Why not always cut the 20-30 Hz range?

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ok noob question i guess ;), but i read a lot in tutorials, mixing and mastering mags, posts etc. that mostly you can use a HPF to cut the 20-30 Hz range. the monitors i checked so far can mostly go until 35 Hz. so why wouldnt you cut those frequencies always away?

this is meant serious if this sounds stupid, i just hope to learn why you keep em ;).


No need to add a process if your signal doesn't need it. It's like falling and putting a bandaid on, even though you didn't get scraped up.


Maybe your speakers don't go that low, but they do in clubs and other people might listen to it and have speakers that cover the lower freq ranges.

I talked to a pro techno producer who told me that, once he started cutting everything below 30-40Hz, his mixes improved massively. Then he got famous. Maybe it wasn't as simple as that!

ps I still don't do it, even though i think i should. maybe that's why i'm not famous :D

[Major disclaimer: i'm NOT an expert on mixing]


One of the main reasons people, cut freqs that low is that it's possible in some cases to have infrasonics that are affecting how loud you make your track. Liek you say, in most cases they are inaudible, so people will cut them to be able to boost their overall loudness more.

BUT, most filtering techniques actually can create a bit of a volume BOOST around the cutoff point too (depending on how steep the filter is), so it's a bit of a game deciding if cutting those infrasonics are worth the slight volume boost tyou might get as part of the process. So if you don;'t have any information that low, arbitrarily adding a filtering process can in fact make things worse, not better.

Never do something "just because", always make sure there's a need for it first.


On the opposite side, some ppl don't even know what is under 40Hz because they use monitors not going that low.
Or they use subwoofers in non-treated mixing rooms...witch is even worse.

You can use a good EQ, like Sonalksis, to cut some lows.
It got different stepping curves, very useful.
There are good freewares too.

But you need to hear what you cut.
And you need to cut what you don't hear (or "feel" with your body, like very low subs) because you don't know if it is good or not.

That's why the word "monitoring" exist : if you can't monitor what happen, you're dead.It can be good or wrong, but you made your mix without hearing it...so you need to remove it.

If you give your tracks for mastering, don't touch anything of course : they will do the job for you ;)

The funny thing : everything under 20Hz will be cut by MOST CD players and MOST lossy compression schemes, like MP3 ;) (read the word MOST)
Some very bad mp3/lossy settings even cut upper, like 30-35...even 45Hz.
Try to listen to 240/380 quality Youtube song, and listen to 720 quality after ;)
Or try to compress a big bass electro song in default 128 kbps mp3 format, and compare the bass with the wave/CD version ;)

Putting anything under 20Hz is just a waste of energy if you want to release your tracks on CD/mp3/streaming...in fact, any format, because it will be cut 90% of the time at the end of the chain :D
I don't even speak about most crappy boom box subs not going lower than 45Hz (my monitors go 45Hz, without subwoofer...)

That's why there is a default 20Hz low cut and 20kHz high cut integrated in any serious mastering limiter/suite.

You need to cut it properly yourself at mastering stage if you don't want it to be cut like a butcher by the CD player/lossy/streaming format crappy filters.
But you are not obliged to cut it higher than 20Hz ;)

That's part of the mastering : adapting the music to the release format and future listeners sound systems ;)
If you mix toward crappy boom box only : cut anything under 40Hz by default :lol:


megadeth wrote: That's why there is a default 20Hz low cut and 20kHz high cut integrated in any serious mastering limiter/suite.
Disagree completely. Sure there MAY be an option to hipass at 20Hz, but there is almost no reason at all to low pass at 20kHz. I don't know where people got the idea that this is a good thing to do, but I see it all the time in tracks that people send me. Leave the high end alone, there's nothing up there that should need to be adjusted mastering most of the time, and certainly you don't want to be putting a low pass filter on every one of your songs.

I can't stress this enough, don't do things to your music just because you heard you should. Understand what's involved, and do it because there's a real reason to do it. Sorry, nothing personal, this is just one of those bits of production advice that has no grounding in real world audio engineering.



Why ?

Just because MOST CD players will cut them (20Hz and 20kHz)...and so mp3 compression/streaming too.
You read the posts ?

I prefer to do it properly than relying on crappy filters of a CD player/mp3 compression/streaming engine...but you are not obliged.
You can let those crappy filters do it for you.

I think not doing at least a 20Hz-20kHz cut is just bad mastering relying on random crappy filters...because they are not on your side and you don't really know what they will do.

