Getting the best results out of your studio setup comes down to two basic elements: your production skills and the capability of your gear. The first part is up to you, but the second is something you can take care of starting right here. Equalizers and signal processors are some of the core pieces of equipment in any studio, so it's certainly worth investing in high-quality hardware that can take on the challenge of delivering the performance you need.
Exactly where that level of performance falls will depend on the style of your setup. Are you looking for a straightforward, no-frills EQ to equip a hobby studio or budget-oriented community venue? There are plenty of affordable options like the Peavey QF series or DBX 2031 Single Channel 31-Band Equalizer/Limiter. On the other hand, for the most demanding professional applications, you might be more inclined to look into ultra-high-end units such as an Elysia, Daking or Tube-Tech model.
You'll also want to keep your eyes peeled for the specialty features that make each equalizer and signal processor unique. For instance, let's bring Tube-Tech back up as an example: like their name implies, they're all about tube-based electronics and the results are something you've got to hear to believe. Tube-Tech gear is sitting in the racks of legendary audio pros everywhere, including Grammy winners Al Schmitt and Joe Chiccarelli - and that's just one of the manufacturers in this section. Each and every one of them has their own claims to fame.
When all is said and done, it's simply a matter of discovering what works best for you. Narrow down your options based on budget, which features you need, how many bands and channels you're looking for and whether the equalizer signal processor should be active or passive. Once you've done that, you'll have a great list of contenders and you'll be ready to choose your favorite.