a Tuesday nights [0] or half of Mystic State dropping 140 [1] like it was a night in London (prefect example of this thread @ 1:00 mark) because of how healthy the scene/community is thanks to Nicole and Sub.Mission. It's come a long way from the aggro-brostep noise that it was back when it first came to the US!
I think the sound progressed so much from the early days; but for me 2008-14 were the real glory days with so much talent and collabs from DnB/Dubstep/Grime/Purple etc... It also helped I had actually been working in Europe most of that time so I got to go to some raves in the EU/UK whenever I had the chance.
It's been a while since I've been to a 140/170 night since COVID messed up everything, but I'm glad to see it's back. Denver really was/is like a mini-London time capsule of that era and sound so if you can make it out to a night to re-live some of those nights, the system in the mainroom is RC1 spec and sound-management are a bunch of heads, and the bar/mezzanine room usually has DnB nights (ReCon) with a more tamed system but still a good spot to rave.
I'll drop you a line when I'm back state-side and we can try and go rave in Denver.
Sounds good to me :) I'm in a rural area, it's all lagged behind by a few generations out here, so the denver scene is probably insane compared to what we have. By the time it got to us, Borgore and Rusko were having their time, but -every- once in a while, you'd catch a 'dubstep' track download that had a distinctly different sound that didn't leave your ears ringing, it left my soul ringing, and rattled the keyboard right off the desk. That's when I knew I found the right stuff. I think the first one that comes to mind was Loefah.
reading your comments brings back memories of the good ole days..Denver still has the best scene in the US. the Midwest holds it down too but its slowed down in recent years, except for infrasound which is always worth the trip out. ill never forget seeing Quest in the basement of a bookstore in downtown Minneapolis when i was randomly there many years ago. I'd love to go to the UK to see some shows, your lucky to have been there. recently, the youngsta, ntype, hatcha project Trilogy has got me wanting to hop on a plane. speaking of ntype, he's got some US shows in a few weeks.. some day id really like to send it to Outlook too. the brostep movement is fading, or atleast from my perspective it is, can't say I didn't partake back in the day, but I grew out of that fad pretty quick. however I will say, the loudest show I've ever been to was excision in Madison Wisconsin the first year he toured with the 100k Watt PK rig, before his style got really out of hand. to this day I haven't felt my insides vibrate like that again..unsettling to say the least
The first time I ever took MDMA was in Fabric many years ago. John Digweed was playing. I will never forget the sound and the feeling of that dance floor.
~2010 worked in Farringdon and this was our local club. Went in Fridays after the pub. Once took a holiday to cycle tour Romania, ran in to Romania's most famous DJ in a ski resort, and he told me his dream was to play there. Almost choked on my beer...
You can get a similar effect with a floating or semi-floating floor and a huge sub hanging from the ceiling. You have to tune it though.
If you are on the Bay Area, The Great Northern had a setup like that on the hallway at the entrance before the main floor. They use VOID for their soundsystem but I don't think that particular part of the setup is COTS.
they actually had to turn down that system for being too loud. but at that level, none of the stuff is really COTS because it requires a ton of tuning due to each particular venue's layout and acoustics
I don't think the subs hanging from the ceiling on the hallway in front of the bar are COTS. If they are it's not on their websites or catalogues. Like it may be the same cone but it's not the same enclosure or anchoring.
Most club owners will not spend half to two thirds of their budget on room acoustics and speakers. They build an expensive looking bar and VIP room instead.
> Most club owners will not spend half to two thirds of their budget on room acoustics and speakers. They build an expensive looking bar and VIP room instead.
It also is worth noting most people aren't really going to clubs just to listen to the music, so much as they are to socialize and drop money on booze. And I guess now to record themselves at an event for social media likes/marketing/influencer stuff.
I've seen far too many people having full blown conversations for 20+ mins on the dance floor over the years in other genres and could over hear their conversations and it was so off putting, where as with bass music their was an etiquette of going outdoors in the smoking area if that is what you wanted to do as the dance floor was for just that.
It's also worth noting when you step on to the dance floor with those heavy systems (Funktion One/RC1) and music optimized for those low sub-bass levels the whole place would shake [0] from the bass weight (bar included) so it was pointless to try and record anything worth showing if they all had these systems this way and only until recently have mics on phones been good enough to get anything but boomy noise.
The issue with those ultra-deep frequencies is that the waves become really long and the acoustics to make them behave become increasingly unwieldy the lower you go.
Dampening a the 9.8 meter long wave of a 35 Hz tone is already hard, dampening a ~19 meter long 18Hz wave mist be pretty much impossible.
The only thing more amazing than loud low bass is bone dry loud low bass that starts and stops precisely.
The only thing more amazing than loud low bass is bone dry loud low bass
Bone dry sounds awesome.
My frustration with rock venues is that there's usually lots of bass, but it's super sloppy. Everything below ~80hz sounds like a giant audio sludgeball.
