How do I know what frequencies my instument need or not need ?
I mean Lets say i have a kick than how do i know if to boost it at 60 Hz
or 50hz and so on
And the opposite, how do I know what frequncies my instrument NOT need to cut out ?
Thanks ahead .

The best way to do it is to listen (soloed AND in context) and judge for yourself. There are some charts that show the general frequencies for specific instruments.
60 and 50Hz are both in the "boom" area of the bd, though, so you will have to listen hard and judge for yourself anyway. It might help to try with a high and narrow boost on the specific frequencies to make it easier to hear what they sound like and then finish with a more modest eq setting.

You need a good analyzer to examine the harmonic content (freq range)of the audio. The highest peak is the fundamental frequency and the peaks after are called the 2nd and 3rd harmonics and so on. They increase in cycles as the range increases on a mathematical ratio of 1:2- 2nd harmonic, 1:3 for the third and so on. So lets say you get your analyzer and check your kickdrum, your gonna see a Peak around 60-120htz and a lot of other peaks that follow that are not as powerful as the main one(the fundamental frequency). You need to listen to the kickdrum and make certain decisions about what you want, for instance if its too weak you could add a small boost to the main peak to increase its power and focus. A good tip is also try cutting a little out of the 200-350htz range as this is where a lot of mud occurs, but also in cutting some of the lower mid freq it allows the peak of the kick a lot more definition and room to be defined. This is not a one click fixes all kind of thing, you really need to familiarize yourself with which area of the freq range boosts adds what type of character impartation to the audio such as body and air, and vice versa with the cuts you make. You need to make very detailed accurate decisions about the boosts and cuts as it all determines how the overall and final sound of your mixdown will turn out. The best sound advice i can offer at the minute because there is such an entirety of answers that can be distilled from this one question is as follows. Get a good analyzer and listen to the sound of your drums and watch them as they play out on the analyzer. Span from voxengo set to peak maximum values would probably be a good start and check out the various peaks to familiarize yourself where all the strengths and weaknesses of the said audio take place. Spend a lot of time with one kickdrum or snare and practise applying EQ and listen to the audio with it enabled and disabled paying careful attention to the difference it makes and take note of the good and bad. In this you will find indeed that practise does make perfect. When knowing what frequencies to cut you have to consider all the other elements and aspects that make up the mix your completing. If you have a kick and bass with the same fundamental freq's the they are both going to form one really powerful Low freq thats gonna suck up a lot of headroom. So, you could either cut the bass freq or choose another note so that they dont clash together, this applies to everything. If you have a loud snare thats stopping your hats from shining and sitting on the top of yor mix, gently apply a high shelf cut until the snare is just right and the hats come through instead of just applying more boost to the hats. When they sit on the top after cutting the snare, then apply a gentle boost with a good EQ for air aound 10-16Khtz to give them the shine_(1973 from stillwell is a great Eq for trying this and is uncrippled demo version, give it a try), or even use a high freq enhancer. Its all about studying and making proper decisions concerning the material you are mixing. Finding out how much to boost, Q width and what type of filtering to use will all come down to what you think and feel about them, dont just listen to what people say about doing this and doing that. Sure it seems a lot easier but its a lot better to gain the understanding and experience for yourself. I really hate these kind of questions because I know just what it is to ask the same question myself, but i can tell you its hard to start with learning and making mistakes, then getting the experience from learning from the mistakes. However, that being said-once you have learned and start to really notice it, it then becomes a really liberating and extremely fun process knowing what to do and how to do it as you find that all the frustration and problems that you endured before simply dissipate as you make progress. Better get started then.
It wouldnt help to also study a little theory concerning things such as stereo phase, harmonic content as the Equalizers you will use will aslo have a small but profound effect on other areas in your mix- I wish you well.
Trakstar.

the super super long post before me was to long to really read the whole thing at 7am so Im going to say yes a high quality analyser is good but remember its up to your ears. put it this way if your doing a kick and you notice its a little muffled boost and sweep around 150-500. And I mean around not anywhere exact on that. With a semi thin q at least. when you hear the cardboard sound there you go you found something to cut. If you notice the snare needs more snap sweep around till you hear where it really sound honking take that out notice how the good sound of the snare just seem to jump out almost like your boosted.

Also remember cutting is better than boosting 9 times out of 10. I like to remove unwanted noise and help bring the best parts out by taking the less than perfect parts and doing small cuts. this way you get a clean sound and you dont get a volume boost. If it sounds better at the same volume or even a little lower its probably better.

oh and before I forget mix in mono. that way you can really hear when something is fighting with another instrument. stereo has a nice trick you into thinking things sound good because they are separated thing. trust me mix in mono for your eq and compression. Then when you listen in stereo you can A B it and you will notice a nice clear sound with all that muddy sound out. also high pass non bass stuff

There're two long post above mine, which are very useful. But I should point that in order to know which frequencies to cut or boost, you need to hear them. Spectrum analyser is good tool, but it is only useful when you hear something that you want to adjust, but can't really pick out only by ear. A quick look at spectrum in this case will tell, what to adjust.

I agree but I was just saying when it comes to sound. Like if it shows where the problem is don't trust the analyzer. Use your ears. But yes this is the perfect combo

I would advise anybody to use and train your ears well before you start using an analyser to check EQ.

You need to understand what you're hearing before you can determine what it is you're seeing.

IMO

You need to listen to the kickdrum and make certain decisions about what you want, for instance if its too weak you could add a small boost to the main peak to increase its power and focus. A good tip is also try cutting a little out of the 200-350htz range as this is where a lot of mud occurs, but also in cutting some of the lower mid freq it allows the peak of the kick a lot more definition and room to be defined.

+1

very true it took me a while to fine tune my ears.
a suggestion is try out those ear training programs and like tehlord recommended in the super long post get some know how on music theory and pitch.
one way I know of that some people do is they get a song in there DAW copy it flip the phase and use the eq to boost to hear what that pitch sounds like. I have not really done it myself but a buddy of mine that is a very successful mixing engineer told me its how he learned.

Or getting to know both together so as to also visualize the sound as you hear it. Same thing with stereo phase, Like with stereo kicks when you have a lot of unbalanced frequencies flying all over the panorama. Unless you have really good monitors that pick up on all these things your going to struggle. I find it is a lot more informative getting a look at the grand picture as it helps me make a lot more informative decisions and what not. But saying all that, if your ears are not hearing what they are supposed to better improve on them as the other stuff only works with a "Pair of proper Ears".

This decision will largely be based on reference. As humans we hear a lot of music sometimes we listen deeply and sometimes not. This will be sub consciously and consciously creating a bank of "what sounds right" in your consciousness. Then there is the technical and practicing aspect which this text will help with:

How to use EQ

cheers

SafeandSound Mastering
Audio mastering

Didn't someone on these forums have a graphical map showing typical instruments and their EQ sound ranges?

I recall seeing one some time back, but cannot find it now.

It might help the OP, as a QRG for basics with respect to EQing....

OK I've found it!

quick google search
http://www.independentrecording.net/irn/resources/freqchart/ main_display.htm

Not sure if this will help... can be a good guide when starting out.

First of all thx to all of u guys i read all of ur posts and its realy helped me i got to conclusion that cut off freq is might be better, but I still cant get my sound clearly and punchy.

z.electric - Thx for ur map and help but sound is a LIVE and BREATHING thing u cant just determine that the kick drum will boost in 50Hz , if its more punchy and fat at 60Hz ?
than I advice to use the map but also use ur ears as the guys mentioned here.
So Thank u all !