Electronic Plan for microphones + amp (Electric and acustics)

Closed - This job posting has been filled and work has been completed.

Job Description

EXPRESS HELP NEEDED.

Hello we need help with a electrial plan and we need a idea how to get to working product. Consulting or more!

- define microphones
- define amp
- draw plan

The product:
http://screencast.com/t/MAWCTIft
http://screencast.com/t/7FDrDUCY


Picture of plan:
http://screencast.com/t/EbMX98mE81

Problems:
Sound is transmitted unintentionally also from the housing to the microphones. Slight knock on the housing transmits the respective microphone.
It comes to feedback, the cause is unclear.
In the non-installed state (individually without switch and case) the microphones to hear better.
The microphones of ELV are louder but also more susceptible to interference and noise relatively strong. In part, this could be improved by adjusting the potentiometer.
To switch the audio signals, a circuit board with a NLAS52231 used. The circuit was fine. In tests without housing when switching no fault could be found.
1 Proposal for the microphone ( type, manufacturer ) and the electrical circuit ( circuit diagram) .
Second proposal for the amplifier modules ( type, manufacturer ) and the electrical circuit ( circuit diagram) .
3 What must be considered when creating the layout of the circuit board?
4 Can the circuit parts microphone and amplifier are distributed on different circuit boards ? If so, what must be selected when the connection cables (cable type , shielding, etc. )
5 Are there any special requirements on the power supply or a battery sufficiently ?
6 How should the microphone be mechanically fastened or added ? (Material, solid compound or rubber suspension, etc. )
7 How should the hearing be collected mechanically ? (Material, solid compound or rubber suspension, etc. )
8 How will the sound be directed to the microphones ? (Conductor material , closed or open system)
9 as it is prevented that the sound is transmitted to the housing microphones ? (Acoustic emission )
10 If the selected electronic switches suitable for the application ( NLAS52231 , ON Semiconductor) ?
11 How the environment affects the structure ?