What are the payment terms?

All projects are priced individually based on the size of the project. When you give us all details / send multitrack for mixing or a mixed track for mastering, we will come back to you with a quote for your project.

For mixing and mastering services, full fee must be paid upfront, before our engineer starts any work. You will receive the invoice once we examine if your files are ready for mixing or mastering, depending on which service you will hire us for. Payment is accepted only via Direct Bank Transfer.

Should you need more than 2 revisions included within the price, we are happy to continue working on your project but we would charge you an hourly fee based on the size of the project (minimum 1h of work).

For music production, first half of the fee must be paid upfront. Second half must be paid after the production is finished and accepted as final multitrack. You will receive all applicable files after both payments (including any potential revisions) have been made.  For any additional studio engineering you will receive an invoice after each session.
Our engineer / producer 
shall retain all the standard PPL and performance royalty agreements where applicable.

Returns and refunds are not applicable.

How should I prepare my files?

The multitrack that you provide must be ready for mixing (or editing if you choose additional post production service). If your DAW has a   NORMALISE option for bouncing, please make sure to turn if  OFF. Also, please make sure that your tracks are not  clipping before you bounce them out.

 All tracks must be clearly labelled and numbered in the following scheme:

1. Kick in
2. Kick out
3. Snare top
4. Snare bottom
5. OH
6. Room
7. Bass DI
8. Bass AMP
9. Guitar (mic model 1)
10. Guitar (mic model 2)
11. Piano
12. Synth 1
13. Synth 2
14. Lead Vocal
15. Double Vocal
16. Backing vocal

Please note that this is just an example. You can name your tracks the way you like, but please be consistent, make it look clean and label the tracks with numbers as presented above.

Tracks can be mono or stereo.

You must consolidate your session into individual files from the start point of your song, including at least 1 bar of silence before the actual beginning of the song. Ideally the multitrack should not contain effects such as reverb or delay, unless these effects are integral part of the sound (example: guitar pedal fx, creative use of distortion on a synth, etc). Effects such as MELODYNE or AUTOTUNE shall be printed into the vocal tracks. You’re welcome to give us both “clean” and “tuned” version, but must make sure to label them properly.

Please make sure that all of your files are correct before uploading. If you have midi instruments please bounce them as audio – we do not accept midi files for mixing unless you specifically ask us to change certain virtual instruments (which will be charged as additional production on the track).

Feel free to include any mix requests that you have and include a rough mix (if you have one) as a reference.

1. For mixing – we will ask you to send us a folder with the multitracks – we accept the multitrack as  .WAV or .AIFF  files at either 44.1 kHz 48 kHz or 96 kHz  (24 bit or  32 bit). You must ensure that all of your tracks are of the same file type, bit rate and sample rate and that they are included in the folder, which name consist of your artist name, song title, song tempo (BPM) and the date of the upload.

2. For mastering – we will ask you to send us either stereo mix  or mixed stems – we accept the stereo mix or stems as  .WAV or .AIFF  files at either 44.1 KHz 48 KHz or 96 KHz  (24bit or  32bit).  You must ensure that all of your tracks are of the same file type, bit rate and sample rate, and that they are included in the folder, which name consist of your artist name, song title, song tempo (BPM), and the date of the upload.

Your multitrack should be uploaded via  WeTransfer (we choose WeTransfer because their links expire after 7 days, which gives you better protection over your files, making sure they won’t stay on the internet for unspecified amount of time). Should the size of your folder exceed the free transfer of 2GB, please let us know so that we can choose a different methood of file delivery.

Should you have further questions, feel free to  contact us.

What is the review process and what files will I receive?

For mixing and mastering services – you will be able to hear the final mix / master & all revisions on a private link with an audio player accessing the lossless, full resolution WAV File. You will receive all applicable files (details below) after the final mix and / or master is accepted.

If you only apply for mixing service, you will receive .WAV files (24 bit – 48 kHz or native sample rate that the multitrack was delivered at) of:
Full mix
Instrumental mix
Backing track mix

If you apply for mixing and mastering, or just mastering service, you will receive the final masters for:
Streaming (.WAV 24 bit  – 48 kHz if applied for mixing and mastering, or 96 kHz if only applied for mastering)
CD (.WAV  16 bit – 44.1 kHz)
Video Distribution ( 24 bit – 48 kHz)
Instrumental and Backing Track (If provided with this type of mix file) – both  48 kHz if applied for mixing and mastering, or 96 kHz if only applied for mastering.
–  DDPi format (if requested)

Do you deliver mixed stems?

For mixing service, you will not receive mixed stems to assemble the mix from. Due to the use of multiple shared effects, shared parallel compression and complex mix bus processing it is impossible to assemble the same mix from different groups of instruments exported separately. If you would like to receive a customised set of stems for LIVE performances, let us know exactly which tracks from the mix session you would like to receive as individual mixed files.

Should you need additional mix version on top of the initial package we deliver, these would be charged extra £20 if our engineer would have to spend some time on potential editing to make a shorter version of a mix for radio or TV. That would require a little bit of post-production work in order to make smooth transitions between different sections of the songs.

What happens if I loose my files?

We do our best to keep multitracks, mix and mastering sessions as well as all final mixes and masters on external hard drives after the final files have been delivered, however, sessions might get lost (if the computer or external drives require a format without the possibility to recover any files) or the session files might get corrupted, therefore,  it is your responsibility to back up your multitracks / mixes / master files. Once these files have been delivered and paid for, we do not take any responsibility: if you loose them; if the hard drive with backup sessions breaks; if the session file gets corrupted and won’t be openable anymore.

We will not share any of your sessions, audio files, mixes or masters with anyone except you (or any associated person that has been approved by you to receive those files)

In the future, if we would like to use a production / mix / mastering session of your song for educational purposes, we will contact you to ask for your permission (this would only mean showing the content of the session to the potential audience. We are never going to physically share any of your files unless you specifically ask us to do so).

How do I credit your contribution?

You are obligated to include the appropriate credit in relation to any CD or other record that our engineer have recorded, edited, produced, mixed, or mastered, using the following scheme:

Engineering / Editing / Production / Mixing / Mastering (choose the applicable)
Krzysztof Kessler

Such credit shall be included in a suitable place in the inner sleeve liner notes of the CD or record and shall be in the same size, typeface and font as any other similar information included in such liner notes.

Also, you agree to include the same credit (as displayed above) in the description of any YouTube video, Soundcloud player, Bandcamp track (and any other place where applicable) with the song that our engineer either mixed / mastered / engineered or produced.

By applying for our services, you give us the right to use your song which we worked on as an example of our work to other clients. This includes uploading it to our website (once the song / EP / Album is released) under the “Featured Artists” panel into our custom built-in audio player. This audio player will not include a download option. A post with your song on our website will include all appropriate credits, as well as links to your social media.

Where can I listen to your work?

We have a few Spotify playlists which include all of the tracks that our engineer worked on:

Mixing portfolio
Mastering portfolio
Production portfolio
Full Portfolio

If you would like to check the exact details (our role in each project) please visit

Should you need more, we are also authorised by some artists whom we have worked with, to showcase their yet unreleased music on a private link as a part of our portfolio.