The Weiss EQ1 is a modern classic when it comes to mastering grade equalization. Designed without compromises, featuring five Sharc processors and state-of-the-art digital filtering technology it's the one and only digital hardware for mastering purposes. The Weiss EQ1 plug-in is a line-by-line port of the original Sharc assembler code and has the exact same sound as it's hardware counterpart.

The heart of Weiss EQ1 is its two processing modes: dynamic and linear phase. Since these modes have fundamentally different architectures, you decide if you either want the ability to do dynamic processing per band (dynamic mode), or if you want to have all bands processed in linear phase mode.

While the plug-in has the exact same sound as the hardware, its functionality has been extended beyond the capabilities of the hardware, with for example a user friendly "large screen" mode that allows you to click and drag in the EQ curves, a frequency analyzer display, and additional options in the dynamic section, such as the ability to set the ratio, attack and release times on each band.

We hope you will enjoy the sound of the Weiss EQ1!


User Interface


Click on the Large Screen button next to the screen to get into a click-and-drag mode!


There are two main modes of operation when it comes to the audio


The first is the dynamic EQ mode, which you can either use as a normal, low latency EQ, or set a Threshold to get the EQ to react to the incoming audio. The second mode is the linear phase mode, which allows you to process the audio without introducing phase distortion, in many cases a cleaner and less intrusive processing.

The parameters for each band are different for these two modes, but the operation is very similar and it is easy to switch between them.

What Mode Should I Use?

If you want to do dynamic processing, you will obviously need to use the DYNAMIC MODE, but if you're just doing "normal eq:ing" there are a couple of differences between these:

  • LINEAR PHASE has no phase distortion, but will instead introduce "pre-ringing". It's best suited for subtle EQ changes or mastering purposes. This mode has a lot of latency, since it needs to "look ahead" of time in order to compensate for the phase shift.
  • DYNAMIC MODE is a "minimum phase" eq, which means that the phase shift is the lowest possible without being able to look ahead, that is also the same way nature tends to "eq" audio. It has lower latency and is the normal mode of eq:ing.

Both modes are implemented with high-precision low-noise calculations.


Start with the EQ in DYN MODE, then switch between LP and DYN to audition the difference.





General Parameters

Soft Bypass: Bypass the unit.

A/B: Switch between settings stored in A and B for easy comparisons.

DYN Mode/LP: Mode Switch between dynamic minimum phase and static linear phase equalization.

Mid/Side: Engage the Mid/Side routing mode, where CH1 affects the Mid (L+R) and CH2 affects the Side (L-R).

Ganged: Link the controls to both channels.

Ch 1: Adjust the controls of Channel 1 (LEFT or MID).

Ch 2: Adjust the controls of Channel 2 (RIGHT or SIDE).

Options: Access additional settings and options.

Large Screen: Switch to a mode where the EQ curve screen covers the entire plug-in.

Normal/Advanced: In DYN MODE, it's possible to show the entire set of band parameters (ADVANCED) or just the original EQ1 parameters (NORMAL).

Analyzer: Turn on/off the spectrum analyzer display

Gain: Adjust the output volume of the plug-in, either for both channels (in GANGED mode) or for the selected channel.

Over 1 and 2: These LEDs indicate when the output signal level has surpassed 0 dB for a selectable number of consecutive samples. You can adjust this value in the Options menu.




Band Parameters

Each of the seven bands has an identical set of parameters, but the parameter set is different in LP and DYN modes.

On: Enable/disable the band.

Boost: Sets the amount of gain for a peaking or shelving filter (from -39 dB to +18 dB).

Filter Mode: Switch between shelving, peaking, or cut filters. In DYN MODE it's possible to select DYNAMIC PEAKING mode.

Q/Slope: Adjust the Q of a peaking or shelving filter, or the slope of cut filter (6 or 12 dB/oct)

Frequency: Adjust the center or cut-off frequency

Solo: Solo the current band.

The following parameters are unique to the DYN MODE operating mode.

