Looking for some guidance on EQ strategies for making sounds more professional. I know this is a very general question and maybe this falls more into mastering, but when I hear sounds in libraries or whatever, many tend to have a pro sound that mine do not. I'm just not sure which frequencies to boost/cut to get that sheen and which EQ plugins are best. Are people stacking EQs to get this sound or is there some pro suite that really does it? Again, I know this is general and I'll probably get responses like "depends on the sound", but really just looking for some EQ guidance to dramatically up my game. I've been at this too long to still be struggling with this. Also if you can recommend books or videos that would help as well I would be forever grateful.
Your real problem is most likely recording technique and possibly the gear you're using. A good sound recorded properly doesn't need any EQ to sound professional.
Where you place your microphone is the most important thing in capturing a sound and works just like EQing when in the right hands.
First of all: An EQ can not add something to a sound that is not there!!!! This is a very important fact, as a lot of beginners feel like they need to put on a magic frequency response in the EQ to make a sound big or stand out.
But there are roughly 3 situations where you want to use an EQ:
On all of those as a rule of thumb: Wide Q boots and small Q cuts!
To clean up a sound: To clean up a sound you can remove unwanted bottom end with a high pass filter or low shelf. You can also remove feedback, resonating frequencies and static screaming created by guitar amps and lamps via notch filters. Moreover you can dampen room modes via a bell curve. For EG: to cleanup a Vocal recording you high pass at 120 Hz to remove the steps of the vocalist, you notch 2 kHz and 4 kHz because you had a lamp in the vocal booth that created screams and you cut 6 dB at 250 Hz since this is the biggest room mode of your vocal booth.
To improve the timbre: By Cutting or boosting different regions in the frequency spectrum you will change which parts of the sound are pronounced. Normally the best approach is to cut 3-6 dB of frequency areas that are too present. -> you then are left with what you like. There are some EQ that also add some kind of sweetening effect like small distortion, resonances etc in comparison to digital EQs that are often described as harsh. A very good area to cut a little bit is between 200Hz and 800 Hz. This area is referred as the Mud/paper/boxy. If you remove some content there on some "unimportant/background sounds" you often get a cleaner mix. On the other hand boosting 8-12 kHz often is often referred to as giving the sound brightness, clarity and breathing. A very good area to look at. For EG you have a piano recording that plays chords on the background of a song. So why not remove some mud at 450 Hz with a medium 4 dB cut. Also a 2 -3 dB High shelf boost at 8kHz can give the piano some life, clarity etc.
Fit the sound in the context of your mix: If you bring in sound after sound in a mix scenery, you sometimes have the effect that you want to have a sound louder, but if you push the fader another sound disappears partly or looses something. This is where you use an eq for mix purpose. For EG: you recorded a bass and a wurlitzer EPiano. When you bring in the wurlitzer, you loose some punch of the bass. So why not remove the low end of the EPiano with a high pass at 180 hz to give every instrument its place.
So by removing unwanted frequency content and carefully hearing which instrument dominated which frequency area you will get a more professional sound by EQ. But you will never get something new out of an eq, you will just make the things you have cleaner.
Listen for what you want to add or remove, then equalize.
It comes through experience that you learn to hear when an equalization sounds good and when there's something to adjust. Mainly it has to do with contrast (e.g. removing "mud frequencies" to bring out the essentials or to "clean" the sound, or equalizing different layers so that they either sound "blended", tightly layered or separated.).
The main difference in equalizers comes from the exact shape of the curve. You should hear the difference (if there's any) between different equalizers by dialing in the same numerical settings.