I feel like even a little bit of tuning and room correction (the sort one can do at home with freeware and a $89 calibrated microphone) would help tremendously, but there's no appetite for that on the part of concertgoers or sound techs.
I'm glad there are dance venues getting this right.
Hey stemming from this is a lot of talk of eq and rooms. I hope no one minds but may I also add something for budding sound techs: mics and speakers and why it’s easier for a dance venue compared to a live rock venue. These are what I’d call newbie-ish problems so forgive me if you’re talking about pro level rock venues. Low end builds up on stage and unless managed gets into mics you don’t want it to leading to lots of sloppy bass. One might low cut mics that aren’t meant to be receiving low end content for example or mute ones not in use. Another thing is that producing bass frequencies requires the speaker diaphragm to move more air and so there’s a slower transient response or time to complete a cycle. If you send too many different things at once to the low end the poor thing gets ‘confused’ and things get sloppy. Double hangs seem to be getting quite popular for this reason, less instruments fighting over the same cycle. Otherwise don’t send everything you can to the sub just because you can. Personally, unless there’s some reason to, I rarely let anything go below 80 anyway and defs not 60. I hate giving advice, tell me how I’m wrong.
It sounds like you frequent some questionable venues. You'd be hard pressed to find many live sound engineers operating today that won't be working with a dual channel RTA (Smaart, or similar) and keeping an eye on the venue's transfer function during a gig as the acoustics change (different crowds, temperature etc).
That sounds like something I could do for my own loungeroom. I mean, I have no fancy gear but it seems like a process to make the best of what I have. For the cost of a decent microphone it could be worth it.
- use REW (Room EQ Wizard, free) to take several measurements in your room, in the listening area(s)
- REW will average them and generate an inverse EQ curve to compensate
- you can export the parametric EQ settings and use them anywhere that supports parameteric EQ such as EqualizerAPO (windows, free) or CoreAudio parametric EQ units (Mac, free) or in a standalone hardware device like the MiniDSP (~$100 IIRC)
you can always tweak the parametric EQ curve to suit your personal taste, like some extra bass or extra treble to compensate for aging ears (like mine)
Good starting tip, but readers should be aware that you can only help with frequency domain issues here.
The thing that might break your acoustics might more often be time-domain issues. No EQ on earth will get rid of the reverb in an empty warehouse. The same is true on a smaller scale in your place. And because it is smaller you will have specific frequencies (room modes) ringing out longer or shorter at your listening position. These are issues you can only fix with actual physical alteration of the space by putting in more stuff and adding absorbers, diffusors and such.
So EQs can help, but you should also think about the actual surfaces of the room itself.
Forgive me! It's a broad topic, and one must always choose what to cover in a short internet post.
In short I think speaker selection and placement are about an order of magnitude or two more important than everything else. If those are the only two things you pay attention to and don't drastically screw the rest up, you'll have a nice sounding system.
Room correction (which is also speaker correction) is probably the next most important thing, although well into optional territory IMO.
There's lots more that I fuss over, but I don't want people believing that they need a lot of elaborate rituals and room alterations to achieve good sound. It's not true, it's counterproductive, and scares people away from this really fun hobby. =)
No EQ on earth will get rid of the reverb in an
empty warehouse. [...]
So EQs can help, but you should also think
about the actual surfaces of the room itself.
You're completely correct, but I don't emphasize room issues too much for beginners. Why? In my experience, most residential rooms are actually pretty acoustically decent for a few reasons.
1. They tend to be filled with comfy padded furniture, bookshelves, etc. which do a nice job of breaking up high and mid frequency reflections.
2. The brain already performs a lot of "room correction" and it's particularly good at performing it in familiar spaces like our own homes.
3. Most people's home systems (especially those of beginners) aren't putting out the kind of massive low frequency output that's really troublesome to tame.
Of course there is always going to be a room mode or three, usually with a prominent one somewhere in the midbass range.
https://holoplot.com/ give a two dimensional array. The hangs of speakers that you see at most concerts are a line array, and within each of them will be an array of transducers that control the pattern of the individual cabinet (eg cardioid subs. You'll also quite see digitally steered columns in a lot of spaces these days too. None of these remove the reverb, but they do provide control over where energy is directed to minimise it occurring in the first place.
Neat! "All" you need on top of that for reverb cancellation is for the 2D array to be a surface enclosing the region of interest and for the way it itself mechanically interferes with the sound to be predictable. If you're a bit careful with where you send the sound then perhaps the top/bottom exits wouldn't matter too much.
REW is an excellent piece of software. You may be able to make some improvements for a single listing positioning, but just a heads up that you can't EQ away room level issues.
Right, REW is not a cure-all. Speaker selection and placement are orders of magnitude more important than anything else.
