Digital Tape: Recreating Analog Signal Flow in the Box

In an earlier series, I wrote about the power of gain staging to structure your mix and shape your sound. I wanted to touch on that again and lay out a plugin chain that recreates an analog workflow. In short, it looks like this:

  • Clipper
  • VU Meter
  • Console Input Stage
  • Tape

You can use any of your favorite plugins for this, but below I’ll go through the ones I like and how I’m using them to shape the mix.
Clipper // TDR Limiter 6 ($60)

DAWs work in 32-bit floating point resolution, which means they’ll let you get away with murder as far as gain-staging goes. Placing a clipper first in the chain simulates how analog gear responds to peaks; come in too hot and it shaves them right off.

Keep in mind that if you’re gain-staging properly, you should only be clipping off a peak or two across the whole song; this is just a safety to catch the big spikes. Vocals and sustained instruments shouldn’t be anywhere close to clipping; as such, I only use this on percussive tracks such as drums & slapped bass.

tdr

Limiter 6 is an incredible plugin, and a full-fledged mastering tool in its own right. Here, I’m just using one of its modules to clip off incoming peaks. You can tune it to focus on LF & HF content, and you can set a soft or a hard knee as desired; I usually set it to a -6dB threshold with a 2db knee.

VU Meter // Klanghelm VUMT ($25)

A VU (or PPM) meter is the next step in the path. It has zero impact on the audio, but it’s a powerful tool to gain-stage your mix via the clip gain (before it hits any plugins). I wrote pretty extensively on using meters to gain-stage vocals & drums, so you can check that out for the details. Here, I’ll just say that VUMT is an incredible plugin, and it should be in everyone’s DAW.

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Console Input // Klanghelm SDRR ($25)

The clipper recreates the headroom of a console, and the meters recreate the visuals; in this stage, we’re recreating the tone. Vintage consoles add some subtle distortion to the mix as audio passes through their transformers & amps; it’s hard to notice on a per-track basis, but it adds up across the board.

sdrr4

There aren’t a lot of plugins that can do convincing saturation; SDRR is one of the few pieces of software that’s gotten high praise from the analog crowd. And it’s much more than just a console emulator; it has several other modes that can create some pretty drastic distortion effects. But for this use, I’m putting it in desk mode and leaving the drive control very low (1-2) with drift at 100% to add just the slightest touch of warmth. If a track needs heavier saturation down the road, I may come back to this stage and crank up the drive for effect; for now, we’re keeping it subtle.

Tape // U-He Satin ($130)

Tape, glorious tape! For all that’s been said in praise of the stuff, it’s still pretty subtle on individual tracks; this is another element that begins to show its character once it’s stacked up across the mix. Depending on the tape & speed, it can add some low end, enhance the highs, roll off the air, and add some gentle saturation & mix glue.

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There’s no lack of tape emulations on the market right now; Waves, Slate and CDS are all great options. But I wanted DSP (not convolution), and I love how Satin lets you get under the hood; you can tweak every possible setting while viewing the sonic impact on the analyzer. It’s also got the incredibly useful feature of groups; you can create one machine for your master, one for your drum tracks, one for your instrument tracks, and change them all with one knob. It’s a powerful tool for hearing how your changes impact several tracks at once.

Whenever I’m looking for an analog vibe, I set up this chain on all my tracks before I start any mixing (that way I’m not compensating for any changes in tone down the line). And there you have it; a plugin chain that recreates the analog signal flow and adds some subtle warmth & saturation across the entire mix.

Digital Tape: Gain-Staging Drums

Note: the following post makes use of Klanghelm VUMT and TDR Limiter 6. To get the most out of these posts, head over to their sites and support some awesome developers!


drums

In our last post we covered how to apply analog gain-staging practices to melodic material. However, our ears respond much differently to percussive material, which is composed of transients instead of tones.

ppm

A PPM meter responds much more quickly to level changes, and as such it’s better suited to drums and percussion. Using VUMT, pull up a DIN meter and apply it to a snare or kick track. Adjust the pre-fader clip volume so that the needle is reading a little under 0.

