Knowledge · Blog · Sound Techniques

Mixing & Mastering —
Sonaxis Knowledge

We regularly share our techniques, tips and reflections on the history and evolution of the arts of sound — from analogue mixing to digital tools, from plate reverb to artificial intelligence. A space for transmission, by practitioners for practitioners.

Franck Pasquotti, sound engineer
Franck Pasquotti Sound Engineer · Founder Sonaxis Studio · 25 years of expertise
8
Published articles
25+
Years of practice
500+
Projects mastered
192k
Hz high definition

All articles

Click on a title to read the full article. Each article closes automatically when you open another one.

Mixing and audio mastering are two fundamentally distinct stages in the music production chain, and confusing them is one of the most frequent mistakes made by artists approaching professional production.

Mixing involves adjusting the sound levels, panning and effects of each element of a song to create coherence and sonic homogeneity. It is a sculpting exercise on the raw material of recorded tracks. Mastering, on the other hand, aims to prepare the final stereo track for distribution by adjusting overall levels, equalisation and compression to improve sound quality and compatibility with different media — streaming, CD, vinyl, broadcast.

Why a sound engineer? An experienced engineer has the skills and tools to achieve the best results. They master sound quality standards, distribution formats (Spotify LUFS, Apple MFiT, DDP for CD) and know how to use equalisation, compression and limiting to improve clarity and power without losing dynamics.

The quality of converters is essential — they convert digital signals into analogue signals for faithful reproduction on speakers. At Sonaxis, we use the Prism Lyra 2 and Lavry DA10, two absolute references in the field. The Klein & Hummel O 300 monitoring speakers guarantee faithful reproduction across the entire frequency spectrum, and the acoustic treatment of the room, designed with Gérard Lavigne, allows for precise and reliable sound decisions.

In summary: entrust your mixing to someone who understands the artistic intention of your music, and your mastering to someone who knows the technical requirements of each distribution platform. Ideally, the same person — for total coherence from start to finish.

Franck Pasquotti · Sonaxis Studio
Request a mixing / mastering quote →

An effective audio mix rests on five fundamental pillars. Here is how to master them:

  1. Level balance — every element must be audible and balanced. No instrument should mask the others without artistic intention. Start with a static mix before automating.
  2. Clarity — each instrument must occupy its own frequency space. Subtractive equalisation (cutting rather than boosting) is the most powerful tool for creating definition.
  3. Dynamics — a good mix breathes. The balance between quiet passages and intense moments maintains the listener's interest. Volume automation is your best ally.
  4. Spatial placement — use panning and reverb to create a wide, immersive soundscape. Place each instrument in a space that is coherent with the artistic intention of the track.
  5. Multi-system listening — test your mix on headphones, small speakers, in the car, on a phone. A good mix works everywhere.
Franck's advice: I advocate intuitive listening and experimentation rather than the strict application of rules. Connect emotionally with the music you are mixing. Take regular breaks — ear fatigue is the number one enemy of a good mix. Come back to your mix with fresh ears and you will immediately hear what is wrong.

It is crucial to work in an acoustically treated environment. Without this, you are making decisions based on acoustic artefacts of the room, not the real sound. This is the raison d'être of our studio — offering an absolute reference environment for reliable sound decisions.

Franck Pasquotti · Sonaxis Studio
Have your project mixed →

Creating depth and dimension is one of the most subtle skills in mixing. A flat mix, without depth, sounds as if all the instruments are placed at the same spot, at the same distance. Here are the techniques to remedy this.

Level control

Louder instruments seem closer, quieter ones more distant. This is the basis of sonic perspective. But beware: an instrument that is too loud masks the others — the art lies in the balance.

Stereo panning

Panning places instruments in left/right space. But front/back space is created differently — with reverb and delay. An instrument with little reverb seems close, an instrument drenched in reverb seems distant.

Reverb and delay

The most effective reverb plugins for creating depth include the Waves H-Reverb and SuperTap. These tools allow you to create realistic virtual spaces. An advanced technique involves using acoustic space modelling plugins to simulate the acoustics of different concert halls — cathedral, jazz club, recording studio — and thus blend different sources into the same coherent space.

Practical tip: Send your tracks into 2 or 3 different reverbs (a short one for close elements, a medium one for mid-range, a long one for ambient elements). This hierarchy instantly creates a realistic sense of depth. Also use a slight pre-delay (15–30ms) on your reverbs so as not to drown the attack of the instruments.

According to Mike Senior's book Mixing With Your Mind, the combined use of delay and reverb is one of the most effective approaches to enriching a mix. The key is consistency: all sonic spaces must seem to belong to the same acoustic universe.

Franck Pasquotti · Sonaxis Studio
Work together →

Plate reverb processors are among the most iconic pieces of equipment in the history of sound recording. Their story begins in the 1950s with an invention that would revolutionise the way sound engineers create space in their mixes.

The EMT 140 — the original legend

The EMT 140, developed by the German company Elektromesstechnik (EMT), was the first commercially viable plate reverb processor. Its principle is remarkably simple yet ingenious: a thin steel plate suspended in a frame is excited by a transducer (like a loudspeaker), and two contact microphones capture the resulting vibrations. These vibrations create a reverb of incomparable richness and density.

