Frequently Asked Questions


What is Mastering?

Mastering is considered the last creative step in the production of a piece of audio. Mastering uses a number of creative practices in order to shape a source in accordance with the strengths and limitations of the target medium (vinyl, streaming, Apple Digital Masters etc) whilst enhancing and augmenting the listening and tactile experience.

The Mastering process achieve this by modifying the frequency spectrum, altering the dynamics and/or phase content as well as texture.

Furthermore mastering engineers account for the possible differences between tracks on an album in order to make the listening experience more coherent and create appropriate dynamic changes throughout.

Mastering can “correct” aspects of the mix that were overlooked due to imperfect monitoring/acoustics, but is mainly concerned with enhancing a pre-existing musical/sonic intention.

How should tracks be delivered for Mastering?

All songs should preferably be delivered as .wav or .aiff files, in 32 or 24 bit and at the same sample rate as was used during mixing. We support sample rates between 44.1kHz and 192kHz.

All tracks delivered should also not exceed 0dBfs. This is usually indicated by a red lights above your sequencer’s level meters. Also, compression and limiting should not be on the master bus when exporting. You can however send your reference track with compression and limiting to give us an idea of where you are going with the effects.

All uploads for mixing & mastering must occur to no later than 24 hours before scheduled.

Where should my mixes peak before I send them to mastering?

Any level between -8dBFS and -2dBFS is fine. What is important is that there is NO CLIPPING anywhere and no “monomaker” is active.

Do you accept analog formats?

We do accept analog formats like 1/4 inch and 1/2 inch tape but make sure to get in touch beforehand so that we can set things up.

I have a reference track I would like you to listen to. Can I include it with my tracks?

Our rule is that reference tracks are fine as long as they have been used as reference during the mixing and/or production process. Also please point out what it is you like about your reference track. Is it the tonal balance? Or perhaps just the loudness?

Please don’t send the music as a file but just include the title, artist and version in an email.

Which mix and mastering engineer will be working on my master?

All mixing and mastering tasks are performed by Joel Krozer. Some assistant work may be done by Mikael Tobias.

Will my song end up being as loud as song “x” after mastering?

Loudness is a balancing act and extreme levels are always a compromise with dynamics and distortion. We will generally push your tracks as far as they can go without any compromise. Some tracks benefit of the density, saturation and dynamic shape loudness processing imprints on a track. It is our job in mixing and mastering to determine if a track will benefit from more or less of these effects and we will only ever add them if they have musical/sonic relevance.

A couple of facts to help demystify loudness:

1. There’s no correlation between sales and how loud your record is.

2.Hyper-compressed material will actually sound weaker over the radio as the broadcast compressors will over process the signal.

3. DJs in clubs adjust the gain manually and more dynamic tracks are known for going off better than very compressed ones on big PA speakers.

4. Loud tracks seem impressive at first but quickly become fatiguing. Listening to an entire album of hyper-compressed music is often found to be unpleasant.

5. Louder tracks are automatically turned down on streaming. This is an oversimplification though. Please also read our FAQ on LUFS to get more info on how loudness translates to streaming.

What is stem mastering?

Stem mastering is a type of finalising of a production where the engineer doesn’t work off a single stereo file but instead a number of groups exported on separate tracks. These are summed together in the mastering session and allows for more control and more precise coloration of the total. Stem masters are charged at a different price so please get in touch with us regarding pricing options. They usually consist of 4 to 12 (maximum 14) channels e.g. kick, snare, percussion, bass, synths, gtrs, lead vocals, backing vocals.

Anything from there onwards is considered a mix.

What are ISRC codes and why do I need them?

ISRC are identification codes for your music. They will become useful to your national royalty association for keeping track of where and how often your music has been played.

Once you have acquired your code you can easily modify it yourself for future releases. The code consists of 12 characters, “OO-XXX-YY-NNN-TT” where “OO” stands for the country of origin of the submitter , “XXX” the personalized code you received, “YY” the year of registration, “NNN” the release number and “TT” the track number.

ISRC codes should preferably be supplied prior to the mastering session.

How long until I receive my final master?

If you attend the session, you’ll receive your master disk or files immediately after your session.

If the entire process is handled online you will receive your files on the day that has been specified to you in you first email correspondence with us, or at the latest the day after.

What format will my final master be in?

