I wrote this stuff a while back and though it's a bit out of scope, I thought I'd share it because bass is a concern to most of us here.
I wrote this because after doing a mega sub-bass mix, I came down with a headache and just plain "I'm about to puke" syndrome, and being asked what the heck was going on, I replied with this. And some of you may know, I'm a BIG fan of Celmo's sub-bass device.
Anyway, it's a casual, "short cookie break" kind of text so relax, and enjoy.
The sub-bass thing is usually considered anything below audible frequencies, which is below 20hz.. but generally, in musical contexts, under 40hz is sub-bass.
Most acoustic sounds have some sort of sub-bass. Pianos and guitars are among some of the instruments that have sub-bass although the sound of the instrument itself doesn't sound low at all. In fact, sub-bass exists in most natural sounds.
The use of sub-bass in studio recorded material came after the introduction (early 80's) of a device called the dbx120, which analyzes the low sounds of an incoming signal and synthesizes a sine wave several octaves below the original sound.. It effectively increases the bass, in a rather musical way. For example, if you played a bass line, the sine wave would play along with you.
Anyway, the dbx120 box was targeted mainly at discos and helped form the sound we all associate with clubs and discos. (the "big speaker" sounds) But the situation was that the record was made without the sub-bass, and the sub-bass was added to it when it was played back in the discos.
Since the application of sub-bass was almost an automatic process, naturally, artists started to use sub-bass within their mixes so they could control the volume etc. of the sub-bass in a more creative way.
Well, because it's been around for quite a while, most modern musicians (especially club music) use sub-bass. It's a must. Usually, it is applied to low instruments (duh!) such as the bass (doiii!), or the bass drum. Over use usually results in a mucky mix or phase cancellations. (phase cancellation is perceived as a modulation in amplitude)
So that was about using it in songs.. Let me explain sub-bass by itself... Since sub-bass isn't even audible, chances are, many people don't know what it's like... Well, club sound is one example... but it's not sub-bass in pure form, as in there's a whole song going on on top of the sub-bass. When you hear sub-bass only, you can definitely "feel" the difference. One thing is that you'll feel the impact with your body. (imagine watching fireworks really close.. MAJOR sub-bass) Also, when you hear continuous sub-bass (as opposed to fireworks being instantaneous), it feels like the density of the air had changed... Like there's some sort of gas filling up the air. It's an interesting effect. Think about when an airplane... that's a good example of sustained sub-bass.. Sometimes you know it's an airplane even before you actually hear the sound of its propellers.
Why in the world does this give me a headache even though it's a part of natural sounds? This phenomenon was pretty hot in the area of psycho acoustics a while back... There are a couple of theories but here's one that I know of.
The brain/body has a tendency to synchronize with external oscillation sources. This is a very general phenomenon such as the biological clock trying to synchronize with the sun... women synchronize with each other (you know what I mean)... But all these oscillation sources have one thing in common.... the cycle is very, very low (low frequency). So it seems that the sub-bass range is barely sync-able for the brain so the brain tries to regulate things using it as a source. Of course, since 20hz is much, much higher than, say the sun's cycle (ok, I'll calculate it for fun... 1.15741e-5 hz.. wow) so of course the body gets messed up.
Your heart rate increases, oxygen efficiency drops, and psychologically, you become agitated easily. Then, as you keep applying sub-bass, the body grows weaker, and enters self-protection mode where your white blood cell count rises and you body starts to use its resources more efficiently. It is close to how psychological depression affects the body.
Now, we're talkin' serious effects... and US army thought so too. They actually built a "bass cannon" sort of thing that spurts out low frequencies at entire towns and other wide areas, and was intended to be used for crowd control. Historically, there are many cases where entire towns were wiped out (not by death but people generally moving away) because the area was flooded with sub-bass from underground water, crust movement, or volcanic action. (the flowing/moving object oscillates, and the ground acts as an amplifier)
If you think about it, this fact is dreadful... it means almost every house in the world has a similar type of WEAPON. Though the amplitude is much weaker compared to the town wiping sub-basses, the effects are still similar.. only it affects a smaller area... like MY ROOM!!
