{"id":62792,"date":"2022-04-13T16:04:07","date_gmt":"2022-04-13T20:04:07","guid":{"rendered":"https:\/\/www.hajim.rochester.edu\/senior-design-day\/?p=62792"},"modified":"2022-09-12T09:53:56","modified_gmt":"2022-09-12T13:53:56","slug":"custom-audio-interface","status":"publish","type":"post","link":"https:\/\/www.hajim.rochester.edu\/senior-design-day\/custom-audio-interface\/","title":{"rendered":"Audio Interface"},"content":{"rendered":"\n

Our Team<\/h2>\n\n\n\n

The interface team is comprised of University of Rochester Audio & Music Engineering seniors Cassius Close, Junwei Ma, Zack Uchima, and Madeleine Vogel. The primary project mentors are Professors Michael Heilemann, Sarah Smith, and Daniel Phinney. <\/p>\n\n\n\n

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From Top Left, team members Madeleine Vogel, Cassius Close, Junwei Ma and Zack Uchima<\/figcaption><\/figure>\n\n\n\n

Project Background<\/h2>\n\n\n\n

Recording music in the digital age presents a unique set of challenges. Nearly all recordings utilize effects such as reverb, compression, and equalization. However, these effects require going back and forth between multiple hardware and software components and knowing exactly which settings to adjust. This takes time away from the recording process, hindering what should be a creative endeavor. Being able to quickly get the sound the user wants is crucial to having a successful recording session. The key to solving this problem is making effects easy to use and quick to implement.<\/p>\n\n\n\n

One of the key components in this chain is the audio interface, a device which connects microphones and instruments to a computer. In an interface, audio goes through a preamplifier to an analog to digital converter, and is then sent to the computer to be processed. Our interface differs from existing devices by processing the audio independently of the computer. This allows us to put all of the controls in one place and to make them simpler and easier to use. <\/p>\n\n\n\n

Market Research and Product Design<\/h2>\n\n\n\n

The team constructed a survey of questions about specification preferences and submitted it to the Facebook group \u201cHey Audio Student\u201d, a forum of over 35,000 online members. It received many responses that helped the team understand the preferences of users of various skill levels. We also conducted interviews with local Rochester audio engineers, who gave us advice about how the interface should function. Design choices that came from this included the ability to control effects with only one knob, an easy-to-read digital screen, and high-resolution audio metering.<\/p>\n\n\n\n

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Figure 1: Sample Questionnaire Response<\/em>s<\/figcaption><\/figure>\n\n\n\n

Based on our research, time, and budget, we decided to prioritize flexibility and ease of use over features such as higher channel count and bit rates. The interface has two input channels on XLR-1\/4\u201d jacks, allowing the user to plug in almost any instrument, microphone, or device. Users can connect both speakers and headphones to monitor the audio. For ease of use, our effects are controlled by a single knob. This simple control helps users quickly get the sound they want. <\/p>\n\n\n\n

Processor Chip<\/h2>\n\n\n\n

Most audio interfaces do not have digital effects, therefore, their processors do not have the memory required for more intensive effects such as reverb and delay. After extensive research, we chose the PJRC Teensy 4.1. This chip maintains a good balance of price, performance, and memory and has built-in DACs and ADCs designed specifically for audio. <\/p>\n\n\n\n

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Figure 2: Teensy 4.1 chip<\/em>
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Software & FX Design<\/h2>\n\n\n\n

One of the main goals of the interface is to quickly get the sounds in your head onto the computer. This has been achieved through single knob controls of carefully crafted preset effects. The single knob controls a variety of parameters depending on the effect. For example, with a compressor, the threshold, ratio, attack, and release times may all change based on the \u201camount\u201d of compression the user wants. The effects include equalization, distortion, compression, and reverb.<\/p>\n\n\n\n

Shown is a mock-up of the UI on the interface\u2019s screen. On the left is high-resolution metering, which allows users to closely monitor their gain levels. On the right, the screen displays the selected effect presets, as well as the \u201camount\u201d of each effect on each channel. The videos are DAW demonstrations of just some of the presets that are available within the interface. <\/p>\n\n\n\n

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Figure 3: Display Mockup<\/em><\/figcaption><\/figure>\n\n\n\n
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