[Dana Nielsen]

Hey, @lucastlee! What an excellent question. I’ll respond briefly here with my practical “take” on EQ differences rather than diving deep into a technical answer. I’m also going to assume you’re referring to EQ plug-ins rather than analog hardware EQ units.

Here are a few possible reasons as to WHY:

1. Physical model: When plug-in manufacturers attempt to capture the sound of, say, a vintage Pultec EQP-1A (one of my favorite musical EQs), the resulting plug-in’s “sound” is derived from a specific hardware unit; and hardware units can vary in tone (and electronic components) from year to year, model to model, and serial number to serial number, especially as they age. This is one explanation for why a Waves Puig-tech might sound different from an Avid or UAD Pultec, even when they’re all EQP-1A models.

2. Algorithms, processing, and math: Each manufacturer will employ different means by which they recreate a familiar analog sound or circuit into a digital plug-in, which can also create sonic differences for the end-user to notice and compare.

Here is my philosophy and WHAT I do about it:

1. “huh … interesting.” I notice these differences all the time.

2. Move on. 😂 I, long ago, took a decidedly “meh” approach to gear paranoia and elitism with regard to hardware and software. Arguing over 1176 revs is so not my style and utterly pointless to me. You won’t find that kind of attitude here on Mix Protégé. There’s already plenty of that whining on Gearspace (see below).

3. I’ve got LOTS of options to choose from in my plug-in EQ collection. Several versions of the EQP-1A by different brands, several Neve and SSL recreations that are identical by model number but differentiated by plug-in manufacturer. I try them ALL, and honestly for the most part I LOVE them all! But choosing my “favorites” will come down to a few simple considerations:

• It sounds great and operates as expected
• It loads fast in my DAW and isn’t a processing-power-hog (bonus points if it’s available in AAX DSP, since I’m on a Pro Tools HDX system)
• It has some extra features that make my life easier and/or routing more flexible, especially for dynamics processors — like a mix/blend knob, key input, input/output control, sidechain filter. Even when those features are not true to the vintage analog version, they sure make my life easier and are welcome additions in a plug-in emulation.

Lastly, FWIW, here’s ….

My process for any EQ -digital or analog- and any other effect. Err, scratch that, this is pretty much my process for MIXING ANYTHING:

1. Have desired sound in brain/imagination
2. Pick tool that will get me there quickest (with zero F$%#s given about the brand name of the tool)
3. Experiment with tool until the sound in my brain is coming out of the speakers
4. Repeat steps 1-3

Hope this helps you (and anyone else reading), and sorry, I guess it wasn’t so “brief” after all! 🤓

[Jesse Lewis]

Great question and a very helpful answer! Thanks for this response!

[Dana Nielsen]

Sure thang!! 🙏🏻

[Lucas Lee]

WOW! Thanks so much for the awesome info!

[Dana Nielsen]

My pleasure, man!