After that comes room issues. Surprisingly I think most residential rooms are decent, acoustically, because they tend to be filled with padded furniture and such and aren't overly reflective in obnoxious ways. Also most people aren't running massive subwoofers and if they are, they generally know what they're getting into. With all that said, I think REW is great for cleaning up the rest.
If all people did was pay attention to speaker selection and placement, I think most people would wind up with a very good listening situation.
And if all people did was pay attention to speaker selection and placement and clean up the remaining issues with REW, I think most people would wind up with a great listening experience.
Good luck! Corporate meeting rooms tend to be a bit of a worst case scenario for sound.
The absolute worst case scenario for sound is an empty rectangular (or cube) shaped room with bare walls and most corporate meeting rooms come pretty close to this.
Yeah, foam deadening has gone a long way for us to reduce echo and other issues over Zoom, along with many directional mics condensed into a mixer. I am a bit of a stickler with sound quality over conference calls, so anything to improve it is very interesting to me.
I'm curious, if these waves aren't heard, is there much need to dampen them?
Are we talking about to reduce the physical effects on those around, or is there a mechanism that makes these audible at some point?
Without damping them you get a few problems around standing waves and room modes.
Those modes will make it so that you have some areas in the room where that frequency will be uncomfortably loud, and other areas where it goes away entirely.
The article is talking between 8 and 37hz, iirc. General given hearing range is 20hz to 20khz. So the vlf is flirting with that range. Throwing in an aside here, inaudible might be a better word than undetectable. I was always told just because you can’t hear it doesn’t mean you can’t feel it, for both high and low end. As for why you might want to dampen inaudible low end aside from a fastidious want for control, or not wanting a build up of that feeling only for some lucky punters, you might just not want to shake a ceiling tile loose or a vibrating air duct might be annoying: there is more energy in the low end.
This is one of the factors that make decently large, remote outdoor electronic events (bush doofs etc) such an experience. There's no better way to enjoy the tranquil surrounds of nature than slapping a giant Funktion One system into it.
It bums me out that most music recording and reproduction equipment drop off drastically outside 20-20,000hz. I wish that we could open that range up a bit more, the low end for haptics and the high end for the other beings in our house that can hear in that range (dogs, cats, etc)
The new amplifiers from Purifi are incredible when it comes to delivering a flat response to 0hz, at high power into complex loads.
I’m curious to see if I’ll be able to tell a difference in how their amps coupled with their new power supplies drive my ButtKickers :)
I wonder if you could just transpose the lower end, say 20-30 hz down to the 10-20 hz range since you can't hear them anyway so it won't sound bad, but you would "feel" it.
That’s what subharmonic generators do and I’ve heard mixed reviews.
Like, if you were to take the bottom octave of a piano pieces and replicate it on the next octave down, it could easily sound like crap. Might sound decent for some songs though?
I've got a lot of classical SACD and DSD recordings from many moons ago that were mastered very well.
You are right that you need to pay attention to the entire signal chain. A bad DSP or DAC somewhere in the middle will make your quarter ton of LFE completely worthless.
It's not even necessity a "bad" device. Sometimes circuit designers add a DC blocking capacitor on an input to avoid damage to the equipment (especially in an high powered analog amp you might want to avoid feeding DC into the speaker).
The digital domain is much more forgiving; reason why I preach going all-digital up until I2S into the class-d amp IC :)
(No, I don't do that at home due to lack of available equipment - I'm still fully analog after the DSP/DAC combo).
Rocket launches must have so much of these frequencies. Being at one was nothing like I expected after listening to the audio of launches on normal devices.
> Rocket launches must have so much of these frequencies. Being at one was nothing like I expected after listening to the audio of launches on normal devices.
Agreed, I've been to lots of clubs and listened to heavy bass music most of my adult life. Launches are still indescribable and it just put an instant smile on my face and still gives me goosebumps after all these years as I wasn't even that close to the launch site (bluffs about 10 miles away): I saw the Falcon 9 launch at Vandenburg that made people think the aliens arrived [0].
As a music producer I've been ranting for a while now about how a lot of modern music cuts low end out in order to be louder on mobile devices and on streaming services like Spotify...
It's also been reported that the algorithms on sites like Spotify favor music that has less low end on it (especially pop songs), which only encourages this trend of loudness.
I've found that sub frequencies are also a good anchor for preventing music from being turned up too loud into areas where ear damage occurs... At live events in the past I've frequently had to wear ear plugs (or rolled up tissues in my ears if I forgot plugs) in order to protect my hearing from the trend of louder music composition.
In all of our music, I usually tune low end frequencies to create bass pressure that can only be felt on excellent sound systems, this is also likely why our spotify stream numbers have been low for years now, despite us doing well in places like audiomack and YouTube (where bass music aficionados are more likely to go for music...
I've long wondered about skipping the speaker and just going for a method to create long-waves to vibrate everyday environments. In sync after tuning it could be like a 360 earthquake internally.
