As a professional mastering engineer, I've worked on thousands of mixes over the years from producers of all experience levels. While every mix is unique, there are some consistent best practices that can elevate your mixes and make my job easier when it comes to mastering.
In this comprehensive guide, I'll walk through everything you need to know to properly prepare your mix for mastering. Follow these steps and your music will sound more professional, balanced, and release-ready.
Step 1: Get Your Mix to 90% Before Mastering
The quality of your final master is hugely dependent on the quality of your mix. Garbage in, garbage out. No amount of mastering can "fix" a bad mix.
Before sending your mix off for mastering, get it to around 90% of the sound/quality you're aiming for. Mastering should account for that last 10% of polishing and loudness maximization.
So don't expect the mastering to radically alter or "save" your mix. The goal of mastering is to take a good mix and give it that last bit of commercial polish.
Here's a checklist of elements your mix should have before mastering:
- Solid songwriting and arrangement - The core musical ideas are strong, and the arrangement showcases them effectively.
- Clear, uncluttered production - Every instrument/element has its own space and purpose in the mix. Things aren't fighting for the same frequency range.
- Good overall tonal balance - No extreme boosts/cuts across the frequency spectrum that would require dramatic EQ'ing during mastering.
- Consistent volume levels - Instrument levels are balanced well with nothing poking out or getting buried.
- No sloppy edits/timing - All edits are clean, fades are smooth, and the timing is tight throughout.
- Great vocal tuning/pitch - The lead vocals (and any harmonies) are perfectly in tune with no sour notes or pitchiness.
- No unwanted noise - Every vocal/instrument recording is clean with no pops, clicks, headphone bleed etc.
- Stereo width is controlled - The low end is mono, the sides aren't too wide, and elements that should be centered are.
- Mix sounds great in mono - Listening in mono reveals no major phase issues or holes in the arrangement.
- Reverb/delay levels are just right - The send levels aren't overwhelming or making things blurred/distorted.
- Only essential elements remain - Mute any tracks that aren't clearly improving the overall mix.
- You can enjoy it objectively - Step away from "mix mode" and just listen as a regular listener. If you're still in heavy critique mode, it likely needs more work before mastering.
If you follow this checklist and get your mix to around 90% before sending to mastering, you'll get much better results and avoid headaches.
Step 2: Pick Great Reference Tracks
One of the best ways to get your mix sounding more professional is to compare it to commercial tracks in the same genre that have a sound you're aiming for.
Using reference tracks while mixing gives you a target to shoot for. You can directly A/B your mix with the reference and make adjustments until they sound comparable.
Choose Wisely
When selecting reference tracks, choose songs that have:
- Similar instrumentation/arrangement - Don't reference a solo piano ballad if you're mixing a full rock band.
- A similar vibe/style - Pick references in the same general genre and with qualities you want to emulate.
- Great sound quality - Avoid references that sound amateur. You want great commercial examples to inspire your mix.
- Similar dynamic range - If your song is very dynamic, don't pick a heavily compressed/limited reference track.
- Similar overall loudness (within 3LUFS) - Level match your mix and reference track when comparing.
Picking the right references that closely match the qualities of your mix will make comparing and improving way easier.
Tools to Level Match
When referencing, it's absolutely crucial that you level match your mix with the commercial reference track. Human hearing is biased - louder music sounds punchier and richer.
If you compare your quieter mix to a blasting loud reference, you can't make honest judgments about tone, punch, width etc. It will skew your perspective.
Tools like Reference by Mastering The Mix make level matching easy. It will compensate for loudness differences between your mix and reference in real time. This allows you to rapidly A/B between them and make mixing decisions accurately.
Level matching is a must for fair comparison. Don't skip this step.
What to Listen For
Once your mix and reference track are closely matched in loudness, you can critically compare specific qualities like:
- Overall tonal balance - Does one have more low-end warmth? More sizzly highs?
- Clarity and punch - How do the transients and instrument detail compare?
- Stereo width - Is one mix wider or more centered overall?
- Compression and limiting - Does one sound more dynamic or restrained?
- Effects levels - Is the reverb/delay more/less blended?
Switch back and forth rapidly making subtle adjustments to your mix to get it closer to the qualities of the reference. Having specific elements to focus on makes this process much faster and more effective.
Matching the vibe and sound quality of commercial references is key. This will ensure your master translates and competes at a professional level.
Step 3: Optimize Peak Levels and Headroom
Once you've got the tone, punch, and overall balance of your mix dialed in nicely, it's time to optimize the peak levels and headroom before exporting your final mixdown.
