designlab nodog 15jan03 Project Specifications ---------------------- ACOUSTICS/AUDIO Multi Voice Synth (MIDI, digital) - The project entails the creations of a two voice analogue synthesizer. * The synthesizer should have line level output. * The synthesizer should be able to create multiple distinct tones, all at the same time. * The synthesizer should be controllable by a standard MIDI in signal and connection. * Each tone generator should be controllable as a distinct MIDI channel or instrument number. * If you choose an analog synth, then the number of voices is two. * If you choose a digital synth, then the number of voices is four and each voice must be able to play at least four notes at once. High Fidelity Speakers (acoustics) - This project entails the creation of a set of two high fidelity loudspeakers. * The speakers should cover the range from 50 Hz to 20 kHz. * The speakers should accept a full range input signal. * The speakers should have a nominal impedance of 8 ohms. additional -- * overload protection Solid State Stereo Amplifier (analog circuits) - This project entails the creation of a solid state stereo amplifier for car or home use. * The amplifier should take line level input (e.g. from a CD player or car stereo head unit). * The amplifier should be full range (20 Hz to 20 kHz). * The amplifier should have "speaker out" connectors for full range speakers. * The amplifier should provide 30 W / channel into 8 ohms with less than 1% total harmonic distortion into a resistive load. additional -- * The amplifier should have it's own regulated power supply with < 1% ripple or compensation must be made for an unregulated power supply. Multi Microphone Talker Locator (DSP) - This project entails the creation of a multi microphone system that can locate and listen to a single moving talker. * The locator should "listen" for a single moving talker travelling no more than one meter parallel and no more than one meter distant to the line of the microphones. * The locator should have a single line-level output of audio. * The talker should be able to speak at a normal talking level amidst other non-speech noise with a signal to noise ratio of > 10 dB. * The system must handle the audio range of speech. Amplified Subwoofer (analog circuits, acoustics, power) - Construct an amplified subwoofer system for either automobile or home placement. * The subwoofer should be able to receive full range line-level input (whether from a CD player or a car stereo head unit). * The subwoofer should have a selectable cutoff frequency (including one well above subwoofer level so a pre-filtered signal can be used). * The subwoofer should provide sufficient sound pressure levels to supplement normal speakers at moderate to moderately loud listening levels (around 85 dB SPL at 1000 Hz). * The subwoofer should have a gain control so that it can be turned "off." MIDI Drum Trigger (MIDI, acoustics) - Construct a MIDI drum trigger capable of generating a standard MIDI signal. * Output channel should be selectable (0-15). * Trigger can be either a small element for mounting on an acoustic drum or a standalone "pad". * Piezoelectric speaker can be used for the trigger. additional -- * velocity-sensitive * use DAC on analog trigger input * multiple triggers with different note numbers Automated Two Channel Mixer (MIDI? microcontroller?) - Construct a two channel stereo mixer capable of automation. * The mixer should be capable of accepting line level inputs * The mixer should have some mechanism of automated control of the individual channel levels. * The mixer output should be stereo and line level. additional -- * physical record mode * output channel should have automation as well * MIDI controllable Two Channel Crossfading Mixer with Digital Output - Construct a two channel stereo mixer capable of crossfading. * The mixer should be capable of accepting line level inputs. * The mixer analog output should be stereo and line level. * The mixer should allow crossfading between any two channels. * The mixer should also provide a digital output in a provably usable format. additional -- * accept phono input with the standard R.I.A.A. frequency rolloff characteristics. * headphone output with volume control and * cueing Mind Machine (microcontroller or DSP) - Construct a sound and light entrainment device (SLED a.k.a. "mind machine") for meditation. * The SLED must create a controlled and changing series of pulses of flashing lights at beta, alpha, theta, and delta brain wave frequencies. * The SLED must create a controlled and changing set of sounds at beta, alpha, theta, and delta brain wave frequencies. * The visual and auditory stimulus must be synchronized. * The user should be able to choose from several preprogrammed "journeys" through different brainwave states. Parametric 2 channel Equalizer (DSP or analog circuits) - Construct a stereo 3-band parametric equalizer (EQ). * The EQ must have three bands of equalization (low, mid, and high). * The low/mid cutoff frequency and the mid/high cutoff frequency must be controllable. * The output level for each of the three bands must be individually