The EMT 140 weighed nearly 270 kilograms and occupied an entire room. Despite this — or rather because of it — it became an absolute standard in the world's greatest recording studios, from the Beatles to the Rolling Stones, from Phil Spector to Quincy Jones. Its unique sonic character, at once dense and transparent, remains unmatched.

Personal experience: I had the pleasure of using the Arturia Plate-140 on the vocals of singer Caroline Joy Clarke for the last album I produced, Dust Opéra. The warmth and density of this virtual tool brought exactly the dimension I was looking for — an organic presence without the heaviness sometimes associated with large digital reverbs.

The Arturia Plate-140 — the digital resurrection

Arturia, the French company specialising in virtual instruments, has produced a remarkably faithful emulation of the original EMT 140 with its Plate-140. This plugin models not only the acoustic characteristics of the original plate, but also offers two other types of plate reverb, thus providing a very complete sonic palette.

Its main features: an integrated tube preamp to add subtle harmonic saturation, pre-delay controls, high-pass filter, modulation and sonic contour. The interface is intuitive and the presets provide an excellent starting point.

I invite you to try it without limits — its versatility constantly surprises. On vocals, of course, but also on drums, acoustic guitars, or even entire mixing buses.

Franck Pasquotti · Sonaxis Studio
Discuss your project →

Saturation is one of the most powerful and most misunderstood tools in modern mixing. Far from being mere distortion, saturation well applied brings warmth, roundness and presence to a signal, reproducing the sonic characteristics of analogue equipment — tape recorders, mixing consoles, tube preamps.

I regularly recommend it to those who want to enrich the texture of their instruments without resorting to heavy dynamic processing. It is often the difference between a mix that "sounds" and a mix that remains clinically correct but lifeless.

The BlackBox HG-2 — my reference tool

Among the saturation plugins I use regularly, the BlackBox HG-2 holds a special place. It emulates "creamy" tube and transformer sounds with remarkable precision. Its architecture is particularly well thought-out:

  • Pentode and triode tubes in series — two distinct characters: the pentode brings clarity and presence, the triode a rounder, more enveloping warmth. You balance the two to your taste.
  • Density control — pushes both tubes simultaneously without altering their balance or the output level. More roundness and mass without audible compression.
  • Calibration menu — simulates the effect of an internal adjustment of original equipment, modifying the high-frequency response for a darker, normal or brighter colouration.
  • Air button — adds airy high frequencies, ideal on vocals, strings, piano or complete mixes to bring "presence without aggression".
  • Mix control (parallel) — allows blending the processed signal with the dry signal, combining tube warmth with the precision of the original signal.
Usage tip: Use the HG-2 in parallel (mix at 30–50%) on your drum buses to add warmth without compromising dynamics. On vocals, triode mode with a touch of "dark" calibration can transform an ordinary recording into something memorable.

This plugin is remarkably accessible despite its depth: the interface is clear, the presets well thought-out. An essential tool in my daily mixing chain.

Franck Pasquotti · Sonaxis Studio
Contact the studio →

Artificial intelligence is profoundly transforming the music industry — and this is only the beginning. As a sound engineer with 25 years of practice, I observe this revolution with both fascination and discernment.

What AI can do in music today

Current applications are already impressive: fully automated music generation, creation of original harmonies and melodies, recognition and categorisation of musical works, translation of scores between formats, stem separation from a stereo mix (Spleeter, Demucs), automated mastering (LANDR, iZotope Ozone AI), personalised content recommendations.

These tools can analyse a user's musical preferences and suggest works consistent with their tastes. They can predict upcoming musical trends and help labels and artists anticipate market developments.

My position: AI is a formidable tool for assistance and exploration — but it does not replace the emotional intelligence of a sound engineer. An algorithm analyses frequencies. A human understands the artistic intention behind each note. This is the fundamental difference that Sonaxis embodies in each of its services.

The real limits of musical AI

Music creation remains above all a human activity that requires passion, inspiration and expertise. AI lacks emotional memory — it does not know that this guitar riff recalls a heartbreak, that this harmonic progression evokes a particular childhood, that this tempo corresponds exactly to the urgency that this artist wants to express.

The challenge for the coming years is to use AI responsibly and equitably, to amplify human creativity without replacing it. The best results will always come from the collaboration between the analytical power of the machine and the irreplaceable emotional intelligence of the human.

Franck Pasquotti · Sonaxis Studio
Emotional intelligence at the service of your project →

It's the most universal complaint in music production. You spend hours on a mix, listen to it on your monitors and it sounds perfect — warm, balanced, powerful. Then you send it to a friend, play it in the car, listen on headphones on the tube, and suddenly it sounds hollow, muffled, or worse, harsh and thin. What happened?

The short answer: you're not listening to your mix — you're listening to your room.

The acoustic problem first. An untreated room creates resonances called room modes — frequencies that build up in corners, others that cancel depending on your listening position. If your room amplifies 80 Hz, you'll compensate by cutting the low end. On another system, those lows are missing. You didn't mix the music — you mixed your room's defects.

