EQ8: Serious issues with Bass. Here is the proof.

[ze2be]

Hey folks!

I just did a solid test on EQ8 regarding phasing/DC offsets, and issues with High Pass cuts at 30Hz.
C is at 32Hz and is used in a lot of bassy music. I thought I should share this with the community.

Basically because EQ8s high pass is limited to 30Hz there is a big problem with bass down there,
like C at 32Hz. The problem is that EQs lower the volume by -3db at the cut position! This is the
reason vst eqs usually goes much lover. Pro Q reaches down to 10Hz. So at 30Hz the standard EQ8
12db/oct filter lowers the volume with -3db, then its -1db at 40Hz, and gradually flattens out at
60Hz. So if it would reach down to 10Hz it would not lower the volume at all at 30Hz. The
fundamental frequency of a low C which is at a pretty standard octave in all bass heavy sequencer
music today is exactly there. With the 4x cut aka 48db/oct filter it lowers also the volume by -3db
at 30Hz, but it flattens out already at 40Hz. For the volume test we used a pure sinewave osc from
Operator, and made a slow automation sweep on the midi clip from 20Hz and up to 80Hz. Then we
recorded it to audio and read it of there with measuring peak volumes at different positions.
Aligned with the midi and its automation we could read out the exact peak position of each frequency.

The second problem is DC offsets, or phasing issues. The standard 12db/oct high pass filter puts
the DC completely off! Trying to correct this with Utility DC does not fix this, just a tiny bit.
The DC offset problem is gone with the 4x aka 48db/oct filter but it still cuts -3db at the major
frequency on a low C bass note. DC offset makes the bass sounding thinner, plus it can introduce
other possible problems like for instance clipping. We did this test with simply reading out the
visually recorded audio waveforms in Live.


So use the 4x 48db/oct filter or use a low shelf if it cuts too much. Leave the rest to mastering.

The algorithm designer of the EQ8 is aware of the 30Hz limitation and has tried to reach Ableton
to fix it, but apparently they don't care. His words, not mine. The designer is Andrew Simper from
Cytomic. He is also the creator of the new Live 9.5 filter algorithms in EQ8 and Auto Filter.


The DC offset issue is all in this jpeg:




imgurl

Live 9.2.3, 64bit


PS. a little tip for anyone working with Pro Q: On the plug, use Processing: Medium Latency while
working, and set it to High or Maximum on project export. Its the best compromise. Zero Latency
introduces huge DC offsets. Low Latency introduces audible crackles but no DC offsets from here on.
Medium Latency introduces about 1/16th note latency. Its corrected by Live's Delay Compensation but
the visual play line is of at that much time. Its ok working like this though, and the crackling is
almost not audible now. At High Latency the crackling is gone but the latency is now huge, and its
really annoying working with the play position line now completely off. Its almost a full beat aka
1/4th note. At highest quality setting; Maximum Latency, its off by 1 and a half beat.

[ZaBong69]

Hi,

thank you, I did not see that EQ8 has this restriction. Maybe you want to try out TDR Nova, it is free and has a HP filter that goes down to 10hz. It also has a brutal 72db filter slope...

All the best,

K

[Rold]

This should get more attention! You should create a suggestion in a Live beta forum.

[zeepster]

How destructive is this side effect in EQ8? I'd think a post like this would be discussed more!?

[Joel W-J]

That's a shame, I just got into the habit of DC offsetting prior to last limiter. Not much to hear down that low anyway. Shame about the EQ 8. I think it could do with some lower capabilities just so that we producers can at least see what is down there even if we can't hear it that well. I always shy away from the x4 cut because of the change it applies to sounds. I find it works best at the mixes top and bottom ends that tend to be inaudible <40 >18500.

Anyway, what do I know.

Its ironic that Wavelab ele 8 goes down to 0 and shows the entire range but I can't cut like you can with the EQ8. I always use Wavelab to analyse and Ableton to cut. I guess the moral of the story is that we producers can't rely on just one piece of software, well not yet eh, Ableton

[andy_cytomic]

Most DC blockig filters in analog gear are around 2-10 hz. As a final mastering / cleanup stage having a DC blocking filter of around 15-20 hz is good, 30hz is too high and you start cutting your bass and I'm talking with the guys at Ableton on fixing this. I think this limitation was due to them previously using "DF1 bi-quads" which started to fall apart and do horrible things to your audio with low cutoffs. This is now fixed with the new SVF eq algorithm, but the parameter range still needs fixing.

