What Is Additive EQ : Everything You Need To Know

In the dynamic world of audio engineering, one technique stands out as a catalyst for sonic enhancement: Additive EQ. This fundamental tool serves as the cornerstone of precision and creativity, offering engineers a means to elevate audio production to new heights.

As we embark on this journey into the realm of Additive EQ, let us explore its techniques, applications, and nuances, unlocking the true potential of audio engineering mastery.

Index

• What Is Additive EQ
• How To Do Additive EQ In a Mix
• When To Use Additive EQ
• When Not To Use Additive EQ
• Use Semi-parametric EQ For Additive EQ
• Parallel Additive EQ
• Additive EQ Cheat Sheet

What is Additive EQ

Additive EQ, at its core, is a method of sculpting sound by selectively boosting specific frequency bands using an equalizer. Unlike its counterpart, subtractive EQ, which attenuates frequencies to shape the sound, Additive EQ empowers engineers to amplify desired frequencies, accentuating nuances and enriching the sonic landscape. In Additive EQ the audio frequencies of an audio source are boosted using an equalizer. 

By employing Additive EQ, engineers can breathe life into audio sources, enhancing clarity, presence, and character. Whether it's emphasizing the warmth of a vocal, accentuating the punch of a kick drum, or enriching the timbre of a guitar, Additive EQ offers unparalleled versatility in shaping sound with precision and finesse.

Through subtle adjustments and meticulous attention to detail, Additive EQ transforms the ordinary into the extraordinary, imbuing audio productions with depth, dimension, and vibrancy. By accentuating specific frequency bands, Additive EQ empowers engineers to sculpt the sonic landscape with precision and finesse, enriching the mix with enhanced clarity and presence. This also helps to accentuate the frequency bands that you want to be more prominent in the mix.

How To Do Additive EQ In a Mix

Mastering the art of Additive EQ requires finesse, attention to detail, experimentation and practice. Here's a step-by-step guide to executing Additive EQ in your mix:

1. Select the Right Equalizer: Begin by inserting an EQ into the signal chain of the sound source. Opting for a semi-parametric equalizer, such as the revered SSL EQ, offers the advantage of predefined Q values, facilitating broader bandwidth adjustments essential for Additive EQ.

   Example: When enhancing the clarity of a vocal track, consider using a semi-parametric EQ to isolate the presence frequencies (typically around 5kHz to 10kHz) and gently boosting them to accentuate articulation and intelligibility without introducing harshness.

2. Identify Target Frequencies: Determine the frequencies you intend to enhance, whether it be the fundamental frequency or harmonics, to achieve the desired tonal balance and character. Frequency identification takes practice. The more you mix the better you get at it. Key is to keep your mixing end goal in mind and accordingly work on the areas require a boost.

   Example: When sculpting the tone of an electric guitar, listen for the fundamental frequencies (around 80Hz to 200Hz) to enhance its body and weight, or focus on the upper harmonics (around 2kHz to 5kHz) to add sparkle and presence to the sound.

3. Exercise Restraint: Start with subtle boosts, typically ranging from 1.5 dB to 3 dB, and meticulously evaluate the impact on the mix. Incrementally adjust the boost level, ensuring cohesion with other elements while avoiding sonic clutter or phasing issues. Another way to do a boost is to boost by 9db to 15db and reduce from there to levels that are acceptable. Experiment and figure out which approach works for you.

   Example: When enhancing the punch of a kick drum, begin with a modest boost in the low-end frequencies (around 60Hz to 120Hz) to reinforce the thump without overpowering the mix. Gradually increase the boost until the kick drum sits well within the mix, complementing other elements without dominating the frequency spectrum.

4. Course Correction: If Additive EQ introduces adverse effects or compromises mix integrity, consider employing subtractive EQ and avoid additive EQ. Remember, in most scenarios moderation is key with additive EQ. Restraint ensures Additive EQ enriches without overshadowing the mix.

   Example: If boosting the high frequencies of a cymbal results in harshness or sibilance, use subtractive EQ to attenuate specific problem frequencies (such as around 3kHz to 8kHz) while preserving the overall tonal balance and clarity of the mix.

5. Compensate for Gain Changes: Account for input to output gain adjustments resulting from Additive EQ modifications, maintaining overall mix coherence and balance.

   Example: After boosting the midrange frequencies of a piano to enhance its presence, adjust the output gain to ensure that the instrument remains appropriately balanced within the context of the mix, neither overpowering nor receding into the background.

When To Use Additive EQ

Additive EQ is better to use when you wish to accentuate a particular frequency band in a sound. It helps boost the frequency bands and makes them more audible.

