When to Solo

Jun 27 2009

Every term, without fail, I get a few assignments handed in with all of a mixer’s solo buttons enabled. The usual problem seems go something like this, “I turned a solo button on and it muted all of the other channels on the mixer. I’m not sure what happened but in order to hear my mix again I had to turn all of the solo buttons on.” As ridiculous as this might sound to a pro, it’s a common mistake for beginners. If you don’t know what the purpose of the solo button is you’re not going to understand what’s going on when you press it. So, let’s clear this up once and for all.

At its core, the solo button on a mixer channel allows you to quickly audition a signal all by itself, or with a group of other solo enabled channels, without needing to mute all of the channels that you don’t want to hear. For example, if you see a signal on Channel 10 but you’re not sure what it is because you haven’t labeled that channel yet, press the channel’s solo button. Or, if you need to have a closer listen to the blend on a three part vocal harmony, press the solo buttons on all three harmony channels and instantly mute all of the other tracks in your mix. Then, to return your mixer to its normal monitoring mode, turn off all the solo buttons. Pro mix engineers are constantly switching back and forth between listening to soloed signals and the whole mix as they’re working.

The obvious reason why you don’t want to leave mixer channels in solo mode is because you might have a channel muted somewhere on your mixer that’s supposed to be in your mix. It’s easy to hear if you’re missing something really obvious like a guitar or vocal part, but you might not so easily realize that you’re missing an aux effect return channel. For example, if you’ve soloed a bunch of tracks your reverb return channel might be muted, and, consequently, you’d be missing much of the depth and space in your mix that was being created by your group reverb effect. (If you’re not sure about how a group reverb effect works, check out my earlier blog titled, “Let’s Talk Reverb“.)

At this juncture, it’s worth noting that there will be channels you never want muted when you press a solo button. For example, if you always want to hear a soloed track with its group reverb effect intact. Or, when you have a MIDI control track that always needs to be running in the background (such as a drum track or controller data). In these situations, you never want the tracks muted when you solo a mixer channel. So, to safeguard these tracks the best designed mixers have a function called solo-safe which allows you to disable the track mute action for those channels in solo-safe mode. For example, in Digidesign’s Pro Tools you press Command (Mac), or Control (PC) and click on a solo button to enable a channel’s solo-safe mode.

It’s also worth noting that there are several different types of solo modes, dependent on the level of mixer (hardware or software) that you’re using. Top of the line pro mixers may have three or four different solo modes that you can switch between, while a basic home studio mixer usually just has one set solo mode. The two most common modes that you need to understand are latching and canceling. They may have different names dependent on the mixer’s manufacturer, but they will always operate in the same basic fashion. On a mixer with latching solo the solo button stays on until you turn it off. You can keep pressing solo buttons and they will all stay on until you turn each one off. On a mixer with canceling solo pressing a solo button turns it on and pressing another solo button turns the last solo button off. Consequently, in canceling mode you can only have one channel soloed at a time unless you hold down a modifier key while pressing additional solo buttons (such as the Shift key in Pro Tools).

I wish every mixer had, at the very least, these two basic solo modes. However, more often than not most mixers only feature the latching solo mode. And, those mixers that do have both modes are usually set by default to latching. Though, I can’t help but think that having the default solo mode set, instead, to canceling would help beginners avoid a lot of confusion. This, and Mackie’s brilliant feature on their hardware mixers, the Rude Solo Light. It’s a big red indicator that let’s you know whether you have a solo button engaged somewhere on your mixer. Indeed, novices and pros alike can use this feature because when a mixer contains a ton of channels and a solo button is accidentally left on somewhere on the mixer, especially on a channel that has little or no audio, trying to figure out where all of your sound went can leave even the best producer scratching his (or, her) head for a minute.

Mackie Rude Solo 420
photo credit: inweaknessbe’s photostream

In lesson 2 of my Remixing with Pro Tools and Reason course I ask students to cook up a comprehensive rewire session that will work as a template for remixing. Needless to say, we go over all the details and really get deep into it. But, often, because there are so many possible ways to build your environment (the Reason rack and the Pro Tools tracks) students are often left questioning whether their setup is really the best. Well, the only way to know for sure if your rewire session setup will work well for you is to jump in and start using it. This way, you’re actually working with your setup instead of just thinking about it. No doubt, you’ll be making changes and improvements over time.

In the spirit of sharing and knowing that a really good example is worth a thousand words (or more), I’ve cooked up a rewire session template based on what works well for me when I’m composing and mixing. I’m attaching it here as a Zip containing the Pro Tools 8 session file, the Reason 4 song file, and a Word document listing my suggested rewire inputs. The rewire session is for all of you to study, use, and modify. There’s a short demo in the Pro Tools session that’s just there as a sound check. Erase the demo before you start writing your own music so that you can start with a clean slate.