Normal "minimum phase" type high pass analog filters do not "introduce dc" or "shift the dc", they remove it. This may make asymmetric waveforms like a sawtooth look like they are "above the line" / "below the line" but in fact the dc part has been removed from them. Try your test again with a symmetric waveform like a square wave and you will see the spikes happen above and below the centre line.

PS: also don't go crazy with the steepness of your filters, -24/dB is plenty, -48 dB is probably overkill since you start introducing a lot of phase shift to your bass and may make it sound worse.

[mekanism1200]

C is a normal note in Bass music? I thought E was the lowest most producers go as that is what most sound systems can accurately reproduce. I think even a Function 1 setup only goes down to 40hz before the bass drops off.

[doghouse]

You are severely misguided The way filters work is that the cutoff frequency is (get ready) where the response is down by 3 dB. So your EQ8 works fine at 30 hZ although it seems you wish it could go lower.

[ze2be]

Dont use any C notes! Yeah, great work arround!

Nah, I just use a 3rd party eq for the bass, and sometimes the kick. All the rest eq8 is fine for me.

Regarding Funktion 1, I play on them regularly. Outdoor parties, clubs, and most of all festivals around the world. All the usuall F1 subs go below 30hz. The 18"s, the 21"s. Some goes down to 24Hz, some down to 20Hz. Some of the smallest like single 15" subs ends from 35 to 45Hz, but I never play on those. Im a bass junky so im all over the lower octave. Usually I hp cut somewhere between 10 and 30Hz just to clean up and clear up without messing up, though sometimes it changes the bass sound too much and then I use a low shelf instead. Sometimes I leave it open. All depends on the note range and synth sound. I perform mostly on big nice soundsystems so I design my mixes for that enviromemt. All the modern PA sound systems go down to 30Hz at least, usually lower.

And I DO NOT want C notes to be 3db lower then the other bass notes. LOL
I would like eq8 to reach down to 10hz like all other similar vst eqs, exactly so you can use a hp filter without forceing the lowest bass notes to -3db!

[rekloos]

Never really understood abletons options for dealing with low frequencies in this day and age where we're all aware how important the relation between kick&bass is ....eq8 goes down to 30, multiband goes down to 30, eq3 goes down to 50, autofilter goes down to 26. I dont know of any eqs outthere that can't cut below 30...They even advertise it as a tool for mastering and quite honestly i don't see any proper engineers ever touching such eq.

You are severely misguided The way filters work is that the cutoff frequency is (get ready) where the response is down by 3 dB. So your EQ8 works fine at 30 hZ although it seems you wish it could go lower.

Not sure what you mean..... I'm not very scientific with music and mostly tend to listen more then look at numbers and i can tell you everytime i drop eq8 on a bass track i can hear a (not so good) difference on the lower freq, even when is all the way down.

[ze2be]

I'm not very scientific with music and mostly tend to listen more then look at numbers and i can tell you everytime i drop eq8 on a bass track i can hear a (not so good) difference on the lower freq, even when is all the way down.

12db/oct filters, aka the normal hp filter on EQ8, if you leave it at 30Hz, the lowest setting, the nature of 12db/oct HP filters is that it will lower -3db at 30Hz, and -1db at 40Hz, and is flat/does nothing at 60Hz. So it even cuts a little at 50Hz when its at 30Hz. With the 4x hp filter on EQ8 aka 48db/oct it also cuts -3b at 30Hz, but it flats out at 40Hz, so it is a little less damaging.

This is standard for ALL filters.

It is always entertaining when people attack a post without even reading the OP. Its all there with a picture and everything.

[andy_cytomic]

I would like eq8 to reach down to 10hz like all other similar vst eqs, exactly so you can use a hp filter without forceing the lowest bass notes to -3db!

Something I requested a long time ago has now happened, EQ8 now goes down to 10hz in Live 10

[Stromkraft]

I would like eq8 to reach down to 10hz like all other similar vst eqs, exactly so you can use a hp filter without forceing the lowest bass notes to -3db! :D

Something I requested a long time ago has now happened, EQ8 now goes down to 10hz in Live 10 :)

Wonderful!

[ze2be]

Yippy yippy Ya!

All in all Live10 is a really great release! Already bought presale to show my support and apreciation on day 1!

Hey Andy, is that some of your code in those new saturstion/distortion fx devices?

[ze2be]

I would like eq8 to reach down to 10hz like all other similar vst eqs, exactly so you can use a hp filter without forceing the lowest bass notes to -3db!

Something I requested a long time ago has now happened, EQ8 now goes down to 10hz in Live 10

Review score: 10/10 !