The Million Dollar Tone

In February of 2013, I was invited to meet with the top editors of a major gaming magazine to demo BandFuse: Rock Legends, still in development. Little did I know that they were all formidable musicians who knew guitar amps and tones. And I had a problem: our proprietary cable that connects the guitars and bass to the console wasn't final yet.

We set up in a soundproof room, routed everything through their recording equipment, and anxiously prepared to go through the many game features. They filed in and we cranked up the game. But just as I was about to start, the comment came, "Before anything else, we need to hear the tones." Disaster.

Afterwards, at a bar across the street, I confided in my PR guy that the demo had gone worse than any I had been in. Once the tones weren't there, you could tell that the editors basically stopped listening. It was painful. They cared, and though we had the goods, we just couldn't show them that day. Fortunately, they would invite us back eight months later.

How Do You Start This Thing?

My role as the Game Director for BandFuse: Rock Legends started three years ago in November 2010. I was the first person on the production team. I had the unique background of video game design, music, and technology. And I saw the project through from initial concept to completion in November 2013.

From the beginning, one of our biggest concerns was that, after the success of Guitar Hero and Rock Band, others had tried to do something like this and [arguably] failed. There were several half-baked attempts, and one of the major hurdles was getting quality tones and low latency.

Since we were already five years into the previous generation hardware, the first question was what engine to use. Right away it was clear that a tremendous amount of processing would be necessary to get the tones. We needed a solid, flexible engine that was somewhat lightweight and had amazing audio support. It quickly became clear that every engine out there was focused on graphics with audio as a second class citizen.

To decide to not use an existing engine was a difficult call. But as we started looking at requirements like running the game at 1000 fps and needing a custom built system around tablature instead of 3D art packages, it felt right. So we did what any self-respecting game developer would do: we built an engine from scratch, and we named it the ZZEngine after our favorite little ol' band from Texas.

The initial version did run at 1000 "audio" frames per second. [Spoiler: the shipped version is considerably faster.] It also sounded awful. The first cut at simple guitar gain was like someone grated a bag of cutlery across a tin roof. (code listing 1)

//-----------------------------------------------------------------------
// Embarrassingly Simple Distortion Audio Effect
// Copyright 2010 Realta Entertainment
//-----------------------------------------------------------------------

static float simpleDistortion( float in, float gain, float threshold )
{
       // simple gain
       float out = in * gain;

       // simple foldback
       out = ZZMath_Fmod( out - threshold, 4.0f * threshold );
       out = ZZMath_Fabs( out ) - 2.0f * threshold;
       out = ZZMath_Fabs( out ) - threshold;

       return out;
}

We Are Not a DSP Company

When making games, it's critical to keep in mind that you are in the business of making games. Read that again. It sounds obvious. It's tempting to try to be the best at everything and that's just not realistic.

DSP is short for digital signal processing and encompasses a specialized area of mathematics primarily used for audio filters, effects and emulation. There are companies with decades of experience in DSP, and guitar amp emulation has made great strides. In our case, while it was tempting to think we could develop our tones from scratch, I often reminded people that "We are not a DSP company. We make games."

So a long story short, we went looking for partners and found McDSP.

McDSP is an award winning company near us in the Silicon Valley. Founded in 1998 by Colin McDowell (thus the name), they develop industry acclaimed professional audio plugins used predominantly by the music and movie industries. Add to that, they're fantastic guys to work with.

We started with one of their existing plugins, an array of amp simulations, and ported it over to the console. While this was a good start, the quality wasn't even close to what we knew would be needed. But now we had a framework to start from and Colin and his guys were up to the challenge.

Finding Balance

One of the unique challenges of working in the Games Industry, and one of my favorite things about it, is the necessity to work across multiple disciplines. In this case, we were straddling three critical areas: musicality, hardcore tech, and game design. If any of the three were not in balance, the end result would not be right.

Let’s look at what could have happened with three simple cases.

For me, the craft of game making is in these critical crossroads, this fragile process where it’s so easy to go wrong and so hard to figure out later just what was missing. I’ve seen so many games where things simply did not “fire on all cylinders.” Everyone including the layman can tell when it doesn’t work.

Shoot ‘Em All

Let’s recap where we were: we had an engine that ran fast enough to deliver imperceptible latency, a baseline set of amp modeling algorithms running in said engine, and the option to simulate most of the amps in the pantheon of rock. So we were all done right?