controllable. * With all controls in "neutral," the EQ must pass through the input signal with no distortion. * The input and output should be stereo and at line level. additional -- * 5-band Microphone Preamplifier (analog circuits) - Construct a single-channel microphone preamplifier. * Gain should be continuously adjustable from 0dB to at least 60dB. * Design can be solid-state or tube. * Pre-amp input should be from a microphone. * Output should be appropriate line and mic levels (selectable). additional -- * 2 channels (or more) * 48V phantom power supply for capacitor mics * phase reversal switch for balanced inputs * balanced output * electromagnetically shielded DSP Audio Effects Unit (DSP) - Construct an audio effects unit providing controllable standard DSP effcts. * FX unit must have line level input and output. * FX unit should provide digital delay with specified feedback, parametric filtering, stereo panning, and flanging. additional -- * reverb using several all-pass and comb-filters * all parameter control must be handled without restarting the program Instrument Tuner (DSP) - This project entails the creation of a small instrument tuner which will allow a musician to tune their instrument both by ear and by measurement. * The tuner must accept electrical or acoustic input appropriate to the instrument. * The tuner must allow tuning of each note appropriate for the instrument. * The tuner must show at least five levels of tuning: very flat, flat, tuned, sharp, very sharp. * The tuner must emit a tone for each note appropriate for the instrument to allow tuning by ear. additional -- * The tuner must accept acoustic input if electrical originally chosen Electric Guitar Amplification System (analog circuits) - This project entails the creation of a guitar amplifier for an electric guitar. * The amplifier must accept the electrical output of an electric guitar. * The amplifier should output at least 5W of power. * If the amplifier is solid state design, the amplifier must include "distortion," "reverberation," and "three band equalization" effects and bypass must be available on all effects. * The amplifier should include a speaker which is the output of the amplifier. additional -- * The amplifier should include a mic level input. Class D Power Amplifier (previous amplifier design) - This project entails the creation of a class D power amplifier. * The amplifier should output 100W of power at > 80% efficiency and < 5% total harmonic distortion. * The amplifier should take line level input (e.g. from a CD * player). * The amplifier should be full range. * The amplifier should have "speaker out" connectors for full range * speakers. Telephone Vocoder (DSP?) - Create a "vocoder" system to transmit broadband audio over narrowband telephone lines. * The encoder should accept line level full range (20Hz-20kHz) audio and output band limited control signals for telephone transmission. * The decoder should accept band limited control signals and recreate full range audio output. additional -- * actually interface with real telephones Voice Message Recorder (DSP or microcontroller) - Create a "message box" voice recorder. * It must be able to record at least 50 seconds of total message. * It must record voice transmitted in the air. * It must play the messages out of a speaker. * It must be intelligible. Noise Canceling Headphones (DSP) - Create a set of headphones which cancel consistent noise from the listening environment while providing playback of a musical signal. * They must give at least 10dB cancellation for constant tones. * They must accept a standard audio input. * They must handle noise at different levels in each ear. * They must not "go unstable" (and therefor be unsafe to use). Acoustic Fountatin Tube (pure acoustics) - Create a demonstration of the acoustics phenomenon called "acoustic fountains." Acoustic Levitation Box (pure acoustics) - Create a demonstration of the acoustics phenomenon calle "acoustic levitation." Real Time Spectral Analyzer (DSP?) - Create an "impressive" display of the spectrum of a sound. * The analyzer must have at least 11 segments across frequency. * The analyzer must cover the entire audio frequency range (20 Hz - 20 kHz) * The analyzer must be capable of displaying both line level input and an acoustic signal in the air. Voight Tube Speakers (acoustics) - Create a stereo pair of Voight tube loudspeakers. * They must handle appropriate electrical signals for loudspeakers. * You must create and simulate a model for how they work. Audio Compression/Transmission/Decompression Mechanism (DSP?) - Create a set of boxes which compress an audio signal into some other type of signal, transmit that signal, and then decompress that signal on the far side. * The input and output must cover the full audio frequency range and be at line level. * The tranmission must require less than audio bandwidth. extra * stereo Wireless Audio Transmission - Create a mechanism for transmitting audio in a wireless way. * The transmitter must accept standard line level input. * The receiver must provide standard line level output. * THD must be less than 3%. extra * stereo