Part 2: How to Minimize the Distortion and Negative Effects of EQ, facts and solutions.

While the use of EQ is usually a "good thing" in a mix, it can have a negative side as well. Some say that EQ adds distortion to their music, making their music lack definition and clarification. This article is all about what causes this distortion and the negative effects of EQ, and what solutions are available to keep them to a minimum.

Fact 1: When you boost or cut frequency bands, it will boost or cut something unwanted or unexpected.

This happens because inside parametric EQs we usually adjust frequency bands. If thess bands also cover the unwanted part of a sound (eg noises) we just might boost this, too.

Another possibility is that our vocal might need a little boost and that band around 1000Hz is the same frequency where much of our guitar is. So if you raise the vocal, the guitar gets louder, too. Or, perhaps those high bands (over 8000Hz) - the high end of many instruments - might need a little boost for clarity, but most of the background noise is also in that range. Boosting the instrumental's high frequencies increases the noise, something you certainly don't intend to do.

Ideal Solution: Keep the bandwidth as narrow as possible. If the band is really narrow, it will be less likely to contain the unwanted frequencies.

Drawbacks: narrow frequency bands can only lock onto some of harmonics we'd like to change, but will miss most of them, making the EQ less effective. For example, a narrow bandwidth would allow you to lock onto 880Hz (which is 2nd harmonic for A4) but this narrow frequency band may lead you to miss the 2nd harmonic for C5 (which might also need some adjustments), making this setting less than ideal. With tight frequency bands, the final results might not sound changed at all.

Solutions from the pros: Pros will usually try to compromise between a narrow bandwidth that has very little results and a wider bandwidth that brings out aspects of the music that they don't want to. Pros know the sound that they are looking for and can calculate the benefits and losses precisely. They ARE pros, right? Their choices nearly always lead to the "more benefits" side of things.

Fact 2: EQ can indeed bring distortion, due to an effect called "Group Delay".
EQ consists of many filters, and each of these filters has a slight delay in sound. While this is a tough concept to understand, suffice it to say that, different frequencies will have slightly different delays associated with them.

To understand this better, let's look at an example to see how group delay can add distortion to the sound. First let's say that our 8000Hz is delayed by 10ms while our 1000Hz is delayed by 2ms after passing through a single filter of our many filtered EQ. Not a big deal and we can't really hear any difference in most cases. Now, unfortunately, the effect can be cumulative with each filter. (Depends on the signal's dynamic and this IS what often happens when you apply EQ to your audio track.) After some time (usually less than 1 second, measured by ms), the delay in our 8000Hz becomes 100ms and our 1000Hz delay is 20ms. We now have 80ms difference between the 2 frequency bands. And suddenly you can hear the effect of those two frequencies separated in time, commonly described as a loss in clarity. Highs tend to be have a metallic flavored sound, the overall sound is blurred and so on...

Ideal Solutions: in order to keep the influence of group delay to a minimum, we should keep the boost/cut amount to a minimum, so the EQ won't work too hard.

Drawbacks: Of course we have to acutally USE our EQ, how can we artificially limit the amount we need? No one can even hear the effect of a minimum boost/cut in most cases.

What the pros do: Use the minimum amount possible and only use more when really needed. Or they can use a skill called Frequency Furthering, which is a trade off with wider bandwidth. See the figure below for example

A Better Solution: Sound Magic Neo EQ provides a better solution for minimizing the distortion and negative effects of EQ. How?

First, Neo EQ tracks the pitch as music changes, and locks the frequency point, not entire bands. During this process, it can keep a very narrow bandwidth and this will less likely to boost or cut in the unexpected/unwanted frequencies.

Second, Neo EQ's maximum filter range boosts or cuts +/- 5dB, far less than the +/-18dB common range for other EQs. Because Neo EQ is more efficient in changing the sound, these boost/cuts can be kept to a minimum. It's not unusual for Neo EQ's 2dB boost to sound comparable to an 8dB for common EQs. Below is a graph that compares both THD+N (Total Harmonic Distortion plus Noise) for Neo EQ and a common parametric EQ worth $149. (Lower THD+N will be always better!), which you can clearly see which one has a cleaner and more transparent sound.

In our next tutorial, we will explain some specific usage of EQ

Previous: Part 1: How to lock in the right frequency, quickly and accurately, and optimize your EQ methodology

Next: Part 3: (Link will be active when it releases)

Below is a list of relative Products/Service you may interested, Click on the GUI picture to see more details

Neo EQ Pitch Tracking EQ	Neo DynaMaster All Powerful Dynamic Processor	Neo MasterTool Multi Process Mastering System	Vocalist Unique Vocal Processing	Supreme Piano Hybrid Modeled Pianos

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