Cue maniacal laughter. We were just getting started.

It was at this stage that many things happened at once. Now, knowing what was possible, we stepped back and audited the entire history of amps and pedals in rock and roll history. We carefully chose a collection that covered the signature sounds.

For example, some of the guitar amps we voiced include: Fender® Tweed Bassman® 4x10, Vox® AC-30® 2x12, Fender® Blackface Deluxe Reverb® 2x12, Mesa/Boogie® Mark I® 1x12, Marshall® “Plexi” Super Lead 100 Model 1959 4x12, Marshall® JCM-800 4x12, and Peavey® 5150® 4x12. Elements of these amps show up as our Vintage/British/American Clean and Hi-Gain Guitar Amps in game.

We unified the control schemes across all our amps, removing complicated controls in favor of simple gain, volume, reverb and equalization tuning. Sharp eyes may have noted that we paired each amp head with the speakers that would produce the most iconic sound for that amp, rather than leaving this up to the player to screw up.

Then all the amps were sent to a soundproof professional studio and “shot” (see sidebar “A Word from Seth Chapla on Amps”) and the data collected was delivered back to McDSP who used this to custom model everything according to our control schemes. The amp simulations we ended up with were designed around signature amps, but certainly achieved a unique sound we wanted. The listening sessions involved comments like “not enough sustain,” “the notes need to bloom,” “doesn’t respond correctly when we scoop the mids,” and “more sparkle in the high end.”

When we finally got tones that worked the way we wanted, the team was ecstatic. There were many meetings toward the end where we would just pass the guitar around the room and everyone would shred (or try to) with big smiles on their faces.

Overcoming The Resistance

And this brings us full circle. When the tones were developed, everything had been tuned around a special reference cable that we developed in-house with a particular impedance. For those who don’t know the term impedance, it has to do with the electrical resistance of the wire from the guitar to the amplifier. Subtle changes in that value have a large impact in the gain stages of amp modeling.

It was that cable, or rather that latest batch of final product cables that we brought with us, that was out of whack when we went to our big demo back in February. With the wrong response in the cable, none of our carefully tuned algorithms responded properly.

But we were invited back. And starting where we left off, we were immediately asked about the tone, more specifically “…can it do Gilmour?” (see sidebar “The Million $ Tone”)

David Gilmour’s tone is complex, varied across different songs, and instantly recognizable. Fortunately, Marcus -- who was responsible for dialing in every tone in BandFuse: Rock Legeds -- was on site. He quickly dialed up a gorgeous bubbly tone that was close enough for anyone but a total purist. Eyes widened, smiles moved across faces, and we proceeded to rock the casbah for several hours.

Outro Solo courtesy of Jimi Hendrix

During the course of making BandFuse: Rock Legends, nearly every person I worked with admonished at some point, "Now you know it has to have amazing tone." I got good at nodding and smiling. Whether it was the editor at a major gaming publication, my own notetracking team, the Chairman of the Board, or even Slash, everyone agreed the buck stopped and started there. No pressure.

Then, to turn it up to 11, we announced that we were launching our DLC (downloadable content) with none other than Jimi Hendrix as the centerpiece! Talk about the true test of what our audio engine could handle. [So far it’s going incredibly, but stay tuned throughout 2014 as there are a total of 15 songs from Hendrix coming.]

But the real response has been overwhelming around the tones. We have people who sit and noodle on their guitars while on the Start Menu – just opening up the Quick Rig and dialing in that virtual 4x12 cabinet sound of rocket ships and rolling thunder. It’s super easy and fun to dial in, and we use our own in game UI to create the tones ourselves for every song in the game and all the DLC to come.

It’s fun to blog about it, but the fact is that this is a game made by musicians for musicians – and if you’re not a musician yet, then BandFuse: Rock Legends will get you on your way there. Go forth and rock!

A Word from Seth Chapla on Amps

By Seth Chapla, Audio Director, BandFuse: Rock Legends

We were lucky enough to have an awesome selection of amps at our disposal on this project - I had a few really cool ones that were iconic for certain eras/styles, and Marcus loaned me a couple ridiculous ones - when he gave them to me, it was the kind of moment that reminded me of that scene in Star Wars when Han is loaning the Millennium Falcon to Lando and says: "I've got your promise... now... not a scratch". I had a full-fledged recording studio in Emeryville, CA at that time so I brought them down there, put them in a dead room, and started "shooting" them (AKA miking them up and recording the unique frequency curves of each amp circuit and speaker).

