Crackling sound no matter what I do

[itsphlippy]

Hi!

Audio in LMMS is almost never smooth for me, I cannot avoid it even on basic one-track projects. The buzzing is so slight but so constantly irritating.

I've had this issue for all the years LMMS has been in my life. I usually just cover it up with bitcrush noise / distortion so it's not noticeable, but I do want to make music with smooth audio at some point. The video below showcases a Triple Oscillator, but its a consistent problem no matter what plugin I'm using, even down to simple AudioFileProcessors.

You can see the sound meters never enter red territory. I adjust the 'drone' volume slider at one point, you can still hear crackling even on a lower dB. The CPU and Oscilloscope graphs are fine the whole time. I have limiters and compressors on every channel. I also have a declipper on master (toggling this on and off does nothing to help). I've tried adjusting the buffer size to no avail.

Since I forgot to show it in the video, this is the envelope/filter settings screen on the oscillator. The LFO modulation has nothing to do with it unfortunately.

Screenshot 2026-09-04 200602.png (41.14 KiB) Viewed 237 times

If any of you guys have had similar problems and have been able to fix them please let me know. I've exhausted everything I can think of. My pirated copy of FL Studio runs perfectly fine on my PC, but I kinda despise the workflow and would much prefer LMMS if I can get things working. Thank you in advance!

[mjolnir]

What are your sound device settings in LMMS?
And are you on Linux or Windows?
If Linux, are you using PulseAudio or PipeWire or ALSA or JACK, etc?
Do you have your wifi turned on in the background?
Did you do any optimizations/tweaks for DAW use?
Do you use any demo/trial plugins?

[itsphlippy]

I use Windows, and use SDL as the audio interface. Devices are set to system defaults. Sample rate is the same as my headphones, though I've played around with that number (and broke sound on the PC entirely).

My wifi is directly line-in to my router.

As far as optimization goes, I've done simple things like disabling Windows enhancements on my headphones, but nothing crazy. In general practice I close all other windows/background processes while running LMMS so there's nothing taking up CPU space.

I have a bunch of VST plugins to use with VeSTige but would that affect a clean file using nothing but an oscillator and built-in effects?

[mjolnir]

Hmmm,

Personally, I get glitches if I accidentally have a web browser open in the background AND if the internet connection is turned on. In the past, on the Sound On Sound forums, for example, it was documented for Windows laptops that certain internet connection hardware ALWAYS interfered with audio.

I don't know what's available for audio settings on Windows as I'm on Linux.
In the past, I'd have said to try using WASAPI drivers and/or increase the buffer size.
If you happen to run any other audio on your computer that installed ASIO drivers, then use those maybe (if they're available).

In terms of optimizations, Windows OS tends to require A LOT of optimizations to run audio without glitches. There used to be a lot of online guides found by keyword searches for: Windows audio tweaks optimizations DAW "pro audio".

I used to go as far as using the BlackViper registry tweaks (now unavailable) to get tons of Windows OS services turned off and unneeded things blocked from interfering. I don't know where to begin to tell you how to do it on your system, just that, if possible, do as many tweaks as possible, including filesystem tweaks like disabling "last access time logging" in NTFS.

I got tired of fussing with Windows OS and I didn't like how Microsoft kept making everything harder to do, so I quit it and moved into Linux. However, Linux does require some tweaks and optimizations too, including disabling filesystem "last access time logging".

Last but not least, some demo/trial editions of VST/VST3 plugins will make either a crackling sound or will hiss or will fade out every few seconds or minutes--it's to make you want to BUY the full version. U-He Hive does that for example.

I wish I could be more helpful, but I'm not really sure what to say.
Try running LMMS with your ethernet disconnected and turned off, try using Windows OS's WASAPI audio (or ASIO: FL Studio, for example, installs ASIO), and definately turn off as many unneeded and unwanted services and tasks as is possible--that part might seem overwhelming but it's what us audio guys used to do for every version of Windows. I just don't have much faith in Windows anymore.

If you were running Linux, I'd have more specific advice, but since you're not my advice is incompatible. Shucks.