Have fun and keep finishing your productions!

ReWire Session Template

ReWire Session Template Zip

Download directions:
Right-click PC and from the pop-up menu choose, “Save Link as…”
Control-click Mac and from the pop-up menu choose, “Save Link as…”

Ever wish that you could do take after take in a session without having to look at the clutter of tracks piling up? How about the ability to turn one take on at a time and listen to it without having to turn all of the other takes off? The old school term for this sort of function is, virtual tracks. These were widely employed in the first hard disk recorders to hit the market because they had a limited track count but a not so limited storage capacity. For example, you had 24 voices that could sound simultaneously, for 24 track playback, but each track could have up to 99 virtual tracks associated with it (dependent on the size of the internal hard drive, of course). This greatly expanded production power, giving you more options in the number of takes you could record, or create through editing, per track.

Even today, with our powerful computer based digital audio sequencers, virtual tracks are still very useful. To this end, Pro Tools features a type of virtual tracks function called playlists. Each track (MIDI and audio) in your Pro Tools session (LE and HD) can have as many playlists as you need attached. These might be different vocal takes, different real-time groove settings applied to a MIDI performance, or different arrangements of the track’s audio or MIDI regions.

A sound designer I know in Los Angeles who has developed sounds for many movies and TV shows uses playlists to quickly audition different treatments of sound effects for the director. He uses AudioSuite to process the sounds ahead of time, and when the director comes to listen he can fluidly play different versions of his effects while locked to picture. Pretty darn cool.

Here’s a video I made about using playlists in Pro Tools to easily record and manage different MIDI takes.

When it comes time for students to mix their final class projects, a common question I hear is, “Should I put the EQ before or after the compressor? Which way is correct?” There’s not actually a right or a wrong way here. Instead, it’s about the sound that you’re going for, the sound that you hear in your head. Each position, EQ pre (before) or EQ post (after) compression produces a distinctly different sound, a different tonal quality and coloration. As a rule, using EQ in front of your compressor produces a warmer, rounder tone, while using EQ after your compressor produces a cleaner, clearer sound. So, the question you need to ask yourself for each channel in your mix is, “Do I want to EQ the compressed signal or do I want to compress the EQed signal? What sound do I want for this signal?”

I find that in most of my mixes about 80% of my EQ is post compression. I usually start with all of my channel EQ set up post compression, but in Pro Tools it’s a snap to drag and drop the EQ plug-in to a different insert slot and hear the difference. To facilitate this workflow I have my compressor plug-in inserted in slot C and my EQ plug-in inserted in slot D. If I then want to hear the EQ pre compression, I simply drag it to insert slot B. This works great even when I’ve already created my EQ curve post compression, I simply drag the EQ plug-in pre compression and Voila! I can immediately hear how my signal sounds when I’m compressing the EQed signal, versus EQing the compressed signal.

It’s also fine to insert your EQ pre and post compression. But, you should employ this technique sparingly because over doing will likely lead to an over EQed mix that sounds harsh and grating. An acceptable way to apply EQ pre and post compression would be to employ a single High-Pass EQ band pre compression, to sculpt your signal at a macro level before compression, and a multi-band parametric EQ post compression to really fine tune the sound.

EQ Pre and Post Compression

Of course, I can talk about how EQ sounds pre and post compression until I’m blue in the face. Carefully listening to the difference between the two positions is what will cement the sonic image in your mind and allow you to reach for the appropriate color in your mix. Below is a rather heavy handed EQ job pre and post compression for you to hear the difference. However, don’t just take my word for it—especially since streaming Web audio and computer speakers lack the clarity necessary to hear this level of fine sonic detail—you should also experiment with these two EQ positions in your own DAW software program in order to hear the difference on your own system.

When enabled, the Elastic Time plug-in analyzes two dimensions of your audio in order to calculate the recorded performance’s tempo. It looks at the audio region’s duration in bars and beats, and it looks for transients that represent a regular periodic rhythm in the recording. In theory, if the rhythmic content of your recording is clear, with distinct transients, Elastic Time can figure out a performance’s tempo regardless of whether the audio region is trimmed to a perfect loop or not. This is really neat when it works, but it doesn’t perform miracles (nor should you expect it to, that’s not producing your own music).

Instead of relying blindly on Elastic Time to perform your beat matching (as in, crossing your fingers and hoping for the best), there are several simple steps that you can take ahead of time to prepare the audio and ensure perfect results every time. Performing this pre-processing, even though it’s a tedious task, helps to preserve the audio quality and the groove of the original performance after your tempo change.