I've been miking amps and recording guitars since I was 14 years old, so when it came time to choose the mics, I picked my 3 favorites - a ribbon mic, a dynamic mic, and a condenser. From there, I paired up the amp heads with 3 different iconic guitar speakers, and in the case of the combos, I shot those with their respective internal speakers. From there, we had McDsp build the tone stacks (the way that the mid, treble, and bass controls respond on each different amp) to reflect the style and era of each amp. This was a magic moment – because, even when you can build an amp in software to respond like the real thing on one setting, when you start tweaking the knobs, the amps have to feel right with the treble on 7, mids on 10, bass on 3, etc.

There were so many steps in the process, so many details we were trying to encompass, but Marcus, Jon and I talked a lot about how we wanted to implement them in the game - whether we wanted to break the amps apart or not, and let people hot swap speakers, mics, etc. Ultimately, we came to the conclusion that certain speakers really belong with certain amps, and certain mics and mic positions sounded better than others depending on the rig. We picked the most musical combinations to our guitar player ears because we wanted the people at home playing our game to be able to pick an amp in the quick rig and start melting faces without having to get a degree in physics to figure out how to set up their guitar or bass tone. What we ended up with was an elegant and simple user interface that made it pretty much impossible to get bad tone.

Suffice it to say, Marcus, Jon and I weren't pulling any punches when it came to the design and review process on these amps. They had to be the best out there in console gaming, and they had to sound and feel good enough that we'd be willing to bring them on the stage with us. They had to sound good enough that we would sit around shredding with them for hours on end without getting tired of them. When we got the final code drop from McDSP, implemented and iterated, and finally heard the finished product in the game, it really blew our hair back, and that's what rock and roll is all about!

A Word from Marcus Henderson on What is the Million $ Tone

By Marcus Henderson, Master Guitarist/Game Designer, BandFuse: Rock Legends

“That sound? God. I’d have to search for a whole string of words. It would be a whole chapter in itself.” -- Billy Gibbons

The Million Dollar tone. The tone of the gods... Whatever you call it, it's the sound of complex engineering wielded by the capable hands of a certified guitar hero. Guitar players like David Gilmour and Eric Johnson are a few of the stellar guitarists with a tone that most of us drool over. But what makes their tone so valuable? And how did we recreate the necessary tools available for players to develop their own million dollar tone in BandFuse: Rock Legends?

Signal processing is an art form. It requires great ears and an innate sense of tone that spans over several decades of technological development, from the basic tube-based designs of Jim Marshall's early amps, to the high-tech modeling systems of today. A deep understanding of music history is also helpful for identifying components that can be digitally modeled and recreated. Essentially you have to know what to put in the digital realm by appreciating and understanding the analog methodology of earlier amp builders and innovators.

When it came time to model amps for BandFuse: Rock Legends, Jon, Seth and I put together a wish list of our favorite tones and in effect, set a ridiculously high bar to aspire to by insisting that our tech could handle any song across all genres and styles, take on all comers, and still be strong enough to create the most complex of sounds; even the "Million Dollar Tones" if you will.

The true test came at one of the major Gaming mags later on in the fall... You know the story- After nervously setting up our dev kit we were immediately hit with "Yeah, it's great, but can it do Gilmour."

Challenge accepted! I called up the British High Gain amp, dialed in the perfect low gain stage and knowing our amps are designed to emulate a Tube amps "bloom" (having a note rise and sustain; a desired trait in high quality guitar amps), I spun a few more knobs and threw off the first few bars of the solo to "Another Brick in the Wall" by Pink Floyd... Sweet success! The Gilmour tone suddenly enveloped the room and everyone went wild.

Now, I'm not saying that Eric Johnson and David Gilmour are going to chop an hour off of his sound checks by cabling up a console and hitting the quick rig (they certainly can if they feel so inclined), but with our technology, a hardcore sonic ethos and good ol' California persistence, we can safely say that we can not only emulate any sound but also lovingly and faithfully reproduce even the most complex of tones. From cheap pawn shop amps with lots of lo-fi fuzz, all the way to the "Million Dollar Tones' of some of rock’s royalty. We spent countless hours perfecting these for your enjoyment. We hope you like them as much we enjoyed making them. Regardless of what you play there's a sound in BandFuse: Rock Legends waiting for you! See you in the game!