This ensures your mix doesn't get clipped or distorted during mastering which requires undoing work. Getting the gain staging correct going into the mastering chain is crucial.
What is Headroom?
Headroom refers to the space between the peak signal level in your mix and 0 dBFS (the maximum before digital clipping).
Leaving ample headroom gives the mastering engineer breathing room to work without hitting the ceiling and distorting your mix.
For best results, your mix should peak between -6 dB and -3 dB FS. This leaves enough headroom for mastering while still keeping the signal strong.
Tips for Optimizing Levels
Here are some tips for optimizing levels and headroom:
- Use a peak meter plugin to identify the true peak level of your mix's loudest section.
- Insert a gain/trim plugin on your stereo output bus to attenuate and get peaks between -6 and -3 dBFS.
- Make sure there are no limiters or clippers on your output bus skewing the true peak level.
- Measure peaks with dBTP (True Peak) to account for inter-sample peaks.
- Don't normalize or apply any output gain when exporting the final mix.
Getting your mix's peak level optimized with adequate headroom before exporting is a crucial step. This empowers the mastering engineer to maximize loudness and dynamics effectively.
Step 4: Check the Mix Loudness
In addition to peak levels, you should also check the overall loudness of your mix before mastering. While peak levels relate to headroom, loudness relates to how we perceive the strength of the entire mix.
A mix that is too quiet or too loud going into mastering can cause issues like excessive compression or a lack of flexibility.
Use LUFS Readings
The best way to measure loudness is using LUFS (Loudness Units relative to Full Scale). This gives you an objective numeric reading of your mix's overall loudness.
Most DAWs have LUFS loudness meters built in or available as plugins. Levels by Mastering The Mix is also a great loudness and true peak metering tool.
For the widest dynamic range and flexibility, your mix loudness should be between -25 LUFS and -18 LUFS before limiting and maximizing from mastering.
Super quiet mixes force more compression and limiting during mastering which can hurt your transients. Overly loud mixes with little headroom also remove possibilities and strain the gear.
Shoot for an integrated LUFS loudness in that optimal range as you export your final mix stems.
Dynamic Range Considerations
The genre and vibe of your music also impacts the ideal loudness. More dynamic genres like jazz and classical often have lower LUFS levels. Super compressed genres like EDM tend to peak closer to -18 LUFS.
Let the natural dynamic range of your mix dictate the loudness rather than trying to push it. Dynamics can be reduced during mastering but not restored once squashed.
Step 5: Check the Stereo Balance
Analyzing the stereo balance of your mix is crucial before exporting stems for mastering. An unbalanced or excessively wide mix causes issues like phasiness, masking, and an inaccurate depiction of the musical elements.
Getting your stereo image precisely dialed in before mastering avoids unnecessary corrective processing downstream.
Here are some key techniques for optimizing your mix's stereo balance:
Listen in Mono
As a first pass, listen through your entire mix in mono. This will immediately reveal any glaring phase issues causing clarity problems. If the mono balance sounds thin or has obvious holes, you have alignment problems to address.
Mind the Bass and Low Mids
Pay special attention to the low end and low mids when checking mono. Excessive stereo information below 200-300Hz can really undermine your mix's cohesion and punch on smaller speakers.
Use mid/side EQ to reduce stereo width in this range if needed. Also reference on mono club systems.
Center Lead Vocals
The lead vocal is typically centered or nearly-centered in most modern mixes. But make sure any stereo effects like short delays aren't pulling it too far out of phase and causing problems. Reel these in if needed.
Watch the Width
Across the spectrum, ensure the stereo width isn't too extreme in any one frequency range. For example, having super wide 1-2kHz on keys might cause masking issues or feel unnatural.
Use visual stereo analysis tools like Vectorscope to spot any problem areas pulling too wide.
Mind the Arrangement
When evaluating width, also factor in the arrangement. For example, if a guitar doubles the vocal line during choruses, is it occupying the right space relative to the vocal? Are complimentary tracks with harmonies centered together?
Make sure your stereo balance accurately reflects the core arrangement.
Check on Multiple Systems
Finally, check your mix's stereo balance on multiple systems. Does the image hold up on headphones? Small nearfields? Laptop speakers? The car?
Fix width issues causing problems on specific systems before finalizing your mix.
A clean, accurate stereo image eliminates many mastering woes. Take time to get it right before your final export!
Step 6: Check for Phase Issues
Along with stereo balance, you also want to check for any potential phase issues and correct them during mixing before mastering. Phase issues like comb filtering can seriously undermine your mix's clarity and punch if not addressed.