The easiest way to demonstrate my pre-processing approach is to take you step by step through the process. This is the best way to understand not only the steps in the process but the logic behind my approach. (Try it a different way and you’ll find out just how quickly you can end up with a train wreck.) The DRM (Digital Rights Management) free stems being offered for your remixing pleasure by Radiohead, of their song “Nude”, on iTunes is perfect for this example. The stems are $0.99 each and you only really need two of the five available, the “Drum Stem” and the “Voice Stem”. But, it’s nice to have all of the stems in your session, even if you don’t use the “Bass Stem” and “Guitar Stem” they’re handy for finding the key of the original, and the “String FX Etc. Stem” contains several sounds that are perfect for a remix.
iTunes Nude

Remixing Radiohead

1. Create a new Pro Tools session and import all of the “Nude” stems. When prompted, select the import Destination as New Track with a Location of Session Start.
step 1

2. Arrange the tracks in the Edit window with the Drum Stem on top and the Voice Stem just below.
step 2

3. Mute all of the tracks except the Drum Stem. Use Tab to Transient to locate the very first downbeat in front of the vocals (approximately 1946229 samples in from the session’s start) and separate the regions.
step 3

4. Select the Edit Group, double click on the latter Drum Stem region and separate all of the regions.
step 4

5. Select the Shuffle Edit Mode and delete the first set of regions so that the downbeat of the second set of regions scoots to the beginning of the session.
step 5

6. Disable the Edit Group and using Tab to Transient find the downbeat every two bars in the Drum Stem and separate the regions. (The only region that I left as 4 bars is the drum break, having 2 bars before the break itself.) In some instances, you can make the separations every 4 bars, but with “Nude” there’s a lot of human tempo variation and every 2 bars will produce the most precise overall beat match.
step 6

7. Select the Edit Group and double click on each 2 bar Drum Stem section and separate the sections.
step 7

8. Select each 2 bar section and apply Identify Beat to generate a tempo map for each section. This will beat match and lock each 2 bar section to your session’s tempo grid. (You could use Beat Detective to generate a tempo map, but my method preserves the original performance’s groove every two bars, while simultaneously guaranteeing that the original’s downbeat is locked exactly to the grid every two bars. This way, your beat match never drifts.) At this stage, it’s also helpful to create a Click track in order to audition your tempo lock.
step 8

9. Change the Timebase selector for all of the tracks to Ticks. This will lock the regions to their relative bar and beat positions so that they stay in beat when you make your tempo change. Then, enable the Elastic Time plug-in for each track. Set the Drum Stem to Rhythmic, the Voice Stem to Monophonic, the String FX Etc. Stem to Polyphonic, the Bass Stem to Monophonic, and the Guitar Stem to Polyphonic. Give Pro Tools time to analyze the audio. (For now, leave the Elastic Time plug-in set to Real-Time Processing.)
step 9

10. In the Transport bar, disable the Conductor and enter a new tempo in the Current Tempo field, or experiment with the Manual Tempo Slider. Since the original tempo is about 42 BPM, it’s nice to bring the tempo up to about 62 BPM. At this tempo you can then record drums in double-time (124 BPM) and be at a dance tempo! (Once you decide on your remix target tempo, if your computer is running short on processing power, your can set the Elastic Time plug-in to Rendered Processing.)
step 10

Here’s what the final results sound like, using all of the stems at 62 BPM, some effect processing, and backed by Digidesign’s Strike virtual drum instrument playing in double-time at 124 BPM:
Nude – The Strike Remix (by Erik Hawk)

With the introduction of Elastic Time, in Pro Tools 7.4, it’s clear that Digidesign is taking a proactive stance against competing programs boasting easy to use, time compression/expansion based, automatic beat matching algorithms. Though it’s tough to proselytize that Elastic Time is as easy to apply as similar functions in competing software applications, I can say, without a doubt, that it kicks butt in terms of its audio quality and the level of direct control you have over how the algorithm is processing your audio. It’s deep and offers a variety of ways to fine tune the processing, from multiple Elastic Audio “plug-ins” (Polyphonic, Rhythmic, Monophonic, and Varispeed), to individual control panels for each plug-in type, and the ability to freely edit Warp markers directly in the Edit window. Talk about control! Due to the simple fact that you have such a high degree of control over the Elastic Time processing, it requires a bit of homework to master, but once you do, you can achieve absolutely stunning results.

