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PWM audio issue

Posted: Sun Jun 11, 2017 4:18 pm
by nickz
Hey all,

I have my GBZ configured to use PWM audio. Everything is soldered to the right place and I've configured RetroPie with the necessary config entries, but the speaker output is extremely low. You have to literally smash your ear up to the speaker grill to hear anything, even with the audio wheel turned all the way up. It worked great with headphones. I can hear everything with great clarity (minus some continual static noise.)

I'm using Helders AIO board v2.2.

Any advice on what could be going wrong with the speaker audio?

Re: PWM audio issue

Posted: Sun Jun 11, 2017 6:24 pm
by the antithesis
Can you take a picture of your set up? I've done some work with audio, although not PWM on the PiZero. I have made a speaker out of paper plates (and then my roommate set it on fire) If you can hear something, then you are getting a signal, so nothing wrong with your set-up. What could be the problem, as was my problem with the plate speaker, is the signal is just not strong enough to drive your speaker. Do you have an audio amp circuit in your set up? I looked up this PWM business and it seems to be intended for headphones. This won't be strong enough to move a speaker, possibly even a small one for a handheld device. I had to get an audio amp to use the paper speaker off my iPod.

If that's not it, then on Adafruit's tutorial page on Pi Zero PWM Audio there's a bit on adjusting the volume output from the Pi about 2/3rds of the way down the page. Try that and see if it helps. If it doesn't and you don't have an amp, get one and see if that works.

Re: PWM audio issue

Posted: Mon Jun 12, 2017 2:29 am
by Boydee
If it's a fresh install of retropie your using the default of the audio settings is set to something like 50%. Go to retropie configuration then audio, then mixer - adjust output volume. Turn it to max then you can use your volume wheel to adjust.

Re: PWM audio issue

Posted: Mon Jun 12, 2017 7:40 pm
by nickz
Thanks for the responses friends. I will respond back with proper pics/results when I have some more time to work on my project. Maybe later this week / this weekend. Cheers.

Re: PWM audio issue

Posted: Tue Jul 04, 2017 5:39 pm
by nickz
I'd like to report back and say that I needed to turn the volume up in the RetroPie settings. Thanks to the both of you! It's not super loud with everything max (emulation station, retropie, and volume wheel all max) but it's audible. And of course very audible with headphones.

Re: PWM audio issue

Posted: Thu Jul 13, 2017 1:44 pm
by Cyborg_delta1
I had the same issue it was the resistors just before the speaker the value was too high even with the software setting up and the pot on max. I can't remember where but there is a thread where Helder replied and gave step by step instruction on changing the resistors to get the speaker louder I will see if I can find it.