Transcript
Science and Engineering Festival: The AV Experience Lab
Lesson Plan
The Perfect Video Game Setup Objective(s) • Identify the location that provides the best viewing experience for a video game setup using AV industry standards and best practices. Duration • 15 Minutes Prep • Calculate the 4, 6, 8 rule before the class begins, using the room’s dimensions (height of image on screen / distance from the farthest viewer to the image = 1 / the viewing task of 4, 6, or 8). Mark these spots on the floor with tape. This tape should be a different color than what the students will use for their predictions. Materials Needed Qty. Item 1 65” Plasma Display with Pen Overlay 1 X-Large FUSION™ Manual Height Adjustable Mobile Cart 1 Video Game System 2 Powered Speakers, at least 8” 2 Speaker Standards for above 1 Hypercardioid Microphone 1 Microphone Stand 1 Light Kit: 4 lights, 4 stands, 2 dimmers, 1 dim controller 1 Roll of Yellow Measuring Tape, feet and inches 1 Spot Photometer Lot Long HDMI Cables, microphone cable, speaker cable
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Student Tasks 1. Predict the Best Location. a. Open the InfoComm University video game presentation. b. Have the students predict the best location for sitting and playing video games. Give the students a piece of tape and have them put their predictions on the floor. Tell them that you are going to show them the math of picking the best spot to sit, and how to make their video games look good on the screen. c. Turn on the display. 2. Nearest Viewing Distance. a. Show them that the nearest viewing distance is 1x the screen height by measuring the screen with a tape measure, then showing them that distance on the floor. Ask them “would you really want to play a video game while sitting this close to the screen?” 3. Farthest Viewing Distance. a. Show the students the farthest viewing distance markers on the floor. Explain that there are different farthest viewing distances that depend on what you’re watching. b. If you are watching a moving, for example, you don’t need to see every little detail. You are observing content at a general level. So you want to sit a little bit farther away. This is the factor of 8. c. If you are still just generally observing content, but you also need to read words off of the screen, you will want to sit a little closer. Like if you are playing a racing game and need to see some information, like which place in the race you are in, for example. d. If you need to see lots of text, like in a MMORPG (massively multiplayer online roleplaying game), like World of Warcraft or Skyrim, then you will want to sit much closer. Direct the kids to move up to the factor of 4.
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4. Horizontal Off-Axis Viewing a. Next, show them off-axis viewing. Ask the students “which is better – sitting directly in front of your TV, or sitting off to the side?” b. If the TV is on a mount that allows it to rotate side-to-side, have the kids stand still and rotate the screen around them. Tilt it 45 degrees off-axis and ask them “can you still see the image?” c. If the TV is on a fixed mount, tell the students to walk until they’re 45 degrees off-axis. d. Tell the students that a few things happen when they move off-axis. First, images become distorted in off-axis viewing, so circles “O” look more like ovals “0” when they don’t look straight on. 5. Tie it all together a. All of these factors combined should show you the optimal viewing position. Mark the spot within the nearest & farthest viewing distances, and within the best axis viewing area, as the “optimal spot.” Ask the students, “Is this what you expected?” b. Switch to the video game so the students can see the application of the principles they just learned about. 6. Contrast ratio a. Invite a volunteer up to the light kit to adjust the contrast ratio switches. Have them turn the light all the way bright on the screen. Ask the students, “Would you want to play a video game with the lights glaring on the screen like this?” b. Then, have the volunteer turn the lights all the way down. Ask them, “Can you see all of the details on the screen? Would you want to play a video game in a room this dark?”
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Audio Lab Objective(s) • Equalize vocal and instrumental program material by using the graphic equalizer included on common mobile phones, while avoiding clipping and distortion Duration • 20 Minutes Materials Needed Qty. Item 2 60” LCD or Plasma Display 2 X-Large FUSION™ Manual Height Adjustable Mobile Cart 2 Hypercardioid Microphone 2 Microphone Stand 1 Audio Mixer, 8 Input 1 Audio Equalizer, Two Channel 1 Audio distribution Amplifier, 4 output 1 Audio power amplifier 2 Powered loudspeakers, at least 8” 2 Speaker Stands for above 1 Laptop with Smartlive and OScope software loaded 1 Smart Oscilloscope 1 VGA Matrix Routing Switcher, 2 X 2, 4 X 2 50 Small (2” or so) speakers to blow up 5 Audio sample clips 1 iPad 1 Document Camera Amplifier – more powerful than the loudspeaker, same impedance between 1 amplifier and loudspeaker so your amplifier doesn't damage too 1 SPL Meter
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Student Tasks 1. See your voice a. Using the laptop, show the students this image of a sine wave:
b. Say, “When you speak, your voice is actually a bunch of waves, just like the simple one in the picture. The amount of waves, and how big they are, depend on your specific voice.” c. Ask for a child volunteer. Ask them, “Would you like to see what your voice looks like?” d. Have a child come over to the microphone. Direct them to say something in their normal voice. It could be the alphabet, their own name, “I love science,” etc. Record the voice using software such as Audacity and put the recorded time domain signal on the screen. Point out how their voice is a complex wave form. e. Direct the child to repeat what they said in a really high and squeaky voice. Then have them repeat it in a really slow and low voice. Alternatively, if the instructor is proficient in the audio program, they could adjust the sound clip by slowing it down or speeding it up. f. Pull up all three examples on the audio software. Ask the students, “what is different among these sound waves?” The lesson here is that high frequencies have short wavelengths and low frequencies have long wavelengths.