E.g., if you wish to increase the presence of a vocal, try boosting 10kHz above the region using a high shelf filter.

Below are certain scenarios where Additive EQ might be suitable and help in serving the mix:

1. Frequency Enhancement: Additive EQ shines brightest when you need to accentuate specific frequency bands to enhance clarity, presence, or character in individual tracks or the overall mix. Use it to boost frequencies that contribute positively to the desired sonic aesthetic without overpowering or overshadowing other elements.
   
   Example: In a dense mix where the vocals lack clarity, use Additive EQ to boost the presence frequencies (around 2kHz to 5kHz) to enhance articulation and ensure the vocals cut through without overpowering other elements.

2. Targeted Emphasis: When certain instruments or vocals need to cut through the mix or stand out in a crowded arrangement, Additive EQ allows you to selectively boost frequencies that highlight their unique qualities. Use it to emphasize the brilliance of vocals, the warmth of guitars, or the punch of drums, ensuring they remain prominent without compromising overall balance.
   
   Example: When mixing a rock track with a prominent guitar solo, apply Additive EQ to emphasize the midrange frequencies (around 800Hz to 2kHz) of the guitar to ensure it stands out and commands attention amidst the instrumentation.

3. Tonal Sculpting: Additive EQ offers a versatile tool for sculpting the tonal balance of individual tracks or entire mixes. Use it to shape the timbre and texture of instruments, enhancing their sonic character to suit the genre or mood of the composition. Whether it's adding sparkle to high frequencies, depth to low-end resonance, or body to midrange warmth, Additive EQ empowers you to craft captivating sonic landscapes with precision and finesse.
   
   Example: In a jazz composition featuring upright bass, use Additive EQ to accentuate the low-end frequencies (around 80Hz to 120Hz) to enhance the instrument's warmth and resonance, contributing to the overall depth and richness of the arrangement.

4. Creative Expression: In addition to corrective or corrective purposes, Additive EQ can serve as a creative tool for experimentation and exploration. Use it to push the boundaries of conventional sound design, introducing unique textures, colors, and dynamics to your mixes. By thinking outside the box and embracing unconventional approaches, you can unlock new realms of sonic possibility and innovation
   
   Example: Experiment with Additive EQ on synthesized textures in an electronic music production, boosting unconventional frequency ranges to create otherworldly timbres and textures that push the boundaries of conventional sound design.

5. Strategic Application: While Additive EQ offers significant potential for sonic enhancement, it's essential to apply it judiciously and in moderation. Avoid overloading the mix with excessive boosts or indiscriminate frequency adjustments, as this can lead to sonic clutter, phase issues, and overall imbalance. Instead, exercise restraint and discretion, focusing on subtle adjustments that complement the mix's natural dynamics and musicality.
   
   Example: When mixing a dynamic orchestral arrangement, employ Additive EQ sparingly on individual instrument  or section bus, focusing on subtle boosts to highlight key harmonic frequencies while preserving the natural balance and coherence of the ensemble.

An important thing to consider while doing additive EQ is that additive EQ decreases headroom and may emphasis phasing issues if not done right. If it is done wrong it will make your mixes sound cluttered.

It is better to consider doing additive EQ as a creative process. This means using additive EQ to change the tonality and playing around with the sound pallet. If you wish to clean up a mix or make space, you are better off with subtractive EQ.

When Not To Use Additive EQ

Additive EQ is a powerful tool for enhancing specific frequency bands and accentuating desired sonic characteristics. However, it is essential to recognize situations where Additive EQ may not be the optimal solution:

1. Frequency Overload: When multiple elements within the mix occupy similar frequency ranges, indiscriminate boosting with Additive EQ can lead to frequency overload and sonic clutter. In such cases, prioritizing subtractive EQ to carve out space for each element may yield better results.
   
   Example: In a dense mix featuring multiple keyboard layers, indiscriminate boosting of the midrange frequencies (around 500Hz to 2kHz) with Additive EQ can lead to frequency overload, causing muddiness and masking of other instruments. Instead, use subtractive EQ to carve out space for each keyboard layer, ensuring clarity and separation within the mix.

2. Phase Interference: Excessive boosting with Additive EQ can introduce phase issues, especially when applied to multiple tracks simultaneously. This can result in a loss of clarity and coherence in the mix. Exercise caution and use Additive EQ sparingly to minimize phase interference.
   
   Example: When mixing a complex arrangement with layered guitars, excessive boosting of high frequencies (around 5kHz to 10kHz) on each guitar track with Additive EQ can introduce phase issues, resulting in a loss of clarity and definition in the overall guitar sound. To minimize phase interference, use Additive EQ sparingly and consider using complementary EQ settings on different guitar tracks to maintain coherence in the mix.

