Unformatted text preview: E85.1801 Fundamentals of Music Technology Instructor: Juan P. Bello Assignment # 4, Mixers and Signal Flow Full Name:____________________________ NetID:_________________________ Practical Experiment Description: For this assignment you are expected to perform a set of small experiments as explained below. Please record the results of the experiments on a short report (max. 3 pages) that also: (i) discusses the reasons for the results you record, (ii) describes any difficulties that you had during the set‐up of the experiments and (iii) provides answers to the questions below. While the experiments can be done in small groups of 2 or 3 people at a time (as long as everyone participates), the reports should be individually written. Important notes: Due to the size of the 1/8th in adaptors we have in the equipment room, two computers are needed for this experiment. Instructions: • The experiments on this assignment can be performed in studios E or F. (see 8th floor support desk for studio booking schedules). • For the experiments you will need to borrow the following from the support desk: 1. A “roll around” mixer or other 16‐Channel Mackie mixer (ONYX or 1604 work, the 1202 will not work for this experiment) 2. 2 x 1/8”mini to 1/4” male cables • Connect one of the computers such that it is sending sound into the mixer (using line input to channel 1), connect the other such that the sound is send out of the mixer (using main out Left) into the line input of the computer. • At the end of the experiments please return all equipment and leave to studio in the same or better condition than how you found it. Experiments: Set all knobs and faders to the “unity” setting, if there is no obvious unity setting set knobs to 12 O’clock and faders to halfway. 1. Adjust each gain stage that does not have a unity setting, such that a signal generated at 1kHz produces a reading on the analysis computer of negative ten decibels ( ‐10db). 2. Record each of the gain stages that affect the level of the signal (how many, what setting.) 3. Adjust each of the EQ knobs, note and record which ones alter the signal and how so. 4. Adjust the generator frequency to 100hz and 10kHz, and repeat steps 1‐3 5. Unplug the analysis unit from main out and repeat this process for “Aux 1 send”. Engage/Disengage the Pre‐fader switch and note how this changes which gain stages affect the output. 6. Unplug the analysis unit from Aux 1 Send, and plug into Control room out. Note how the Main output faders and the control room knob controls are (in)dependent. Questions: How does the signal meter on the main output of the mixer relate to the readings shown on the analysis computer? Which EQ parameters did you expect to affect the readings at each of the frequencies generated? For example, what did you expect to see in the readings as you adjust the low shelf filter while the 10kHz sine wave was playing into the mixer? What was the unity position of the control room fader? How would you describe that position, if there were no unit markers? Who did you work with on this experiment? What did each person do? Report: Answer each of the above questions as complete thoughts in formal English. Analyze and discuss the results of the experiments, trying always to relate your findings and observations to the theory discussed in class and the demo sessions. ...
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- Fall '09
- control room, Juan P. Bello, Music Technology Instructor, 16‐Channel Mackie mixer, Main output faders