Stereo Tool

By the way, have you tried what happens if you increase the ASIO latency a bit? The high CPU load might be causing the problem...

Edit: Ow, that makes sense. In ASIO mode I'm asking for 32-bit data. I guess I should first check if the hardware/driver supports it.

Edit 2: Low latency bass artifacts: That makes sense, because in Low Latency mode all the new bass processing stuff is turned OFF. I may have an idea to fix it, will look into that later (I hope to be able to build my current deep bass protection filter into the 0-latency multiband processor. Which would be quite a bit change though).

Good news: 0-latency multiband processing seems to work MUCH better than I had expected. With what I found so far, I should be able to reduce the latency of the noise gate, Pre Limiter and multiband filter to 0, if in the Multiband filter the clipping is turned off.

So, in the latency calculation, that would mean:
8 ms 0 ms for the noise gate
8 ms 0 ms for dualband processing
6 ms 6 ms for removing remaining loud peaks in the dualband signal
16 ms 0 ms for multiband processing
64 ms for the final limiter

Which gives a gain of 32 ms with nearly no effect on the sound - except that clipping is no longer possible. The remaining loud peaks in the dualband signal can probably also be removed using a singleband compressor, which would reduce it by another 6 ms.

On top of that, the new processing will PROBABLY (I still have to test it) use LESS CPU power.

great!
But is it good to have 0ms latency .. i was thinking thare will be at least 2-3ms because of look-ahead ?

The current multiband filter doesn't look ahead either (!). So that won't make any difference.

However, since both post filter and clipping are disabled, you shouldn't use too aggressive settings or you'll get artifacts. (The clipping basically removed peaks that remained because there is no look-ahead).

That's nice Hans! I'm very interested in a lower CPU usage and can't wait to test it

Not yet ready to upload anything, but I can tell you this:
- The CPU load is lower
- Loud peaks (over 5-10 times the maximum output volume) are not handled very well. But they should be removed by the pre-limiter anyway...
- The upper 2 bands (10 and 16 kHz) cannot be controlled separately anymore
- I had to slightly increase the latency for the stereo widener, it's now 2 samples

sounds promising...

I've made a few more changes. The CPU load is slightly higher, but I hear almost no difference anymore between the normal and the low latency version... (based on the default settings, if you change the multiband max peak settings the sound may change a lot).

And - I might have an idea that might enable clipping with a very small latency (I expect about 4 ms) - not for the lowest few bands though.

hi Hans,

How is low band ? still artifacts ?

Hi Bojcha,

That won't change - I'm only working on the Multiband / Pre Limiter / Noise Gate latency, but those artifacts are caused by Loudness.
When this step is finished I'll look into it again to check if I can fix it somehow - I have some ideas that I want to try, but I really doubt the sound will improve without increasing the latency... (I could increase the latency a bit to get closer to the "Low quality" processing. Most likely I'll make it configurable.)


Note to self:
- Try a few (2?) Loudness(8) in series with a limitation of the drop of highs. This will probably cause 'bad bass' again, so limit that too.
- Some time ago there was a Loudness which performs multiple processing steps without adding latency in between. That might give a MUCH better sound. At the very least, combine the latest bass protection filter with a loudness filter in a single step.
- A frequency drop should last for some time (so limit below 88 means keep limiting below 88 for a few frames). That should also remove bass distortion. But: Don't limit too much, say lowest point is 60 then limit to 80... This might allow performing Loudness in just 12 ms - but it might cause ringing artifacts, and the output volume will probably be lower. Solution: 2 steps: First this 12 ms step, then another one with stronger clipping and without delayed drops.