Whitney Bandel

Hello, I am fairly new to Max MSP. I am currently working on a patch where I have serial input coming in from two serial ports. These are taking signals from an electret microphone and processed through FFT using an Arduino sketch. I would now like to take this serial information, average it together, and use it to control the volume/gain of an audio file. So when you blow or speak into the microphone the volume would go up, and when you stop the volume would be low. I haven't done a lot with audio in Max yet, so I'm a little stumped as to where to begin. I have tried to look up tutorials, but can't really find anything that explains it. If anyone knows of any examples or tutorials they could share that would be great.

This is what my patch looks like. Most to the top right is irrelevant. I'm working with the top left section where I'm accessing an audio file from a folder. Then in-between all the videos are two areas that are bringing in serial reads. I want to take the counter number and find a way to average it and tie it into perhaps a live.gain that connects to the audio at the top left.

using-live-gain-with-serial-input

So I found this live.gain stuff, and I kind of have it set up in the way I think it should work. Could someone please tell me what I'm doing wrong and how to properly connect these bits, or if I'm totally off base by thinking this is how I want to do things. It's obviously doing something, but it is definitely not taking in my serial reads.

I looked around a bit and tinkered with gain and live.gain. I made these additions and it works decently. I am getting a relationship between the serial reads and the gain, which is good. However the "Audio Meter/Gain" in the bottom right is kind of ruining the range of gain I am getting. I'd prefer it to be very little to no noise on one end, to high on the other. But it seems like changing the audio meter value in the bottom right scales everything proportionately. So I get constant noise with high readings when I blow into the microphone, and no noise or low readings when I don't do anything to the mic. Is there a way to scale the gain output before it goes to the speaker? And is that the best way to solve my problem?

Thanks for any input, I really am new to all of this, so what seems like common sense is a bit above me.

What do you mean by scaling? A simple scaling of a signal can be done by multiplying it with a number or another signal using the *~ object. Is that what you are trying to do?

e.g. *~ 0.5 would be -6dB and *~ 0.1 would turn your signal down -20dB

Or are you rather thinking of dynamic range compression?

What do you mean by scaling? A simple scaling of a signal can be done by multiplying it with a number or another signal using the *~ object. Is that what you are trying to do?
e.g. *~ 0.5 would be -6dB and *~ 0.1 would turn your signal down -20dB

Or are you rather thinking of dynamic range compression?


Yeah thanks, I should have said amplify, not scale. I just don't like that the master volume limits my range. Multiplying might work. What I don't understand is if I add a cycle~ 440 to the gain scale, the audio works in sync with the master volume, but if I use my own signal it ends up having a smaller range. I don't really understand why that would be different.

I think what I'll do is create a threshold for my serial read numbers, so only the top half gets put into the gain. This will cut out the possible low end noise I don't want when the gain levels are set higher. I wanted my audio clip to play by subtlety coming in. The more I've tested speaking or blowing into the electret microphone, the more I've realized the sound waves will be too short of bursts for the audio files I'm playing anyways. I might just skip using the serial to adjust the gain, and instead make a threshold for the serial reads that plays/stops the audio clip like a trigger. Then just set the volume permanently. I think that will be more simple, and I think ultimately it will create a better experience because the audio won't sound choppy.

Thanks for your input, I will still test it out, just so I can practice more.

Help with using live.gain with serial input