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i've never low cut a sub bass in my life, but watched the mala red bull acadamy video again he mentions cutting low frequencies on the sub to clean it up.

so on this track im making, i low cut at 25hz and lose headroom on my sub bass channel?
its not causing any real problems with the track i just cant figure out how by cutting the low frequencies out can ADD volume??

i would of thought cutting the low frequenices would give me more headroom?


also does anyone else low cut sub at the real low frequencies? i always thought it as a big no no in the deeper sides of dub step?

Not sure 'bout losing headroom; the idea, I think, is that there's all this 'rumble' in the very low end that can clutter up the mix just by taking up room with data that doesn't really translate into the final mix (< 40Hz usually.)

i've heard loefah hipassed his subs at 40Hz

This is caused by filter resonance or phase rotation. By adding any kind of filtering or EQ, you're affecting the phase of the affected frequencies. If they're rotated in such a way that they become additive with each other or the unprocessed frequency spectrum, you'll see a boost in volume. Also, if there's resonance added to your highpass filter, that will of course cause a bump which might introduce more energy than is cut out below the filter.

If it's a resonance problem, the solution is pretty simple, just turn down the Q of the filter.

If it's a phase problem there's a couple approaches to take. You can experiment with linear phase filters, or you can try to correct it afterwards with an allpass filter or phase rotator.

You can also just compress it a bit to account for the gain bump.

Just a matter of weighing the pros and cons of having no filter vs filtering plus whatever method (if any) that you use to compensate for headroom loss.

Get a linear phase EQ like Fabfilter Pro-Q

obviously you'll need to set it to Linear Phase - Maximum

claudedefaren wrote:Get a linear phase EQ like Fabfilter Pro-Q

obviously you'll need to set it to Linear Phase - Maximum

i bought fabfilter pro q couple of weeks ago.
so by setting it to linear pahase maximum will help?

its not so much of a problem, just like to know whats going on to get my head round things

SunkLo explained it better than I could.

This used to do my head in. Now I don't care anymore.

Geey wrote:

claudedefaren wrote:Get a linear phase EQ like Fabfilter Pro-Q

obviously you'll need to set it to Linear Phase - Maximum

i bought fabfilter pro q couple of weeks ago.
so by setting it to linear pahase maximum will help?

its not so much of a problem, just like to know whats going on to get my head round things

Yes.

Phase rotation, etc. SunkLo said it all

^ Yes. SunkLo and Sharmaji are like fucking grandmaster ninjas when it comes to this shit, man. You guys are awesome.

OP - One other thing to consider - might be stupid, but - you're not experiencing this while mixing with any kind of compression/limiting on the master bus, right?

Does sub really not lose any power when you hi-pass it? I thought it'd be pointless with a pure sine sub but then... I got got rid of 2 db from my sub just by hi-passing at 25 hz. Well, the sub was at its lowest at 40 hz. So, I shouldn't have lost any weigh while I'd have gained headroom, right?

Genevieve wrote:Does sub really not lose any power when you hi-pass it? I thought it'd be pointless with a pure sine sub but then... I got got rid of 2 db from my sub just by hi-passing at 25 hz. Well, the sub was at its lowest at 40 hz. So, I shouldn't have lost any weigh while I'd have gained headroom, right?

This kind of thing confuses me as well.

Iif theres any low end noise, hipassing it can save you headroom, yes. always use freq analyzers to see what's going on

Geey wrote:i've never low cut a sub bass in my life, but watched the mala red bull acadamy video again he mentions cutting low frequencies on the sub to clean it up.

so on this track im making, i low cut at 25hz and lose headroom on my sub bass channel?
its not causing any real problems with the track i just cant figure out how by cutting the low frequencies out can ADD volume??

i would of thought cutting the low frequenices would give me more headroom?

Yeah, as others have said it's caused by the eq causing phase issues.

Firstly, I'd ignore the advice saying to use linear phase eq and all pass filters, that's just overcomplicating the problem. Linear phase eq's bring in their own problems, such as pre ringing. Someone posted a video here a while back that explained the differences, I think it was this one:



This video explains the pros and cons of each type of eq, along with some audio examples.

Geey wrote:also does anyone else low cut sub at the real low frequencies? i always thought it as a big no no in the deeper sides of dub step?

It shouldn't be necessary to do a lot of high passing on a sub - where would those frequencies be coming from? If you're using a synth to make a sub bass, just make sure the fundamental note isn't too low. High pass all of your other tracks - things like vocals can be cut a lot higher than kick drums, so do each track individually and there shouldn't be much going on in the sub region.

If you are going to high pass, use a gentler slope. The phase issue will still be there, but won't be as pronounced.

Also, just because one producer does it one way doesn't mean others don't do it another. I leave any cutting off my sub bass because I'd rather leave that to the mastering engineer if it needed it.

ThisIsSovereign wrote:

Genevieve wrote:Does sub really not lose any power when you hi-pass it? I thought it'd be pointless with a pure sine sub but then... I got got rid of 2 db from my sub just by hi-passing at 25 hz. Well, the sub was at its lowest at 40 hz. So, I shouldn't have lost any weigh while I'd have gained headroom, right?

This kind of thing confuses me as well.

Well, the human ear won't perceive a drop in volume at that frequency but you did loose something a big driver might be able to reproduce I think. You might have lost chest rattling

Also, as was already said, inserting an EQ in a channel might alter the phase a tiny bit. So that can either be de- or constructive in terms of volume.

I just tested this on a sine with a frequency analyzer, and even at 25 or 30 hz, you do lose volume at 40 hz. So it might do good on a more harmonic sub, but on a sine I think it's pointless. I assume also on bare saws or squares.

A sine is just 1 frequency near enough innit. Why bother filtering nothing. If it has some harmonics then i understand but a pure sine im sure you might as well just leave it alone.

Sinestepper wrote:A sine is just 1 frequency near enough innit. Why bother filtering nothing. If it has some harmonics then i understand but a pure sine im sure you might as well just leave it alone.

That's MY line. :'0 I was just wondering if there's just an added advantage to doing it to a sine as well, without having it lose punch at its fundamental frequency.

But the same would have to be true for saw and squares too, since the harmonics are in the upper register, not below the fundamental (right?).

I think this is really only helpful to subs with an additive process.

yeah actually there shouldn't be anything below the fundamental so why is this even a thing.

Genevieve wrote:

Sinestepper wrote:A sine is just 1 frequency near enough innit. Why bother filtering nothing. If it has some harmonics then i understand but a pure sine im sure you might as well just leave it alone.

That's MY line. :'0 I was just wondering if there's just an added advantage to doing it to a sine as well, without having it lose punch at its fundamental frequency.

But the same would have to be true for saw and squares too, since the harmonics are in the upper register, not below the fundamental (right?).

I think this is really only helpful to subs with an additive process.

I know that some synthesizer will have higher frequency added to there sine waves, I know massive dose for fact so lowpassing will give you a cleaner sub.

Also like Genevieve said I like to highpass my subbass group I use for my sidechane at about 30hz ish. As soon as I do that a bunch of messy crap sounding stuff disappear from my subs. I don't know why the 30hz bellow frequency are there but they are and it sounds better when I remove them.