But the catch is that since it causes the brain to enter this "altered" state, sub-bass, if used right can be a powerful tool to drastically improve a song's image. Simply put, if sub-bass itself has the ability to raise heart rates, then you can put anything on top of it and your hear beat will rise.. causing an illusion of "hey, this song is exciting". But, it's the ever lasting artistic dilemma... just the right amount of pain is exciting.. but too much will kill ya. (not in this case anyway)
So the conclusion is that I drove my professional monitor speakers (in effect, a very well built CANNON) with mega lots of sub-bass, and blew my self away with it. Smart huh? And scientific? Cooooool.
THE SUBBASS
Tu es fantastique, Ken! Here's some OT, but might be fun for some.
After performance critical component changes, we go for test runs with the engine, we boost it let's say to 105%. On take-off, you, being passenger, hear the engine go to 87/95%. The 105% (used in emergency or on our test runs) creates another real exiting effect: the engine first makes real heavy bass noise, but a little more power and the vibrations create overtones which give enourmeous feel of power
The whole aircraft starts to shiver. The 2 persons in pilots' and co-pilots' seat have to press the brake pedals quite hard to keep the aircraft in park position, one hand never releasing the throttles. Imagine the aircraft would brake loose, power reduction would need to be accomplished very quick! And the enginces take a while to slow down too... Once you start skidding, you're off the spot quicker than you think 
When an A300 approaches you, you first hear the high tones, like a whistle, once it's past you you'll hear heavier basses and more white noise.
Another story are the JT8's. They are the kings of sub bass. For this reason, they're soon to be banned from Europe- they make too much noise.
The CV580 is a prop aircraft, and is most fun to fly I think. No luxury, but way overpowered
These 2 props cause a flanging effect, cos the are set to run at fix frequency (13820/11). But this frequency cannot be maintained exactly. There's always small frequency deviations up and down, thus causing interference. I remeber recognising one of our planes from in my room or even when I was on holidays in France or Italy. It had problems with it's sync system. The sync tries to keep both engines at perfectly same speed (power is varied by prop blade angle). When the sync system is kaput, you get very deep phasing and flanging (amplitude & frequency changes). Not fun to hear when you sit inside, the high peaks are above pain level sometimes in such cases. Poor pilots.
Even worse off are the jumpseaters (we call our passangers jumpseaters, we have to sit in/behind the cockpit cos in the back there's freight in containers). The CV580 engines are designed to run w 15° phase difference, so the max sound volume (highest peaks in soundwave crossings) would be heared in the catering corner. Passengers in the back would then sit more confortable. Unfortunately, there's now only 2 seats left in the back. Right in the catering corner.
I can recognise most commercial aircraft by their sound, and after a while on the airport (I work there 6 years today), I started to see the logic behind that. The way the engines are positioned on the aircraft, the number of engines,... ie. C-130, Hercules has same engines as CV580 but 4 instead of 2, so the phasing/flanging is much less, C-130 sounds smoother, CV580 is more pronounced.
They all make your bones tremble if you tune their engines while running That's the power of sound, in another context!
I'd never want to be pro musician, cos I'll miss my planes!
<font size=-1>[ This Message was edited by: at0mic on 2002-05-05 18:40 ]</font>
<font size=-1>[ This Message was edited by: at0mic on 2002-05-05 19:00 ]</font>
<font size=-1>[ This Message was edited by: at0mic on 2002-05-09 19:27 ]</font>
I work on 4 different commercial aircraft types (CV580, B727, B757 and A300). Actually, the A300 engines, when they spool up (start sequence) create a SSB Phasing effect. The first sound that comes, is a low sub. Because of the engine speeding up on start, these basses will become higher and higher frequencies, untill they become unaudible. In the meanwhile however, new low frequencies (caused among others by the different stages in the fan/prop, compressors and turbine) arise and take over untill they get so high frequency that we cannot hear them anymore. This process goes on for about 1 minute, it's super cool!Think about when an airplane... that's a good example of sustained sub-bass.. Sometimes you know it's an airplane even before you actually hear the sound of its propellers.
