Equalizer: Lowpass filter broken at 48dB

[BaraMGB]

-🅱oublas- reported on Discord that the Lowpassfilter at 48dB is broken. I made some pictures to illustrate that:

Edit: I can reproduce this only in the latest master branch. In stable-1.2 it seems to be fine.

This is the EQ of an earlier version:

This is the current EQ behavior:

[Spekular]

I tried reproducing this when I saw it on Discord, and again after seeing this issue, but I can't get it to happen. Win 10 64 bit on RC6 64 bit:

This screenshot is 3xOsc white noise played on the instrument keyboard, but it also works fine when I play a clip in the song editor as you did, and when I put a filter on a sample rather than 3xOsc.

[BaraMGB]

@Spekular can you test master?

[Spekular]

I can try, but I haven't tried compiling LMMS since the whole sub-modules thing was added, and even before that I struggled a bit with it 😅. I'll give it a shot as long as it doesn't eat up too much of my time.

[BaraMGB]

Since that sub-module thing I clone everything in a seperate folder.

git clone --recurse-submodule -b master https://github.com/LMMS/lmms.git myNewFoldername

works well for me.

[Spekular]

It seems to be even more broken than for you

Ubuntu 16.something LTS, if that matters. Compiled from master. Same 3xOsc white noise test as earlier.

[PhysSong]

Can anyone try reverting 1e777cf and then re-test?

[Spekular]

I'm trying but
git revert 1e777cf gives error: Your local changes would be overwritten by revert.
So I tried git reset --hard
But then a revert gives fatal: Not a git repository: /home/spekular/Desktop/lmms/.git/modules/plugins/FreeBoy/game-music-emu
So I tried git init, but then I'm back to local changes would be overwritten.

Gonna redo the whole clone I guess.

[Spekular]

Reverting that commit fixed it for me.

[PhysSong]

Then I guess it's a regression from #4260. Tagging @curlymorphic.

[zonkmachine]

Here's a line that mix 'hp/lp':

lmms/plugins/Eq/EqEffect.cpp

Line 127 in 1e777cf

m_lp481.setParameters( sampleRate, hpFreq, hpRes, 1 );

[PhysSong]

@zonkmachine Good find! I think L125 and L127 should be dropped.

[curlymorphic]

Please dont drop the lines, I will issue a fix shortly

[curlymorphic]

Closed by #4396