I'm not surprised anyway : most KVR threads are going this way.
"you don't use your ears", "you don't know what you are talking about"...but never give any real argument.
And when there is one (like CD player/mp3/streaming cut and crap boom box not going under 45Hz), strangely ppl don't see it...

Wait some posts and you will see ppl saying they EQ at 7Hz on their master to get more vibes in their mix :roll:

PS : i'm bored and will stop posting on this thread and playing the troll.Some ppl are better at this game than me :D


I would say, unless you're doing rap/RnB that uses a strong sub, then your mixes would never suffer if you cut in those ranges. The more instruments you got, the more that energy will build up otherwise, and you'll wonder why you can't get your master to commercial levels! And your mix will be cleaner too. I say do it.


Tarekith wrote:BUT, most filtering techniques actually can create a bit of a volume BOOST around the cutoff point too
that isn't true. filters can increase peak levels, but the real amplitude of individual harmonics will not be boosted - the phases will just be different. the only time you'd get a boost would be when using a filter that intentionally boosts the level - anything with greater Q than a butterworth.

unfortunately it's semi-rare to find basic highpass filters in most eq tools. the best type of filter to use in my opinion is a simple 6db highpass at about 40hz.

it's important to check your signal chain and ensure you haven't introduced content below 40hz or so without it being intentional. any place that content has been inserted should be filtered with a highpass designed for the particular purpose.

if you leave sub-sonic content in the signal and decide to apply a single "one size fits all" filter at the end you'll get problems with peak levels being vastly increased due to the need to use a steeper filter. sub-sonic content will also interfere with tools like limiters and distortion effects.

no process should introduce such sub-sonic content - if you've applied 24db of boost at 10hz, you're doing it wrong.

it's important to be careful when using steep highpass filters - you'll get ringing at the cutoff frequency which will increase with greater orders of filter. a 6db highpass has minimal ringing - a 12db highpass however starts to ring and will cross zero. this problem occurs even when you use highpass filters at multiple points in the signal chain. for example if after a synthesizer you use a 6db filter, followed by another at the final output immediately before the limiter they will form a 12db highpass together if all the in-between processes are linear. you can partially avoid this by using different cutoff values but to achieve a good low peak to rms ratio you'lll want to minimize the amount of filtering happening in series.

i suppose a shorter explanation would have been to say that they "smear" the "low frequency transients" i just don't really agree with that terminology.
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i cut a fart @ 50hz
Last edited by alixxila on Mon Mar 28, 2011 1:34 pm, edited 1 time in total.


alixxila wrote:I would hope our audio interfaces and/or A/D converters are "automatically" doing this for us now...??


megadeth wrote:I think not doing at least a 20Hz-20kHz cut is just bad mastering relying on random crappy filters...because they are not on your side and you don't really know what they will do.
... Don't add content with all that shit if you're going to cut it all out in the end. Make your mixes all about the source, not the mixdown. If you have content that has some shit way up in 20k+ then tune that element specifically. Don't just slap a filter (no matter how good) right up on your track and cut off the top and bottom, no matter how extreme.

And another thing - u serious about producing and releasing your music? U planning on making a career out of it? Learn what a mastering engineer is, what they do and why you should be using one. Then learn how to mix a track specially for the mastering engineer, and not as if you're the final stage in production. You aren't. Make sure you provide the next person to touch your music with exactly what they need to master properly. This means not removing something that he/she can do in the final mastering stage, with probably far better equipment, even though you KNOW you won't want it in there. A mastering engineer is much more prepared to remove those unneeded frequencies him/herself. Unless you pick a shitty one who just runs your tracks through T-Racks (no offense IK, but it ain't a mastering product).


Recording LP records at the moment to move them to CD
They get a 30Hz roll of to get rid of the rumble from the record player.

Otherwise leave it as it is unless you have some troublesome instrument or sample with too much low-end.
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"Accept All the Good"

Sound design for SQ8L and Alchemy


Yes, why not?!?
circuit modeling and 0-dfb filters are cool


hmmm seems this is nothing where you can say yes or no, but i read now in musich tech magazine that even in clubs the speakers dont go more than to 30 Hz. so they also say you can cut those frequencies out, and i dunno a place where you can lsiten to till 20 Hz sounds?

and you dont mix or master for high tech professional studios but for listeners who dont mostly have high tech monitors which go perhaps till 20 Hz, if these exist?

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