If it works for microphones to catch radiant sound (as I learned in on-set film production) then it probably works the other way too (as I learned when in the booth watching a DJ friend plugged his headphones into the mic jack and used one earpiece to talk to the crowd).
There was this DIY design I came across decades ago that I've been trying to re-find for years. It had 4 12-15" cheap paper cone woofers mounted 2 sets of face to face with both sets axially loaded and wired so that all 4 cones move together. The whole thing was put in a big loaf of bread shaped box and then some kind of bandpass something and vents to the outside. It was reportedly very good for this low low base stuff, not so good for higher end responsive bass stuff. Anyone have any pointers for where to look?
Interesting. They also have flight simulation among the applications, which made me recall an old family friend who was a passenger airline pilot during the 70s and 80s. He also played a bit with older Flight Simulator versions, and one time he commented "yeah, it's very accurate but it can't be the real thing: you don't just pilot with the instruments, you also need to feel the airplane with your ass".
They're pretty common in more expensive sim-racing rigs too. I wish I could add some to mine, but I've read online that it will be perceptible to the downstairs neighbors without a lot of floor damping.
Dumb question but how is the piano capable of generating these frequencies? I thought the strings couldn't get nearly long enough and the low frequencies that you heard from piano were just psychoacoustics.
The amount of space needed for a certain frequency in air is different to the length needed for that same frequency in a wire.
It might help to see the formula, which is:
Frequency = sqrt(tension/(mass / length)) / (2 * length)
So length, tension, and mass are all factors. Modern upright pianos also string the bass strings diagonally to give them a bit of extra length.
Having said all that, the same bass notes on longer pianos that can fit longer strings sound more sonorous. I'm not sure exactly why that is. For an extreme example see for instance the Alexander Piano[0], or the Klavins 370[1].
Plenty of organs go below 20Hz though, and even an otherwise good sound system starts to struggle around 40Hz if it's not built specifically for playing such notes.
I'd say timpani drums, tubas, largest/lowest pipes on an organ (if the hall has one), and double bass. Contrabassoon, the lowest notes of a piano. Other percussion like a gong.
Basically, by necessity, whatever the largest instruments are in diameter or length. And then it's all being amplified by some mutual resonance with each other and possibly other physical structures like the floor.
Your car likely does not have enough volume to accommodate the required equipment. Just one of these subwoofers occupies the entire bed of a typical pickup truck. Two of these are used in my listening space.
The lower the loudspeaker goes, the bigger it needs to be.
The smaller the volume of air you need to move, the less this matters (which is why IEMs have more bass than tiny bookshelf speakers, despite being way smaller. It should be theoretically possible to do just replace the trunk and backseat of a saloon and have a 2 seater with good bass extension
IEMs can develop high pressures at low frequencies because the volume of air they are moving is very small. A compact car with the windows rolled up here is analagous to the ear canal in the IEM. If 50% of the internal space of the car is speakers (easily achievable if you remove the backseats and use the trunk space), then you ought to be able to generate large pressures at low frequencies as long as the windows are rolled up.
I'm not sure that's entirely true/necessary. Standing waves in the cabin can help compensate a decent bit. A good transmission line speaker can likely fit in the boot/trunk, though stereo imaging will likely be poor in any car audio system I think.
You can at least partially trade width with depth, that is, making a speaker narrower but design it so that the cone can travel farther and move the same air volume, but it also have drawbacks, and thicker speakers are also harder to accomodate.
They really should have said "inaudible" rather than undetectable. It is detectable (as they note)... just not as what we think of as sound. [edit - fix; how did I leave out words?]
I don't know how common this is now, but at one time it was popular in the car audio world to mount "ass shaker" devices to seats to emphasize bass feeling without requiring the space of a normal speaker. I think cinemas have done this too.
Their specific claim is "not consciously detectable" (different from "inaudible"), which they had a side-experiment to verify:
>To confirm that the VLFs were not consciously detectable, 17 new participants completed a two-alternative forced choice task using the same VLF speakers ... Participants performed at chance
I have to say I think they did something wrong then in their testing of detectability? On a club/concert setup, or even plenty of subwoofers, you can very much feel the 20-40hz range that they are adding/removing in figure C. Something seems off here.
I know places that do it. One was three block away from where I lived. It made goddamn impossible to sleep, these waves travel trough ground like it's nothing and you don't usually hear them, but when you lay on the bed you can feel them it scrambles your brain.
I used to love crouching at a rave and feeling the super low bass. At standing height all the human meat soaks up the vibrations, at crouching height you get the full power of the bass bins snaking through everyone's legs
On the EQ, there's a really tight frequency band, near the top of a kick drum, that you want to boost to get that chest-thumping feeling that really gets people into it.
Great read, and happy to be a part of the "how low can you go" trend in guitars with my Agile Baritone LP style 27" scale. Sounds epic dropped lower run through a bass amp.
