Oct 25th 2013
Know How... 66
How to Build a Raspberry Pi MAME and Choosing Your Podcasting Mic
Hosted by
Fr. Robert Ballecer, SJ
What kind of microphone is best for you, build your own raspberry pi MAME, how ROMs are made, and more.
Although the show is no longer in production, you can enjoy episodes from the TWiT Archives.
Guests:
Iyaz Akhtar
What kind of microphone is best for you, build your own raspberry pi MAME, how ROMs are made, and more.
Podcasting Mics 101
In this segment, Fr. Robert shows you how to go about choosing the right microphones for your podcasting setup. Dynamic or condenser, XLR or USB, cardioids or omnidirection, you'll be able to get the mic that fits your needs, style and budget.Mics On Set
Name | Element | Pickup | Address | Freq. Response | Interface | Price |
Audio Spectrum AS400 | Dynamic | Cardioid | End | 80Hz - 12kHz | XLR | ~$20 |
MXL 990 | Condenser | Cardioid | Side | 30Hz - 20kHz | XLR | ~$80 |
Audio Technica AT2020 | Condenser | Cardioid | Side | 20Hz - 20kHz | XLR | ~$100 |
Audio Technica AT2020USB+ | Condenser | Cardioid | Side | 20Hz - 20kHz | USB | ~$120 |
Sure mx391 | Condenser | Omnidirectional | Omni | 50Hz - 17kHz | XLR | ~$130 |
Heil PR40 | Dynamic | Cardioid | End | 28Hz - 18kHz | XLR | ~$320 |
Sennheiser ME66 | Condenser | Super-Cardioid/lobar | End | 40Hz - 20kHz | XLR | ~$475 |
Step 1: Choose your Transducer
The first step in choosing the right microphone is to decide if you need a dynamic or condenser element.Dynamic Microphones
In a dynamic microphone, soundwaves strike a diaphragm that is attached to a coil of wire. The diaphragm vibrates, moving the coil, passing it through a magnetic field created by a permanent magnet. As the coil moves through the magnetic field, a current is induced within the coil that is an electrical representation of the soundwave. The Dynamic Mic differs from the condenser microphone in several ways. First, it doesn't require phantom power. Second, it is far more rugged: able to withstand physical shock and much higher sound pressures. Third, its frequency response tends to be narrower and curvy: meaning that it will respond to certain frequencies more than others. Pros: Durable Self-Powered Versatile (vocals, instruments, etc.) because it is NOT as sensitive to loudness. High Gain before feedback, which makes them EXCELLENT for LIVE sound Cons: Narrower frequency response range than a Condenser microphone Not good a distant or low volume soundsCondenser Microphones
In a condenser microphone, the transducer is comprised of a diaphragm and an electrically charged backplate. As soundwaves vibrate the diaphragm it changes the electrical field generated by the backplate. That change in the field is an electrical representation of the soundwave. Microphones that use condenser transducers typically have a flatter frequency response than their dynamic counterparts. This means that you get more accurate sound production across the entire range of frequencies, from vocals to woodwinds to strings. The construction of a condenser element brings with it two important differences from a dynamic element. First, a condenser mic requires "phantom power" – typically 48-52 volts that must be provided by a pre-amp, the mixing board, on an integrated power source. Second, a condenser microphone is more fragile that its dynamic counterpart: physical blows to the microphone can permanently harm the audio qualities of the mic, as can too much sound pressure. (screaming into the mic or placing it too close to percussive instruments.) Pros: Wider frequency range CAN provide a higher quality audio signal Good for studios with controlled audio environments Cons: FRAGILE Sensitive to loudness Requires external powerStep 2: Choose your Mic Addressing and Polar Pattern
"End Firing" vs. "Side Address"
Mics can be either "End Firing" (in which the membrane is parallel to the microphone body) or "Side Address" (in which the membrane is perpendicular to the microphone body) – USALLY, but not always, side address microphone have larger diaphragms than end firing microphones. Large Diaphragm Microphones (LDM) provide "deeper" sound. It "warms" the sound of whatever it's recording Small Diaphragm Microphones (SDM) and best for wide frequency response and "fast" sounds (strings).Polar Pattern
The "polar pattern" of a microphone is the "pickup pattern": a pattern that describes the different sensitivities that a transducer will have to sound generated in the 360 degrees surrounding the microphone. http://en.wikipedia.org/wiki/Microphone#Microphone_polar_patterns Most mics used in podcasting will have a cardioid polar pattern, but there are opportunities to use omnidirectional, supercardioid, and bi-directional polar patterns.Step 3: Choose your Interface & Price
There are really only two interfaces you should consider for your studio mics, XLR and USB. XLR interfaces use balanced cables, allowing for long runs with very little interference. XLR interfaces are standard throughout the pro-audio world, meaning that an investment in a XLR microphone will most likely last you through the growth of your podcast. If you think that you want to use a mixer to mix together multiple audio streams, you will DEFINITELY want to use XLR mics. USB Microphones like the AT 2020USB+ and the BlueMics Yetti are popular because they are quiet, easy to use and portable. They include a A/D (analog to Digital) converter within the microphone body, meaning that you don’t need a XLR-USB converter or a mixing board with computer output options. However, there are very few USB microphones that allow for multiple sources on a single computer.Raspberry Pi M.A.M.E.
TD and editor extraordinaire Bryan Burnett was building himself a MAME (that stands for "Multiple Arcade Machine Emulator") with a Raspberry Pi. This setup will work fine on either the 256MB or 512MB Raspberry Pi. Bryan tried this project with both models and they both work well. The RetroPie Project has a lot of different emulators available, but he focused on the NES, SNES, and SEGA systems.Materials list
Software- Cyberduck
- TextWrangler or Notepad++
- Raspberry Pi (512) Model B
- Pi Case
- 8GB SD Card
- USB SNES Controller
- Keyboard
- Mouse
- Monitor
- HDMI Cable