The final master will be delivered as optimised wav files for streaming or a DDP file. We also specialise in vinyl masters i.e. masters optimised for vinyl cutting. These will also be sent as .wav files, either as individual or per side consolidates, depending on the manufacturers preference.

What is DDP?

Think of the DDP file as the master disk on your computer. It contains all of your tracks in the correct order including all crossfades, ISRC codes, PQ codes etc.

What if I would like a revision?

All tracks have revisions until LIM3 included in the price. Further revisions require a surcharge. New files provided to us after the work has been completed is to be charged an extra fee. Our work is so detail oriented that we can’t simply apply the same settings to an alltered mix.

How can we get you paid?

Please provide us with your invoice details including name, company name, address, email and phone number and we will send you an invoice at the end of the process. We prefer bank transfer. For clients from abroad we highly recommend Transferwise which is much cheaper than bank transfer and very fast to set up and send.

There is a mistake on our master. How do we solve this?

Glitches are rare but no machine in the world is perfect and we are also only humans after all. It is therefore very important that you thoroughly listen to all your masters before sending them off to the pressing plant/iTunes/etc. We assume no responsibility for masters that were sent off to manufacturing without your final approval and your not compensated for any damages caused by this.

We are however very solution oriented and will do everything in our power (obviously free of charge and asap) to correct any errors or glitches that could have appeared during mastering. Luckily this rarely ever happens.

What are LUFS and at which LUFS will my track be after mastering?

LUFS is a unit of dB intended to measure perceived loudness. Streaming services currently measure LUFS integrated levels to determine the amount of dB a track should be turned down or up in order to create a continues loudness stream between songs on playlists. This compensative process is not destructive, it is a mere gain adjustment, that ensures the listener has as uniform an experience as possible. It has helped to counteract the so called ‘loudness wars’ by securing no song will play back louder than any other, by simply turning down hyper compressed, loud, shrill songs more than quieter ones.

It is not necessary for the artist to be concerned about LUFS, LUFS is here to help not to hurt.

We have developed techniques to ensure our masters work with and not against LUFS measurements. We will never default to any loudness adjustment at the expense of musicality though. Therefore there is no answer to the question of which LUFS level is best. We test out a number of settings and let the material determine the optimal level.

Note: Loudness match on streaming services like Spotify and Apple Music is intended to work as follows: Every album gets a loudness score and each song on that album gets a loudness score. All songs on the album will be turned down the same amount to ensure songs intentionally mastered louder or quieter remain that way. When a song is put on a playlist it is the songs own loudness score that determines its level.


What is mixing?

Mixing is the the process of balancing, spatial placement and processing of timbre, phase and dynamics of a recording to enhanche the sources musicality, sonics and intention. It is the part of the record production process that occurs after the recording and before the mastering of a record. Mixing can be anything from minor tonal changes of the recording to a complete sound overhaul, depending on the desire of the artist and what the music itself demands. The final result of a mix is always dependent on the quality of the arrangement, recording and sound design done prior to it. In simple terms, a good mix enhances depth in a way that allows the listener to step into the song, instead of only observing it from the outside. It plays with contrasts to achieve a more tangible experience, enhances the beautiful and amplifies the ugly – makes the valley deeper, the peaks higher, the horizon wider whilst making narrow even more claustrophobic. A good mix can amplify clichés and genre specific characteristics or break them and defy the norm, depending on the intention of the artist and the engineer and producer.

Joel has mixed a number of songs we like. Can you make it sound like song x?

Yes and no. We can adopt certain characteristics from other tracks but it should never be an ambition to sound like another track for two reasons. 1: it is creatively uninteresting. 2: It is not possible for the most part as other tracks sound the way they do not just due to the mix but also the composition, arrangement and most importantly production and sound choice.

What we can however do (on some occasions) is adopt a characteristic off another song such as a thick sub bass, or a vocal reverb effect. Therefore you must specify precisely what it is you think we should reference.

How many revisions can we do to a mix without extra charge?

All revisions up to LIM3 are included in the price.

Are instrumental versions included in the mix price?

Yes. Although not in the stem mix/mastering or mastering price.

Are mixed stems (after project is completed) included in the mix price?

No. These are charged separately. Please write us for an offer from the beginning for the best price.

How should I supply files to you for mixing?

We have a detailed form that we can send you for this specific purpose. Please get in touch.

