Speaker "pop" on BeagleBoard

Hello,
Further to my questions about using a BeagleBoard/RISC OS system for music, can I ask if the speaker “pop” bug is still present? I just wish to play MP3s via DigitalCD, and want to know if the speakers will “pop” between tracks.

Thanks

Garry

Yes, the bug still exists. If I get a chance I’ll have a go at fixing it tonight.

Hi Jeffrey,
Thank you very much, you’re doing a truly remarkable job for the future of RISC OS.

Garry

If I get a chance I’ll have a go at fixing it tonight.

Thank you very much, you’re doing a truly remarkable job for the future of RISC OS.

Jeffrey, if you fancy replacing the contents here (or elsewhere) with a few wished-for films/music/whatever else keeps you running, I reckon a few of us would be more than happy to chip in and try to arrange that!

At the moment I think the only free thing I’d be interested in getting is some free time ;-)

But thanks anyway!

I’ve checked in some changes to fix the speaker pop, so be on the lookout for when a new ROM image is up for download.

I don’t think the audio hardware on the beagleboard is particularly high quality. The anti-pop hardware seems to cause an audible high-pitch whine when turning the audio output on and off. I’ve tried to stop it from being too annoying (and long) by reducing the time which the anti-pop is active, but I can’t reduce it too much without reintroducing some minor popping. I think I’ve found an acceptable balance, but let me know if you hear any popping with your setup and I’ll increase the anti-pop time again.

Of course this wouldn’t be such a big deal if the hardware didn’t need switching on and off just to change the sample rate.

Jeffrey, that’s fantastic, thanks so very much. I’m afraid I can’t test as I don’t actually own a BeagleBoard right now, as I was evaluating the idea for a music system which I’ve not got yet. This is a great step towards me biting the bullet and going for a RISC OS system over a Windows tablet though. The amazing thing is that I think the RISC OS system may even end up cheaper. I hope to report soon on my new RISC OS based music system though.

Just one thing, you say that the BeagleBoard’s sound system may not be too great, is it likely the PandaBoard is any better?

A new ROM image is available for OMAP3 from here;
www.robheaton.co.uk/riscos/roms

It might be worth waiting to see how the Pi works out.

Is HDMI audio likely to work on RISC OS? If so then that could be used with a good quality DAC.

The other possibility is if USB audio becomes an option.

Just one thing, you say that the BeagleBoard’s sound system may not be too great, is it likely the PandaBoard is any better?

No idea – you’d have to talk to someone who’s used one. And I’m not sure if audio is working yet in RISC OS.

Is HDMI audio likely to work on RISC OS? If so then that could be used with a good quality DAC.

It won’t work on the beagleboard (the pins aren’t connected), but I think it’s possible to use it on the pandaboard and the Pi.

No idea about the Panda but there have been “Some very good audio news” about R-Pi

You may remember that we were discussing the audio output from the 3.5mm jack earlier. I know some of you who have media centre-type applications were disappointed that the audio quality from that jack was only going to be equivalent to FM radio. Happily, our very, very smart hardware team has managed to push all the noise out into a frequency that can’t be heard by humans (I believe it’s also dog-proof), so the audio quality from that jack will now be CD-quality.

This means that you will be able to deal with two high-quality audio streams, one via HDMI and one through that jack. Thanks very much to the hardware team – I don’t know precisely who came up with this particular hack, but I’m really, really chuffed you managed it.

http://www.raspberrypi.org/forum?mingleforumaction=viewtopic&t=430

Rob, that was really fast!

OK, so I think I’m still better off with BeagleBoard. I’ll consider R-Pi, but I think at the moment, the BeagleBoard is looking the most like a complete RISC OS machine.

I’m not personally fussy about HDMI audio, I’m looking to connect to a fairly basic valve amp, so the simpler the better as far as I am concerned.

Thanks again to Jeffrey, and also to Rob, I’m going to have to start pricing up a system soon.

Cheers

Garry

Nice work Jeffrey!
I’ve just tested out a ROM with your fix for the “pop” included.

I can’t hear any “pop” between MP3 files anymore!!

Rob, that sounds great. Could you say whether otherwise the sound quality is good? Jeffrey mentioned that the sound hardware may not be wonderful on BeagleBoard (and who am I to doubt him), would you say it was distinguishable from a RiscPC or Iyonix?

Cheers

Garry

Hi Garry,
I’ll try some decent speakers out tonight.
I’ve only been using some cheap aweful ones!!

Rob.

That would be great, thanks Rob.

Garry

Not sure where last night went, I didn’t get a chance to try out anything on the BeagleBoard.
I’ll try again tonight!

Rob, no problem at all! I’d just be interested to know your thoughts.

Cheers

Garry

Garry, sorry for the delay in getting back to you!
I tried out the BeagleBoard with a set of M-Audio studio monitor speakers, the sound output from the BeagleBoard is quieter than that of a regular PC/Laptop.

However I thought the sound quality was pretty good!

Hi Rob, no trouble at all. I’ll be going through an amp anyway, so I’d hope that can get the volume up to where I want it. I don’t need all that loud anyway. Thanks a lot for giving it a shot.

Right.

I have finally moved over to RISC OS 5.19 to test this issue out.

Jeffrey is right there is still a noise when swapping tracks.

However it is much less than before – it is still audible but it isn’t the huge thump that was there before.

Whilst I had my ear up against one of the speakers I could hear some serious high frequency hash breaking through even on these speakers! <— points to a cheap and poor DAC at the least…

Speaking of which – Jeffrey, this starting and stopping of the soundsystem is it just restarting the DAC or is it deeper than that? The reason for asking is that if it is the just the DAC then streaming the sound down another bus, say USB (hint hint :-) ) for instance, might cure the problem.

I am playing WAVs over the network through DigitalCD right now. I’ll use MusicMan to convert them to mp3 over night and see if another player is more forgiving…

Speaking of which – Jeffrey, this starting and stopping of the soundsystem is it just restarting the DAC or is it deeper than that? The reason for asking is that if it is the just the DAC then streaming the sound down another bus, say USB (hint hint :-) ) for instance, might cure the problem.

It only restarts the sound system due to limitations in the DAC. If you were using another audio device (like a USB one) then it should be fine (assuming your USB device doesn’t suffer from the same limitation!)

Slightly off-topic, but I’ve made some changes to the ROM and sound setup plugin which increases the available volume range. So you should be able to get the sound output much louder than you could before. In fact the new maximum setting seems to be louder than my Iyonix (although I also spotted the Iyonix isn’t using the full volume range, so I might fix that too). However I haven’t submitted the changes yet since I don’t want them to get in the way of the 5.18 release. Maybe I should drop ROOL a line to see if they’d be willing to include it.

Is it possible to use the ‘RomPatch’ program for small updates?

Yes, a ROM patch could be produced if necessary.