It’s important to note that Digidesign calls Elastic Audio a “plug-in”. However, it’s not applied in the way you’d normally think of a plug-in, as an insert on a mixer channel or an offline AudioSuite processor. Instead, it’s applied directly to a track in the Edit window, with its plug-in menu located just below the track’s Timebase selector.

ET Selector

Beat Matching Made Simple
Elastic Time is at its most intuitive when browsing for loops in the Workspace. Simply turn on the Audio Files Conform to Session Tempo button (it looks like the ticks metronome) in the Workspace, select one of the four plug-in types (they’re pretty self-explanatory), and when you click on a loop’s play button (the little speaker) the loop will be automatically analyzed and played back at your session’s tempo. You can even do this while your session is playing, allowing you to hear immediately whether the loop you’ve selected is a bang or a bust. Talk about optimizing your workflow! When you find the loop that you want, simply drag it into the Edit window and it will be deposited on a newly created ticks based audio track, and conformed to your session’s tempo. It doesn’t get much easier than this.

Workspace ET

For those of you who are used to working with REX loops, it should be noted that with the introduction of Elastic Time, the Processing Preference setting, Import REX Files as Region Groups is off by default. So, if you’ve recently updated to Pro Tools 7.4 and you’re wondering why when you drag in a REX file it no longer comes in as a region group, mystery solved. To return to your old way of working with REX loops, make sure that the Processing Preference for Import REX Files as Region Groups is checked, as well as the REX and Acid Files Only selection for Drag and Drop from Desktop Conforms to Session Tempo. From the Workspace, you can also audition REX loops at your session tempo when the Audio Files Conform to Session Tempo button is on. And, if when you drag a REX loop from the Workspace into the Edit window, you want the REX loop to automatically conform to your session’s tempo, again, the Audio Files Conform to Session Tempo button must be enabled.

REX Import Preferences

Using EQ Effectively

Mar 31 2008

A common question that students ask is, “How do I use EQ? What’s the best way to EQ each instrument in my mix?” Unfortunately, there’s no simple answer to this question. Unlike a compressor plug-in, most EQ plug-ins don’t have presets—if only it where this simple. Instead, EQ curves vary from mix to mix, and from track to track. Even the same instrument, recorded during the same session, but in a different song, will be treated differently. This is because no one instrument is ever heard in a vacuum, and every arrangement is unique. Consequently, each mix requires its own set of individual EQ curves to make it sparkle and shine.

That said, here’s the rub. The secret to efficient EQ processing is twofold: an ability to hear the frequencies that you want to change, and a working knowledge of the EQ controls with which to do the job. Both of these orders are easily accomplished by themselves, it’s putting them together that can be challenging.

In order to accurately hear your music you must have a good monitoring system, professional studio monitors, and, preferably, more than one set of speakers. (See my earlier blog on Setting Up Multiple Monitors for Better Mixing.) Your monitors must be positioned properly in your room and your room should be tuned to achieve the best possible listening environment. (I’ll discuss how to tune your room in a future blog.) The bottom line is this, if you can’t hear what you’re working on because all you own for monitoring is a pair of headphones and computer speakers, you can’t expect to become an EQ master.

Next, you’ll need to understand all of an EQ processor’s parameters. For example, the difference between Frequency and Q controls, and when to use a high-pass filter versus a low-shelf EQ. Such details are explained very nicely in the PDF document that comes with Pro Tools 7.4, and can also be downloaded directly from the Digidesign Web site, the DigiRack Plug-Ins Guide (version “v74”). (Some versions of the DigiRack Plug-Ins Guide without the “v74” appear to be missing the DigiRack EQ plug-in chapter.) Consequently, I won’t waste space trying to explain all of these parameters here, just read the manual.

Now, let’s jump to the chase, how to go about finding a particular set of frequencies in your signal that you can hear needs help (and you can hear this because you have properly set up monitors and a fine listening environment). My favorite technique is to insert a parametric EQ, and to use it like an EQ magnifying glass in order to find my troublesome frequencies. This is a technique that has been in use ever since the invention of parametric EQ, so I’m sure it has several other names, but I call it the “magnifying EQ trick.” Here’s a video I made on how the process works.

Let’s Talk Reverb

Nov 02 2007

It’s true that with a Mac Pro computer you can probably insert a D-Verb reverb plug-in on practically every audio track in your Pro Tools session. However, this is a clear cut case of, “Just because you can do it doesn’t mean you should.” Reverb should be applied as a parallel effect, on a bus, in the send/aux return position. There are a few reason’s why:

1) The purpose behind reverb is to mimic the ambiance that’s captured during the recording of a live performance. With multitrack recording, performances are recorded at different times, often in different spaces, and sometimes with no ambience at all (as in the case of a direct line input recording or a virtual instrument). Consequently, there is an absence of the cohesive ambiance that naturally occurs in a live recording situation. Placing a reverb on your mixer’s bus let’s you send an appropriate amount of signal from each performance in your session through the same virtual space, just as if you had recorded everything live, in one space.