Here’s an example of a snare track after I’ve adjusted the gain:

snare

You’ll notice that while the hits are fairly consistent, there are couple hits around the 1/3rd mark that are much louder than the rest. In our last post, we dealt with this problem by manually adjusting the volume; while this is a completely valid approach, it’s not always an option to go through hundreds of hits by hand. Instead, let’s take an analog approach. Continue reading “Digital Tape: Gain-Staging Drums”

Digital Tape: Gain-Staging Vocals

Note: the following post makes use of Klanghelm VUMT, an incredible plugin that costs about $15 USD. To get the most out of these posts, head over to the site and support an awesome developer!


vocals

Hugh Robjohns begins his article on VU & PPM meters with the following quote:

These are both, strictly speaking, obsolete analogue metering formats! In short, the VU meter shows an averaged signal level and gives an impression of perceived loudness, while a PPM indicates something closer to the peak amplitude of the input signal. However, in our modern digital world, neither meter really performs adequately.

He has a point; if you’re mastering for broadcast, you want a digital meter that’s able to respond with pinpoint accuracy. However, I’d like to focus on part of that quote:

The VU meter … gives an impression of perceived loudness.

While digital meters do a great job of letting you know if your signal is clipping, they don’t correlate much with what you’re actually hearing. One of the reasons people love mixing outside the box is that analog meters move the way the music does. So let’s set up some analog meters.

meter

Klanghelm VUMT is my favorite meter plugin, and it has far more features than we’ll need today. For now, just bring it up as a simple VU meter and apply it to a vocal track. Adjust the track volume (pre-fader) in the DAW so that the meter is reading around 0VU for sustained vocal phrases. Continue reading “Digital Tape: Gain-Staging Vocals”

Digital Tape: Analog Gain-Staging in the Box

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In my opinion, gain-staging is the most important step of the mix process. Properly preparing your audio sets the foundation for your mix; unfortunately, this step is often neglected or misunderstood. So in the hopes of simplifying this process, I’m starting a series of short posts on how to apply analog mixing practices to the digital domain.

One of the biggest differences between analog & digital is the way the equipment responds to level. When recording through tape & tube equipment, there’s a sweet spot in the middle of the range where fidelity and signal-to-noise is optimized. Get the level too low and your signal gets lost in hiss; get the level too high and it’ll distort. 24-bit digital is an entirely different picture; get the level too low and it’s not much of a problem, as long as your peaks aren’t clipping. Compounding this problem is the fact that digital meters don’t do the best job of representing what we actually hear.

Because we’re not fighting for a smaller sweet spot, we tend to be more relaxed when it comes to gain-staging in the digital world. This is fine for recording, but it creates big problems when you enter the mix stage, because:

  • if your levels aren’t consistent, your faders won’t be representative of the actual mix.
  • if you have multiple tracks that are close to peaking, they’ll clip your master bus when combined.
  • saturation, distortion, and analog-emulation plugins are level-dependent just like analog gear.

What we want is tracks whose levels are consistent in relation to each other, high enough to optimize signal-to-noise, low enough to leave plenty of headroom on the master bus, and gain-staged for use with analog emulations. How do we do this? Read on.

>> Digital Tape, Pt. 2: Gain-Staging Vocals

Gear Talk: Quality Over Quantity

Noname


I’m a firm believer in using a small set of tools that you know inside & out, and this applies very strongly to my audio workflow. Rather than downloading massive plugin bundles, I’d highly recommend learning to work with just one DAW, one EQ, one compressor, and one reverb until you’re intimately familiar with the principles of each. 90% of my work is done with 4 very powerful pieces of software that I’ve listed below, and I’d highly recommend them to anyone who’s doing audio work at any level.

