I have two effect chains on send tracks with 13 effects in each. CPU is pretty steady around 30%. All of a sudden I hear crackles and the CPU overload prevention kicks in. I have even mapped my midi knobs to “safe” ranges, so there is no 100% feedback in delays, flanger and the like.
On VST plugins you can check “use static processing buffers”. Looks like I could use something like that on native effects. Or is it some bug causing this. Increase in CPU shouldn’t be that sudden.
I’m thinking maybe I should abandon Renoise for my live setup while there is still time to make one in Bidule. Would be a shame.
(This is a continuation of my topic in Tips&Tricks: Dsp-Chains Vs Cpu)
Sure. I have just stripped the setup I’m working on, removing Bidule VST, mTonic VSTi and four midi tracks. I could still cause a freeze by increasing feedback on flanger and chorus on send 3.
Definitely something weird going on here. If I simply play your song in its orignal state (without tweaking feedback or anything else) then the sound will become completely overloaded and cut out after a few seconds. I don’t even get the CPU overload message, the sound simply cuts out and even the track scopes start to glitch out a bit. After this I’m forced to hit panic (press the stop button twice) to re-enable the sound.
I have to say this is a pretty extreme DSP chain, haha. It seems to be completely overloading the signal path somehow. But after a bit of experimentation I think I found something that should help, and will hopefully not change the overall sound of your chains too much.
I reduced both of your Maximizers a little bit to the following settings:
Boost 12dB (down from 18 dB)
Threshold -6dB (down from -0.020 dB)
Ceiling -6dB (down from -2 dB)
At least on my system this seems to stop the DSP chains from completely freaking out, and to my ears (what little I could hear of the original before it breaks down) it sounds pretty much the same overall.
We’ll obviously have to take a closer look at what might be happening here, though.
Haha, I know it’s extreme. And in the example it’s pretty much maxed out. It’s for live tweaking and it probably won’t come to this extreme (perhaps towards the end of the set ), but I’d like to feel reasonably safe from overload.
Nice to see you get the same result, I was worried that it was my gear that caused the problem… couldn’t afford a new computer now.
I have tried fiddling with the maximizers a bit but got a totally different sound, but I’ll test your suggestion.
I could still cause the sound to cut (no CPU overload message as you mention, I’ve gotten those occationally), just had to go a little bit more extreme with the feedback sliders. It seems a bit better with changed maximizer settings, but it didn’t solve the problem.
This is a bug right? It shouldn’t be possible to overload the sound like this when there is no “real” feedback?
I have no problems playing it here, CPU stays at 11-13% without touching any parametres. Are you using the line-in device for some kind of feedback effect? Could that be the problem?
I’m using Duplex:Recorder to record loops, the line-in is for “monitoring” that, and for playing live through the effects chain. Plus I thought I’d use it with signal follower to control some parameters. No feedback there, the instrument is connected directly to sound card input.
Try increasing feedback on flanger, chorus, delay to overload.
Yes it’s pretty crazy. Basically every effect I might want to use during a set. And I’ll record loops and feed it through one of the two chains. And slowly build with effects, kinda like this test: http://soundcloud.com/robotpushkey/robot-push-key-20110701-testing
The xrns is set to the max to provoke the problem. I didn’t pay much attention to what it sounded like.
The problem is I don’t know exactly what causes the problem, just a few hints. Maybe I can keep to “safe” settings once I know what these are, or remove effects that are causing problems once I know which they are. I’m not sure if I should keep working on my setup or if I should start over and build in Bidule. Would really like to do it in Renoise, but I also need to keep the deadline.
Seems like it might be a case of too hot signal. Some of the effects are quite loud on extreme settings, and the signal kept getting louder down the chain. I did a test where I put a limiter after each effect. Then I could set feedback to 100% on everywhere without overloading… for a while at least.
The weird thing to me is there is no indication of distortion, in the sound or visually… other than on the end of the chain.
Anyway, looks like I might do the gig with Renoise after all, adjusting the levels + limiters and avoiding 100% feedback it should be fine
I mean it would be nice to get some kind of warning that the signal is too hot before it overloads. I can see at the end of the chain that it peaks, but had to move around an effect with vu-meter along the chain to see what effects cause this. Something like a small single led peak indicator on each effect would be nice.
), but I’d like to feel reasonably safe from overload.