Week 2: Design Proposal

Design Proposal: 3.5mm Stereo Audio Mixer-Multiplexer

Objective (Why?)

• Today, users possess many devices that support 3.5 mm audio output (computers, cell phones, game consoles, streaming devices, mp3 players, physical media players...)
• Using different devices with external headphones/speakers requires cables to be plugged, unplugged, and continuously swapped, or to buy several sets of headphones/speakers. Additionally, speaker levels will have to be adjusted for different devices
• The user needs a product that allows them to combine and adjust several audio inputs and switch these inputs to several audio outputs without adjusting any cables
• Commercial products exist to address this problem, however, these products have shortcomings that prevent them from being practical to the user; such as
  • RCA mono audio instead of 3.5mm stereo, adapter required for each device
  • Support only mixing inputs or switching output, not both
  • Marketed to advanced/professional user; domestic users pay high price tag for complex features they will not use

Background (Who? Where?)

• The product will be marketed for domestic use; straightforward product for the basic user
  • User will not pay for extra frills
  • User will not be intimidated by complicated device
• Customers will connect the product to any media center that contains more than one 3.5mm audio input/output
• After configuring gain for each input/output, user will only need press a button to switch between various input/output configurations

Methodology (How? When?)

• Product will consist of a circuit board connecting several 3.5mm jacks through switches and amplifiers
• To reduce cost, product will only contain simple features
• Design is simple, each design aspect can be found in several existing products
  • Novelty of the design comes from combining these aspects in way that is not addresses by current products

Expected Results (What?)

• Product will accept 3.5mm stereo input(s), and produce 3.5mm stereo output(s)
• Several inputs/outputs can be configured as on/off, with adjustable gain in the on state
• User will be able to control several 3.5mm audio inputs and outputs from the product without having to touch a cable
• Product will allow for serial interfacing via USB cable; user will be able to switch inputs/outputs on/off from software program in addition to physical switches

Costs (How much will it cost?)

• The device will be no more than $100. Ideally, the device will be under $50, but design complexity may require the price to increase
• Design phase will not be complicated, the technology exists across several products, but is not utilized in the best way for the customer
• Different models could be produced with varying features to focus on different price points

Block Diagram: