Manley MASSIVE PASSIVE STEREO TUBE EQ - MSMPX 2/2004 - Manual (Page 6)

OUT
BELL
SHELF
CUT
BOOST
DB
0 20
BANDWIDTH
100
22
33
47
68
150 220
470
1K
680
FREQUENCY
BOOST
OUT
CUT
SHELF
BELL
560 - 27K
DB
16K
0 20
BANDWIDTH
FREQUENCY
560
820
1K2
1K8
2K7
3K9
5K6
8K2
12K
27K
22 - 1K
330
GAIN
CCW = FLAT
BANDWIDTH
CCW = WIDE
FREQUENCY
SELECT
BOOST
OFF
CUT
BOOST
OFF
CUT
LOW SHELF
BELL
HIGH SHELF
BELL
1
2
3
4
5
1) BOOST / OUT / CUT, TOGGLE. Each band has individual toggles to select whether that band will boost or cut or be
bypassed. "OUT" is a hardwire bypass for that band. Unlike most EQs, you must select boost or cut for each band. There are
several good reasons for this arrangement. First, because the boost part of the circuit is in a different place than the cut part because
it is passive, this allows us to use the same components in both sections but doing essentially opposite functions. The conventional
arrangement of a boost/zero/cut pot (baxandall) circuit was avoided to really make it passive. This switch also allows twice the
resolution of the "GAIN" pot and a much more accurate "zero". The center detent of conventional EQs is rarely the "electrical"
center of the pot so what you expect is zero is often a little EQed. This toggle allows some of us, who use dip EQ to reduce offending
frequencies to verify those frequencies in "Boost" and then switch to "Cut". Finally, it allows us to bypass each band individually,
without losing our "GAIN" pot setting rather than resetting a band to zero or bypassing the entire EQ.
2) SHELF & BELL. The two lowest (leftmost) bands can each be a special Low Shelf or conventional Bell shape. The two
highest (rightmost) bands can each be a special High Shelf or conventional Bell shape. Shelf & Bell describe the EQ's shape. We
included some diagrams to help visualize these curves. Bell curves focus their boost and cut at given frequency and the further
away we get from that frequency, the less boost or cut. The bell curves on the Massivo are moderately wide and the "Bandwidth
Control" does not have a lot of range and it also affects the maximum boost and cut (like a Pultec). Shelf slopes generally boost
(or cut) towards the highs or lows (thus high shelves and low shelves). These are not to be confused with "high or low filters"
which purely cut above or below a given frequency. Shelves also have gain or dB controls which allow you to just boost or cut
a little bit if desired - filters never have these controls. The Massive Passive allows each of the 4 bands to be switched to shelf.
The two mid shelves are almost the same as the outer ones but just have other (interleaved) frequency choices. For example, you
can set up the mid-high shelf to start boosting at 3K3, say 4 dB, then apply another high shelf to boost 12K, say for 10 dB, which
provides a few gentle gradual steps. BTW, the maximum boost in the example is 10 dB (not 14) and occurs around 20 kHz. You
may notice that as you switch between bell and shelf the amount of "grab" may seem to be less in shelf. Not really, both are capable
of 20 db boosts but towards the extremes that boost may be sub-sonic or super-sonic because we "spec" the shelf at the 1/2 way
point (10 dB), not the 3 dB down (or up) or maximum point. When you choose frequencies closer to the mids this "effect" is much
less however if the "bandwidth" is medium to narrow the "effect" is more pronounced. Most EQs don't allow one to switch from
bell to shelf and don't have a functioning "bandwidth" in shelf mode and this may be understandably unfamiliar ground.
3) GAIN. This sets the boost and/or cut depth or amount and works with the BOOST, OUT, CUT, TOGGLE. FLAT is fully
counter-clockwise not straight up "12:00" like most EQs. It is more like a Pultec in this regard. Maximum boost or cut is fully
clockwise and can be up to 20 dB - but not necessarily. There is a fair amount of interaction with the BANDWIDTH control. The
maximum of 20 dB is available in Shelf modes when the Bandwidth is CCW and is about 12 dB when the Bandwidth is CW.
The maximum of 20 dB is available in Bell modes when the Bandwidth is CW and is about 6 dB when the Bandwidth is CCW.
At straight up "12:00" in Bell mode "narrow" expect about 8 dB of boost or cut. In other words, you shouldn't expect the markings
around the knob to indicate a particular number of dBs. Many Eqs are this way. On the other hand, this interaction is the result
of natural interactions between components and tends to "feel" and sound natural as opposed to contrived.
These 4 GAIN controls have some interaction with each other unlike conventional EQs. It is a parallel EQ rather than the far more
common series connected style. If you set up all 4 bands to around 1kHz and boosed all 20 dB, the total boost will be 20 dB rather
than 80dB (20+ db of boost and 60 dB into clipping). This also implies, that if you first boost one band, that the next three will
not seem to do anything if they are at similar frequencies and bandwidths. Virtually all other parametrics are both series connected
and designed for minimal interaction, which seems to be quite appealing if you wear a white lab coat with pocket protectors ;.)
Actually, there are valid arguements for those goals and there are definately some applications that require them. However, there
is also a valid point for an EQ that is substantially different from the "norm", and for audio toys that have artistic merit and purpose
and not just scientific interest or gimmickry. We tried to balance artistic, technological and practical considerations in the
Massivo, and offer both some new and old approaches that appealed to the ears of recording engineers (and our own ears).
6
THE 4 BANDS