Oh, one other thing I did realise: Putting a limiter on you master channel could help.

Maybe the crackling sound is from your track levels being too high? Drop the levels of every channel down a bit so they're not possibly "clipping". LMMS isn't as user-friendly as other DAWs in this regard--metering and levels management, but you can at least assign a lot of channels to individual mixer channels and lower their corresponding faders/put limiters on each channel if needed.

[musikbear]

Hi!

Hi, Welcome to the Forum itsphlippy !
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Audio in LMMS is almost never smooth for me, I cannot avoid it even on basic one-track projects. The buzzing is so slight but so constantly irritating.

mjolnir is correct when he points at you sound-devise, but you are already using the correct devise for windows: SDL -So we cant find anything wrong there.
Some questions:

• Does the artefact appear in every project, also in the demo-projects that is included?
• Have you experimented with buffer-size?
• Does the master-channel spike-out into red?
• Does you use effects in the project?

[itsphlippy]

Thank you for the advice. Yes, unfortunately Windows is incredibly resource-hoggy and slow. I've been intending to install a Linux distro as a dual-boot for a while now just to see how things would work, but I've been busy and have put it off. Might be worth checking out now that I have a legitimate reason to do so.

Like I said, I've tried everything. I always put limiters on every track and sometimes the master- which I did in the example video. You can see where I lowered the volume of the oscillator and reverb channels individually and the crackling was still present on a lower setting - I even have a compressor with the threshold set to very high and 0 extra gain and nothing changed. I wish things were that simple but I'm convinced now its a problem outside of LMMS control.

To answer your questions musikbear,

• It's almost every project. Especially ones that use TripleOscillators (which also happens to be the plugin I use the most)
• I've tried every setting on the buffer size meter (restarting after each configuration), and nothing helped.
• Never. I always put Fast Lookahead Limiters on every track as well as compressors and keep a close eye on volume
• Always built-in effects. The demo video used a phaser, multi chorus, and multi spread on the main oscillator channel, and a simple calf reverb on the 'rever' channel (+ limiter and compressor for both).

[mjolnir]

Well... I am still learning LMMS more and more every day. I am by no means any expert.
But your question got me thinking... and noticing...

When I added too much LMMS Equaliser (boosting) to one of my normalised WAV sounds, I got a few clipping clicks and pops. The solution was to just lower the boost by a dB or more.

But I think you might have clipping within your original samples maybe, or maybe the inherent amplitude volume of your OGG or WAV files might be too high. There a plenty of places within the chain of audio where levels can be tweaked.

It sounds like you're on the right track; somehow you'll figure out something.
Here's what the LMMS Equaliser looked like on my track right after I lowered the boost:
(I had been boosting a LOT)

I noticed that if there was even the slightest peaking into the red LED's, then I could also hear clipping as tiny pops (crackling).

I'd suggest checking all your LED meters for any red and drawing down wherever you can, and spreading out the attenuation accross a variety of sources, even within the synths at the envelope generator level.

Last but not least, I also noticed lately that some modulation effects can have big effects on levels, so be sure to check the "depth" as well as the "mix" levels.

[musikbear]

• Always built-in effects. The demo video used a phaser, multi chorus, and multi spread on the main oscillator channel, and a simple calf reverb on the 'rever' channel (+ limiter and compressor for both).

I think you may have to many 'competing' effects. Try switching all effect off, and listen to the output. You will most likely have to turn volume down, but what does it do to the crackle?
The thing is that having a lot of default effect-plugins is not really the best of ideas. Only EQ on all instruments should be a standard, but other effects should really only be added for purpose. It also makes a difference what effects you have placed in what position in the effect-chain. Then there is the chance of random phase-cancellation Here you need to switch instruments off and on, and see if you can find some that 'clashes' with other instruments.
Then there is the selected sample-model in AFP. It is default Linear but you may try Sync but it is much more CPU demanding than Linear or None.
-And ofcause, everything must have own channels in Mixer.
The ace in the sleeve could be the new Alpha.2 ..