Manley Labs STEREO EQ owner manual Phase Shift?

Phase Shift? Mini Massive and Massive Passive - Similarities & Differences

Deadly topic. This is probably the most misunderstood term floating about in the mixing community. Lots of people blame or name phase shift for just about any audio problem that doesn't sound like typical distortion. We ask that you try to approach this subject with an open mind and forget what you may have heard about phase for now.This is not to be confused with "time alignment" as used in speakers, or the "phase" buttons on the console and multi-mic problems.

First - all analog EQs have phase shift and that the amount is directly related to the "shape" of the EQ curve. Most digital EQs too. In fact, one could have 3 analog EQs, 3 digital EQs, and an "acoustic equivilant", and a passive EQ, each with the same EQ shape, and ALL will have the same phase shift characteristics. This is a law, a fact and not really a problem. The two exceptions are: digital EQs with additional algorithms designed to "restore" the phase, and a rare family of digital EQs called FIR filters based on FFT techniques.

Second - Opinions abound that an EQ's phase shift should fall within certain simple parameters particularly by engineers who have designed unpopular EQs. The Massive Passive has more phase shift than most in the filters and shelfs and leans towards less in the bells. Does this correspond to an inferior EQ? Judge for yourself.

Third - Many people use the word "phase shift" to describe a nasty quality that some old EQs have and also blame inductors for this. Its not phase shift. Some inductor based EQs use inductors that are too small, tend to saturate way too easily, and create an unpleasant distortion.TheMassivo(ofcourse)usesmassiveinductors(compared to the typical type) which were chosen through listening tests. In fact we use several different sizes in different parts of the circuit based on experiments as to which size combined the right electrical characteristics and "sounded best". The other very audible quality people confuse with phase shift is "ringing". Ringing is just a few steps under oscillating and is mostly related to narrow Qs. It is more accurately described as a time based problem than phase shift and is far easier to hear than phase shift. For our purposes, in this circuit, these inductors have no more phase shift or ringing than a capacitor.

Fourth - A given EQ "shape" should have a given phase shift, group delay and impulse response. There also exist easy circuits that produce phase shift without a significant change in frequency response. These are generally called "all-pass networks" and are usually difficult to hear by themselves. You may have experienced a worse case scenario if you have ever listened to a "phase-shifter" with the "blend" set to 100% (so that none of the source was mixed in) and the modulation to zero. Sounded un-effected, didn't it, and that may have been over 1000 degrees of phase shift. Group delay and impulse response describe the signal in time rather than frequency and are just different ways of describing phase shift. Some research shows these effects are audible and some not. The Massive Passive tends to show that group delay in the mids is more audible than towards the edges of the spectrum and there may be interesting exceptions to generalities and conventional wisdoms. The audible differencesbetweenEQsseemstohavemoretodowith Q,distortions, headroom and topology than with phase shift.

Fifth - Phase Shift is not as important as functionality. For example, we chose very steep slopes for some of the filters because we strongly believe the "job" of a filter is to remove garbage while minimally affecting the desired signal. A gentler slope would have brought less phase shift but would not have removed as much crap.

The Mini Massive is obviously based on the lowest and highest bands from the Massive Passive. In fact, they share about 95% of the same components and about 85% of the same circuit board layout. Most settings using those two bands can be easily transferred from one to the other.

One intention of the Mini Massive is to be a good answer for those who took issue with one or another factor of the Massive Passive even though the number of those who had any issue were few and most likely the noisiest of these individuals will still find some rationalizations in their attempts to be internet-orious. But they did raise some valid points and inspired an alternative version.

Number 1) The Massivo is too colored for mastering. Maybe for some, but many of the top mastering engineers do use it 5 days a week and it happens to be one of the most likely pieces of gear to be seen in professional mastering rooms. That said, the Mini Massive is designed to be one of the cleanest and most transparent equalizers ever offered and which is easily verified by you hitting the hardwire bypass switch reasonably frequently.

On the other hand, the Massive Passive was designed with tubes and transformers for deliberate color and for those situations where some departure from digital sterility is desired it is a better choice over the Mini Massive. These days you might have a variety of ways to generate "warmth" so the choice of EQ is more open. In other words the Massivo was designed more with vintage console and Pultec EQs in mind and created for similar applications. The Mini Massive was designed more for buss EQ and mastering as well as for surround and maybe tighter budgets, which brings us to.....

Number 2) The price... Not much we could do about the cost of the Massive Passive because it does require a lot of parts and many of them are custom and most are premium quality. By halving the number of bands, making the chassis smaller and simpler, going with solid state, and making the output transformers optional, we were able to offer a slimmed down version with a slimmed down price tag.

Some might also see the Mini Massive as a single channel 4 band EQ and set up their cabling or patch bay with that in mind. This gives them the versatility of a 4 band EQ or a stereo 2 band in a 1 rack unit package at a competitive price, but with that well known Massive sound. Great for tracking, great for overdubs, great for mixing.

Number 3) Sculpting in the extreme lows and highs. The Mini Massive is an evolution of the basic Massive Passive concept and is designed to really provide some interesting abilities to create huge bottom that remains tight (transformerless) plus amazingly sweet air for brilliance or sparkle tweaking. In fact, a warning to not over-do those kinds of boosts needs to be mentioned. Just because you can now doesn't mean that you always should. And if you lose fidelity in other parts of the chain, boosting here might exagerate problems.

Number 4) Portability and reliability. Reliability has never been much of an issue with the Massive Passive nor are tubes in reality a fragile technology - quite the opposite, though eventually they should be replaced. However the myth remains, and for live and broadcast applications many prefer solid state. These situations also tend to prefer the smaller size, less heat, the simplicity and lighter weight. This is for them.

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