One of the goals for ValhallaPlate was to have a minimal user interface. The goal was to have as many controls as necessary to sculpt beautiful plate reverberation, but no more. Any parameters that were deemed superfluous, or were even on the edge of being so, were removed from the interface.
The Diffusion control has become a standard feature of most reverb plugins. But ValhallaPlate is the first Valhalla reverb to not have a diffusion control. Why? Read on!
Why is Diffusion important in music?
Diffusion is used in reverbs to adjust the initial echo density of the reverb. The Diffusion control is present in most algorithmic reverbs as a way of dealing with artifacts. A diffusion value that sounds good on vocals may not sound good on drums, and vice versa. By dialing in a given Diffusion value, the user can figure out the right compromise for the input signal. The Size control is often used in conjunction with the Diffusion control, to balance out grain vs. metallic coloration.
How do you make a Diffusion plugin?
In an earlier blog post, I discuss how the Diffusion control commonly works in algorithmic reverbs. The most common technique is to use several short cascaded allpass delays to build up the initial echo density of the reverb, where the Diffusion control adjusts the allpass coefficients of these delays. These cascaded delays give rise to various sonic artifacts, depending on the number of delays, their lengths, and the allpass coefficient settings:
- If there are only a few allpass delays, the initial onset of the reverberation will be sparse, but with a natural attack/decay.
- Using a larger number of allpass delays will result in a slower attack time for the reverb, that can sound unnatural.
- A higher valued allpass coefficient (i.e. somewhere between 0.7 and 0.99) will result in a faster attack and a higher echo density, but will also create a metallic sound.
Why did you leave Diffusion out of Valhalla Plate?
ValhallaPlate doesn’t have a diffusion control, because it doesn’t need one. During the development process, I figured out a new diffusion technique, that resulted in a sharp attack with no grain, while avoiding the metallic sound commonly found with cascaded allpass diffusors. The result is a reverb that works on pretty much any input signal, without any adjustments necessary. The simplicity of the GUI stems from solving issues at the algorithmic level.
The improved diffusion technique used in ValhallaPlate is reflected in the presets available for the plugin. The presets are arranged by decay times: Huge, Large, Medium and Small. There are no specific preset categories for drums, or vocals, because the same ValhallaPlate settings work equally well on both. The presets names in many reverbs are a reflection of “this sounds good on this source,” but this is also a way of saying “yeah, you probably want to use it on this source, as opposed to something else.” ValhallaPlate doesn’t need to be handled that gingerly. Put ValhallaPlate on whatever source you want, and adjust the SIZE and EQ controls to get the sound you want.
I view ValhallaPlate as being closely related to an SM57. Or a hammer. No need to be delicate with the tool. No need to think about things too much. It just works.