We didn’t follow the mix form. Can you just do the mix anyway?

We really need you to follow the form unfortunately. This saves us a lot of time and will improve your mix radically as it will allow us to focus on the music, not on the practicalities around it.

What kind of tools do you use for mixing?

All mixing is done in a hybrid fashion using the best tools of both worlds. Our studio has a huge array of colours form vintage Pultecs to modern Shadow Hills gear as well as an array of clean surgical tools. Some mixes require little colouring others need loads to – we pick our tools on a case by case basis.

Can we attend the mix session?

All mixing is unattended here. Upon agreement, attended revision sessions may be possible.

Vinyl Mastering, Cutting and Pressing

How is vinyl made?

Please note that the following is a simplified description of the process.

The vinyl mastering and manufacturing process can be looked at as a 4 step process.

1. The creation of a vinyl premaster file – sometimes identical to digital master, sometimes different depending on program material)

2. The cutting process – This is ideally done at a cutting house and not at a manufacturing facility (pressing plant). Cutting engineers take our files and cut them onto a lacquer disk that is then sent off for pressing at the pressing plant.

3. The pressing plant – They create test presses that simulate how the final product will sound and ship it to your address.

4. Upon approval of your test press, the pressing plant replicate your record the specified amount of times and ship the result inside the sleeves that you picked out.

Is Six Bit Deep able to handle this process for me?

We are able to handle steps 1 and 2 (see above info) for you entirely. This will yield the best result as we only work with the best cutting engineers around and are able to get better availability and prices through them. The price of handling all this depends on the size of the project. Get in touch for a quote.

My record does not sound as loud as other records. Can you make it louder?

The loudness of a record is not determined by how much limiting and compression we apply, unlike digital masters. A loud cut is done by the cutting engineer and a good one can always work with a good sounding master. The cutting engineer does however have limitations and they are the biggest determining factor when it comes to loudness:

– Playing time 12″ 33 1/3rd RPM is ideal at 12-16 minutes length and 12″ 45 RPM is ideal at 6-9 minutes length (depending on the amount of low end energy). Longer playing times are possible but will decrease loudness significantly. Cutting around 6 minutes per side at 45 RPM will yield the loudest possible master!

– high end information in a mix. Mixes with a lot of high end will need to be reduced in volume in order to be cut without distortion, alternatively high end can be reduced for a cut without distortion at the expense of fidelity and transients

– mixes with excessive transients will need to be reduced in volume or compressed more in order to avoid saturation in the cutting stage.

My vinyl is distorting on cymbals or ‘s’ sounds. How come?

This is a common issue on old turntable pickups. Make sure to listen on several systems that have a good clean modern stylus!

If the problem persists, you need to contact the cutting engineer and explain this problem. They should provide you with a new cut that does not distort. Please be detailed in your descriptions.

There are a lot of crackles and pops on my record. How come?

This problem could also be your playback system. Listen on several systems and compare to other records. Good cutting engineers use high end Japanese lacquers that have a low noise floor. Some crackles can however not be avoided. If they indeed are excessive it could be a fault with the pressing plant also. The only way to find out is to communicate with both and ask to have a listen to the test cuts (not test press).

Do I really need test presses? I hired the best team in the world!

Oh yes you do. The process is of manufacturing vinyl is sensitive and the money you spend on test presses will pay off in the long run!

Can I have my money back if I am not happy with the result of the vinyl?

Cutting engineers and pressing plants have a responsibility to deliver a quality product. So yes if they commit grave errors and do not try to rectify them it is our opinion that you should have your money back from them. Things you are unhappy with that are a matter of taste or a limitation to the medium should not be reimbursed by them.

The way we work is on the basis of approval. If you are happy with the way our masters sound and the cutting engineer commences working on it without protest we consider the files approved and therefore do not assume any responsibility. We do however take pride in our work and can therefore advise you on how to proceed if your record is sub-par.

My artwork came out looking different than expected. What to do?

This is something you should take up with the pressing plant. We are not able to help with this process as it is an error in step 3 of the vinyl manufacturing process (see above info).

Can’t I just let the pressing plant handle the cutting?

In our experience no! Cutting is a very different process to pressing and requires specific skills and not least rare and expensive tools that hardly any pressing plant owns. Find a good cutting house or let us help you.