After performance critical component changes, we go for test runs with the engine, we boost it let's say to 105%. On take-off, you, being passenger, hear the engine go to 87/95%. The 105% (used in emergency or on our test runs) creates another real exiting effect: the engine first makes real heavy bass noise, but a little more power and the vibrations create overtones which give enourmeous feel of power
The whole aircraft starts to shiver. The 2 persons in pilots' and co-pilots' seat have to press the brake pedals quite hard to keep the aircraft in park position, one hand never releasing the throttles. Imagine the aircraft would brake loose, power reduction would need to be accomplished very quick! And the enginces take a while to slow down too... Once you start skidding, you're off the spot quicker than you think When an A300 approaches you, you first hear the high tones, like a whistle, once it's past you you'll hear heavier basses and more white noise.
Another story are the JT8's. They are the kings of sub bass. For this reason, they're soon to be banned from Europe- they make too much noise.
The CV580 is a prop aircraft, and is most fun to fly I think. No luxury, but way overpowered
These 2 props cause a flanging effect, cos the are set to run at fix frequency (13820/11). But this frequency cannot be maintained exactly. There's always small frequency deviations up and down, thus causing interference. I remeber recognising one of our planes from in my room or even when I was on holidays in France or Italy. It had problems with it's sync system. The sync tries to keep both engines at perfectly same speed (power is varied by prop blade angle). When the sync system is kaput, you get very deep phasing and flanging (amplitude & frequency changes). Not fun to hear when you sit inside, the high peaks are above pain level sometimes in such cases. Poor pilots.Even worse off are the jumpseaters (we call our passangers jumpseaters, we have to sit in/behind the cockpit cos in the back there's freight in containers). The CV580 engines are designed to run w 15° phase difference, so the max sound volume (highest peaks in soundwave crossings) would be heared in the catering corner. Passengers in the back would then sit more confortable. Unfortunately, there's now only 2 seats left in the back. Right in the catering corner.
I can recognise most commercial aircraft by their sound, and after a while on the airport (I work there 6 years today), I started to see the logic behind that. The way the engines are positioned on the aircraft, the number of engines,... ie. C-130, Hercules has same engines as CV580 but 4 instead of 2, so the phasing/flanging is much less, C-130 sounds smoother, CV580 is more pronounced.
They all make your bones tremble if you tune their engines while running
That's the power of sound, in another context!I'd never want to be pro musician, cos I'll miss my planes!
<font size=-1>[ This Message was edited by: at0mic on 2002-05-05 18:40 ]</font>
<font size=-1>[ This Message was edited by: at0mic on 2002-05-05 19:00 ]</font>
<font size=-1>[ This Message was edited by: at0mic on 2002-05-09 19:27 ]</font>
They had this car - a vw golf - on tv the other night that was the loudest car in the uk. the windows were all bulletproof and the windows and doors were all screwed into place with an automatic drill. the car weighted approx 3 tons and all doors and floors were filled with concrete. All this was to contain the sound emmitted by some rather impressive amp/speakers that could generate 175 db of sound!
It could only produce 1 note and had to be controller by a panel on the outside of the car becuase if you sat inside, the noise would kill you. apparently anything about 150db will kill you. they put a glass of water inside on the dash and turned up the volume and the soundwaves just chucked the glass into the air.
so next time someone invites you for a drive in their car and tells u they have an impressive car hifi... be careful!
It could only produce 1 note and had to be controller by a panel on the outside of the car becuase if you sat inside, the noise would kill you. apparently anything about 150db will kill you. they put a glass of water inside on the dash and turned up the volume and the soundwaves just chucked the glass into the air.
so next time someone invites you for a drive in their car and tells u they have an impressive car hifi... be careful!
To be or not to be. What was the question?