10.2 is twice as good as 5.1!

I was told that IMAX theatres use 10.2 surround sound. I remember the first time I went to an IMAX in my hometown of Bristol, it was quite an experience.

After some Googling, I found out a lot of interesting information about IMAX theaters, and how they can achieve that chest rumbling bass, as well as the precisely positioned high pitched tweets.

I came across an informative website known as in70mm.com, on which I found these snippets of information.

This article I was reading was written in 1997, and seemed as though it might be slightly out of date here and there. It did state, that "Each channel consist of JBL speakers model 2404 H tweeter, 2445 J driver, 2123 H midrange and 2245 H woofer".

Obviously, in our project we're not looking to produce particularly loud sounds, but highly positional sounds. Bass is something to take into consideration, as even though frequencies which humans can't hear, they can still feel, at high enough amplitudes. These feelings will certainly add to the experience of the ride.

I quote from in70mm.com:

"Most newer IMAX films are now using the IMAX digital sound DDP designed by Sonics. DDP is short for Digital Disc Playback. The system is a digital sound source specifically made for IMAX. Sonics uses compact disc technology to create the highest quality sound delivery possible today. Wide frequency response, dynamic range and the accurate perception of time are the attributes of DDP. A frequency response of 20 – 20.000 Hz is maintained over the entire audio spectrum of ten octaves. Six octaves is found in conventional cinemas. Three CD’s are used for each soundtrack, one CD for every 2 channels. The audio is sent to the Sonics TAC-86. From the TAC-86 the signal is sent to the computer-controlled 1/3 octave equalization unit, developed for IMAX. This unit matches the sound system performance to suit the acoustics of the particular theater in which it is installed. The equalization can also be used to compensate the response of particular films for optimized playback in a particular theater."

Manipulating the sounds

Still feeling inspired, I began manipulating some of the sounds which I had captured.

I was trying to achieve a pneumatic release type sound. A large amount of air, escaping through a small aperture very quickly, to put it another way.

I began experimenting with aerosols, until I managed to record a sound which I thought would be appropriate.

In the screenshot, you can see how I was using the timestretch effect in Adobe Audition to make the sample longer, and at the same time sound slower. I found this sample, reversed, also made a very good sci-fi pneumatic sliding door.

Sourcing sounds

I started off by recording sounds around the house. At first, I thought we were in need of some Atmos, i.e. some background, ambient noise which can be used to cover up any silences between tracks.

The atmos which we would need for this assignment needs to be mechanical, electronic, spacey sounding. It's quite difficult to properly define the sound we need, and I hope as I continue to blog I'll find more appropriate ways to word what I'm trying to say.

Moving around the house, I found the fridge/freezer to be one fantastic source of such a sound.

I set up one microphone as shown:

Seeing as I was doing these recordings at home, I was limited to the tools which I had brought up to University with me. This included a Samson CO3 Microphone, which I've used for some years. This is connected to an Alesis Mixer, which is connected to a laptop running Adobe Audition. The recording was completely clean, with no effects applied.




Staying in the kitchen, I made several recordings of our gas cooker. It creates fantastically vicious sounds when one ring is turned all the way up. I again, set up the same mic in the same configuration as shown:


Obviously, I couldn't put the mic any closer, as it would burn. The mic was positioned well enough to be able to pick up the sound of the flames on the stove, and I thought with some editing I would be able to make this sound like the jets coming out of a rocket during takeoff.

Spaceland!

So, this is where I'll be posting my progress about our current project, the soundtrack for a roller coaster ride, for a fictional theme park named Spaceland.

The brief for the assignment states that no human voices, instruments, or pre-recorded audio may be used. I felt that these constraints were fairly loose, and gave us a lot of scope to experiment with, in order to create the sounds we needed.

As I said in the brief, the sound scape needs to be very precisely timed in order to fit with the ride, which means we will need to produce a very accurate timing script, to which we'll need to adhere to very strictly.

First of all, I'll need to source some sounds in order to then manipulate them, using Adobe Audition. I have used Audacity before, and feel it's an excellent open source alternative to Adobe Audition (or Cooledit) though I feel more comfortable using Audition, as I've used it (and Cooledit) many times before.