Audio Volume Control?

[Daniel98321]

I listen to a voice podcast with poor audio. The host's voice is very low in volume but the guests on the phone are always very loud. Commercials boom out even louder. I would like to build an audio volume limiter so that I can boost or limit the volume to a single level and then control that with a volume knob. I dont care to do anything more sophisticated than that.

I have an Arduino Uno R3 starter kit, digital multimeter, and basic/limited skill set. Can someone tell me what it is I am trying to do and steer me towards a solution?

Thanks,
DM

 

[gophert]

I listen to a voice podcast with poor audio. The host's voice is very low in volume but the guests on the phone are always very loud. Commercials boom out even louder. I would like to build an audio volume limiter so that I can boost or limit the volume to a single level and then control that with a volume knob. I dont care to do anything more sophisticated than that.

I have an Arduino Uno R3 starter kit, digital multimeter, and basic/limited skill set. Can someone tell me what it is I am trying to do and steer me towards a solution?

Thanks,
DM

It would be much easier to complain to the podcast podcaster and let them know about the bad audio. If you want to keep it to yourself and turn a knob, use external speakers (with external power) plugged into your audio jack. Put a dual gang pot (stereo) across the cables to limit the volume (full volume for host, then turn down for guest and commercials).

 

[ronsimpson]

If the podcaster knew much about broadcasting or recording there would not be this problem. Now that it has been recorded you could record while a human adjusts the volume by hand. In my studio I would re-record using a "limiter" and/or a "compressor". The machine will turn up/down the volume like you want.

The podcaster is not watching his meters, and does not know what he is doing.

 

[tomizett]

Ron is right!
It might be a solution to download the entire podcast and use an audio editor to apply a compressor (might also be known as an AGC or volume leveler) before listening to it. "Audacity" immediately comes to mind, but there may be something better.

If you're interested in building a circuit to do it (called a compressor, limiter or automatic gain control), this circuit that I designed (10 years ago - feels like yesterday!!) might give you some ideas.

 

[audioguru]

A problem is that speech (and sometimes music) on a podcast is already limited and compressed. Adding more compression so that the average levels are the same might sound bad. Frequently the first word or first part blasts very loudly then the compressor reduces the level a little while later. When the audio level becomes low then the compressor increases it a little while later.

 

[tomizett]

Yep. You can bet that those commercials are already heavily compressed - probably partly why they sound so much louder than the programme.
You'd probably want far slower attack/release times than commonly used in production if you where intending to flatten out entire sections of audio.

A feed-forward compressor might do the job well - with careful setting you could make the adverts quieter than the content!

AG is right though - in short, you can't undo what the podcast producers have already done... but you may be able to improve on it slightly.

 

[ronsimpson]

problem is that speech (and sometimes music) on a podcast is already limited and compressed

If it was compresses/limited there would not be a large difference in volume.

 

[audioguru]

If it was compresses/limited there would not be a large difference in volume.

Each program and commercial is separately limited and compressed. But some are much louder than others. If you compress all of them together then when a person speaking begins by taking a breath of air into their lungs it first sounds like a jet airplane flies past. When they stop talking then you will not hear low level voices for a while until the AGC slowly increases its and the background noise levels.