2nd year throwing the party they setup a nice stack of hay bales near the back of the dance floor. And then bought a double wide trailer and parked that to right of the stage, the camp site is also on that side.
Well animals can hear sounds at frequencies that we can't, so the cutoff shouldn't be when we can detect something. But in that case, do we set a cutoff on the lowest/highest frequencies that we know some animal can hear? Then we might discover something later that increases the range, what do we do then? It just makes more sense to generalize sound past what's actually audible, in my opinion at least.
(I was implicitly including other animals, some of which can hear sounds outside the human range, even if they cannot participate in online conversations.)
Exactly. It's not sound, it's infrasound. "Sound" means audible to humans, much how "light" means visible to humans (e.g. radio waves are not considered "light").
I couldn't find if this is the case in the paper but unless they created a pure tone at 20Hz (i.e. a sine wave oscillating at 20Hz) any sound will have higher harmonics. Even though the fundamental is 20Hz, it'll also sound 40Hz, 60Hz, 80Hz (in decreasing volumes) etc and these higher harmonics can or will be audible. Besides, especially in Western classical music, when we use double bass at very low frequencies, it's not always meant to be audible, it's sometimes meant to create a physical effect i.e. feel it through your skin/body instead of your ear, similar to percussion in some settings.
> Some VLFs were above the predicted perceptual thresholds, although consciously undetectable. Because VLFs were relatively near thresholds (that were determined in silence) whereas non-VLFs were far above thresholds (see supplemental material), we believe that auditory masking of the VLFs contributed to their being undetectable.
> To confirm that the VLFs were not consciously detectable, 17 new participants (one of whom participated in the concert experiment) completed a two-alternative forced choice task using the same VLF speakers in the LIVELab. On each trial, participants heard two pairs of 3.5 s excerpts from the concert audio and indicated which pair’s excerpts were different (all excerpts in the trial were identical except for the presence or absence of VLFs in one excerpt). Participants performed at chance (mean 49.8% correct, SD = 4.56%), and a Bayesian t test on participants’ rates of correct responses indicated substantial evidence for the null hypothesis — that participants could not detect the presence/absence of VLFs (n = 17; prior = Cauchy distribution centred on 0 with width = 0.707; BF0+ = 4.36; Figure 1F).
Do I have to quote the whole article for you to read it?
If deeply wide low frequency waves are detectable as we both agree, that would genuinely explain why the horses and wildlife fled the area around the Mt. St. Helens eruption with seemingly uncanny head start. Enough of a mass run that it was observed and noted. Just like here in North Texas when big prairie thunderclaps can rattle just about everything in a brick house set solidly on a foundation.
Anyone who's ever been to a live music event can attest to "detecting" sound <20Hz without their ears. And it's pretty obvious how feeling the sound in your body, especially the percussive elements, would encourage dancing.
I can confirm this. It’s also nice to see a new paper on this. I’ve been using this knowledge professionally for the last 24 years as a front of house engineer.
Anecdotal story time:
You’ve may have seen this video, or some variation of or maybe even the TED talk inspired by it…
…what few people know and most don’t because I have not shared this publicly (in media at least) is that I was mixing this show.
We we’re on in the middle of the day and a few bands had been on before us. By this point in my career I had already been to the gorge several times and the hill has always been a problem. On this particular day during the already frantic pace of a festival changeover with no sound check, the system tech is talking up the new delay stacks they beefed up for this year. This was great news and were geeking out and he’s showing me where they’re at on the console which is of course buried under some convoluted series of navigation and button presses to get to, given the atrocious UI design of digital electronics. Now generally given these circumstances, convention holds that the delays are set to some arbitrary value and the guest engineer generally need not concern themselves as the system techs will be monitoring them. To my horror were getting to the dancy part of our short set and I’m doing my due diligence and looking back at the hill and wondering whats up, why isn’t anyone dancing!?! The delays were not turned up! None of the previous engineers that day had thought about them and the techs while excited had set them to some arbitrarily safe low level. So for me this video marks the moment I checked the delays that day and turned up the bass. So if I may add to the TED talk; if you want to start a movement, turn up the bass.
This effect is literally everyday at work for me and why I have a job.
This effect is also used in dramatic movies, for example sci-fi and horror. It was used in the recent sound-award-winning Dune movie, where they used some interesting techniques for recording low-frequency sound, like recording moving sand dunes:
There's also an app for detecting low-frequency sounds, although it seems surprising that cell phone microphones have the necessary frequency sensitivity. They seem to use some interpretation processing though the code is proprietary:
> although it seems surprising that cell phone microphones have the necessary frequency sensitivity
IANAAudio/Signals Engineer, but shouldn't microphones pick up everything down to 0Hz by default? For the stated sampling range, I assume the top end is limited by Nyquist theorem, and the bottom end by a low-stop filter in software.