Here are some tips for identifying and fixing phase problems in your mix:
Listen in Mono
temporarily set your master bus to mono and critically listen to your mix. If the balance suddenly sounds hollow, thin or has cancellations, you likely have phase alignment issues between some tracks.
Use Correlation Meters
A correlation meter like the one in Levels shows the phase relationship between the left and right channels. A centered 0 reading indicates the channels are perfectly in phase. Values toward +1 indicate more mono correlation, values toward -1 indicate more phase cancellations.
Keeping an eye on this while mixing can reveal phase problems you may not hear.
Address Individual Tracks
If you detect phase issues, zoom in on problem frequency ranges on your EQ and apply subtle boosts. Then go through your session soloing instruments to identify which ones are out of alignment.
Use track delays, mic positioning adjustments, or polarity flipping to get problematic tracks back into phase alignment.
With your mix's phase and stereo balance optimized, the mastering process will be much smoother with less corrective processing needed.
Step 7: Choose The Right File Export Settings
When you've finished the mixing process and are ready to export your final mix stems for mastering, choosing the correct export settings is crucial.
Using the wrong sample rate, bit depth, or file format can immediately bottleneck the quality of your files.
Here are the key export settings you need to get right:
Export as WAV or AIFF
Always export mixes for mastering as high-quality uncompressed audio files like WAV or AIFF. These file types preserve all your mix's fidelity with zero loss of quality.
Match Original Sample Rate
Be sure to export your files at the same sample rate as your original mix session and recordings. For example, if you recorded and mixed at 48Khz, export final mix stems at 48Khz.
There's no benefit to arbitrarily increasing the sample rate. That just demands pointless upsampling and conversion during mastering.
Mix at whatever sample rate allows you to record and mix smoothly, then maintain it for the final export.
Use 24-Bit Depth
For bit depth, 24-bit is the standard for most modern music production applications. This provides an ample dynamic range that retains all the headroom and fidelity from your original recordings.
There's no need to export at a higher 32-bit depth unless your mix session is 32-bit for specific reasons. Stick with 24-bit for reliable quality.
No Dithering!
Export your 24-bit mixes without any dithering applied. Dithering will add unnecessary noise and interference to otherwise clean files. It is only useful when specifically converting 24-bit files down to 16-bit files.
Add Fades if Desired
Lastly, if you want your final master to have fades, add them into the exported mix stems rather than leaving this to mastering. Give the mastering engineer the exact files with fades that you want. Just leave a few seconds of silence at the heads and tails in case more adjustment is needed.
Exporting mix stems for mastering requires precision. Follow these guidelines to ensure no quality or fidelity gets lost before your files even reach the mastering studio!
Step 8: Sequence Your Stems Thoughtfully
In addition to the main stereo mix, most mastering engineers also request individual stems of key mix elements like drums, vocals, guitars etc.
When assembling these auxiliary stems for mastering - typically exported as 24-bit wavs - there are a couple guidelines to follow:
Group by Importance First
The most crucial stems to supply are leads vocals, drums/percussion, and bass. These are the core "foreground" elements of most modern mixes. Make sure these are the first stems in your bundle.
Group by Instrument Family
Beyond the essentials, group any other stems by broader instrument groups. For example, have all guitars stem together rather than each mic of the guitar cab separated. All keyboards and synths together if possible. Grouped backing/harmony vocals together etc.
Keeping stems manageable this way ensures the mastering engineer can selectively process elements by instrument group rather than getting overloaded with minutiae.
Keep Arrangement Details Clear
When compiling multiple tracks into a grouped aux stem, be sure to maintain the exact arrangement of those parts. If a guitar doubles an organ line in the choruses for example, keep that blend intact in the grouped stems. Don't mess with instrumental balances.
Keeping stems closely mirroring the full mix makes it easier for the ME to work with your original vision. Overly messy/combined stems can make that tougher.
Be thoughtful about how you assemble any auxiliary stems for mastering to maximize their usefulness.
Step 9: Add 2-3 Seconds of Silence
Once you've exported your stereo mixdown and any grouped stems at the right bit depth/sample rate, add 2-3 seconds of silence in the audio files at the head and tail.
Having this empty space before and after your mix gives a few benefits:
- Allows the mastering engineer to add fades if needed
- Provides room for slight arrangement tweaks
- Keeps potentially distracting studio noise out of the mastering session
You don't need a full minute or anything excessive. But a few seconds of pre and post-roll silence is customary.
Step 10: Include Detailed Mix Notes
Lastly, when sending your final mix stems off for professional mastering, be sure to include detailed mix notes that give guidance on what you're looking for sonically.
