What is Sound? The Physics of Sound.

Before I write this, please realize, that I am not an expert. I am just a music nut who studies all parts of sound, and then write about everything I learn to help my brain remember everything. I did not go to school for this, but have been self studying for years. This is just a basic scientific understanding of sound, explained with graphs from all over the internet I have found to make my points stand out. Without people putting free info on the internet for me to study, I would never know any of this....so, I felt like I should give back by making a nice understanding with better graphs and in my own words. This is to help me, and if it helps you, great!

What is Sound?

A sound is a vibration. No vibration, no sound. When a source vibrates, it moves particles beside it and vibrates in a chain reaction. Usually, this means air particles, but it can also be water, gas, and other kinds of particles. But, here, we will talk about air particles because that is what we usually deal with in music. When a source vibrates, and then vibrates particles, it comes from a source location (where it is the strongest), and then moves outward in wave fashion until it reaches and vibrates our eardrums. The sound does not travel in bulk, but rather in a sound wave coming from the source, and then disturbs the surrounding area...slowly getting weaker. This is simple energy displacement. Sound requires a medium (air particles), therefor, sound cannot travel in a vacuum. It reacts the same way as if you threw a rock into a still lake...the water ripples will form, and then disappear...returning to its original form.


Now, once this displacement of particles has occurred, we are left with 2 regions. 1 region is of high particle density, and the other is of low particle density (or high pressure, low pressure).

2 keys words to remember

Compressions (Condensation) - Regions of high particle density
Rarefactions - Regions of low particle density.
Rarefactions and Compressions both move in the same direction that the wave travels.


Now, the particles of air don't actually MOVE (physically) in the direction of the wave movement, but instead move within their normal positions in a cycle fashion. 1 cycle is when a particle moves from its STARTING POSITION, to the maximum displacement distance in one direction, back to the starting point, and then to the maximum displacement distance in the other direction.

Now this is just one cycle. Particles can vibrate THOUSANDS of times per second in this fashion. The number of cycles completed by a wave in one second is considered the FREQUENCY of vibration. One way to easily tell how many cycles a wave is making is by listening to the pitch. The pitch is very much affected by the number of cycles occurring. (more cycles at higher pitches)

In music terms, 1 cycle = 1Hz. (Hertz), 1000Hz = 1kHz.

The human ear can hear (depending on the person of course) anywhere from 16Hz - 20000Hz
(normal being around 20Hz - 18,000)

A normal piano range is in the graph below -

But just because a wave is at a certain frequency (on an instrument), does not mean it is going to SOUND the same. This is because of TIMBRE of the sound. If you play C4 on a piano, it will sound different from a C4 on a flute or a tuning fork.

To understand this, you must understand PURE TONES and OVER TONES.

A pure tone is one that is created by a perfect wave (like a tuning fork, or a tone generator). These contain a ONE TONE frequency, meaning, it only creates one tone on the frequency spectrum. A note played on a piano or any other instrument will have OVER TONES, which are other tones within the spectrum accenting the fundamental tone....giving it a unique sound. The tone with the lowest frequency is called the FUNDAMENTAL TONE. All other tones are OVER TONES.

This is where we get into harmonics. If an over tone has a frequency value that is a multiple of the fundamental tone ( x2, x3, x4, up to x14), these tones are called HARMONICS. It is the difference of each instruments over tones and fundamental tones that make up the sounds TIMBRE. Therefor, even though an instrument may produce a fundamental tone at say 4kHz, it has overtones at much higher frequency values. This is why most DAWs and other recording gear must be able to handle a much higher frequency than can actually be produced by the fundamental tone of an instrument. There will be MUCH loss in the dynamics of the sound if it is not able to be captured. Some instruments like cymbals or dog whistles produce frequency levels much higher than the human ear can hear, but they effect the whole sounds TIMBRE if not captured correctly. This is why many analog purist stay analog, and not digital...where most frequencies are cut at 20,000Hz. Below is is a graph of a general saw wave and its harmonic overtones.



Now there are 2 types of sound waves (we will break these 2 kinds down even more in a minute)

One is a wave with a definite pitch (we call a note). Another kind is one with no definite pitch (we call a noise). Music has both almost all of the time. The difference is definitely audible, but what is the scientific difference? A note contains regular vibrations (periodic motion), and a noise contains irregular vibrations(non-periodic motion).



