Stereo Tool

Hello,

I am currently trying Stereo Tool 4.05 out as it has come recommended to me. But I have a rather major problem. This is the setup:

The output of my entire studio comes in on the INPUT of my Sound Card. Stereo Tool is configured as INPUT = Sound Card, OUTPUT = Virtual Cable 1 (of VAC4, which I also have running of course). Then I'm using Cool Edit Pro to record, which has been set to INPUT = Virtual Cable 1.

Stereo Tool had currently a preset of a friend of mine loaded -- which he uses for his Internet radio station -- but this has also been tested on one of the default presets.

Although the sound does get through, it's comes through broken up. So, record 2 seconds audio, then it goes quiet for 2 or 3 secs, then another 3 seconds of audio gets recorded, etc... There are constantly these breaks in the audio.

Has anyone had this problem as well and does anyone know how to solve this? Is there a setting I'm overlooking?

The problem is that I'm reasonably new to processing (software or otherwise) and I don't really know where to start looking.

Thanks!

--=RojanUK=--

Hello Rojan,

If you just send the output to a sound card instead of VAC, does the sound come out ok then?

My first guess when reading this is that your PC cannot handle the processing in time - but if that's the case, I would expect the same thing to happen without VAC.

Can you check what happens if you turn "Bypass all" on (on the top right of the main Stereo Tool window)? That greatly reduces the CPU load.

If you open the "Configure sound cards" window, you can see a bar below each sound card input and output that's in use, indicating how full the buffer is. I think the output buffer runs empty each time when you get silence.


If this is the case, you'll have to reduce the CPU load.
These are the steps that I would advice in that case - in this order (stop as soon as your CPU can handle it):
1. Set the "Screen updates" slider closer to Slow
2. ONLY if Loudness is set above 1.00: In Limiting & Loudness -> Final Limiter enable "Do not preserve loudness ..."
3. In "Multiband compressor / limiter", disable "HQ".
4. Set "Quality" to Mid instead of High. This will slightly reduce the output volume if you're using Loudness, otherwise it will have very little effect. (Low sounds considerable worse, so don't use it if you don't really need to).
4. If this still doesn't suffice, you'll have to turn some filters off...

Please let me know the results!

Hi hvz,

Thanks for your reply.

Before using StereoTool I've had it setup the same way, but using MBL4. So, also using VAC4. This worked fine. The same thing didn't happen then.

The PC is a P4 / 2.66GHz / 1GB RAM running Windows XP Professional SP3. Bar Windows of course, there are only a few programs installed on there and at the time of testing only StereoTool, VAC4 and CoolEditPro were running at the same time.

I can't test all of your suggestions right now -- I will do so later and let you know the results -- but I did try the 'bypass all' option and nothing comes through StereoTool at all if I do that. Whereas the incoming registers in StereoTool normally, with bypass it all stays silent.

I'll try the rest later and let you know, but I just wanted to give you this additional info in the meantime... maybe it's helpful.

Thanks again.

Ok, if "Bypass all" gives silence, you could instead just turn some filters off. The Loudness filter uses the most CPU power.

Given your setup (P4 2.66 GHz) I think the Loudness filter is the cause of the problems here. Because that filter uses A LOT of CPU power.

Are you also using FM output? If so, the required CPU power goes up a lot too.

'Bypass All' doesn't just give me silence... it freezes the last wave pattern from before I switched it on and no meters will react to any incoming sound.

You were right about the CPU -- I've checked it when StereoTool, VAC4 and CoolEdit are doing their thing and the CPU is constantly at 100%. I've tried switching the loudness filter off, but -- unless I didn't do it right -- no change to the problem, or the CPU usage.

No I'm not using FM output. I don't need to, so I keep that off.

I've checked the ST web site, as well as read what you wrote.

Sound quality is set to Medium.
Screen updates are set to slow
Loudness filter has been brought back to 1.25
Processing @ 44.1KHz

None of this made any difference to the CPU load at all.

Oops - that 1.25 is still on the site, but the Loudness value doesn't make a difference anymore in the last few versions. If it's set higher than 1.00, it takes up a lot of CPU power.


Do you need a loud sound? If not, you can also set Loudness to 1.00 and enable "Do not preserve loudness..." on the Final Limiter. And then set the Final Limiter volume low such peaks don't cause a drop in volume. That will really bring the CPU usage down, but the output will be MUCH softer.

Based on my own experiences from some time ago, on a P4 2.4 GHZ with 512 MB memory I could run Stereo Tool with these settings at about 20-30% CPU usage.


Otherwise, try the following:
- Just turn ALL the filters off (press RESET)
- Check the CPU load. I expect it to be very low if only CoolEdit and VAC are running. If not, something else is wrong...
- Then start enabling the filters that you need, and see how much they use.

I've done what you asked and the CPU load is now running around the 40%, while running VAC and CoolEditPro.

However, when I press 'record' in CoolEditPro, the CPU usage shoots back up to 100%.

And before I start thinking the issue is with CoolEditPro rather than StereoTool:- This didn't happen when using the same setup with MBL4, instead of StereoTool.

Ok, that's very strange... Stereo Tool doesn't even know if you're recording in CoolEdit. Can you check the CPU usage of the different processes?

It COULD be that with MBL4 the CPU load is a bit lower than with Stereo Tool, and that that difference suffices to get below 100%.

Can you try another program than Cool Edit Pro to record?

With MBL4 the CPU load, whilst recording, varies between 40 and 60%... it doesn't get anywhere near the 100%.

When StereoTool is not running and VAC & CoolEditPro are, then the CPU load is around the 20-30%.

I could try Audacity to record and see whether that makes any difference... I'll let you know.