The equalizer you don't know you have

Have my awesome EQ, the Onkyo EQ-540 integra, she is a great EQ!
 It gets some use on specifics CDs and albums.

i just like the green lights. :)

I just want to point out that EQ (and other signal processing) takes place in many places along the recording process as well as in playback systems.

As Erik pointed out most speakers systems have some sort of EQ by necessity. All speaker drivers and speaker systems have compromises. When a speaker designer is tasked to design a pair of speakers that will be sold through retail stores that will retail for $2K they must cost no more than $500~$600 to manufacture including overhead, packaging and labor for the company to stay in business. Not all speaker manufacturers have the same resources. Five different speaker manufacturers will each have their own way to meet that price point as well as having their own preferences. So each company will build a $2K speaker that sound different from their competitor's $2K speaker. Also, it is very difficult to accurately predict what people want in a speaker so designer do what they think is best.

Stated in a previous post:
" Part of that explanation is why an outboard electronic crossover, while very useful for some applications, can provide only "textbook" filters, NOT compensation filters for drivers needing help."

With all due respect that statement is not accurate. Frequency contouring or EQ can and often is designed into analog electronic crossovers. They are usually designed for a specific speaker. For example we designed an analog electronic crossover for one of our two way OB speaker systems. Along with performing the crossover functions the unit is used for contouring the upper mid-range and also adds bass boost required for OB woofers. More than "textbook" filters are possible.

"Outboard electronic crossover" is a broad term. I believe the poster was describing analog electronic crossovers. DSP crossovers fit the description too.

There is truth in saying that just substituting off-the-shelf analog electronic crossovers for the factory passive crossovers that have driver and cabinet compensating circuits and other EQ could have very negative sonic consequences.

speakers are there to be heard and enjoyed not measured. Therefore it is crucial that they are custom tuned to your ears only. 

Unfortunately many speaker designers rely on measurements and the result is speakers that sound horrible. 

the prime example of a hidden equalizer is within a phono preamp that has to adjust for the RIAA curve.   The circuitry has to boost and cut the signal by 40 db! from 20 to 20K Hz.  

Kenjit wrote-
"speakers are there to be heard and enjoyed not measured. Therefore it is crucial that they are custom tuned to your ears only.

Unfortunately many speaker designers rely on measurements and the result is speakers that sound horrible."

This is is the exact equivalent of your custom tuned to your ears speakers sounding horrible to the rest of the world.  They were flavored to your liking in your environment via measurements whether by ear or by testing equipment.  

Why is it so difficult to comprehend that there are speakers manufactured at every price point for a multitude of listeners that do exactly what they are supposed to do, bring listening pleasure to that buyer.  The vast array is there for choice of sound and esthetics.  Sure, you can spend a fortune on custom tuned to your ears but those ears will not hear the same five to ten years down the road.  What then?  Pay a small fortune to retune again and again?  

What are your guidelines for custom tuning to your ears?  Please describe the process that you are a huge proponent of.