XARC Mastering - The Online Mastering Studio
faq - Frequently asked Questions
Mastering Glossary


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What We Do


All material is analyzed, evaluated and mastered with the assistance of our high-resolution KRK monitoring system, in a completely optimized room. By combining our advanced technology, innovative mastering techniques, and truly exceptional skill, we consistently produce results of only the very highest quality.

We invite you to explore various aspects of our mastering services. You may read more from each entry below, by clicking each service title:


Vinyl & CD Mastering
Perfecting Stereo Image
Dynamic Enhancement
Harmonic Enhancement
Bringing the Level Up
Transparent Limiting
Applying Best Dithering
High Resolution Processing
Providing CD Image / Shipping
Including PQ Sheet
Preparing for Internet

Vinyl & CD Mastering

cdWhether you wish to release your material on CD or Vinyl (or both), our mastering for both medias demonstrates our uniquely high quality.

We are also one of very few mastering studios that deliver Vinyl masters at 24-bit, 88,2kHz resolution -- enabling the use of the complete available dynamic and frequency range of the medium.

Presenting particularly good examples of our mastering for CD and Vinyl are the following before/after demos:

Demo: Tico Da Costa - Lagartixa - Brazilian (5 tracks of album)
Unmastered:  MP3 WAV   Mastered:  MP3 WAV  

Demo: Soul Militia - Silence Before The Storm - Pop / R & B (5 tracks of album)
Unmastered:  MP3 WAV   Mastered:  MP3 WAV  


consultingMastering is often a process that requires a significant amount of forethought and planning, even before the engineer's work begins. Knowing this, and because we want to produce only results that perfectly match the vision you have for your music, we are pleased to offer full consultation prior to commencing our mastering work for you.

Some items typically discussed during consulting include:

  • Desires for finished product (i.e. amount of bass, overall loudness)
  • References of other artists' tracks/albums to be used as guideline(s)
  • Possible recommendations of adjustments to your mixdown(s) to ensure a superior final product
  • Any questions about the mastering process


equalizerEnsuring proper equalization is a critical part of the mastering process. In our efforts to ensure your music performs and sounds as well as possible across a broad range of systems, we find and apply the correct spectral balance to your mix. This is accomplished via extensive listening and audiophile-quality equalization.

The "goals" of equalization vary widely, and depend on unique characteristics of each individual track. For example, although many tracks require a "bass lift," just as often we master music that requires bass reduction. Other times, "equalization surgery" is required -- for example, to remove certain disruptive resonances. Two improved frequency response demos are:

Demo: Well Red - Corkonian Brigade -  MP3 WAV  

Demo: Brides in Bloom - Push Comes to Shove -  MP3 WAV  

Soundmatching of your tracks

guitaristOften, even when an artist records tracks intended for the same album, it's difficult to produce a well-matched sound; different locales, equipment, instruments, and even recording on different days can conspire to create a collection of tracks that don't quite fit together as well as possible.

We are very proud of our ability to process your tracks so that they sound like one coherent project, rather than just a collection of songs. To hear some examples of this, feel free to listen to:

Demo: Ashes of Soma - Exit 674 (Rock, 5 Tracks)
Unmastered:  MP3 WAV    Mastered:  MP3 WAV  

Demo: J-Mac! - Everything (R&B, 3 Tracks)
Unmastered:  MP3 WAV    Mastered:  MP3 WAV  

Perfecting the Stereo-Image

speakersAnother important aspect of ensuring a high-quality, mastered final product is ensuring that the stereo image of your mix utilizes the full available stereo range, without causing disturbing out-of-phase content.

For example, some tracks we master require a wide-bass expansion to have improved sound; however, in the case of other tracks (i.e. with mastering for vinyl), bass should be mono.

In other cases, the stereo image requires shrinking, while, conversely, other tracks require extensive widening and sometimes even multi-band widening (e.g. different frequency ranges receive different amounts of widening and shrinking). The intricate detail in this process makes it an area where the expertise and trained ears of the mastering engineer are critical to ensuring a perfect final product.

Dynamic enhancement

waveBy utilizing the latest technologies, we are able to expertly modify the "attack" and "decay" phase of the elements in your mix, further improving the overall final sound of your mastered material.

Also, even if the dynamics and attacks of your track have been flattened (as by a limiter or "high tape-compression,") we are often able to bring your music "back to life."

Harmonic enhancement and Improving Warmth

spectrumIt's often amazing how "full" mastered music can sound -- and it's often in large part due to what we call "Harmonic Enhancement."

Here at XARC, Harmonic Enhancement and warmth improvement is a key part of our mastering process. We often dramatically improve material still further at this stage, by adding new harmonic content to the fundamental frequencies through the use of custom tube equalizers and compressors. The result: fuller music that truly comes "alive."

"[XARC] knows how to uncover and enhance the elusive harmonics that make recordings great. [Their] choices of EQ for our projects were right on and very tasteful. Not too much of any one thing. And he also accomplished sinking the boxy or muddy tones out." -- Jason Benassi, Guitarist/Programmer and Mix Engineer of Magnetic North, USA

Bringing the level up

knobFinely-tuned compression will be used to maximize the average level of your mix, while not squishing attacks or making it muddy and flat. In other words, we can effectively maximize the average level, and bring out small details -- what we like to call "ear-candy."

