R.T. Hinkel

What's in my monitoring chain?

Audio

Apr 18, 2021


Sitting between your master chain and your hardware output, the monitoring chain is a great place for utilities, frequency & loudness analysis, monitoring correction and much more. In this post, I outline my main monitoring plugins.

Table of Contents


Introduction

There are a few features in REAPER that really seal the deal for me, and one of my favorites is the monitoring FX chain.

While some DAWs provide a dedicated effects chain for monitoring (REAPER, Studio One, Cubase), implementing your own monitoring chain is as easy as slapping your desired monitoring plugins at the end of your mastering chain (or other monitoring output).

It’s crucial to disable your monitoring chain while rendering, as printing room correction onto the final master distorts it. The benefit of using a DAW with a built in monitoring chain is that the final renders bypasses this automatically, ensuring correction is never printed.

As with most effects chains, the order matters.

Utilities and analyzers do not alter the incoming sound, and capturing the raw output is essential, so early placement is key— analyzing the loudness of a signal that’s been corrected for the listening environment will skew the results, so all correction filters must be placed at the end of the signal while all analysis plugins are placed closest to the beginning.


Utilities

REAPER - Goniometer

REAPER Goniometer

One of many free plugins available through REAPER, this is a fantastically simple goniometer and phase correlation meter.

This plugin visualizes the stereo field of the incoming signal— stereo signals will appear as a shape, while mono signals will appear as a vertical line.

I like keeping this open while my monitors are set to a mono preset, allowing me to see the stereo information while listening in mono.


REAPER - Channel Phase Meter

REAPER Channel Phase Meter

Another dead-simple meter: the readout simply states stereo or mono, and in-phase or out-of-phase. Available for free with REAPER.

This is extremely handy to have, especially while mixing LCR mic’d instruments such as drums. Sometimes hearing phasing issues can be tough, especially if the issue is intermittent. Having the option to adjust the checking interval is very useful, as it allows you to define smaller windows for more precise readouts.

During the final mixing or mastering stage, I’ll keep this plugin visible for the entire track to make sure there are no final phase issues.


Izotope - Ozone 8 Codec Preview

Ozone 8 Codec Preview

Ozone itself is a rather large and multifacted piece of software that deserves more attention than just a cursory overview, and I’m honestly just going to focus on the codec preview functionality. Having the ability to preview your track processed via the MP3 and AAC codecs at varying bit rates is very useful.

It’ll shine a light on what will actually degrade once lossy codecs are inevitably applied to your track during the streaming process— listen closely to the transients of low frequency content, high frequency sustains and stereo placement of mid-frequency content.

As a utility, I recommend this one closer towards the end of the chain, after analysis but before correction.


Frequency & Loudness Analysis

A decent frequency analysis tool is essential— even with a perfectly treated room and optimized monitoring system, a good visual representation of the incoming sound is a great tool to augment your listening experience.

Most EQ plugins come with a visualizer function, and will do in most cases.

Loudness analyzers are helpful during both the mixing and mastering phases. While mixing, one may shoot for an integrated loudness of -18LUFS to leave some headroom for the final master at -14LUFS.


Voxengo - SPAN

Voxengo SPAN

SPAN is free. SPAN can visualize mid and side channels. SPAN is highly flexible in its smoothing options, window sizes and other configurable settings.

You should definitely get SPAN. There’s not much else to say.


Izotope - Tonal Balance Control

Tonal Balance Control

Like SPAN, Tonal Balance Control is a frequency analyzer— however it ditches some of the more standard tools in a frequency analyzer to offer another type of functionality: It compares the current curve to a set of pre-defined target curves. Presets include jazz, rock, hip-hop, bass heavy, country and more with the option to create custom targets from single or multiple audio files.

This is a fantastic option when you’re dealing with less than ideal listening environments to objectively show you how your track stacks up to your target.

In a mixing or mastering scenario, it’s very useful to be able to predefine a curve from any reference tracks and use them without having to actually A/B the tracks as much during the session.

Typically when mastering an album for a client, I’ll create a custom target curve when the project is done, that way I can reference it again for future projects and achieve a certain level of consistency.


Signum Audio - Bute Loudness Analyser

Bute Loudness Analyser

Almost all mastering limiters come with metering capabilities, and in the majority of cases they’re ideal. However for users who like to try a few different limiters, or for limiters that lack true peak metering, having an external loudness analyzer can be a valuable asset. Relying on the built-in metering of limiters can prove to be an issue when you’d like to audition different limiters but still retain the loudness information.

My loudness analyser of choice, Bute, has a fantastic set of features that fit perfectly into my work flow, so it’s a no brainer for me. Pre-defined targets that fit with broadcast and streaming standards, as well as user-assignable targets, and the ability to save sessions or export raw loudness data to be graphed are all very valuable features for me.

In an album mastering context, keeping Bute in my monitoring chain rather than on each individual track allows me to graph the entire album and capture the complete loudness data for the whole program.


