Orchestral Mixing Tips
Here are a few tips that can hopefully guide you in the right direction if you’re seeking to improve your orchestral mixes. I’m not an expert nor do I mix professionally, but I learned quite a lot over a few years of studying and practicing. Note that this is oriented toward a more traditional sound.
Arrangement
As you likely heard before, mixing orchestral music starts with the arrangement. A well-balanced and clean arrangement will sound good before you touch the mixer. It’s most important to have a good balance between the lows and mids during the meat of the track. Many orchestral instruments are mids-focused, so it can be very easy to overload the arrangement with mids and make the low-end sound weak in comparison. As you strengthen the mid-range of your arrangement, remember to add to the low end as well. Balancing the high end with instruments like cymbals, piatti, tambourines, shakers, sleigh bells, chimes etc. helps with achieving a full, open sounding mix, but such instruments don't have to be present throughout the entire track – they can be reserved for important moments and climaxes.
Mic positions
If you’re using non-free libraries, you’ll likely have multiple mic positions to choose from. In most cases you should use a mix of decca tree and far/surround/wide mic positions to get a wide sound that captures the acoustic space where the library was recorded. Close mics add a more direct and focused sound and can be used to emphasize or bring out certain lines in a dense arrangement, but they should be used sparingly and with care. If you use close mics too much you may end up with a very digital-sounding orchestra. If you’re accustomed to composing dense arrangements with close mics, you may find that your arrangements fall apart with the wider and smoother sound of the room mics. It’s of course possible to create dense arrangements with room mics, but the orchestration must be clean, and you have to be strategic with instrumentation.
Generally, with busier compositions, you can use more of the decca tree mics, and with slower compositions, you can use more of the far mic positions. With the right use of mic positions, your mix should sound like it’s in a large space before you add reverb.
Sometimes you will have to use close-mic libraries, often for solo parts. In these cases, try to emulate a decca tree mic with a short, early reflections reverb and EQ. The frequency output of close and distant microphones can be extremely different, so don’t be afraid to go to extremes with EQing to match the tone of the rest of the orchestra. Also don’t be afraid to use a high amount of early reflections reverb to diffuse the sound to the extent necessary. Sometimes adding a subtle delay helps bridge the gap.
Reverb
It’s important to have a decent reverb plugin for a clean and cinematic sound, and reverb is worth investing in if you haven’t already. I recommend Liquidsonics and Valhalla reverbs.
Some people use one reverb for their entire mix, and this is a simple and effective method to get a cohesive sound, but you can get better results by altering the reverbs for each instrument group and sometimes stacking reverbs. Contrary to what you may have heard, it’s okay to use different reverb plugins on different instruments. If you mix a dark reverb with a bright reverb, of course that will sound odd, but you can get away with mixing reverbs with a similar tone and decay. Through trial and error, you’ll find that some types of reverbs suit certain instrument groups better than others.
I usually adjust the predelay, room size, and distance between the different groups to slightly increase the spatial contrast.
I suggest referencing an orchestral seating chart and adjusting the reverb amount according to how far back the instruments are.
To avoid muddying/brightening your mix, it’s a good idea to EQ your reverb below around 350hz and above 6Khz-10Khz. Applying a post-reverb EQ can also help neutralize the reverb’s tonal effects if you notice a substantial difference.
You can use plugins like Room Widener or a transparent doubler to increase the perceived width of libraries that sound too small and narrow or to add more separation to an instrument group.
The reverb decay time should generally vary between 1.7s to 3s depending on the speed of composition. In more ambient songs or for special effects, you can go much higher.
Sometimes high-end/high-register instruments will seem to bypass the reverb because they’re not comfortably within the reverb’s range of effect. You can increase/automate the reverb to make the effect more noticeable or try using a more distant mic setting. I don’t recommend brightening the reverb because that can easily sound fake.
Pre-delay creates a small delay between when you hear the dry sound and the wet reverb sound. Increasing pre-delay will make instruments feel closer to you, and varying this setting can help create an illusion of distance between different instruments. The pre-delay time can have a significant impact on the feel of the room so play around with it to find the right settings. Avoid going too high because that can disassociate the reverb tail from the original sound and ruin your mix. On the highly transient percussion, you might want to turn off pre-delay on the reverb to avoid a secondary transient effect.
Panning
Good panning is crucial to achieving a wide, interesting mix. I suggest referencing a modern orchestral seating chart as a starting point and then adjust it to suit your arrangement. Blindly following the chart isn’t a good idea because it can lead to too many instruments being on one side. If you need to move an instrument to the opposite side, remember to swap the right and left channels so the reverb reflections sound accurate.
Be careful to not use too extreme panning because that can break the illusion of everything being played in one space.
Bear in mind that the wetter an instrument is, the more spread out it will be across the stereo field, so you can pan a wet instrument further in one direction to help establish its presence there.
EQ
EQ will be needed on most, if not all, instruments for tonal shaping and balancing and reducing muddiness and harshness.
Many orchestral instruments have significant tonal variations between notes and registers, and EQ can stabilize the tone and volume. EQ should be used to treat persistent problems, and dynamic EQ can be used to treat short-lasting problems – for example, maybe there’s one note on a French horn that spikes in volume at around 800hz. It’s most important to stabilize the low-end instruments for a smooth, loud mix. Strong dynamic EQ can help keeping the double basses in check. I don’t recommend squashing the dynamics of your low end, but make sure it’s tamed and stable.
Oftentimes when blending libraries from different developers, you’ll find that some are darker, and some are brighter. It’s important to use EQ to reduce this tonal gap. When EQing for this purpose, you’ll generally want to focus on 3Khz+ range.
Many low register/low percussion instruments sound muddy somewhere in the 200hz to 700hz range, so you can scoop some of it out to get a cleaner sound.
Sometimes instruments like strings, choir, and brass will sound harsh in the high-mids, so you can make some cuts for a more pleasant sound.
If you’re trying to push an instrument further back in the mix, sometimes reducing 4khz can help because this is the frequency area we’re most sensitive to. You can also increase it to give an instrument more presence.
When you’re using darker libraries like the cinematic studio series, it can be a good idea to increase the “air” in the sound by boosting 10khz+. There are many plugins that specialize in this.
After all the manual EQing, the Gullfoss plugin can help polish and stabilize each instrument group further. I almost always use the filters on the sides to adjust the area of effect so that it doesn’t brighten the mix too much. By default, it tends to boost the 10Khz area too much for my liking.
Saturation
I find saturation extremely useful in adding warmth to the mix and improving the balance between the low end and mids. It can also be useful to soften high end transient percussion and increase the air in strings and brass. I always find a reason to use saturation somewhere.
Use the right key
The key of your composition can significantly affect your mix as higher keys have less low end and lower keys have less high end. I think this is often overlooked but can be the culprit of many difficulties with orchestration.
Zechnition
So many helpful tips here! I don't plan on doing the same kind of orchestral mixing you do, but you have a lot of experience, so I learned a lot anyways