In any case, a great deal of flexibility is possible -- per our clients' wishes, we can increase loudness, or simply stay more neutral (to create a master with more dynamics).

Transparent limiting

transparent limitingWe also use a very innovative method to retain clarity while still maintaining perceived loudness; this process, which we have termed "Transparent Limiting," delivers tracks with the same perceived loudness as other mastering firms, but with very pleasing, musical limiting that minimizes artefacts and helps to prevent ear fatigue.

"Nothing could be easier or more straight forward than mastering with XARC. The service was professional, friendly and prompt. After making a couple of changes suggested by XARC to the initial pre-mix, the song was mastered and returned in no time at all. The bass was 'tidier' and there is a clarity and presence that has come from nowhere, great work!" -- Michael Tingle, UK

Applying the best dithering

waveformBecause we must convert your project down to 16-bit or 24-bit, we apply what is termed "dithering" at the end of the mastering process. The need for dithering arises because, at low signal levels, there is still a measurable amount of distortion caused by the quantization error becoming correlated to the signal level.

To eliminate this problem, we add random noise to the least significant part of each digital word. This cancels the correlation between the signal level and the quantization error, allowing the digital system to encode amplitudes that are smaller than the least significant part. Although admittedly a technical process, the result certainly isn't -- dither is absolutely required for good digital audio recording and processing.

Read more about dithering in the glossary.


reelWe use the best and newest restoration tools to remove noise and artefacts that your material might contain, whatever their origin.

Some common noise sources include:

  • Tape Recordings
  • Vinyls
  • Guitar Amps
  • Microphones
  • Chains of poorly-constructed analog equipment
  • Spurious room noises

Declicking / Decrackling

groovesIf your mix comes from Vinyl and needs remastering, or if clicks or crackles are present for any other reason, we will make them disappear without leaving any artefacts, nor destroying any musical content.

"The mixes had kept their warmth and detail but was now much louder and more powerful. There was more air in the music and all the clicks, pops and hiss from bad recordings and old vinyl samples were completely gone! It just sounded ace! I believe this is the beginning of a long term relationship." -- Jens Petter Nilsen, Xploding Plastix, Norway


amp50/60Hz humming (and its harmonics) caused by power supplies, guitars/amps, or just bad cable connections will be removed.

One major cause of humming derives from the fact that audio wiring is very susceptible to "ground loops." This can occur, for example, when two pieces of audio equipment are plugged into different power outlets that have a difference in their respective "ground potentials." The result is that if a signal flows from one piece to the other via an unbalanced connection, this potential difference causes a spurious current, in turn creating an audible "hum" at the AC frequency (50 or 60 Hz) and its harmonics (100/120 Hz, 200/240 Hz, etc).

High Resolution Processing

processorAll our processing is done at 64bit Floating Point, 176kHz and is transferred over the best D/A A/D converters.

Some may wonder, "What is floating point?" Simply, it refers to a way of digitally representing, real numbers (typically as a "mantissa" multiplied by a base 2 "exponent"). In the IEEE 754 floating point standard, 64-bit floating point numbers consist of one sign bit (e.g. + or -), 11 exponent bits, and 52 bits for the mantissa.

As for "sampling rate," the technical definition is that it "defines the number of samples per second taken from a continuous (e.g. analog) signal to make a discrete (e.g. digital) signal." All other things being equal, as the sampling rate increases, the digital 'approximation' of the analog signal improves. This is one reason music from a CD (44,1kHz) would normally sound better than music over a telephone (8kHz), even if the same audio equipment was used to listen to the audio.


editingIf you require, we will digitally fade the beginning and end of your tracks, or rearrange whole parts of them.

It thus becomes possible to, for example, swap the first and second chorus components on a track.

Providing CD Image / Shipping

burnerIn addition to receiving your mastered music back as single files, we can also supply you with an image of your Master CD, ready to burn with your favorite CD recording application (for example, programs such as Nero Burning ROM on PCs, or Toast Platinum on Macs). Of course, shipping of your Master CD is also possible via standard mail or FedEx Courier.

Including PQ Sheet

sheetFor every CD image, or snail mail delivered Master CD, you will get a PQ Sheet containing all of the information that the CD manufacturing plant will need for replicating your CD, or for when they transfer to Exabyte.

Some may wonder as to the origin of PQ Sheets. In brief, they are a result of the so-called "Red Book" standard, which defines all aspects of the Compact Disc Digital Audio system. As part of this standard, information other than the bitstreams making up the actual audio/music is digitally encoded onto a CD. This data includes track numbers, times, names, and ISRCs (ISRC = International Standard Recording Code). This is all incorporated into a CD's PQ Sheet.

Preparing for Internet Distribution

mp3 and cdIf you intend to distribute your music via the internet, we can additionally provide you with high quality MP3s of your project. Because we prepare and encode each song with individual settings, you are ensured the very highest quality that is possible within the format.

If you are interested in a bit of further discussion on the topic, please view this blog entry by Lorenz Vauck.

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