Now if we break down the periodic motion vibrations, some of the common vibrations are below -
Most of these waves are created by synthetic sounds. Traditional instruments function in a sine wave form.

In music, we divide these sound sections into groups called OCTAVES. 7 different notes A-G, & the 8th note being the start of the next octave. Each note named the same letter sounds very similar to the others named the same letter because they are in a multiple of the others frequency. (x. 220Hz, 440Hz, 880Hz). This means the actual frequency rate (or cycles) is 2ce the speed of the previous. These notes are said to differ in pitch by ONE octave.

Now lets talk a little about amplitude. A loud sound is produced by more violent vibrations than that of a weak sound. The amplitude is the maximum displacement of the air particles from their original place. As the sound wave continues to displace particles in a wave fashion, it is displacing energy (energy loss). That is why the sound will get weaker and weaker. The energy is displaced in the form of HEAT, and the sound will get weaker as it travels away from its source. To understand graphically, the farther away from the center line on the graph that the wave gets, the higher in amplitude it is.

Now scientifically, the amount of energy loss follows the "Inverse Square Law". (but keep in mind, this is not what the human ear actually hears...because of our ears compensation system).

Scientifically, if the distance from the source is TWICE the distance, the sound drops to one quarter. If the distance is 4 times the distance, it drops to one-sixteenth.


Now, if you think about this....this doesn't make much sense. Because if you are at a club, listening to some speakers, and you move twice your the distance away from the speakers, the audio does not seem to drop in these proportions. This is because of the compensation system in our ears due to the 3 pivot system in place. It helps your ear create leverage on desired frequencies. This system lets your ears hear weaker sounds at maximum strength, while louder sounds are reduced to prevent damage to your ears. That means, that the scientific measurable amplitude differs from what is heard, and what is actually happening. We refer to this phenomenon as "LOUDNESS". Loudness is what we use to measure what our EAR hears in change, and not the scientific term of amplitude. Loudness is also determined by how sensitive your ears are, and differs person to person. It is measured in decibels. (db)

Now, what happens when 2 sound sources meet at the same time. If 2 waves arrive at the same place at the same time, at the same high pressure and low pressure displacement areas...we will get what is called "Reinforcement". (in-phase) This will result in a greater wave intensity. If 2 waves arrive, and one is a half of a cycle late, the high pressure of the one wave, and the low pressure of the other wave will cancel each other out. This is what is called "cancellation". (out of phase)

In the photo, graph 1 is in phase, graph 2 is out of phase.

If we were to set up 2 speakers producing perfect waves at 1/2 the cycle speed difference, this is how it would sound to your ear (cancelled) -



Now, how do we measure all of this. Well, the equation for "Speed of Sound" is rather simple. I liked this tattoo to help explain -


V = speed of sound
f = frequency
λ = wavelength (lambda in greek)

A wave front is a surface on which all particles are in the same phase of vibration. The distance between the 2 wave fronts is called the wavelength. (or the distance between 2 separate compressions, or 2 separate rarefactions)

Now obviously, the speed of sound is affected by other things. This equation only works in a perfect environment with no obstacles. In an everyday situation, we have air pressure, and physical objects that can obstruct a waves path.

When a sound wave is made in air thats temperature changes with altitude, REFRACTIONS occur. This is why sound can travel at different speeds depending on air pressure and particle density.



So obviously the equation for the speed of sound has variables.


Well that's it for my small piece about sound. If you have a better understanding of how sound works, you can begin to change it the way you want rather than just randomly.

Peace!

FroBot

EQ Frequency Chart for Instruments & Electronic Sounds

This is a frequency chart for Kick Drum, Snare, Hi Hats, Cymbals, Bass, Vocals, Piano, Electric Guitar, & Strings. Just gives you an idea of where to boost or cut when you are wanting a certain sound. I found this to be REALLY useful...and it is printed and laminated on the wall beside my studio at all times. I made this link to keep all the charts together for my own reference, if it helps others...awesome! Link to the pdf file below -

(click to enlarge HQ picture)

THE ORIGINAL PDF FILE Here - Frequency Chart (from of emusictips.com, this is not my chart)

A few other nice charts are here too - (All charts from other sources...thank you so much!)











Some nice links on EQing too -

http://www.ethanwiner.com/equalizers.html
http://www.bobbrozman.com/soundhints.html
http://www.recordingwebsite.com/articles/eqprimer.php
http://www.recordingwebsite.com/articles/eqfreq.php


Peace!