Threshold: Adjust the threshold for which the dynamic EQ starts to compress. When there is audio above the threshold in the selected frequency band, the gain of that band will be reduced.

To see the following parameters, you need to click on the Advanced button.




Attack/Release: Adjust the attack or release times for the dynamic EQ. The attack time is three times longer when the band is cutting than when it's boosting, but the parameter value read-out corresponds to the shortest time. The release times are the same for boosting and cutting.

Ratio: Set the ratio of the dynamic EQ band, the ratio between the amount of gain reduction as compared to the level above threshold.

EXPANDING MODE: If the ratio is between 1:2 and 1:1 the band will boost audio above the threshold.

COMPRESSING MODE: For ratios between 1:1 and 20:1 it will attenuate audio above the threshold.




The three different modes of the band parameters, from left to right: LP Mode, DYN Mode (Normal), DYN MODE (Advanced). On LP Mode, the Normal/Advanced options are greyed out.


The Small Screen

The screen has three sections, from left to right:

  • Output meter and volume control.
  • EQ curves and frequency analyzer.
  • Current band parameters and peak/RMS information.

To the left you can see the output meters. If you hover over the meters you can grab the volume control and adjust the output volume. This is the same control as the Gain knob to the right of the screen.

EQ Curves

The middle section contains the EQ curves and frequency analyzer. The red curve is the current EQ, and if there is dynamic equalization that curve will change depending on the input audio.

The light blue curves in the background is the frequency analyzer. CH 1 has a faint white line at the top which makes it possible to distinguish from CH 2 if necessary.

If you hover the mouse over the screen, the curves for each individual band will appear, and you can click and drag each band separately. Use the scroll wheel on your mouse to adjust the Q/Slope.

The right-most section shows the last touched band's parameters, clip meters and RMS and Peak levels. It's also possible to click the PK (or TPK) text to toggle between peak and true peak measurements.

EQ Bands

There are three difference faceplates of the bands, the LP MODE faceplate with three main knobs, DYN MODE with the additional Threshold knob, and in DYN MODE it's also possible to turn on Advanced mode to show all band parameters, including Ratio, Attack and Release.





The following options are available:

Dithering: Apply dithering for 16, 20 or 24 bit output.

Set # Overs: Adjust the number of consecutive peak values above 0 dBFS needed to trigger to Over LED.

PK Reset: Turn AUTO ON if the PK LED in the screen should reset automatically or not.

Copy: Copy settings from A to B, B to A or between the channels.

Dyn Latency: Set to LOW to use DYN mode without the lookahead in the dynamics, in order to reduce the total latency through the plug-in.

Meter Text: The meter read-out in the small screen displays either the "hold" value or the current "peak" vaue.

Analyzer: Let the frequency analyzer analyze the audio on the input or the output.

Analyzer Tilt: Tilt the frequency spectrum with an amount of dB/octave.

Analyzer Speed: Set the response time of the analyzer.

User Interface Weiss/Dunkel: Sets a bright (Weiss) or dark (Dunkel) user interface. The dunkel mode only affects the small and the large screen.

Band Menu: By default, the band menu is activated by left-clicking on the EQ curve's handle. This can be changed to be either on right-click, on mouse over or to always show the band menu (PERSISTENT).


The Large Screen

Click on the Large Screen button next to the small screen to open the knob-less user interface of the Weiss EQ1.



Click and drag to adjust Frequency and Boost. Scrollwheel to adjust Q/Slope. Double click the dot to turn the band on/off.




Right-click the band to bring up the context menu for more band parameters, such as Filter Type, Solo and Threshold.




Click the arrow (▼) in the lower right corner to show more band controls (if available).



User Interface

From the user interface in the Large Screen mode you can do the same things as in the Knob View mode. Some users prefer to turn a knob, others prefer to drag a curve.

When the mouse pointer is outside the window boundary the view will highlight the combined effect of all EQ bands. The filled red curve is the current curve (including dynamic EQ effects), while the transparent red curve is the static curve, the nominal value of all dynamic EQ bands.

Without dynamic bands, the two red curves would be the same.