3. Mix Imbalance: In mixes already characterized by an imbalance of frequencies or tonal inconsistencies, indiscriminate use of Additive EQ may exacerbate existing issues rather than resolving them. Prioritize corrective measures such as gain staging, panning adjustments, or re-recording problematic tracks before resorting to Additive EQ.
   
   Example: In a mix where the bass guitar dominates the low frequencies, indiscriminate boosting of the kick drum's low-end frequencies (around 60Hz to 120Hz) with Additive EQ may exacerbate the mix imbalance, overwhelming other elements and causing a lack of clarity in the low end. Instead, address mix imbalance issues through careful arrangement, level adjustments, and selective EQ cuts before resorting to Additive EQ.

4. Dynamic Range Compression: When applying heavy dynamic range compression to individual tracks or the overall mix, excessive boosting with Additive EQ can amplify noise and artifacts, diminishing overall sound quality. Consider optimizing dynamic range compression settings before resorting to Additive EQ to maintain clarity and fidelity.
   
   Example: When mastering a heavily compressed rock track, excessive boosting of the high frequencies (around 10kHz to 20kHz) with Additive EQ can accentuate noise and artifacts introduced by the compression, resulting in a harsh and fatiguing sound. Prioritize optimizing dynamic range compression settings to achieve the desired balance and clarity before applying Additive EQ to avoid amplifying compression-induced artifacts.

5. Genre Considerations: Certain musical genres, such as classical or jazz, may require a more transparent and natural sound aesthetic. In these cases, subtle adjustments with Additive EQ may be more appropriate than aggressive frequency boosting to preserve the authenticity and integrity of the performance.
   
   Example: In a classical orchestral recording, where transparency and natural sound are paramount, aggressive boosting of specific frequency bands with Additive EQ may disrupt the delicate balance and timbral integrity of the ensemble. Instead, focus on capturing the inherent qualities of the instruments and performance through careful microphone placement and minimal processing, using Additive EQ only as needed to enhance subtle nuances without compromising the authenticity of the performance.

Use Semi-parametric EQ For Additive EQ

Even though you can use a parametric equaliser or any other equaliser for additive EQ, consider using a semi-parametric EQ for the same.

Semi-parametric EQs offer a balance between flexibility and simplicity, making them ideal for precise frequency manipulation during Additive EQ processes. Using a semi-parametric EQ will provide you with preset bands and a better workflow for additive EQ. This also reduces the chances of error while doing additive EQ.

Here are some recommended semi-parametric EQ plugins along with brief explanations to aid you in selecting the most suitable tool for your projects:

1. SSL Waves:

   • Description: The SSL Waves EQ plugin faithfully emulates the renowned SSL G Series EQ, renowned for its transparent sound and musicality. With intuitive controls and versatile parametric bands, it provides precise control over frequency shaping, making it a favorite among professional engineers for Additive EQ tasks.
   • Link: Plugin Boutique

2. Black Tone:

   • Description: Black Tone EQ is revered for its analog-style warmth and character, reminiscent of vintage hardware equalizers. Featuring semi-parametric bands with adjustable Q values, it offers a unique sonic coloration that adds richness and depth to audio sources, making it an excellent choice for enhancing tonal balance during Additive EQ.
   • Link: Plugin Boutique

3. API:

   • Description: The API EQ plugin faithfully emulates the classic API 550B EQ, renowned for its punchy sound and musical EQ curves. With semi-parametric bands optimized for Additive EQ tasks, it offers a wide range of sonic sculpting possibilities, from subtle tonal enhancements to bold frequency boosts, making it a versatile tool for professional audio production.
   • Link: Plugin Boutique

Each of these semi-parametric EQ plugins offers unique sonic characteristics and workflow advantages, catering to different preferences and production requirements. By exploring their features and capabilities, readers can select the most suitable semi-parametric EQ for their Additive EQ tasks, ensuring optimal results in their audio productions.

If you can use a hardware equaliser for additive EQ, definitely go for it. Using hardware emulations or actual hardware EQ will also add the analogue saturation that can bring out the character and also add warmth to your mixes.

Parallel Additive EQ

Paralled Additive EQ is an advanced method for achieving desired tonal enhancements while preserving the original signal integrity. By routing an EQ to an auxiliary channel, engineers retain control over the degree of enhancement, opening avenues for experimental sonic manipulation without sacrificing fidelity. Most engineers will use an aux channel for additive EQ purposes. This will keep the original signal unaltered and provide an engineer with more control over the blending of any alterations you make.