> "All current iOS devices include built-in microphones. These mics tend to be very consistent from one unit to the next, and are wide-range. However, Apple does include a very steep high-pass filter (which cuts low frequencies), presumably as a wind and pop filter. The low-frequency roll-off for the internal mic in these devices is very steep, on the order of 24dB / octave starting at 250Hz."
Normally you find the frequency content by using a discrete fourier transform. This takes a number of data points and transforms them from time domain to frequency domain. It's basically a mapping from one vector space to another. And the frequency domain vector space has fixed base vectors. The basis vectors correspond to frequencies, and being basis vectors they are actually independent of the data. What is data dependent is how much energy those frequencies have. A given window size will have a minimum frequency it can detect. So the low frequency cutoff is actually implicit.
If you want to get lower frequencies you have to use longer windows, and that loses temporal precision, so you have to do a tradeoff. In a fascinating twist that is actually closely related to the heisenberg uncertainty principle.
The larger the wave size is compared to the physical aperture of the microphone the less efficient the surface is at converting the pressure wave into whatever (up to about 1/4 wavelength where things get weird). Electronics can make up for a lot of this to even things out but there are physical limits.
It's reciprocal is more well known. To generate long wavelength sound efficiently you need large speaker apertures. In the same way you can't really use a 2cm speaker to generate bass you can't use a 2mm microphone to sample a 5 Hz (70 meter) pressure wave in the air.
Not necessarily. A lot of analog front ends have a highpass filter around 8-20 Hz (the audible threshold). I don't really know why, it might be to prevent DC drift so that there is no asymmetrical distortion in the signal fed to the ADC, just speculating. But I do know a lot of systems just won't capture <20Hz.
Not to rain on the parade, but in Fig. 1-D I see by comparing the two graphs that the VLF is almost always turned on in sync with a bass drop or with the start of a new section of the song, which I think is correlated with people suddenly dancing more vigorously. I didn't read the main text, does anyone know if they address this?
As someone with with sensitivity to low frequencies: yay, yet another excuse people will use to turn every single public space into an inaccessible bassy sensory hellscape.
don't worry, your sensitivity to all sorts of audio frequencies (low and high, and in between) will start fading soon, as it happens with the accuracy of every other human senses as we get older ;-)
Some people may find this offensive, but try to imagine the person who made the study was deaf in the low range of frequencies and did the study without getting it reviewed by anybody. Now read it again...
> To confirm that the VLFs were not consciously detectable, 17 new participants (one of whom participated in the concert experiment) completed a two-alternative forced choice task using the same VLF speakers in the LIVELab. On each trial, participants heard two pairs of 3.5 s excerpts from the concert audio and indicated which pair’s excerpts were different (all excerpts in the trial were identical except for the presence or absence of VLFs in one excerpt). Participants performed at chance (mean 49.8% correct, SD = 4.56%)
Ok... I'm failing to form the abstract connections necessary to understand the point you're getting at here.
Is the implication that it's inherently unethical to subject others to stimuli under the presumption that the stimulation is uniformly harmless? Surely that's the whole point of studies like this; to rigorously probe such assumptions within the relative safety of a controlled experiment?
I just find funny the idea that people might spun research into something they aren't able to do themselves but is completely obvious to everybody else.
Not saying it is the case here, just pointing a potential for humour.
> To confirm that the VLFs were not consciously detectable, 17 new participants (one of whom participated in the concert experiment) completed a two-alternative forced choice task using the same VLF speakers in the LIVELab. On each trial, participants heard two pairs of 3.5 s excerpts from the concert audio and indicated which pair’s excerpts were different...participants could not detect the presence/absence of VLFs.
But yeah, not to be offensive, my initial reaction to this claim is that extraordinary claims require extraordinary evidence. Here's their claimed spectral production during the concert:
35 Hz sound at a weighted sound pressure level comparable to other bass audio should be audible. They write in the full article:
> At the lower end of the VLF range (10 Hz), intensities were below the threshold for auditory perception, and higher VLFs were above thresholds. Non-VLF intensities were by comparison, much higher relative to thresholds. Given that thresholds were determined by measurements using pure tones in silence, it is likely that in the context of the music at this concert, the non-VLF sound would mask all above-threshold VLFs.
Did they play the follow-up study at the same volume as the full concert? Either the VLF sounds are imperceptible and dancers should have no change in activity, or they're detectable and test participants should be able to distinguish their presence/absence, or your test is screwed up.
We had a similar issue come up when I was at school: To deter pigeons from pooping in the courtyard, the school installed "ultrasonic" bird deterrent speakers. Students complained about getting headaches from the intermittent, piercing, grating whistle that the speakers produced. (It was like nails on a chalkboard...just remembering it makes my skin crawl!) The elderly building maintenance staff could not hear them, and claimed that the speakers were inaudible, that no one could hear sounds over 20,000 Hz so our objections were unfounded and meaningless. We didn't have a lab setup like the one in the article, but just turning our backs to the flowerbed while the maintenance staff plugged it in and unplugged it was enough to prove that yeah, more than half of the students (including all of the students who complained) could hear it.
