Pirate Audio: Line-Out with OMXPlayer

Hello community,

I have a street art project with electronic means. I have a box with a beamer, Raspberry Pi 3 B+,a JBL Go (3W) speaker, Picamera and a Lithium powerbank to power up all the gadgets. When people cross in front of it the projection is activated on the streets walls and a character talks to pedestrians every time motion is detected by the camera.

This is a Python code and OMXPlayer is used for playing the videos and a background music. To improve the sound volume, I gave some gain on the OMXPlayer, but if I cross the +6.0 dB border it peaks and distorts the sound. Nevertheless it isn’t loud enough. So I used the beamer as an intermediary to give more gain, that means, sound leaves from the Raspberry Pi through HDMI to the beamer and then from the beamer through a 3.5mm jack to the JBL speaker.

I got it louder using this method, but also a bit more noise on the signal. And still on the open air it is still not loud enough. I have two questions:

Is the Pirate Audio Line-Out also an amplifier board? Will it give me a better amplification of the signal connecting it to the JBL than the last options?

If yes, will it work with OMXplayer? Because OMXPlayer usually just works with the onboard 3.5mm jack or the HDMI output from the Pi.

Due to the limitations of my powerbank and the design of the box, I wouldn’t like to use a bigger amplifying board such as a HiFiberry or Justboom, which also demand passive speakers.

I had better results with a 20W JBL, but I still have to bridge it to the beamer for a better gain. The only problem is still the noise.

Well, I’m also open for other solutions!

Thank you in advance!

From the Pirate Audio LineOut’s product page it doesn’t seem to have an amp (“Plug Pirate Audio Line-out for Raspberry Pi into your hi-fi amp or powered speakers”). Presumably the Pirate Audio Stero Amp would be a better choice, though you might have to do some wire work if you really need the 3.5mm connector.

At a glance it’s possible to redirect the audio output of OMXPlayer so I would presume it’s possible to get it to output via the Pirate Audio HATs?

Hello Shoe,

thank you for your fast answer! I tested OMXPlayer with the ‘-o alsa’ output and it works even with the Bluetooth (what I couldn’t achieve before). I even had a much better gain with Bluetooth, what would already solve my problem. Unfortunately the Python code triggers the music in the background but not the videos, which are two different instances of OMXplayer. This doesn’t happen using the HDMI or the Analog outputs.

You are right, adding the ‘dtoverlay=hifiberry-dac’ at the ‘config.txt’ will probably work usind the ALSA output. The Pirate Audio Stereo Amp will allow me two passive 3W speakers. I don’t know if this output will be much greater than the active JBL 3W that I already have. Well, I think it’s a matter of testing it.

Thank you for your time and thoughts!

You’re welcome, glad you got a solution!