This style has minimal Gain / Q dependency, smaller amounts of boost or cut still have relatively high Q and it is therefore precise and well defined in use. The EQ lends itself well to percussion uses and resonance modification on drums, since relatively high Q is available at low gain settings. However it is sometimes difficult to obtain overall EQ fill on combined sources or subtle EQ on vocals, as the user needs to adjust the Q control to maintain an effect when the gain is changed. Failure to understand this fact has often added to the reputation of this type of EQ for sounding 'hard' or 'harsh'. However, because the user retains separate control of all its parameters, this EQ is still the most flexible for users that have the time and patience to spend when using it. It is most like the original 4000 series SSLs, and other 'clinical' styles o f EQ that became popular in the 1980's.

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EQ Type 2 (Sonnox Oxford selection 2)

EQ type 2 has exactly the same response as type 1 in boost, but has tighter Q in cut. This response is a true constant Q rather than a symmetrical response. It most resembles some legacy units that gained favour for their ability to perform gentle fill EQ in boost, whilst retaining the ability to accurately modify troublesome resonancefrequencies when recording acoustic and percussion instruments.

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EQ Type 3 (Sonnox Oxford selection 3)

This style of EQ has a moderate amount of Gain / Q dependency whereby the Q reduces with gain. This provides the EQ with a softer characteristic as EQ is progressively applied and since the effective bandwidth is increased for low gain settings, it sounds louder and more impressive when used at moderate settings. The gentler Q curve also lends itself better to overall EQ fills and more subtle corrections in instrument and vocal sources. Turning the Gain control seems to produce the effect that the ear is expecting without needing to adjust the Q control too often. Therefore EQs of this type are often dubbed as 'more musical sounding'. This EQ most resembles the older and well-loved Neve types, their modern derivatives and later SSL G series. Also many of the more popular outboard EQs have this dependency to some extent.

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EQ Type 4 (Sonnox Oxford selection 4)

EQ type 4 builds on the type 3, using a far greater Gain / Q dependency which maintains an almost equal area under the curve in the boosted region with gain control operation. It is extremely soft and gentle in use and is most suited to overall EQ fill and character modification for mixed parts (and completed mixes) where subtle changes in overall impressions are required. Therefore it will also prove useful in mastering situations where there is requirement to match the sounds of tracks from different sources on a common production release.

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