Harmonic enhancers generate new harmonic content. This is different from equalizers, which are able to cut or boost frequencies already present in the source material. They can make the sound clearer and brighter than it originally was. Different manufacturers use different operation principles. For instance, the Aphex Aural Exciter, which pioneered this processing, uses a combination of high-pass filtering, and harmonic generation through distortion and compression. In recent years, we have seen an increasing number of software plugins dedicated to this task. This will be the subject of our next tutorial. We will show you how to process elements of your mix such as basslines, drum groups and even the master bus with harmonic distortion. Let’s get started!
As usual, we have prepared a short sequence in our SoundBridge: DAW. It contains all the essential elements of a full mix. For the multiband harmonic exciter effect, we have chosen Spectre by Waves Factory. There are of course more alternatives out there. Let’s have a quick listen to the unprocessed sequence.
~Full Mix – Unprocessed
We will begin by adding a new instance of the Spectre plugin on our bass lead channel.
The Spectre is a processor that combines the best features of a harmonic enhancer coupled with a parametric EQ. It processes the difference between the input signal and the EQ signal, introducing harmonic content only to the part of the spectrum that you want. The variety of saturation algorithms are based on classic recording hardware. Let’s have a closer look at the interface and its parameters.
On the top part, we can see a parametric EQ section divided into five bands. Each band can be switched on or off by clicking on the filter icon on the top. If you drag and drop any band point you can place it anywhere over the spectrum. Below the bands we have classic EQ controls for frequency, gain and Q. Besides that, just below the Q, you will notice the “Solid” written by default. If you click on it, you will see a drop-down menu where you can choose from eleven different saturation algorithms.
Moving forward, if you click on the part below the saturation algorithms, you can choose between different EQ modes (Stereo, Left, Right, Mid/Side) available for each of the bands. There is also a master section where you can control the input volume, output volume and mix. On the bottom, the “Quality” parameter has three modes: Standard, Good and Best. They determine the oversampling ratio between Normal (no oversampling), Medium (4x oversampling) and Best (16x oversampling).
The Presets menu offers interesting and useful presets to get you started. Mode lets you choose between subtle, medium and aggressive settings. This essentially works like a drive parameter for the saturation.
Finally, we have De-Emphasis. This feature subtracts from the ﬁnal signal the boost in EQ that Spectre has applied on the ﬁrst stage, leaving only the saturation of each band. It can be enabled or disabled.
Now, let’s move to some practical audio examples. As you can see in the picture below, on our bass channel’s Spectre we have boosted low, low-mid and a few mid frequencies using the Diode saturation algorithm.
Let’s have a listen to the unprocessed and processed versions.
~Bass Lead – Unprocessed
~Bass Lead – Processed With Spectre
Moving forward, we could use the Spectre to process our drums. As you can see in the picture below, on the drum group channel we have added Spectre, but this time with a bit more drastic settings. The main boost happens in the middle frequencies. The saturation algorithm we have chosen is Tape since we want a bit of a warmer sound for our drums. Besides that, we gave a boost on the high frequencies, around 10kHz.
Let’s listen to how our drum group sounds unprocessed, and then processed with Spectre.
~Drum Group – Unprocessed
~Drum Group – Processed With Spectre
Master bus harmonic processing
Finally, we will process our master bus. In this case, we have used Spectre in a more subtle way. As you can see in the picture below, we have used a high shelf filter for the high frequencies and boosted them a few dB. We have switched this band to Side mode. This will give us more presence of high frequencies in the stereo field. Again, let’s hear the unprocessed and processed version.
~Full Mix – Unprocessed
~Full Mix – Processed With Spectre