FroBot

Using Instrument Racks w/ Drum Racks To Have Effects Per Row Using Chains

So, yesterday, I was putting together huge drum kits....8 kits per rack...all made for my Trigger Finger. (see yesterdays blog for more info). The thing I really wanted to do was to be able to control effects based off of rows of my trigger finger. I want to be able to use the knobs on the trigger finger for effects, but without them effecting the whole group of samples. Specifically, since these drum pads are mostly for production, I really only want my tools on there so I dont have to waste time with that. Effects, well, im never really sure what I am going to want. I only have 2 knobs per row...one definitely being a frequency shifter. The other, I really want something to transpose the samples note up and down (+6, - 6) like I do with my samples...but that requires either using an audio pitch vst (which I dont really like), or, individually mapping each samples transpose to the same knob....LAME, and will take forever. So I need to think about this.

Another problem with the frequency shifter is that I need to to have a large range, but but also be able to get back to the 0 point easily...because some samples sound like shit if they are even just a few frequencies off....so I might have to use midimap to split a knob into 2 knobs, one going from (on the shifter) 0 and up, and the other knob going 0 and down. That way by putting the knob ALL THE WAY to one side or the other, it will be at 0....instead of trying to find it in the middle of the knob. In that case, I will use up both buttons...so shit....looks like I cant get exactly what I want without tons of mapping work.

ANYWAY....all that aside, lets get into how to make instrument racks w/ drum racks, so you can put different effects per row (or column if you like).

Ok, so what I have done is created a blank instrument rack in a new midi track.

Then, what I want to do is open up the chains of that rack. Now, I will take one of the drum kits I made yesterday (8 kits on 1 rack). Drag that into the device chain 4 times (for all 4 rows) like this -
You can see the exact same drum rack 4 times. Now, what you want to do is go to chain 1 (which is my case are the kicks). You need to delete every sample within that chain that is not a kick.

Then you need to go to chain 2, and delete every sample that is not in row 2 (or column 2 if you are doing columns). In my case, they are snares.

Again for 3, and 4. Also, rename your chains so its easier. Mine now looks like this -


You can see on my grid on the right side of my drum rack, now in rows instead of taking up every square.

Now you have individual chains to put your effects into. I went ahead and put in my frequency shifter to try it out. Click the chain you want, and put the effect after the chain, like this -


Now, any mapping you do to your controller for the effect, will not save when you save this instrument rack. But it is there. Considering I only have 8 knobs, its not a big deal just to map it when I want to use it. Its a lot better than manually putting it in, and I really need a rack that has per row effect options. REMEMBER, CLICK SAVE!

Now, it did take a lot of time to delete out all the samples I didnt want in each rack. If you want, you could just MAKE it right the first time. But, I also like to have copies of JUST my drum racks, in case I am doing improv and my friends want to use my racks their own way. So I put a little extra time into making both. It is a little bit time consuming considering the slow action of deletion of samples within a drum rack.

Also, one little thing I hate about drum racks, is how when you go to view the next 4x4 square within the grid view, it only jumps up 3 rows, not all 4....makes deleting confusing sometime. Maybe a fix for Live 9....please!

Well, now you have an instrument rack that have effects per row on your drum pad. Hopefully you can get the sound you are looking for even faster now.

Peace!

FroBot

TIME IS YOUR ENEMY WHEN MAKING TRACKS

(My session today above)

So....for the last year...I have been practicing exclusively DJ skills with ableton live. I said when I started into it, that it would be a good idea to play around with other peoples music, learn the effects and improv elements to DJing, and then it would be good to apply that to track making. I was SO right. After learning what I have in the last year....i'm ready to stop Djing (just too time consuming)....and get deep into the track making process. For my birthday, my wife bought me the Novation Launchpad....and its a perfect addition (well not perfect, ill explain in another blog all about midipipe) to my setup. I now use the VCM 600, Launchpad, Trigger Finger, Microkontrol, and a little nano kontrol while making tracks. Each have their functions, but that is for another day.

What I didnt realize until recently is that my improv set, containing fixed up samples, huge drum kits with youtube pulled samples, and having all the most used effects....all prepared, has made the track making process a breeze....which brings me to the topic of this post.