Yeah I 100% agree with this. Something is wrong with how they tested this perceptibility. Anyone familiar with club/concert systems knows the 20-40hz range they are adding/removing is semi-audible and definitely feelable. You can even faintly hear a 35hz sin wave on a laptop speaker.
There's also a difference between hearing sounds and feeling them. It's not clear if the participants were exposed to the sounds through headphones or through massive sound systems. I'd hypothesize that the latter would probably have a much, much stronger effect, just based on personal experience.
They did say "using the same VLF speakers in the LIVELab", suggesting it was in the same room where the concert was previously held, using the same speakers. I'd imagine that sitting alone in a room and heating three seconds of silence, 3.5s of EDM concert-volume audio, 1s of silence, and 3.5s of high volume audio would be pretty disorienting, perhaps they played it too quietly to engage the speakers?
Maybe EDM fans are conditioned to react to bass sounds, the lower the frequency the better? Would be interesting to try if the same effect can be achieved with other music genres too...
I'm not an EDM expert, so I'll refer to the Wikipedia definition ;)
> Techno is a genre of electronic dance music (EDM) which is generally produced for use in a continuous DJ set, with tempo often varying between 120 and 150 beats per minute (bpm).
I get the instinctual response of distinguishing EDM and Techno or any genre for that matter. Yes, Techno is technically EDM. But when people talk about EDM they generally mean commercialized electronic pop-music. I think it comes from the fact, that people who not have delved deeper into what "EDM" is, mean something like Avicii (no hate) when talking about it. Since that is all they now.
It's like bundling metal, rock, alternative, blues, country, and string quartets together as "guitar music."
Old schoolers used the term electronica as the umbrella. But eventually electronica shifted to replace "IDM" (intelligent dance music) to mean very electronica-ish music.
EDM became a term as EDM went mainstream, starting around 2010. It defines a specific range known for the commercially well-produced electro/progressive house, dubstep, & trap.
From the outside, EDM is technically correct. But for insiders, we probably just say "dance music" or "electronic music" as the umbrella.
EDM is a specific subgenre of electronic music that became popular in the 2010s with Skrillex and those big mainstream American festivals.
The most general term would be 'electronic music', or 'dance music', but not 'electronic dance music'.
Similarly, if you say 'dubstep' to a person in the UK they would think of something like this https://www.youtube.com/watch?v=DHRf9DNdkgY while an American would think of something terrible. (Good track for this discussion about bass, incidentally).
'Garage' is another one. Totally different genres in the UK and US.
Personally I just say "electronic music" as the generic term to reference any/all sub-genres. Anything more specific falls apart quickly - even the "d" in edm implies danceability, which neglects several sub-genres.
Old-heads like to distinguish early electronic music genres because the term EDM didn't come along until much later thus Techno and Ambient being specified.
if someone points it out I generally just say, we get it, you like neuro-funk jungle house and don't want it lumped in with other genres.
In my experience "EDM" fans will skew more towards newer genre's of electronic music.
I know this is probably some off-hand joke. But do you know some tracks that combine jungle and house? Doesn't have to be old-school jungle but just some breaky beats.
There was a bit of a trend in the UK over the last 12 to 18 months, to mix breakbeats and house. Early 90s house (particularly from Europe) used sub bass and breaks quite often before all the formulas got more settled. The trouble is the influences don’t quite match up very well between Jungle and House.
I can't say I have ever heard that. This might sound weird but I think Phonk music is probably the closest you can get since Jungle and Phonk both use deep baselines and sample dub/hiphop as well as Phonk having a House-y bpm and driving bass kicks.
I wouldn't say the lower the better. A lot of bass music is written in keys around E/F since that places the root note just within the lower end of audible range. Most sound systems don't respond much below around 20 Hertz, anyway.
Bassist here. Oddly enough most speakers made for bass use have diminishing response below roughly 80 to 40 Hz. Mine included. There is a tradeoff between low end response and other aspects of tone quality -- depending on your preferencea of course.
One of the first tricks one learns in electronic music production (possibly also other genres) is to roll off the frequencies below 40 - 50Hz across most/all your tracks as down there it all starts to smudge together and makes your mix sound muddy. I'm guessing your bass speaker does the same for a live performance.
I tend to high pass most tracks except for the kick and bass, but it's less about mud down at <100 Hz and more about dynamic range. When you have high amplitude low frequencies (inaudible or not) then the higher frequency content has less head room when stacked on top of that giant wave before it starts clipping. Consider how at the limit, a 0 Hz DC positive offset sounds like nothing but pushes the entire signal closer maximum sample value. In order to avoid that clipping, you have to turn everything down and now the whole track doesn't sound as loud as other comparable music, which is bad news for something you want DJs to play.