As soon as the mouse pointer enters the window, individual EQ curves will get highlighted. When ever the dot at the center frequency of the curve lights up, you can click and drag to adjust Frequency and Boost.




  • Click and drag to adjust Frequency and Boost. Scrollwheel to adjust Q/Slope.
  • Double click the dot to turn the band on/off.
  • ⌘ (Mac)/CTRL (Win) click to adjust Q.
  • OPT (Max)/ALT (Win) click to set Boost to 0 dB.
  • Shift-click to limit adjustments to either Boost or Frequency.
  • CLICK AND DRAG IN WINDOW: Selects multiple bands at the same time. Selected band's handles turn red to indicate that they are selected.

Right-click the band to bring up the context menu for more band parameters, such as Filter Type, Solo and Threshold.




Other Stuff of Importance

With great powers come great responsibility. That is true for most things, and that might be true for this EQ as well. Either way, it's a nice lead-in to this chapter about the intricate parts of the Weiss EQ1.



The original Weiss EQ1 had a fixed ratio on the dynamic bands. With the Weiss EQ1 plug-in Daniel Weiss wanted to add variable ratio, attack and release times, as well as an option to to expansion with the ratio.



20:1, 10:1, 5:1, 2:1 ... Compression!

These are the compression ratios, and 10:1 is the default value and the ratio built-in to the original Weiss EQ1. For example, using 10:1, for every 10 dB that the input signal goes above the threshold, the dynamic band will reduce the output to 1 dB.

With the dynamic EQ, the maximum gain reduction is decided by the band's Boost. The Boost will function as a range control for the compressor.

For boosts, maximum gain reduction means that the band is flat at 0 dB. For cuts, maximum gain reduction means that the cut is at its specified value.

1:2, 1:1.5, 1:1.2, 1:1.1 ... Expansion!

These are the expansion ratios. For every dB above threshold, the compressor will increase the gain by the ratio. So using 1:1.5 as an example, with 10 dB above threshold, the resulting gain is 10 times 1.5 = 15 dB.

As with the compression ratios, the maximum gain change is limited by the setting of the Boost in the band. The unit can never increase the gain more than what Boost is set at.


If you want to enhance a loud sound, like a kick drum, use the expansion ratios to only boost the EQ when the kick hits.


Latency/Low Latency

The Weiss EQ1 was built for mastering, and its algorithms require a lot of latency. We have however created a Dyn Latency = LOW mode which you can enable if you want to use Weiss EQ1 in low latency applications.

Linear Phase Latency

The LP MODE requires latency in order to correct the phase (the time) of the processing. There's no way around it, linear phase is just a trade off between a delay and phase distortion. The LP MODE latency is typically around 250 ms.

Dynamic EQ Latency

The DYN MODE uses latency for a lookahead to the dynamics section. The lookahead makes the compressor react faster (earlier in time), without having to set fast attack times. It is possible to disable this lookahead by selecting Dyn Latency = LOW in the OPTIONS menu.

Dyn Latency = Low (Dynamic Mode Only)

Low latency mode is only available for DYN MODE, and will process the audio without the lookahead buffers. The only latency in the plug-in comes from the Weiss oversampling filters used in 44.1 and 48 kHz.

Dynamic Latency Compensation

The plug-in will update the reported latency whenever switching between the different modes. This enables the DAW to properly compensate during playback. Most DAWs support dynamic latency compensation, but some require a start/stop before the compensation is updated.

Please see the documentation for your DAW for more info on Dynamic Latency Compensation.


Extended Features

A whole range of added control can be accessed with Extended Features. Please see the separate "Extended Features" manual for more information.



Anton Eriksson – DSP programming
Jacopo Lovatello – DSP programming
Björn Rödseth – DSP programming, framework programming
Filip Thunström – UI programming
Niklas Odelholm – Product design, programming
Johan Bremin – Quality assurance, presets
Ulf Ekelöf – 3D rendering
Daniel Weiss, Joschka Weiss – Product design
Andreas Mood, Jamie Dockerty – Presets