The double bass and the bass guitar have their use, but sine waves are crucial in bass science. Producers who don't have them in their toolkit might as well pack up and leave. Here's what they sound likeIf you are still a bit confused about frequencies after this video check the bass frequency table in episode 2 of Basswatch.
Tits or ass?
And this is what a sine wave looks like. The original meaning of the word sinus in ancient Latin is bosom and the curves of the sine wave look feminine indeed. But times change. Nowadays when people hear a heavy bass they usually picture a big bottom. 
And what's even more puzzling: while a low frequency sine wave may sound like a fat ass, a high frequency sine wave sounds thinner than the skinniest supermodel. That's the mystery side of the sine wave i'll try to explain here.Bass history
Back in the 80's and 90's rappers were always boasting about the bass power of their tracks. Chuck D asking "how low can you go" and people were even dissin each other saying things like "you don't understand the power of the 808 bass drum". The legendary Roland TR-808 drum machine had become an industry standard and producers were exploring the limits of pure bass pressure. Here's an important bass fact: the famous 808 kick drum is basically a sine wave.
Is it really that hard to understand the power of the 808 bass drum? Theoretically there's no simpler sound than a sine wave. Some people call it a 'pure' sound. You could even say the sine wave is the most boring sound man has ever invented because in the higher regions it's just a shrill bleep. But below 100 Hz the sine wave becomes a beast if properly amplified. It turns into an extremely effective heavy wall of buzzing air that can make you feel like you are underwater. Bass.. what is it?
The sine wave is a limit case in sound business.
Just listen for a moment to the sounds that you are hearing right now. If you listen carefully you will notice that each sound you are hearing has lower and higher parts. Sometimes the higher parts are called overtones or harmonics but they can also be noise or other vibrations. The sine wave is fundamentally different. It has no low part and no high part. It cannot be divided, it's just what it is. It can't be filtered because nothing would be left. That's how thin it is. If the frequency drops below 60 Hz you can hardly hear it because it has no harmonics, no high stuff and its tonality quickly fades away just like you can't see infrared light. In the deepest sub bass territory (below 45 Hz) no real sound is left. Here the sine wave is just a carrier of pure pressure revealing the natural mystic of bass.
Bass! How low can you go?
Now that you understand the power of the 808 kick drum there's one more question left to answer. Like Chuck D said: Bass! How low can you go? If you've read the first episode of Basswatch you already know that below 20 Hz things can get a little messy.
The deepest frequency that makes musical sense is somewhere between 30 and 35 Hz. There are no strict rules or exact frequency limits but no home system can reach as low as 20 or 25 Hz. So if you play a track at home with a 20 Hz bass in it you will actually hear nothing at the bottom end. But still the 20 Hz bass waves are eating up headroom and this may cause the track to sound distorted and/or not as loud as other tracks. Clearly a loose/loose situation. This 20 Hz to 20 kHz bass sweep illustrates that you can't hear 20 Hz bass. Unless you use high quality headphones you just won't hear the first part of the sound. Especially not if you play this through tiny little laptop speakers.
Some advice for the bass freaks: try not to get stuck in this 'how low can you go' frequency business. Some people get hung up on musical numerology but i'd say that's beside the point. A properly mixed 808 kick is deep enough to rattle any chest.
Digital sine waves vs. analog sine waves
Usually digital sine waves are more 'pure' than analog sine waves. But as a matter of pride the engineers who design analog sine wave generators (or VCO's) are always struggling to produce the best sine wave possible using analog technique. You can see an analog/digital sine wave shootout over here.
If you are a technical person you might enjoy a document by Bernie Hutchins of Electronotes called "Contrasting sinewave generation in the analog and digital cases". In it Mr. Hutchins explains why digital oscillators are more precise: "there is no drift of any sort associated with numbers".The 'quadrature' VCO design seems to produce the highest precision analog sine waves. The Zeroscillator by Cynthia is a state of the art analog VCO based on a quadrature design. Because of its precision it is capable of FM synthesis but that's a different story.
DIY-time: how to create the deepest bass possible
Digital sine waves are much easier to make and they even sound a little bit deeper than the average analog sine wave. If you have a copy of the free audio editing program Audacity you can create your own 808 ultra blast in a few seconds. Start up the program and go to Generate/Tone. At default settings Audacity will generate a 30 sec. 440 Hz sine wave at maximum amplitude. Now change the settings: frequency down to 30 Hz and length as long as you want. There it is.. you have entered the Temple of Boom.If you must go lower in frequency you'll go from sound territory to LFO territory which can be interesting too. Check out what you can do with LFO's generated in Audacity here.
How to create the ugliest bass possible
If producers need a clear and heavy boom they go for a sine wave. But there are more low frequency sounds. The sonic character of white noise is exactly the opposite of the sine wave. It is also a limit case. Some producers use white noise to rough up clean sounds, but usually in the mid frequencies only. Because bass noise is ugly. If you want to hear the ugliest possible bass sound you take white noise and filter away everything above 100 Hz.
Here's how you do it in Audacity. Go to Generate/White Noise and enter a length. Now go to Effect/Low pass filter and set the cutoff frequency at 100 Hz. Repeat this filtering a few times to get rid of all high stuff and voila! A really shitty bass sound.
That other famous kickdrum
The 808 kick has a simple click attack and a fat round sine wave bottom. The Roland TR-909 kickdrum is very different. The oompf of the 909 kick is not at a fixed frequency like the 808. It jumps down in pitch an has more mid frequencies. Basically the difference is that the 909 is loud and the 808 is deep.By the way i think it's pointless to argue about which kick drum is 'better' because the answer is that it depends on what you want to do with it. You also have to realize that in recordings a 909 kick is usually processed much more than a 808 kick. Most musicians say the 909 sounds more like a 'real' kick but actually you can make the 808 sound quite 'real' too if you try hard enough.
OK that's more than enough tech talk for now. Here are some concluding wise words coming from a parrot named Einstein.