TIME SPENT ON A TRACK

Up until recently, I thought it was a good thing to spend 60 plus hours on a track. Working out tiny little details, so you had a track that stands out against the rest....this is not the case. When you spend so much time on a track, hearing that same 4 bar loop over and over....not only do you get sick of hearing it, but your ears do not hear it the same as when you started....or as the ears of a first time listener. Your brain hears it in a whole different way. Now theres the scientific idea that you are hearing it different...which I do not know much about. But what I do know, is how I come to HATE every song I ever finish...by the time I finish it. (up until now) A good electronic track is NOT about how technical you can be....its about a good funky bassline, some nice high frequency percussions that stand out in their own frequency range, and a nice side chained kick. Tuning everything is important too, that is why ableton 8's new frequency shifter tool is a godsend. I have my VCM all mapped out to the 6 main channels for all my improv beats, and then the left side which is normally for effects, programmed to elements of tracks. (Kicks, Snare, 1/4 HH, 1/16 HH). Each has a frequency shifter right above it, so I can easily improv a nice beat, and then find the perfect frequency of each of the elements to match the light percussion...and WALAH! Its like the backbone of the track can be created in minutes.

Now some might say...thats a REALLY lazy approach to making music....you should take more time and pride in making a UNIQUE sound....ok, ok....i get the purist approach to it....but the bottom line is, you can either love your song when you finish or hate it....so get it done as quickly, and with the most talent as possible. That does not mean to make a shitty track....it still takes a couple days to really get a track finished up (not including EQing or Mastering....which I never like to do anyways because I prefer other ears to do it over mine, and its so damn BORING!!!)

Ableton, used with the right controllers, and right template set (handmade to your controllers) can make all the world of difference when making tracks quickly and efficiently....and as a producer....being signed....labeled...managed....you gotta make them funky beats...and fast.

Another key to speed in making tracks is to dedicate a few weeks, months (or even a year like in my case) preparing everything ahead of time. I made many drum pad kits (drum tool within ableton) filled with my most common used samples. For instance, I have 5 full pads (matching my launchpad)(500+ samples) of only sweeps. These are nice samples I have made, found, or purchased. I never know which one i'm going to like, but, I am 100% sure that every track is going to need them. So, just drag in my saved pad (by clicking the save button after making it...the little icon on the right of the pad). Now I can reuse that pad of samples over and over. Having the pads mapped out the the launchpad is great for switching through them before using them...and much more efficient than searching my 700+ gigs of samples and using the mouse. Using abletons transpose button (mapped out of course) is nice to change the key on the fly to match the song i'm making. Now I dont just have sweeps, I have full pads dedicated to chinese instruments by using the "slice to midi" feature. Ive sampled out arhu and dizi instruments in traditional progressions (even from youtube) into nice playable pads...which I can come back to at any time. I dont even want to get into the number of kicks, claps, and snares I have prepared. These are not just samples like ones in your library....these have all been sampled from songs where I liked the kick, cleaned up, and ready to be used on the fly. All helping to maintain speed during the music making process.

You dont want to waste your time on the simple elements of a track....especially when dealing with funky house or tech house like I am doing. They always have a steady kick, always have a nice sharp snare or clap, always have a nice rolling HH....so have those ready to go, and easily swapable.

Another little tip is to have sample making sessions....where you solely make basses for a whole day, or make nice chord sounds..etc. Once you get deep within a synth or soft synth, that is when you find the best sounds. Take extra time preparing nice loops that you may or may not use in the future....but, you HAVE THEM. You never know when that funky bassline you forgot all about just might be the perfect match for that beat your making. Dont just jump into a synth and pick the first sound that comes. Have a session dedicated to sound making, especially basses and melodies. Toss on a nice background beat without many tones, and JAM AWAY. Record one, after another....funk around with the settings....and record more. Thats when you will find your best sounds. NOT EVERY sit down has to be about MAKING A TRACK...you can't go from point A -Z in the music world without going through B,C,D etc (unless your avril lavine or something)....we all just wanna hear some bad ass beats anyway.

Well, all that being said...remember, time is your enemy. Too much is bad. Keep tracks coming, and dont over do it...especially if you are making a living off of it. Its bad enough being in the club night after night and hearing shitty beats over and over in your head...let alone listening to the SAME ONE over and over at home. Keep it fresh....and your soul will be happy with you...and your musical spirit will come into the track rather than being forced. Stay happy while making tracks, and dont make it a job. The more you prepare before hand, the funner your making session will be.