Here are the five most common causes, in order of impact:

1. Room acoustics. By far the most underestimated factor. Proper acoustic treatment — absorbing panels, diffusers, corner traps — is not a luxury. It's the prerequisite for making reliable sonic decisions. Without it, you're mixing blind.

2. Monitor quality and placement. Listening on €80 speakers or poorly placed high-end monitors amounts to the same thing. Golden rule: tweeters at ear height, equilateral triangle between both speakers and your head, at least 30 cm from the rear wall. And use a proper reference level — not too loud (ear fatigue), not too quiet (low-end loss).

3. No cross-system referencing. A professional never finishes a mix without checking it on at least three very different systems: studio monitors, closed-back headphones, a small mono speaker (equivalent to a Bluetooth or phone). If it sounds good everywhere, it will sound good everywhere. If one system reveals a problem, fix it — don't ignore it.

4. Lack of mono compatibility. Over 50% of music listening today happens in mono — Bluetooth speakers, phones on loudspeaker, pub and shop PA systems. A mix that loses its low-mids in mono has a phase issue. Check systematically in mono by summing your tracks. Elements that disappear have phase problems that need correcting.

5. Streaming platform LUFS normalisation. Spotify, Apple Music and YouTube all normalise files to between -14 and -16 LUFS integrated. If your master is delivered at -8 LUFS (over-compressed, too loud), the platform will turn it down — and that reduction will expose all the dynamic flaws the compression was masking. The result: a flat, fatiguing sound lacking punch. The right delivery level for streaming is around -14 LUFS integrated.

The professional solution. A mastering engineer listens to your mix on several calibrated systems, in an acoustically treated room, making decisions based on what they actually hear — not on the defects of their room. That's precisely why having your mix mastered by someone else, in a different listening environment, is an essential step — even for skilled mixers.

Mastering is the last outside perspective before release. It's a fresh ear, a neutral environment, and 25 years of comparative listening across hundreds of projects. Not a luxury — it's the assurance that your work will be heard the way you intended it.

Franck Pasquotti · Sonaxis Studio
Get my mix mastered →

The question comes up on almost every first contact: "Do you do analogue or digital mastering?" The implicit question: which one is better? The honest answer is more nuanced than most forums will admit — and after 25 years working with both, here's what I've actually observed.

First, let's kill a myth. Digital mastering done by someone who knows what they're doing will always beat analogue mastering done by someone who doesn't. The tool doesn't replace the ear. What follows is about the intrinsic differences between the two approaches — not marketing shortcuts.

What analogue does that digital can't perfectly replicate. When a signal passes through a transformer, a tube or a Class A transistor, non-linear harmonic distortion occurs — essentially even-order harmonics added to the signal in an imperceptible way that creates what we call "warmth". This isn't a defect fixed by digital — it's a colour added by physics. Digital emulations (UAD, Waves, Acustica) get closer every year, but they model an average behaviour — not the exact response of this specific circuit, aged, at this temperature, in this room.

The Sonaxis analogue chain in detail. The signal passes through the Prism Lyra 2 for conversion (one of the world's finest converters — its impact on transparency is immediate and measurable), then through a Pultec clone EQ for gentle tonal sculpting. The Alan Smart C2 compressor brings a subtle glue without crushing the dynamics. The Pendulum OCL-2 — tube and optical — handles transients with a musicality no digital compressor replicates in quite the same way. Finally, the Prism Lyra 2 reconverts to digital for the final limiting and delivery.

What digital does better than analogue. Absolute precision. A digital EQ lets you cut at exactly 237 Hz with a 0.3 dB slope — reproducible identically tomorrow, in six months, across any project. An analogue EQ has component tolerances, thermal drift, a response that varies slightly with supply voltage. For surgical corrections — de-essing, eliminating a precise resonance, notching a problematic frequency — digital is unbeatable. Which is why the modern professional workflow combines both.

The hybrid workflow — why it's the current standard. At Sonaxis, mastering is neither "full analogue" nor "full digital". It's a hybrid workflow where each tool is used for what it does best. Problem corrections (parasitic frequencies, poorly placed transients) happen in the digital domain, with precision. Colour, glue, tonal relief are built in the analogue domain, with the natural harmonics of hardware equipment. The final result is converted and delivered digitally, to each platform's standards.

So, analogue or digital? That's not the real question. The real question is: does the person mastering your project have a calibrated ear, a neutral listening environment, and the tools suited to your musical style? Everything else is technique in service of artistic intention.

If you want your master to sound like a master — warm without being soft, precise without being cold, loud without being crushed — the technical chain matters less than the experience of the person using it. But if you're choosing between purely digital mastering at an equivalent budget, the hybrid analogue chain will almost always provide that last centimetre of relief that plugins alone don't yet deliver.

Franck Pasquotti · Sonaxis Studio
Request an analogue master →

Your project deserves an exceptional ear

25 years of expertise at the service of your music. Mixing, analogue mastering, recording — studio sessions in Bagnolet or online from anywhere in the world.

Book a session → View rates →