2) Reverb creates a sense of depth in your mix, of front to back space. The more reverb a signal is blended with, the further back in the mix it will sound. Alternately, the less reverb a signal is blended with the closer it will sound to the listener. By using a channel’s send to add different amounts of reverb to a performance you can bring an instrument forward, or push it to the back of your virtual sound stage. For example, a lead vocalist can be made to sound in front of the stage by mixing her with only a little reverb, while a cello can be made to sound at the far back of the stage by mixing it with much more reverb.

Always keep your reverb’s dry/wet mix parameter set to a 100% processed return. The reverb effect is created by mixing the dry channel signal with the wet reverb effect return. If your reverb’s dry/wet mix parameter is less than 100% you’re just returning dry signal back into your mix, and this is not the object. Use a channel’s send to adjust the amount of reverb you want mixed with a track. The higher the send level the more reverb effect return you’ll hear for that track.

3) Reverb, used correctly, on a mixer’s bus (in parallel), sounds superior in both clarity and depth than individual reverb plug-ins inserted on each mixer channel. When it comes down to it, that’s really what matters, it just sounds better.

In most modern DAW mixers you can send to a reverb in either mono or stereo. I prefer a mono send and a stereo return for most projects (such as dance, hip-hop, and alternative). However, a stereo send and a stereo return is equally acceptable and I often use this configuration when I want to achieve a higher degree of separation and fidelity (for example, a sparse acoustic recording or string quartet). Pictured below is a mono send/stereo return reverb configuration for Pro Tools (notice my choice of the “mono/stereo” version of the D-Verb reverb plug-in). I’m also attaching a Zip of a Pro Tools 7.3 session so you can dig around and see first-hand how it’s all set up.

Reverb 4 U Pro Tools Session File

Reverb 4 U

It seems like the Pro Tools Accelerated Videos (http://www.digidesign.com/accelerated) are often overlooked as an educational resource. Sure, they’re clearly for promotional purposes, extolling the virtues of Pro Tools. But, at the same time, they are an excellent overview of Pro Tools centered music production techniques and features, both new and old. The videos aren’t nearly as in-depth as our twelve week courses here at Berkleemusic, but if what you need is a quick blast of information, an overview of a feature or technique, the Pro Tools Accelerated Videos are just perfect.

The Pro Tools Accelerated Videos can also be seen on YouTube. Here’s one on using Reason Adapted with Pro Tools and setting up the ReWire connections:

So You Want to Remix?

Oct 27 2007

For starters, it’s a good idea to determine a general stylistic direction for your remix, because not every song will work with every style of beats. In general, the most important factor in making this choice is a song’s original tempo, because no matter how you slice, dice, and warp the audio, there’s always one constant; the less of a tempo change you make on the original the better it will sound in your remix. (This is, of course, assuming you want to hear the original song clearly in your remix. If not, all bets are off.)

Regardless of how great a particular tempo change process is, the further you stretch, compress, and slice up a piece of audio the more warbled, disjointed, and distorted it will become. Since most electronic music styles that are appropriate for a remix inhabit a select tempo range, it’s wise to choose a target remix style with a tempo that is as close as possible to the song’s original tempo. (See the chart below for a sampling of several popular dance music styles and their tempo ranges.)

Tempo changes that are less than +/-20 BPM are usually a safe bet, but this amount will vary depending on the types of sounds and performances you need to alter. For example, slowing down legato bass and vocal performances is trickier than speeding up staccato guitar and percussion parts. Speeding up a performance usually produces better sonic results, with fewer processing artifacts, than slowing it down. However, in some cases, slowing down the original by a few BPM so that you can double-time the remix tempo and reach a suitable dance music tempo can also work. So long as your tempo change doesn’t destroy the musical “feel” and audio quality of an artist’s recording, you’re in safe territory (especially if the remix has been commissioned by the artist or their record label).

To precisely determine the tempo of the original song I fly the stereo mix into Pro Tools, separate out a couple of bars and apply Identify Beat to the selected region. Make sure that the region you create is perfectly trimmed to the downbeat and loops seamlessly. Identify Beat is only as precise as your selection, so if your separation points are off the downbeats by even a little, your tempo calculation will also be off. The clear transient of a kick drum is one of the best landmarks for a downbeat, and the Tab to Transient function can make finding your kick transients an absolute snap.

Dance Music Style and Tempo Chart