Is there a way to fix LADSPA plugins in Ardour not to make them randomly blow my speakers?


I occasionally (would) like to use a few LADSPA plugins in my projects, but as of now I haven’t found a single one except “barry’s satan maximizer” and the “simple delay plugin” that at some point doesn’t randomly clip the track I added it to by+500dbs thus risking to blow my speakers up everytime, even with a limiter plugin at the master channel. This happens even more often when I automate some of the plugin parameters. I’m on Ubuntu 10.04 using ArdourVST 2.8.11 built from source. Some of the ladspa plugins I tried that have this behaviour:

rubberband pitch shifter
Multivoice chorus

The above plugins sound so great it is such a pity not being able to use them, but there’s a lot more I recall having discarded for good because of the “crazy clip” reason (multiband eq is another).
I remember fixing the tap plugins suite by adding “-fno-strict-aliasing” to the CFLAGS before building them from source, maybe there’s an easy fix for the steve harris suite too…


I understand that the core issue you are having is actually with the plugins but…
maybe an outboard compressor set up as a peak limiter might help you? I think this is the “pro” method. One option i have been experimenting with is (hardware dependent, and pretty untested) is creating a bus with a compressor on it and looping it back to the insert on my mic preamps. On a Maudio Delta 1010 it works because it supports hardware monitoring. So say you go “in 10” then through the bus with the effect then “out 10” wired to the preamp insert with a splitter cable. Hop this helps.

Whoa I just re-read my post and I was WAY off. Sorry for the pre-coffee stupidity.

How you have you got denormal handling set? I have found having a setting for this (I think flush to zero) has removed clipping issues… also looser latency timings help…

it shouldn’t be necessary to mess around with de-normal settings and / or latency to stop plugins going full scale or misbehaving. In a well designed plugin this just works.

I experienced this in earlier versions of ardour2. I don’t remember having experienced this issue for some time with newer versions (can’t say which ones though). But again, since all my sessions were mostly song drafts, I happened to have stripped them of all plugins at some point to redo some recording and mixing, etc. I also was curious to mix with mixbus. But … that’s about where I had to stop my daily activities as a self-proclaimed music-composer-arranger-sound-engineer-developer-blabla …

One thing though: not that I want to promote this or that brand of plugins, but the linuxdsp plugins are a very safe bet. If you go the LADSPA route, it’s definitely cheaper in terms of money, but I wouldn’t say it is cheaper in mixing time, not to mention time wasted in being frustrated at how it sounds … :wink:

@linuxdsp… I completely agree and with my coming tax return I will finally have some free budget to buy licenses to your most superb plugins… however for the poorly coded ones, I found the above methods sometimes help…

I’m a happy user of linuxdsp plugins an wish there was one for everything, but when it comes to delays, pitch shifters, tremolos etc. there no alternative to LADSPA.

I keep denormal handling always set to use dcbias+ flushtozero&denormalsare0, so I thing it’s just an issue of plugins not being mantained anymore, thus asking if anybody succesfully patched some (rubberband pitch shifter is the one I need the most) or solved the issue. I’ll try to set a higher latency (ok for mixing, not for recording though, but I barely use any LADSPA at all while recording…) and see what happens…