There's rarely any useful signal that low for instruments other than kick and bass anyway, so stripping those rumbles and thumps out just keeps the waveform more centered overall. That lets you increase the overall loudness without clipping.
For me, things get muddy when I have too much going on around, I don't know, 100-300 Hz. I high pass tracks to clean up the mud there. Below that, the high passing is mostly for dynamic range and loudness.
Hey drcongo long time no speak! But I can’t say that is the way to do it anymore.
Often you have to make sure that there is not multiple things going on down there, so you high pass a lot of the elements in a track. Then the sub of a Kick can’t be out of phase with a sub bass. You can duck one of them so they dont occur at the same time (probably still the way a lot of people do it), or you automate a high pass eq in relation to the other sound which can cause other phase issue but tends to work really well and is easy. Or you align the waveforms of the kick and the bass to match in phase and control the ducking more manually.
It also depends on the playback medium to some extent - vinyl has a slightly different set of challenges to digital.
Indeed, that's what's happening. Now it doesn't prevent the sound tech from feeding it at full strength through the subs, turning it into a wall of mud in the audience.
Waves has a plugin, MaxxBass which is meant for adding/raising harmonics to create the illusion of audible lower bass tones than the system is actually producing. It gets used pretty commonly in electronic music nowadays but was originally made for more mundane applications like audio mixed for television or theme park speakers.
My reply is just a guess. A poorly-quantized saw wave will have “bit-crushing” artifacts at higher frequencies, which can imply the existence of a frequency that’s too low for the speaker to handle.
The video link is to a video showing bit-crushing effects applied to saw waves (and others), along with the audio. Headphone warning: it sounds pretty gnarly.
The visceral feeling of walking into the heavy bass at Cream, a 90s nightclub in Liverpool, for the first time is something I'll never forget, and yeah much dancing ensued :)
As has been pointed out, if the authors knew what they were talking about they would have said "inaudible"; nevertheless, the article is still bogus at best. Fans of Orphx wear motion capture and the it appears the tracks with lower frequecies (lower like a regular rhythmic kick drum or bassline, perhaps?) caused fans more pleasure & dancing when questioned post concert. I found the whole article utter twaddle. Two places that I have experienced being bombarded with very loud and continuous VLFs (their terminology), and not regular rhytmic VLFs, is at a Sunn O))) gig and another at an experiemnt along the lines of a infamous Guantanamo correctional facility. I can tell you no one was dancing at either.
The French movie “Irreversible” famously used these kinds of sounds to make it even more difficult to watch in theaters, I remember feeling a sense of danger and tension.
D&B make those awesome J-Infra[0] subs for a reason. With the low end extending all the way down to 27hz they really make a difference on a large pa system
Modern subwoofers can get up to 15HZ (), so if you want to pump up your party, just make sure you make it in a very big room in order for the waves to travel nicely.
oh... so when you feel the beat, people like to dance?
I've always wanted speakers with about a 3Hz cutoff, for this very reason. I'd be willing to do that experiment... I'd bet kids raised with headphones instead of huge speakers can't tell the difference, but I'm pretty certain I can.
When you see the 15" woofer cone excursions, you rapidly learn what infrasound feels like.
I bet the skill of detecting it can be learned in minutes.
PS: Reminds me of the time in 1982 when we borrowed a function generator and found the resonance frequency of our floor in Sharpenberg Hall at Rose-Hulman. On of the guys had a DC coupled stereo and speakers, and I warned them to watch out for DC offset not to fry the voice coils.
If it isn’t tested in a systematic, reproducible manner, written down, and peer reviewed, then it hasn’t been proven and doesn’t really contribute to our understanding of the world in a meaningful way. This is how science works. Sometimes a seemingly obvious thing isn’t once it undergoes rigorous testing, and sometimes the obvious thing holds up.
Err, the blind control was literally gathering responses. Anyone can have had such an experience with inverse effects. It could have systematic biases and the peer review may be too benevolent. It is not news, but entertaining, even to the peer reviewers.
But isn't science more about problem solving? The problems they must have solved are how do we test this fairly obvious fact? I didn't read the paper and am wondering just what the standard unit for an increase in dance would be.
oh finally the hi-fi market can step up and provide 0 up to 100.000 hz speakers and of course, composers composing feelings of hypothetical effects or melodies under 20 hz!!!!
I used to run experiments with friends and family using a 800L ported subwoofer tuned to ~13Hz with a 40Hz cutoff. Not one person would mistake it for being on vs off. Certain content makes these frequencies substantially more obvious. Classical music performed in large concert halls is one surprising candidate outside of Mission Impossible scenes. Being able to "feel" the original auditorium in your listening room is a very cool effect to me.