Unlocking a realm of creative possibilities, the parallel Additive EQ technique empowers engineers to blend alterations seamlessly while preserving the integrity of the original signal.

Steps To Do Parallel Additive EQ:

1. Add an EQ to an aux channel. I prefer using semi-parametric EQ like SSL.
2. Make the desired EQ changes and mix them according to taste with the original signal. This can open up new creative doors for any given sound in a mix.
3. Adjust levels of the AUX channels as desired.

So, if you wish to go extreme with additive EQ to manipulate sounds without losing the original signal, try the parallel EQ trick. It can be used for individual instruments, vocals or a bus.

Before-and-After Comparison:
Example: Start with a dry vocal track lacking presence and clarity. Apply Additive EQ to the vocal track directly, boosting the high frequencies to enhance brightness and articulation. Then, duplicate the vocal track and route it to an auxiliary channel with the same Additive EQ settings applied. Blend the EQ-processed vocal with the dry vocal using the auxiliary send, adjusting the level to achieve the desired balance. Compare the before-and-after results to hear how the parallel Additive EQ technique enriches the vocal with enhanced presence and definition while maintaining its original character.

Audio Example:
Example: Provide an audio clip showcasing a guitar track with Additive EQ applied directly to emphasize the midrange frequencies and enhance its warmth and richness. Then, demonstrate the parallel Additive EQ technique by routing the guitar track to an auxiliary channel with the same EQ settings applied. Play the processed guitar track alongside the dry guitar track to highlight the subtle tonal enhancements achieved through parallel processing, emphasizing the depth and dimensionality of the sound without sacrificing clarity or dynamics.

Additive EQ Cheat Sheet

Explore the boundless potential of Additive EQ across various audio elements. Below is a cheat sheet to quickly get started with additive EQ.

• Vocals: Enhance vocal clarity and presence by boosting select frequency ranges, elevating performance intensity and articulation.
• Bass: Enrich bass timbre and depth, accentuating fundamental frequencies for a robust, commanding low-end foundation.
• Kick: Heighten kick drum impact and definition, amplifying low-end thump or high-end attack to cut through the mix with authority.
• Guitars: Sculpt guitar tone with precision, emphasizing harmonic richness or transient clarity to suit genre aesthetics and mix context.

Instrument	Frequency Range	Additive EQ Outcome	Additive EQ Tip	Best Suitable Plugin
Vocals	80Hz - 200Hz	Enhanced warmth and body	Pay attention to low-end rumble. Use a high-pass filter if needed.	Waves SSL
	500Hz - 2kHz	Improved clarity and presence	Watch out for boxiness. Cut frequencies below 300Hz if necessary.	Waves SSL
	5kHz - 10kHz	Enhanced articulation and air	Beware of sibilant sounds. Use a de-esser plugin if required.	Waves SSL
Bass	40Hz - 80Hz	Increased low-end depth	Beware of phase cancellation issues. High-pass filter before boosting.	Black Tone
	80Hz - 200Hz	Enhanced warmth and resonance	Experiment with dynamic EQ to control excessive resonance.	Black Tone
	200Hz - 500Hz	Improved midrange presence	Avoid muddiness. Cut frequencies below 100Hz if necessary.	Black Tone
Kick	40Hz - 80Hz	Enhanced sub-bass thump	Use a high-pass filter to attenuate unnecessary low-end rumble.	API
	80Hz - 200Hz	Increased low-end punch	Experiment with transient shaping to control excessive sustain.	API
	2kHz - 5kHz	Heightened attack and definition	Be mindful of boxiness. Cut frequencies below 1kHz if required.	API
Guitars	80Hz - 200Hz	Enriched low-end resonance	Experiment with amplifier and cabinet simulation plugins first.	Black Tone
	200Hz - 500Hz	Enhanced body and warmth	Beware of muddiness. Cut frequencies below 100Hz if necessary.	Black Tone
	800Hz - 2kHz	Improved midrange clarity	Experiment with dynamic EQ to control excessive resonance.	Waves SSL
	5kHz - 10kHz	Enhanced presence and sparkle	Be cautious of harshness. Use a high shelf filter for subtle boosts.	Waves SSL

In conclusion, Additive EQ stands as a quintessential technique in the audio engineer's repertoire, offering a gateway to sonic refinement and creative expression. Armed with the knowledge gained from this article, I encourage you to apply Additive EQ techniques in your own projects and continue exploring the art of audio production. By mastering the nuances of Additive EQ, you can unlock new possibilities and elevate your mixes to new heights of sonic excellence.