STEREO DYNAMIC SHELVING EQUALIZER
In late 2016, I had the first, rough blue prints ready for a dynamic EQ concept that really excited me, but no matter which angle I approached it from, I could never mould it into a shape that felt right. I binned my fifth revision prototype in 2018, and thought that would be the end of it.
In 2019, I spent a lot of time tweaking a custom, precision high and low cut filter, including variable slopes and relay controlled frequency selection. While doing so, I found the inspiration to work on the burried dynamic equalization concept again - I now approached it as a high/low end shaping tool.
This time, it took off in the right direction, and the work accelerated through tests and revisions during the 2020 lock-down, into this final form.
The first stage of the Stereo Dynamic Shelving Equalizer consists of a precision, high and low cut filter, each with 6 selectable frequencies, and 6, 12 and 18dB/oct. switching – all frequencies on relay-switched, precision matched capacitors.
The second stage consists of a high and low shelving filter, each sporting +/-5.5dB of gain, and dynamic control of the shelving, with 11 frequencies on relay-switched, precision matched capacitors.
The dynamic section lets you vary the attack and release times, as well as the dynamic hold on the shelving filters, while the soft/hard switch. takes you from a low, soft knee ratio, useful for subtle sculpting, to a higher, and harder knee ratio, with a high end roll off on the side chain, for a bit more bite and grab.
The controls are differentiated a bit from the low to the high end, because we can get into some faster times without getting in trouble on the isolated high shelving band.
Im frequently asked how it compares to multi-band compression, so I may as well address it here.
This is a dynamic EQ concept! ...and since its all done without the implementation of crossovers in the signal path, it does not suffer from any of the unfortunate artifacts associated with multi-band compression.
I think of it as a high/low end management system, with a very elaborate and carefully designed high/low cut filter set-up, as well as the more prominent dynamic control strapped over a pair of bax-like shelving filters.
It has a characteristic, sonic imprint, and will even lend some weight to the percieved loudness of your program material when desired, anchoring or lifting the density of percieved loudness, not just as a function of RMS, but by shift of focus from the sonic imprint.
So, Its a completely different animal in terms of design topology, features, strenghts and implementation.
It was designed to put a new perspective on shaping the arch of your program material, as well as the sonics, both from the aspect of interface and electronics. If you approach it from that angle, I am convinced it will blow your mind.
High and Low cut filters
3 slopes/6 frequencies each on each filter
Bypass on each filter
High and low shelving filters
11 frequencies each
5.5dB total gain in increments of 0.5dB on each filter
Dynamic control of each filter.
Bypass of each filter
23 step Blore-Edwards switches for attack, release, gain and dynamic control
Hard/Soft ratio & knee selection
Metering displays boost, cut and dynamic movement
Matched to better than 1% relative tolerance
Modern, precision in- & output section
€3360 ex VAT