No sound on playback (Ubuntu Studio 14.04)

Hi there. I have recently got Ubuntu Studio 14.04 up and running on my Lenovo E540 laptop, and am now trying to get Ardour working. It seems to play smoothly and I can see the sound levels on the screen, but I am getting no sound. I have tried a few settings in Jack but to no avail. Another issue is that Jack seems to only run at 48000, which is insufficient for my needs. On my desktop it runs at 96000, and the sound plays back no problem. I assume this is a routing issue as I am trying to get sound through the internal soundcard rather than an external interface. I would appreciate any help anyone can give.

(1) you are probably using JACK with the wrong audio interface.

(2) JACK runs at any sample rate your audio interface will run at. Very few laptop audio interfaces support 96kHz.

I just managed to get it working - I didn’t realise but there was a mixer stage between Jack and my soundcard that needed setting up. However I think you are right about the 48kHz - presumably when I buy an external interface I will be able bypass the built in soundcard and record at 96kHz?

If the external audio interface supports 96kHz, you'll be able to use it. JACK has no limitations of its own.

But you might want to read this first;

Ah yes, I have read this. Certainly some compelling reading, and I did decide against bothering with 192kHz on that basis. However I have decided that since virtually all interfaces run at 96kHz these days, I would stick with it to be on the safe side. I shall run some tests and decide for myself at some stage. I take it you don’t bother with anything above 48kHz?

I stick to 48 kHz to be on the “safe side” compared with 96kHz. Only half the processing power required, so fewer chances of xruns even with a big mix going on, faster exporting, only half the disk space and half data rates to and from disk. There’s lots of reasons for calling that safer.

There are very good reasons for recording at 24 bits and processing/mixing with 32bit float even when the final product will be 16 bits, but there’s no corresponding advantage to higher sample rates in the studio - in fact if you are only ever going to produce 44.1K deliverables (CD) and not video where 48K is standard, there’s a case to be made for recording at 44.1k so you never have to do rate conversion.