FINAL EXAM – MICROTOOLS – SPRING 2002

Due: TBA

Instructions: Print out this page. Using complete and reasonably detailed answers, respond to the following questions. Please type your answers. Exams that are not typed will not be graded. Please turn in a photocopy of your work.

You encounter a recording with 60Hz ground hum in it, what do you do? This hum is harmonic (it has components at multiples of the fundamental) and it can be measured at -47dB. Your audio source is a 1/2 trk 1/4 inch 30ips recording, without noise reduction. Explain in detail the steps that you would take to remedy the situation.

a. First scenario - assume that there is a recording of the offensive hum that does not contain any musical signal

b. Second scenario - assume that there is no available recording of the hum without accompanying musical program material

You have just completed a recording at 44.1 KHz and 16 bit of a final mix and now the producer wants a version for her new CD ROM game "Hannibal the Cannibal". The new version needs to be 8 bit 11025 Hz sampling rate. Explain in detail the steps you would take to convert the music track to this format. Why was this word length and sample rate chosen by the producer?

You have a recording at 11025 Hz sampling rate - what is the highest frequency audible on the microsound? If you sample rate convert this file to 44.1KHz what will be the highest frequency audible? What if you sample rate convert to 48KHz? (Careful: this is a trick question)

Write a batch file which does the above operations (2 conversion) – name your original file original.sf and your 44.1KHz version version1.sf and your 48KHz version version2.sf.

Write a batch file which does the following in the order given:

create 4 filters (Hint: use mkfilt)

lowpass at 15KHz

hipass at 40Hz

bandpass at 1KHz center frequency and 100Hz bandwidth

bandreject a 950Hz center frequency and 10Hz bandwidth

convert from integers to floating point values a file called white noise.sf (a 44.1KHz file) - call it noise.fp (Hint: white noise contains all frequencies)

filter this file with each of the four filters in series (Hint: use filter)

convert the result of the process back to a .sf file called result.sf (Hint: you stay at 44.1KHz throughout)

What frequencies will be present in the spectrum of the file result.sf?

You have just completed a audio track for a T.V. spot and the producer calls you and says that instead of being 33 seconds long it has to be exactly 28 seconds long. Using tscale write a batch file that accomplishes this fix while you go get some coffee.

Your producer is mixed-up again and now tells you that he was wrong the audio track needs to be 38 seconds long not 28 seconds. Write a batch file that accomplishes the fix using the new 28 second file you made earlier as a starting point while you go look in Variety for a new producer to work with.

As if all that were not enough - you need to put test tones on the head of the DAT mix of the spot but the studio's tone generator is busted. Write a batch file to create 30 second tones of 100Hz, 1KHz and 10KHz at -3dB.

(Hint 1: these should be sine waves and recall, digital has no headroom!)

(Hint 2: if your DAT is at 44.1KHz your tones had better be too!)

Explain the difference between BATCH FILE operation of the MicroTools and MSDOS PIPE operation. Which is better and why?

Discuss why the MicroTools are an important adjunct set of programs to MicroEditor. In your discussion be sure to point out the ways in which MicroEditor and MicroTools compliment each other.

Fini

Congratulations: You have just finished a course of study that will add profoundly to your technique as a recording engineer. Best of luck for your future success!