master buss hpf rolloff

[The Sponge]

I noticed in the March issue of this fine publication, Both the Greg Wells and the Mixing & Mastering modern metal article by Mark Mynett talk about hpf at 39/40hz.
My lack of experience has led me to just setting it at 20hz, But I was wondering if there is a rule of thumb on this or is it depended on the program material, Edm at a lower setting than country etc and at what slope ? or do you have a set and forget setting.
thanks all.

[Drew Stephenson]

I always tend to do it by the material. If I've got a fairly prominent double bass part then I'll set it fairly low (but fairly steep), if it's something which doesn't need it (just guitar and voice for example) then I'll run it much higher. If you're working with a sub-heavy style then you'll probably want to go lower still - as long as things are still under control.

[The Elf]

For starters I wouldn't put an HPF over the master buss. The place to sort this out is on the individual channels. Clean it up at the start and you can forget about it. You can also target each source with an appropriate setting - you'd have a far higher HPF frequency on a hi-hat channel than a kick drum.

Then it's all about ears, good monitoring and a spectrum display. Don't look for rules (there are none, anyway) - work with the audio you have and react to what it tells you it needs.

[Wonks]

Generally as The Elf says. I'd always clean each channel first in a mix. But it does depend on what FX you've got on your master buss. If you've got something that's pushing up the bass levels significantly during the mastering process (lots of compression or limiting), then it may be worth putting a high pass filter in after those FX in the chain just to keep the very low frequencies under control if they've been boosted significantly. If not, then there's no need for it.

[Hugh Robjohns]

For starters I wouldn't put an HPF over the master buss. The place to sort this out is on the individual channels. Clean it up at the start and you can forget about it. You can also target each source with an appropriate setting - you'd have a far higher HPF frequency on a hi-hat channel than a kick drum.

Repeated for emphasis -- this is the correct approach in my view. If you're HPF-ing the master bus it's all too little too late in my opinion!

[Drew Stephenson]

It's probably paranoia on my part, i hpf everything individually but I'm very aware that i struggle with analysing the low end so a bit of belt and braces shouldn't do any harm, after all, there's nothing there i want to keep.
On a related note though, even after applying hpfs at source and bus stages, my master eq still shows plenty of activity at the bottom end. Am i just not being brutal enough with my slopes?

[Hugh Robjohns]

Possibly. And remember that compressors will tend to raise the low end tails too.

Reverbs can also generate a lot of unwanted low end -- so it's often worth high-passing the input to a reverb (or sometimes the output)

[The Sponge]

I have been doing the individual channel thing as a matter of course, a hpf is the first step I take and then eq from there, So It sounds like I have been taking the right aproach for the most part. Thanks all for your replys.

[Wonks]

I'd be a bit wary of the frequency displays shown on live EQ displays as I find they often show very low frequencies that simply aren't there, (as I know from when I've just used a very steep HPF first at a much higher frequency setting for test purposes) probably as a result of short 'moving window' time periods which cause inaccuracies in the frequency calcs. I find that if I use an offline frequency response tool in my DAW to check a section of a waveform, those low frequencies that show up on a moving display simply don't show on a static one.

[Hugh Robjohns]

I'd be a bit wary of the frequency displays shown on live EQ displays as I find they often show very low frequencies that simply aren't there...

Very true. The spectral analysis in the EQ plugs is often configured with a very short FFT length to make it fast and responsive, but light on processing horsepower. As a direct result, the low end measurements are very inaccurate and tend to look much more evil and busy than they really are. A longer FFT will help to improve the accuracy, if that option is available.

A bargraph-style 1/3 octave 'real-time analyser' (RTA) is often a better choice of meter for assessing the low-end energy as you check individual channels and mixes, although it doesn't look as impressive!

H

[Zukan]

I band pass every channel and still HPF the master bus. Both sounds and processes will invariably generate sub harmonics through interaction and summing. Good to filter those out too but with a gentler slope than the required aggressive slopes for channel band passing.

[The Bunk]

On a related note though, even after applying hpfs at source and bus stages, my master eq still shows plenty of activity at the bottom end. Am i just not being brutal enough with my slopes?

Good man Drew, that's been on my "Should I ask this question or not?" list for a while...

[Forum Admin]

Good man Drew, that's been on my "Should I ask this question or not?" list for a while...

Never be afraid to ask what might seem like daft or obvious questions in the SOS Forum. Nobody is going to call you out -- there's so much to learn and we're all on this great journey together.

[The Bunk]

Good man Drew, that's been on my "Should I ask this question or not?" list for a while...

Never be afraid to ask what might seem like daft or obvious questions in the SOS Forum. Nobody is going to call you out -- there's so much to learn and we're all on this great journey together.

Of course, and I can speak from experience But isn't it refreshing when someone else asks a question which makes you think "Ah, it's not just me then"!

[Martin Walker]

I band pass every channel and still HPF the master bus. Both sounds and processes will invariably generate sub harmonics through interaction and summing. Good to filter those out too but with a gentler slope than the required aggressive slopes for channel band passing.

A bit belt AND braces, but then Zukan does often work in EDM and hip hop, where low end can be both extreme and very desirable when performed correctly.

Low cutting individual channels as needed, does makes perfect sense, and rolling off top end from some sounds in these more 'creative' genres can indeed create more space in the final mix.

If you still need to HPF the master buss then at least doing it first channel by channel will require less extreme settings across the entire mix, which makes perfect sense to me.

Martin

[Drew Stephenson]

Thanks folks, really useful responses as usual.

[varunbkk]

It is usually OK to roll-off below 24-30 Hz to get rid of any potential rumble.
This can sometimes help to clean up the low-end across a mostly completed mix.

If you're finding that you need to high-pass more drastically,
it's better to go back and address the problem on the individual channel(s).

[ef37a]

I cannot help but think all that design time and effort to make DC coupled gear with fancy servos is a bit of a waste?

Dave.

[James Perrett]

I cannot help but think all that design time and effort to make DC coupled gear with fancy servos is a bit of a waste?

It's great for measuring earthquakes though.

[ef37a]

I cannot help but think all that design time and effort to make DC coupled gear with fancy servos is a bit of a waste?

It's great for measuring earthquakes though.

Probably need a longer integration time than the average 'cork sniffer's' mic pre?

Dave.

[CS70]

I noticed in the March issue of this fine publication, Both the Greg Wells and the Mixing & Mastering modern metal article by Mark Mynett talk about hpf at 39/40hz.
My lack of experience has led me to just setting it at 20hz, But I was wondering if there is a rule of thumb on this or is it depended on the program material, Edm at a lower setting than country etc and at what slope ? or do you have a set and forget setting.
thanks all.

On my side, I simply know that my monitors don't really give me much info below around 40Hz so I'd rather lower it down (as the Elf says, on individual channels rather than the master bus). But then I don't usually mix EDM.

[The Elf]

I don't see that there's any mystique about this, and I don't subscribe to finding a golden rule - just use common sense. If you need that extreme low end to support the mix then keep it, if you don't then clean it up - it's really no harder than that!

The only reason that metal might generally require higher cut-off values is that its speed and reliance on aggressive mid-range excitement will have an easier time of dominating the mix if the low end is generally less dominant, as it might be in a dance mix.