Wow... no shortage of idiots here today... I'll be damned.
Subtractive EQ and additive EQ are exactly the same fucking thing, 180' out of polarity... so unless you have some kind of magic amplifier that distorts less when it's output is switched 180' out of polarity, the amount of distortion is indeed equal in boost as it is in cut.
Cloneboy... active EQ's don't use feedback to achieve amplification, some of them use negative feedback to drop the noise floor, but not to achieve amplification. Active EQ's employ active electronics for the filter set of the equalizer, passive EQ's use passive electronics for the filter set... it's really that simple.
I have to say that the following quote may win a "dumbass quote of the year" award should such an award ever be presented...
Cloneboy Studio said:
whereas passive EQ's (essentially) convert a signal to a lower amplitude and the boosts are actually reducing the amount of attenuation... the key to a good passive eq is an excellent attenuator and clean post eq gain stage that is transparent.
The signal conversion to lower amplitude is called "insertion loss" as it's a passive filter network and will consume some of the energy that comprises the signal so the filter will indeed do it's thing... this is why you have amplifiers [a buffer amp in front, and a "gain makeup" amp behind] on either side of the filter set... how the "boosts are actually reducing the amount of attenuation" statement came to be I must say is a total mystery... if you break it down, it is indeed actually correct... the "boosts do reduce the amount of attenuation"... that's what a boost does... it's also how an amplifier works.
The key to a good passive EQ is a well designed passive filter circuit. Passive filter circuits can be done with "RC" [Restitive and Capacitive] networks, or via inductors... that "clean post eq gain state that is transparent" is something that not a whole lot of passive EQ aficionados are really after.
The reason things like Pultecs... even good working Pultecs are sought after items are things like the even order harmonic distortions created in the amplifiers [though the solid state Pultecs are a bit cleaner than their tube counterparts, and IMNTLBFHO have a better bass character than their tube brethren], as well as the "ringing and overshoot" and additional phase distortion created by the input and output transformers. Same with
the Manley Massive Passive.
Active EQ's like the $11,000 GML 9500 [incidentally, I have one in my rack] are indeed exceptionally low distortion devices... the 9500 also has a bandwidth of [if I remember correctly, Jeffrey told me once, I didn't write down the information] 4Hz to 280kHz... in other words, nary any phase distortion through the audio spectrum, yet the fact of the matter is that with both,
the GML 9500 as well as the Manley Massive Passive [two
radically different working and sounding units] there is one universal truth... that truth is that the "subtractive" EQ works
exactly like the "additive" EQ except that filtered section of audio is 180' out of polarity to the main audio passing through the unit.
Nothing more, nothing less.
You gain no additional headroom using subtractive EQ, you lose nothing by using additive EQ, it's an urban myth that subtractive EQ is any different in it's nature than additive EQ, though I will say that it is more difficult to perceive subtractive EQ so often more is employed, which leads to a greater quantity of phase distortion in the resultant signal.
I don't remember the thread, but I think it was in the forum called "The Rack"... there was a far more indepth discussion of subtractive vs.additive EQ somewhere on this site, I believe it was "The Rack" forum but I could easily be wrong about that location... if anyone gives a shit I'm sure they'll be able to hunt down the thread.
Peace.