Monitor Correction

There’s no such thing as the perfect listening environment. Adding corrective EQ to your monitoring chain can help flatten out the response of your speakers within your specific room and help achieve a natural and flat sound.

I won’t be going too much into the process, as I plan to cover it in detail in a future post, but the process essentially boils down to measuring the reproduction of a known signal through your system with a calibrated measurement mic. The recorded signal is compared to the control signal and filters can be generated to correct the system audio to the target curve.

The same type of correction can be applied to headphones with a bit more consistency, as listening environments are less likely to be skewed.

For headphone users taking advantage of correction filters and a room simulator, correction always goes before the simulator.


Sonarworks - Reference 4

Sonarworks Reference 4

If there’s one thing to gleam from this post, it’s this: Reference 4 is amazing and should be seen as a necessary addition to your tools if you’re looking for accurate and honest mixes/masters.

Offering both loudspeaker and headphone options, it’s really a no-brainer for monitoring correction.

For headphones, Sonarworks measures and creates average profiles for just about every major model of headphones at their factory. This means you can load up a preset for your HD-280 Pros, for example, without having to shell out for a dedicated measurement device such as the MiniDSP EARS.

These are, of course, averaged correction profiles. If you have a measurement from your specific headphones, that will always work better than an averaged profile. Sonarworks also offers the option to individually calibrate your personal headphones, as long as you’re willing to send them in for a few days.

For loudspeakers and nearfield monitors, Sonarworks offers calibrated measurement microphones that pair up to Reference 4 allowing you to take measurements of your listening environment, analyze the response, and generate a corrective filter automatically.

Their customer service is also very effective— I reached out to them inquiring about measurements for my specific mastering headphones (Ollo S series), and within 2 weeks the next update had average profiles for the S4 and S4R wired variants.

For advanced users who want a bit more control such as timing adjustments and phase analysis, consider software such as REW and a hardware DSP unit for correction such as a MiniDSP 4X10 HD.


Fabfilter - Pro Q3

Pro-Q3 Headphone Correction

As stated in the previous entry, if you have the measurement curve from your actual set of headphones it’s always recommended to base your correction off of that. That’s why I have Pro-Q3 living in my chain permanently.

I typically use my Ollo S4X headphones, but have a few others that I like to use— which are covered by Sonarworks. Once I get my hands on a measurement device for headphones, I’ll likely generate correctional curves for all of my sets and simply use Q3 for correctional purposes.

One of the many benefits to the brand that I chose for my daily-driver headphones is that they individually measure each set at the factory and provide that data to you as a CSV/Spreadsheet. From there, you can import the measurement data into REW, generate a correctional curve and export the filter values as a preset for your EQ of choice.

Sadly, REW doesn’t offer Fabfilter preset export options, but taking the correctional filters from the data and applying them to a Q3 instace is as easy as matching the freqnecies, gains and bandwidth for each node.


Goodhertz - Can Opener Studio

Goodhertz Can Opener Studio

For headphones users, I always recommend Can Opener. While there are plenty of “room sim” plugins out there, and they’re definitely nice for the right people, I don’t think I’m the right type of person for those. Emulating a famous studio you’ve never actually been inside doesn’t really seem that useful, personally.

That’s why I opt for Can Opener. Rather than emulating a specific room or speaker, Can Opener adds back some of the effects lost when using headphones instead of nearfield monitors— namely cross-talk.

With speakers, depending on your physical listening position, your left ear will hear the left and right speakers, with a slight delay on to the right speaker, and vice versa. Wearing headphones completely isolates the left and right channels, eliminating any crosstalk between the two.

Can Opener adds that back in, with the added benefit of customizable speaker angle, additional EQ, and other stereo manipulation tools.


Tokyo Dawn Labs - Slick EQ M

TDR Slick EQ M

Psychoacoustics are such an interesting topic to me, and I think truly play a huge role in the mixing and mastering process. Understanding the equal listening curve can prove to be very useful when considering your monitoring levels.

I always advocate for hearing health, so I encourage low-to-moderate listening levels— however there are benefits to listening at elevated levels (for short periods of time) as well. The way we process sound differs depending on the loudness, and having the option to adjust the levels in compliance with this curve is invaluable to me.

Taking advantage of Slick EQs center filter with the equal loudness curve enabled allows me to adjust the amount of contouring applied. I don’t typically use this with headphones, mainly my nearfield monitors, however I do adjust it depending on the room listening levels.


Conclusion

In no way will my exact monitoring FX chain be directly applicable to your situation, so I kept things pretty broad with this list and left out a few honorable mentions such as Izotope Insight 2, Klanghelm VUMT, Youlean Loudness Meter, or the Dynamic Range Meter by MAAT digital.

I hope it’ll be a good starting point for you to build your own monitoring chain and give you a good idea of the order of operations and typical tools commonly used.

Feel free to submit any questions for future posts, or contact me if you’d like more info regarding my monitoring chain and equipment.

Audio, Mastering, REAPER, Production, VST

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