Don't just throw mixes over the fence and expect magic. Giving clear direction improves your results.
Describe the Overall Vibe
First, describe the general vibe you're going for. Upbeat and energetic? Smooth and atmospheric? Aggressive and in your face? Setting the mood helps steer decisions.
Give Creative Direction
Next, offer any creative direction on the kind of processing you're looking for. For example, "I want the drums more aggressive and in your face" or "smooth, warm analog limiting to glue the mix". Being specific with your creative goals prevents guesswork.
Point Out Concerns
If there are any instruments or sections you're concerned about in the mix, point them out so they can receive special attention during mastering. For example, "the lead vocal sounds a bit harsh and gritty to me".
List Reference Tracks
Providing 2-3 reference tracks representative of your goals is hugely helpful for dialing in the right vibe. Mention tracks that have qualities you want emulated.
Offer Multiple Versions
Consider delivering a few different mix versions (like one with the lead vocal louder) to provide options to choose from or combine. Having alternates allows you to get multiple master variations to select the best result.
Approval Expectations
Explain the approval process you expect. Do you just want a master emailed back? Do you require a chance to request revisions? Managing expectations prevents confusion.
Offering this detailed mix guidance gives the ME insight into your creative vision and priorities. They can use your mixes and stems to achieve the sound you have in mind, rather than relying on guesswork.
Thorough mix notes lead to better mastering results.
Step 11: Pick the Right Mastering Studio
Assuming you don't want to master your music yourself, choosing the right professional mastering engineer for your project is critical for success.
Here are key factors to consider:
Listen to Samples
When researching mastering engineers, listen to samples of their work in a similar genre to yours. Get a sense of their aesthetic and skills. Do you like what you hear? Does their style fit your music?
Read Client Reviews
Look for positive client testimonials and feedback. A history of happy customers with great results is a good sign. Beware mastering studios with many complaints.
Evaluate Their Gear
What is their signal chain like? Do they use high-end analog gear, plugins, or a hybrid approach? Make sure their workflow fits your preferences and values.
Consider Their Experience
Look for a proven history of experience mastering professional records in your niche. Check credits and clients. Deep expertise is invaluable.
Communication Skills
Do they communicate promptly and clearly? Are they receptive to guidance and input? You want a mastering partner willing to realize your vision, not ignore it.
Avoid Overly Cheap Options
Be wary of super bargain-bin prices for pro mastering. Chances are the quality will reflect the price. You often get what you pay for.
Taking the time to find the right mastering studio for your needs pays off tremendously in the end result. Don't leave this crucial choice to chance.
Step 12: Plan for Revisions and Remasters
Once you receive your initial mastered files back, listen critically and be prepared to request revisions if needed to get the sound just right.
Mastering your music involves back and forth refinement. Be ready for multiple rounds of notes and adjustments.
Here are some tips for the mastering revision process:
- Listen on multiple systems - laptop, car, headphones, monitors. Make sure it translates everywhere.
- Reference against your favorite mixes - Does it compete? Match for loudness.
- A/B against your original mix - Did elements change in undesirable ways?
- Watch for new problems - Did mastering introduce artifacts like harshness or pumping?
- Have your band/team approve - Get trusted opinions from others before signing off.
- Don't be shy asking for changes - You've paid for their time, utilize it and get the results you deserve.
- Provide reference notes - Clearly explain the adjustments you want made for the next pass.
- Offer alternate options if needed - Ask for multiple masters with different processing chains if you're unsure.
Dialing in the ideal master for your music may take a few rounds of refinement. Stay picky until your music sounds professional and makes you proud.
Recap: 12 Steps to Prep Your Mix for Mastering
For easy reference, here is a recap of the 12 key steps to prepare your music for mastering:
- Get your mix to around 90% before sending off
- Pick great commercial reference tracks
- Optimize peak levels and headroom
- Check the overall loudness
- Analyze the stereo balance
- Check for any phase issues
- Export stems using the right settings
- Sequence stems thoughtfully
- Add silence to heads/tails
- Include detailed mix notes
- Choose the right mastering studio
- Plan for revisions and remasters
Following this checklist will set you up for mastering success. Your professional master will help take your music to the next level and stand strong beside the best tracks in your genre.
If you have any other questions about preparing your mix for mastering, feel free to reach out! I'm always happy to offer guidance to producers looking to improve their sound. Let me know if you need any tips not covered above.
Best of luck with your music and mastering journey!
For more information on the Mastering process check out our Guide To Mastering
