Passive_Mid; Active_Mid - Mesa/Boogie Big-Block 750 Owner's Manual

FrONT PANeL CONTrOLS:
BASS:_
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nature. As the control is increased past 12:00 there is a 6db per octave rise in gain with the frequency topping
out at 321Hz. With 12:00 straight-up representing "flat" (a no boost/no cut setting). As the BASS control is dialed below 12:00, 55Hz
and all associated harmonics are reduced and eventually notched completely out of the signal. Conversely, there is a 6db per octave
cut beginning at 55Hz going down to 20Hz where the shelving ends with a cut gain of -20db as the control approaches 7:30 (off).
This type of broad band, active rotary control makes it possible to achieve bass characteristics far beyond that of a conventional
passive type control. It can increase the low end to an almost absurd level and with a flick of the wrist, dip it to near transistor radio
skinniness. Needless to say, with any control this powerful a certain amount of finesse must be applied to achieve musical results. Be
especially mindful of this when using the 5 Band Parametric in conjunction with the BASS control.

PASSIVE_MID:

This is the only passive style control in the string of rotary tone controls. This scheme was chosen for its inherently
musical blend and for the way the passive style midrange control, with its wide spread and smooth taper, fills in the holes. Unlike the
BASS, this control is a boost_only, and while it can competently remove this broad spectrum of midrange from the mix, it cannot
provide the extreme attenuation of an active style control.
OVERDRIVE
GAIN BASS
For radical and specific scooping of the midrange frequencies for modern R&B and Funk styles, there is plenty of notching power
that is infinitely more accurate to be found in the ACTIVE MID. Because of this, we opted for the tried and true passive style midrange
control that has been working great in all of our amplifiers for decades. It's hard to improve on a classic.

ACTIVE_MID:

In addition to the passive style MID control, the BIG BLOCK features an ACTIVE_MID circuit that allows further
accentuation of specific midrange frequencies across a wide band. This wider band covers the spectrum from high bass/low mid all
the way through to high mid/low treble frequencies.
GAIN BASS
PASSIVE-MID
unbalanced. This combined with the massive power available in the output section can spell real danger to speakers. We urge you to
use this ACTIVE_MID circuit with care and most of all taste, to avoid damage to your ears and speakers. These two simple controls
offer an incredible amount of shaping power in a simple to use format. When combined with the other tone controls, virtually any
sound you desire is available to you quickly and with far less searching than when using multi-band equalizers. This simplicity is at
the heart of the BIG BLOCK'S character...great tone with minimal tweaking.
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You will find, as we did, that this control works amazingly well for shaping the midrange
PASSIVE-MID
frequencies with a natural earthiness and character that is a perfect counterpart to its neigh-
bors. It is hard to dial wrong with this more forgiving control as it seems to give you just
enough and no more.
As you can see, this active circuit is made up of two controls; a GAIN control which is la-
beled ACTIVE_MID that boosts and cuts the selected region, and a FREQUENCY control
that allows selection of a specific range to manipulate. The ACTIVE_MID is the gain or
E N G I N E E
"amount" control. It provides 15db of gain in both plus (boost) and minus (cut) directions at
the specific range selected on the FREQUENCY control.
ACTIVE-MID
Remember that this is a powerful control and that certain frequencies cut through (high
mid/low treble) or seem especially loud (low mid/bass) so it is advisable to add gain with
the ACTIVE_MID control sparingly.
Set unwisely, this circuit is capable of creating sounds that are harsh, tubby or just simply
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