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2. How to Equalize your Music (Graphic Equalizer) a. Next, tell the children that they can use their computers to make their music sound awesome. Explain that music uses sound waves, just as their voices do. b. Open SmaartLive and show the students the RTA/Frequency Domain default display. Explain to them that the different bars represent specific frequencies. The bars all the way on the left are the bass in the sound, and then the bars all the way on the right are the highest frequencies. c. Turn on one of the music samples from the InfoComm music library. d. Play the sound clip for the students without any changes to it. Tell them that we are going to take the “flat” recording (meaning the sound the recording company mixed for you) and make it sound even better using a process called equalization. e. Open up the equalization software. If using a graphic equalizer, the software should look something like this:
Or this:
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f. Explain to the students what a filter is. Filters will add or subtract decibels of sound pressure level from specific frequencies in the music. g. Next, show the students how equalizing these filters will change how the music sounds. I will leave the specific equalization process up to the specific instructor’s discretion (I know some people have strong opinions on what makes music sound the best!) But here is a basic process to follow, as a general guideline: h. Tell the students that it’s better to cut the sounds that they don’t like, rather than boost the sounds they do like. So if they want their music to have a lot of deep bassy sound, they should bring down the higher equalizers, instead of raising the bass.
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3. Equalize your own Music a. Turn on the iPad and invite students to bring out their own cellphones. They can do the following process together. Apple products have auto-EQ settings. The students can access them here:
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While Google Play/Android’s EQ looks like this:
b. Play the same clip for the students with the EQ set to different shapes. Here are some examples; we can adapt them to whatever equalizer we are using. All of my images are screenshots from my Android phone because that is the only EQ I have access to at home. Also, note that we can encourage students to follow along on their own phones/devices if they’d like.
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c. First, play a recording with a completely flat frequency response:
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d. Then, call up a student volunteer, and show them how to cut the highest frequencies. Play the sound clip and ask the students what they hear. Ask them if it what it sounds like:
e. In this setting, the lowest frequencies have been cut:
f. Explain that low pass filters, like in the first example, will take energy out of the higher frequencies, and high pass filters will take energy out of the lower frequencies.
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g. If available, choose some presets and explain what they do to the music. Here are some examples. The dance preset boosts the bass up, which makes the bass sound loud and “thumpy.” It makes the music easier to dance to:
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But the “classical” setting doesn’t need to sound loud and “thumpy.” Classical music has a wide range of instruments, and you want to make sure that the higher instruments like flutes are heard in proportion to the lower instruments like tubas:
And here is heavy metal. The middle ranges are boosted to give guitar solos extra punch:
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4. Blowing up a Loudspeaker a. Now that the students have seen how to make their music sound good, show them what happens when things go wrong. Introduce the students to SPL meters. Set one to A-wtd slow, and hand it to a student. That student will be our official dB SPL tracker – they will tell us how loud the signal is in dB SPL throughout the demo:
b. Next, input the bassy signal into the loudspeaker. It should appear on the oscilloscope as a complex wave form (but not clipped at this point).
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c. Invite up a student volunteer, and show them how to increase the sound pressure level until the signal clips:
d. When the signal clips, have the dB SPL tracker announce how loud the loudspeaker is. e. Raise the bass in the signal to maximum, then turn the volume up to maximum. Have the student announce the dB SPL at this point. f. Stop when you see smoke and fire. Have a fume hood and extinguisher on hand, just in case. g. Tell the students that this is distortion. This is what happens to your music when you play it too loudly. And you won’t just damage your equipment – you can damage your ears too. Wrap Up Once the clipping demo is complete, the lecture is over. You can invite up different students and let them play with the EQ settings while the music plays. Let them hear & see for themselves how boosting and cutting different frequency bands changes the music.
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