Not necessarially.
if a speaker system needs an eq to fix it, something is wrong.
The Bose 901 is a small trapezoidal box with nine 4" drivers in it: One on the long side facing forward and eight facing the two angled rear facing sides. This required some finesse in placement.
Since we know that only two of the three speaker design goals can be had at any one time (small, bass, efficient), Bose sacrificed efficiency here. They went for a small speaker that could produce bass.
And, since small drivers, no matter how many there are, can only produce a certain amount of bass, it was designed to work with an eq that provided about 18 decibels of bass boost, at least in the early series. As such, to sound right, they required a tremendous amount of power.
Moving along, since we all know that equalizers need to be "inserted" into the signal path, some way to accomplish that is needed. Fortunately, tape in/out (or EPL) loops were about as common as ants at a picnic in the old days. Nowadays, they are rare.
The only way most modern receivers can accomplish this is between the pre and power amp stages.
And, to give the devil his due, when the 901's were properly placed and fed enough power, they could sound quite impressive on many types of music.
And, Electrovoice had some more conventional looking speakers, the Interface series, that needed an eq to operate properly and was one of the better speakers of it's day, also.