DAW // REAPER ($60)

Your DAW is your workflow, and workflow is the most important part of the mix process. I’ve been using REAPER for years, and I wholeheartedly recommend it for everything from editing podcasts & recording live shows to mixing & mastering studio albums. REAPER isn’t just cheaper than Pro Tools & Logic; in my opinion, it’s better. There are so many things I love about this DAW; free updates for life, incredible stability, fast & intuitive clip editing tools, flexible audio routing, great hardware integration, and perfect audio quality. I was able to use it competently after a few days of experimentation, but 2 years later I bought a hard copy of the manual and realized how many incredible features I hadn’t even discovered. Continue reading “Gear Talk: Quality Over Quantity”

Gear Talk: Buying Used Software

It took me a while to realize this, but you can buy audio software secondhand. Used software is the same as new software, but with a little patience you can buy your plugins for far less than their sticker price (usually about 50% off). Here’s a list of places where you can buy licenses; all of these are reputable communities with checks & balances to make sure you’re not paying for pirated software.

I’ve been buying from these forums for years now and I’ve only had good experiences; that said, make sure you pay through a service that allows disputes in case anything falls through.

Mixing Live Music: Hippocratic Filters with Bessel Curves

Noname


Around a year ago I came across an enlightening post by Bob Macc on the consequences of treating your tracks with aggressive filters. You should go check it out yourself, but the big idea is that using steep filters causes phase distortion that reaches all the way up and down the frequency spectrum. Phase distortion removes clarity and impact from your mix, so it’s not good. With that in mind, I’ve come up with some points of good practice for filtering your audio.

First, use gentle filter slopes. 6db/octave is my go-to for LPFs, and 12db/octave is my go-to for HPFs. This lessens the impact of phase distortion, but most importantly, it sounds more natural and there’s less risk of accidentally cutting out the good stuff.

Second, use a Bessel curve. Bessel filters are linear phase, which means there’s near-zero phase distortion when they’re implemented correctly. While some EQs have linear phase DSP options, remember that if you’re using steep filter slopes, linear phase will cause distortion too; it’s the combination of gentle slopes and Bessel curves that’ll preserve your audio.

This advice is in line with the Hippocratic philosophy of mixing, e.g. “do no harm.” I’m mixing mostly acoustic music, hut it doesn’t matter if you’re mixing orchestral, folk, punk, or EDM; phase distortion from filters is rarely something you want. Following the two points above will save you a lot of mix clarity and let you put the distortion where you want it.

Digital Tape: Gear is Not Additive

RecordingIsSubtractive_01


I want to take on the mindset that recording is additive.

Here’s what I mean; when musicians are shopping around for a studio, it’s common for the engineer to mention that such-and-such gear was used by such-and-such artist. They do this because it works; people love to hear it. There’s a mythology around famous gear that usually sounds like this: If you sing through Sinatra’s mic, you’ll sound like Sinatra. If you’re mixing through a Neve, you’ll sound like Steely Dan. It might not be explicit, but it’s often implied that the sound comes from the gear. Selling a studio based on its gear is a problem unto itself, but this all stems from the idea that recording is additive; that every piece of gear you record through is going to add something to the sound until your music comes out the other end sounding like a finished product.

But it’s actually the opposite. The microphone, the first item in the signal chain, is essentially a filter. It’s rolling off the frequencies at both ends of the audible spectrum, and adding resonance and noise. The next item is the microphone preamp; a “clean” preamp is going to do its best to preserve all the information in the original signal, while a “colored” preamp is going to lose some information, usually transients & high frequencies. If you’re tracking through a compressor, you’re decreasing dynamic range. If you’re recording to tape, you’re adding noise, losing more transient impact, and further reducing the frequency range. If you’re recording to digital, you’ll need high-quality conversion to translate the analog signal without degradation. Continue reading “Digital Tape: Gear is Not Additive”