Filtering down to the fundemental

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1

hi guys

i know i should just try this out but im at work daydreaming about producing and just wondered if theres some “rule” or generally accepted knowledge about it… lol

this question relates to something howiegroove said in another. i asked about hpf a bass and he said have a look at it in a spectrum analyser. he said the first peak is the fundemental and all the rest after are just harmonics.
so my question is this, can something be filtered down to the fundemental (lpf) and still sound good in a mix? ill actually try a prcatical test later but just wondered if theres something out there i should know?

Thanks!

2

i think if you were to boil it down to the fundimental only, wouldnt that just be a sine wave?

3

Depending what you’re trying to achive, harmonics define the timbre of the sound, this is how we distignuish between piano and guitar. If you cut loads from the soloed instruments it’s not going sound too great, but in the mix it’s different since instruments can ‘borrow’ harmonics from eachother.



So the only advice I’ve got is to eq in the context of the mix, either with all instruments playing or in related groups ( bass and kick, etc)



You can also try note to frequency charts, and cut (or boost) at 2nd, 3rd, etc, harmonic.



The only problem with that is that you can get to technical about it and spent hours trying to eq bass, where it should be 10 min really :w00t:

4

[quote]seanl (15/04/2010)[hr]You can also try note to frequency charts, and cut (or boost) at 2nd, 3rd, etc, harmonic.

The only problem with that is that you can get to technical about it and spent hours trying to eq bass, where it should be 10 min really :w00t:[/quote]this is an interesting idea… do any of you guys eq by harmonics?

5

i try and avoid eq and filters for as long as i can, try and find a place for everything to sit in the mix using pan before you start eq-ing and filtering or you may just kill the life in your track.

6

Jon is right. You find the fundamental frequency of the track to help it gel with the rest of your sounds. However, you dont want to get rid of the harmonics. When you EQ, you should just roll off anything that you really dont hear. in other words, try to roll off as much without changing the sound.

7

Found this in a EQ manual today so I’ve copied it :smiley:



EQ Principles

First cut, then boost: The hearing system is more used to energy

reductions in a frequency range, thus boosts attract more attention.

That is, a 6 dB boost is perceived to be similar in amount to a

9 dB cut. Therefore when wishing to emphasize one frequency, it

is typically better first to consider a reduction in others. The result

will bring more transparency and clarity as well as reduce possible

unwanted coloration of the signal.



Boost harmonics: Harmonic enhancement is one of the foremost

techniques for increasing the clarity and definition of an instrument.

Examples for bass instruments: 400 Hz—bass lines will

be accented, 1500 Hz—more clarity and attack sounds. Note that

each instrument will have at least two frequencies where EQ can

achieve a greater clarity or brilliance.



Cutting fundamental levels: Cutting fundamental frequencies

provides for a perceived increase in harmonics and is therefore

an effective alternative to boosting harmonic levels. This is a common

practice in Rock/Pop productions that can be effective in all

musical recording genre. An example for the bass: reduction at

40 Hz may limit boominess and increase presence.



Boosting fundamental levels: Inexperienced audio engineers

will often first try to make corrections by boosting fundamentals,

something which in fact should be the last thing one considers.

Boosting fundamentals typically lowers clarity and produces a

muddy sound. If two instruments are playing the same part and

thereby produce the same fundamental, raising these levels will

lead to a decrease in the sonic difference between them. This is also

true when two instruments play similar parts in the same key.



Exception: When an instrument sounds thin or small, boosting

the fundamental can help. Or perhaps a microphone was poorly

placed or the harmonics had been raised excessively through EQ.

Finally, increasing fundamental levels can also play a constructive

role when instruments play alone or as soloists with others in the

background.

8

thnaks for that seanl. what manual was it?

9

no worries, SPL EQ I think :slight_smile: