Sound 101: Mix Downs using FILTERS
Nobody said that mixing down and mastering was easy. Everyday I learn new things too either by accident or by working with other producers as well because everyone has their own techniques. So I am sharing many of the techniques I either learned through out the years, but this one is essential for any audiophile who is into music. Basically you use filters to cut off unwanted frequencies. Usually they are called, “HIGH PASS” or “LOW PASS” filters. Or you can combine them to make a “MID-RANGE PASS.” Sounds confusing? Don’t worry, if you are into recording, you already see it all the time but maybe you just never thought of using it. I will be using Cubase since I am familiar with it, but if you know your program, it will be easy to follow.
On Cubase 6 you will hit the “E” button on your channel strip and this will pop up. These are your equalizer settings or “EQ.” The way you read this chart is first finding the “0,” this means flat or un-equalized. Anything above the “0” means that you are adding boost, and anything less means you are taking off or lessening. Let us look at the example. They have 3 EQ points that they set, you can do this by just double clicking on the screen and you can either move it around with your mouse or type in the settings manually. They also have preset settings you can use and manipulate if you would like. Okay back to the chart. You can see the 3 EQ points: 1 = -6.8db at 357hz, 2 = +7.2 at 5198hz, and 3 = -6.4 at 13978hz. So this person is reducing the bass below 357hz by 6 decibals, added some upper midrange at 5198hz, and then reduced the higher frequencies above 13978hz. So why is this important in mixing down and mastering? Here is why:
1. When you isolate the frequency better, the cleaner the sound.
2. The cleaner the sound, the better it will mix into your track.
3. The transient affect will be better, which means the natural presence will come out versus trying to add some affects.
4. The less overlapping of frequencies from other wav.’s in your mixdown, the louder you can push your mix without peaking and/or distorting.
5. The tonal quality will be better, think of an orchestral. Every instrument plays a certain frequency, there is very few overlap if any. When you hear the violin, you know it is the violin. Even with other instruments playing loudly, the sound of the violin pierces through because it is the only instrument playing those frequencies. Got it!
6. Adding the same frequency over and over again in your track or mix down will cause what they call in science a “rogue wave.” It is the same concept in sound, if there is enough waves at the same frequency, there will be an unnecessary adding of extra sound into your mix making it annoying or irritable because you cannot pinpoint where that sound is coming from. So then you try to fix levels, add EQ, put affects, etc… and still cannot fix the problem. It just might be a rogue wave in your mix.
So now that we covered putting filters, here are a few helpful tips I have used:
1. I put filters on every single channel on my mixes. I listen to each channel separately and then with all of the tracks combined. I do this until I get the desired sound.
2. I always try to find the point in each sound at it’s lowest point and highest point. When I do I set filters to cut off these points (just like the chart above). That way I know that I am reducing the chances of having rogue waves in my mix down.
3. Check your final mix down and make sure you use a filter on the low-end especially. Many producers think that adding bass is necessary at final mix down to try to make the track hit harder. Most of the time it lowers the levels of your mix and even distorts it. If you did not know, the human ears can only hear down to 20hz, that is why your recording software does not let you go lower. Also, did you know bone crushing bass is around 40hz-60hz? The famous 808 drums I believe, is at 45hz, and that is what most speakers can handle. Even good studio monitors play to about 45hz. If you don’t believe me, just listen to all the music on the radio. When the bass hits, it isn’t really that low, but pretty hard right? That is bone crushing, body shaking, can’t breathe bass. So you would set your filter to kill all the frequencies below 35hz-40hz because you don’t need them. If you want the earth shaking, hair sticking up on the back of your neck, make you look at your friend and say “Damm, that is some S**T! Bass, you need the lower harmonics. Which is 20hz-40hz, you only need this in movie theaters where they are playing loud explosions or if you produce DRUM N BASS, DUBSTEP, or any other genre that requires such low frequencies. So if you produce this type of music, proceed to the last tip, if not you can stop here.
4. I usually put a steep, 48 octave HPF (high pass filter) in order to kill some of the subharmonics at about 25hz-30hz. Using a steep filter will allow you to push your mix down as loud as possible and maximize the bass frequencies instead of trying to add more bass. You are actually making the bass you already have louder and clearer. For subharmonics, this is especially important because this will save you from damaging your speakers or any system you play on; trust me I have blown a lot of speakers because of lack of knowledge. But in bass heavy music, you have to let subharmonics come thru. With most good club systems, you will be able to hear and really feel the bass!
Next article, I will go over where to put certain processors on the chain of your mix down.