I'm a novice in this and planning to build a small inexpensive audio interface for myself.
It will have:
1. One AUX input, that can be connected with a 3.5 mm jack.
2. One output, that can be connected to a speaker with a 3.5 mm jack, and
3. One knob to set a decibel level.
The idea is to always have the set decibel level as output.
For e.g., if I connect an MP3 player as a source to the device and a regular external speaker as output, and the decibel level in the device is set to say 70db. No matter what the volume is set in the MP3 player, the output from the device's speaker should always be 70db.
If the MP3 player's volume is low, the device will amplify it to 70db. If it is high, it will reduce it to 70db.
I've been searching for such mechanism but all I could find were examples of building Amps.
MP3 is just an example. It can be any source like a TV also. To simply put my idea, if you are watching TV, the commercials are louder and also some channels are louder or much lower in loudness.
I just wanted to know if we can build a device/circuit, that will give a constant sound output (volume/loudness whatever the actual tech. term should be)
I hope you got the idea.
What I'm trying to achieve, is this even possible. If yes, please help me with any pointers. Also, are there any such devices already available.
I found this question here which talks about a similar case but it is done using software.