Raspberry Pi 4 sound
David R. Lane (77) 766 posts |
My Raspberry Pi is silent, apart from the fan. I have put the HDMI cable of my monitor in the left of the two HDMI sockets as viewed from the back, and checked the sound section of Configuration. |
GavinWraith (26) 1563 posts |
If you are using Raspberry Pi OS remember to right-click the loudspeaker icon on the taskbar and select HDMI from the dropdown menu. |
David R. Lane (77) 766 posts |
I had already checked that on the Linux side. I have also set the volume adjustment on the monitor to maximum. |
Bryan (8467) 468 posts |
Mine is silent, including the [geekworm] fan.
Just to be clear, mine is in the HDMI socket next to the OTG socket.
My 5.28 does not have a loudspeaker icon on the taskbar. Where does that come from? Maestro is working well. |
David R. Lane (77) 766 posts |
The lack of sound seems to be do with the monitor, not the Raspberry Pi 4. Trying a different monitor, I got sound (via the HDMI cable). The ‘soundless’ monitor is an Iiyama ProLite B2409HDS-1. I have tried to see whether the menu button on the front of the monitor might show an incorrect setting, but find it difficult as without user input the menu vanishes in what seems like a second. The “Quick Start Guide” doesn’t explain anything about the menu and the User Manual didn’t come with the monitor. :-( Possibly, the HDMI cable is faulty – more testing required. |
Jeffrey Lee (213) 6048 posts |
It’s highly unlikely to be a faulty cable – HDMI transmits the audio using the same pins/wires as the video signal (audio is sent during the blanking periods).
Looks like the manual is linked to from the downloads section near the bottom of the page. https://iiyama.com/gb_en/products/prolite-b2409hds-1/ Page 18 shows that there’s a setting in the “Others” page of the OSD to control whether HDMI audio is enabled or not. |
David J. Ruck (33) 1635 posts |
I’ve got a 3m HDMI cable which has started producing crackling audio, even though the picture is perfect. It is definitely the cable, other cables are fine, and it crackles on other devices (its one I keep in the laptop bag to use when away). |
David R. Lane (77) 766 posts |
I have got sound working on the monitor. In the monitor settings menu, I found it set to HDMI input for sound although it hadn’t been giving sound via HDMI. After accepting that and closing the menu the sound came. Before someone points it out, I should have looked at the information of current settings below in the same window which includes the current input which could have been something else like D-sub. Perhaps the HDMI setting I saw above was the default. |
Charlotte Benton (8631) 168 posts |
That’s seriously weird. I can’t even think of how a malfunctioning HDMI cable could allow video to pass unimpeded, but distort audio, given that both are intermingled in the same data stream. |
Dave Higton (1515) 3526 posts |
I agree. There are substandard and/or non-conformant cables out there in the world in vast quantities. I had a CAT5 drop cable, probably only 2 or 3 metres long. I eventually realised that the connection through it would only ever go at 10Mb/s, despite the hardware at both ends being capable of 100Mb/s. On examination, the cores in the cable were not properly paired. Many of us have had USB cables that don’t have enough copper in them to conform to the USB specifications (which devote many pages to specifying the cables). Goodness knows whether the characteristic impedance of the data pairs is right. Signal propagation along transmission lines is very important – a lot of my professional life has been involved in it in one way or another. So, if that HDMI cable causes distorted or crackly sound, I’d suggest it should be binned and replaced. There are many people who believe that, if the correct pins (and only the correct pins!) are joined between the two ends of a cable assembly, the job is done. It’s not enough in so many cases. |
Steffen Huber (91) 1953 posts |
Not an expert on HDMI handshaking, but isn’t there a a phase where source and sink discuss which audio capabilities exist? Wouldn’t it be possible that a wrong handshake leaves audio broken and video intact? |
David J. Ruck (33) 1635 posts |
I was going to bin the cable, but I think I’ll keep it to demonstrate to anyone who is interested, when we are allowed to meet up at shows again. I didn’t even know it was faulty until recently as I usually use it just to show pictures, but came a cropper when I tried some video. |
Rick Murray (539) 13840 posts |
People who have clearly never encountered SCSI. |
Steve Pampling (1551) 8170 posts |
Memories of dealing with IBM staff1 believing they knew everything about RS232… 1 Do they still do that “I’m an IBMer” thing? Or have they realised they aren’t Gods gift to technology? |
Alan Adams (2486) 1149 posts |
Up to the mid-1990’s it was “nobody ever got fired for buying IBM”. Somewhere around then also, the only way to connect an IBM mainframe to an IBM PC was using DECnet – from Digital Equipment. IBM – It’s Being Mended. |
Clive Semmens (2335) 3276 posts |
Given that the video and audio signals are all digital, and travel along the same twisted pairs, it’s impossible to see how the actual signals go awry in one and not the other. However, a dodgy earth connection could cause a crackle on the audio at the audio amplifier stage, after a perfectly good digital signal has been D→A converted, while the video circuitry might not be affected. |
Jean-Michel BRUCK (3009) 359 posts |
I had the problem to transport HDMI on TV studio. in fact the data are multiplexed into several bands and the audio data are in the upper part of the spectrum. |
Steve Pampling (1551) 8170 posts |
Possibly different levels of error correction in the audio and video, such that what appear as little sparkles in the video on a boundary case of signal attenuation/loss is an audible crackle? |
David R. Lane (77) 766 posts |
@Jeffrey |