FM Synthesis or “Why is this so much harder than subtractive synthesis?”

Welcome to my foray into the mire that is FM synthesis. FM or Frequency Modulation synthesis is quite different to subtractive synthesis. It uses as many or as few oscillators daisy chained together to create the desired sound. This is not as easy as it sounds. Here is my attempt at using FM synthesis to create a small arrangement.

To start off, I decided to create a drum kit using FM synthesis and sample it using Logic X’s EXS24 sampler. I followed the same general principles I used in creating a drum kit with subtractive synthesis, white noise as the base for snare and hi hat, sine wave with a higher frequency click as the basis of the kick and toms.

FMKit

FMKitKeys

I found that I left too much space at the beginning of the samples causing the timing of most hits to be off. Luckily with Logic X you can easily edit the samples. I spent quite a bit of time trying to create some kind of cymbal sound but for the life of me it went nowhere. I will admit I got lazy with the toms, as they are just higher pitched versions of the kick drum synth patch. All of the samples can be found below. The FM8 patches can be found in the resources at the bottom of the page.

FM Synthesis Drum Sounds

FM Synthesis Drum Loop

After I had the drums where I wanted them I moved onto creating a bass synth using FM8. The way I went about this was I pictured the way a bass guitar operates. It has the chunk of the low-end but also some string buzz. To accomplish this I used one oscillator running a sine wave for the low chunk and originally I had another oscillator running a sawtooth for the string buzz. This didn’t end up sounding too good so I changed the sawtooth to a sine and fed the oscillator to itself to create a small amount of feedback. This had the desired effect.

AlexBass

FM Synthesis Bass

The last part of the arrangement I completed was the lead part. As with the subtractive synthesis homework I didn’t really have any clear mode of going about creating the lead sound. This particular sound was originally a sawtooth kind of horrendous pad sound but with the arpeggiator it sounds quite pleasant. I find it sounds quite similar to those steel drums that sound like bells. I found myself using the different oscillators as a kind of global envelope. So one oscillator would be the string hit and that will go into an oscillator that is the resonance of the piano and the last oscillator will be something else. This way of operating really helped with the confusing mess that FM8 is to a beginner. Here is the lead sound.

AlexLead

FM Synthesis Lead

Putting everything together creates something reminiscent of a computer game lobby screen or pause menu. I found FM synthesis to be quite a bit more challenging in regards to achieving the sound I set out to create. I would think this a very useful tool for sound design as well as music creation and intend to investigate FM8’s sound design capabilities in the future. All in all FM synthesis is pretty interesting and very powerful but has a steep learning curve. I am curious as to whether I will need to use FM synthesis in the future or could just stick to the ease and flexibility of subtractive? I will still learn all I can about FM synthesis of course.

FM Synthesis 32 Bar Arrangement

Sampling a Drum Kit

Another part of the homework task was to use our own sampled instruments. I very cheaply sampled my FM synthesis kit with great ease, but that shows little in regards to real sampling. We decided that we would sample a live drum kit as well.

To kick(drum) things off we decided that we would record different velocity levels for each part of the kit. As seen below you can see the set up that we used. An AKG C414 as the close mic and a pair of SE Electronics SE4’s as overheads. This is the set up we used for everything except the kick drum. For the kick we used an MXL A55 Kicker microphone and the SE4’s as overheads again (we had the snare placed nearby with the snares tightened very loosely so as to get some rattle with the kick hits).

10957794_787850021302155_264836104_n

We mostly recorded 5 different velocity levels of each part of the instrument. Also for each different sound the instrument could make. So for the ride cymbal I hit the bell and for snare we did snares on/off and rim clicks. If we had more time or were more inclined we could have added some flams of differing velocity on the snares and toms.

11056721_787850531302104_1722091038_n

Sadly we were denied access to the blue drum kit but I am quite pleased with the results we achieved. Being able to tune the drums helped quite a lot. That being said I only really fixed the small tom as it was beyond buggered and the others were workable.

After recording I edited the samples using ProTools at home. Most of the samples were very good. The one I had the most issues with was the hardest hit of the hi-hat that vibrated the stand and caused this chunk sound to come through the recording. I tried my best to EQ it out but I can still hear it slightly.

Following the editing stage I loaded the samples into the EXS24 sampler in Logic X and set about changing the velocity triggers to go with each individual sample. This was quite time-consuming but then again the whole process has been time-consuming to this point.

LiveKit

LiveKitKeys

I decided to leave the OneShot option ticked as this being a drum sample I figured the whole sound should play as that is the nature of the instrument. An issue we had when we recorded was that there were only 2 toms. If I was so inclined I could set the sample to play one of the toms at a pitch the next note higher or lower to add another drum sound if needed. I also edited the drums with too much space in front of the transient like I did with the FM synthesis kit and had to fix that accordingly. Lastly here is a small example of what my sampled drums can do.

Sampled Drum Sample

Sampling is a tedious but rewarding exercise. It takes quite a bit of effort to record the instrument at different volumes and then the editing takes forever. Perhaps next time I will only use one microphone to cut down editing times? I do like the sound we achieved though. Sampling is a powerful tool that I intend to use again in the future. I already have a drum kit so now to sample something else!

Resources(Google Drive) – Logic SessionProTools Session(Drum Sample Edit)

Hopefully LO coverage is as follows

  • TASK ADDRESSESS LO’s: 4, 5, 6, 7, 8, 13, 16 and 19

I didn’t do as much as the task asked for so might not cover all of the LO’s

Cheers,

Alex

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s