Off-Time Projects, Part 3

by David Morgan
in On the Digital Edge
Note: With some “free” time between tours, David continues to retell his unending quest for the ultimate acoustic guitar tone. If you missed the first two parts, they can be found online at Enjoy! —Ed.
Note: With some “free” time between tours, David continues to retell his unending quest for the ultimate acoustic guitar tone. If you missed the first two parts, they can be found online at Enjoy! —Ed.

Last month, I discussed first deconstructing and then re-imagining the input channel settings for one our touring acoustic guitars. That article focused on using the various tools available within the DiGiCo SD5 mixing system. I re-auditioned and modified the onboard settings for channel delay, tube emulation, parametric equalization and dynamic equalization and the Waves V-Comp compressor plug-in.

This time, let’s explore employing three slightly more experimental tools that one can choose from the Waves plug-in menus. Exclusively intended for the acoustic guitars, I have added a second IR Reverb algorithm and a Waves 6 Tap Delay to the SD5’s onboard plug-in rack. I also employed the Waves Vitamin Sonic Enhancer plug-in to the insert chain on each of the four acoustic guitar inputs.

While working at home during my time off, my record/playback capability was defined by my 2-in/4-out Apogee Element 24 Thunderbolt interface. Now that we are in production rehearsals, I have access to the full Clair Global touring FOH gear package that includes the SD5 console and a 96-channel Pro Tools rig. Using a multi-track recording from last year’s tour, I have been able to work separately on each of the four acoustic guitars that are played during live performances. These handcrafted Olson SJ models are exceptional sounding instruments. Over the years, we have incorporated several hardware and software additions and upgrades during our quest to maximize the quality of reproduction. We like to think that the audio product gets a little better with each passing year.

Before leaving California for the tour, there was just enough “hands-on” console time to begin work on adjustments and additions for only one of the acoustic guitars. Using saved presets from that work I had done while home, I loaded the channel settings and plug-in information from the abbreviated session file to the full show layout on our SD5. While playing a full band multi-track recording back from our Pro Tools rack, I began auditioning preliminary sound modifications using a pair of 12” Tannoy nearfield monitors. Production rehearsals for this summer’s tour are being held in a very reflective hockey arena in Albany, NY. Using these reliable nearfields gave me a clearer initial picture of the results as I was manipulating the various software parameters.

‡‡         The Experiment Continues

The first area I wanted to explore was adding a modified room reverb algorithm to the Waves rack. I found an excellent wood room simulation that I loaded into a Waves IR Live plug-in. Next, I cut down the room size parameter to the point at which I could hear only the early reflections with no reverb tail at all. I then shaped the effect’s outputs with EQ to simulate what you might hear if you listen very closely to the sound hole opening on a deep body acoustic guitar. The goal was to add some harmonic complexity to the output of a piezoelectric saddle pickup that is always trapped in a block of wood. I discovered that I couldn’t use too much of this effect without dramatically altering the overall sound. But using it judiciously did create a conglomerate sound that seemed more dense and complex and eventually produced a more pleasing lower midrange element. All four guitars are the same body type and the effect worked noticeably well on each of them. Finally, I outputted the room reverb returns into the longer gold plate reverb algorithm that we have been using for many years on the acoustics to add just a bit of the same spaciousness to the new effect.

That ringing, bell-like quality of a finger-picked acoustic guitar is one of the attributes that does seem to find it’s way through the piezo pickup. Therefore, a one-in, two-out Waves 6 Tap Delay was the next effect I added. The intended goal is to create the illusion of a reflective space around the guitar. Getting to the desired result has been a trial-and-error process of constant discovery. Deriving a complementary combination of delay times, panning, feedback percentages, output volumes and overall equalization has presented an interesting artistic and intellectual challenge. This effect is still a work in progress, but the initial results are very encouraging.

This multiple delay system is another effect that works best at low return volumes. When listening to the stereo return, I generally move the fader up to the point at which I can distinctly hear the effect – and then I usually pull it back by 3 dB. However, in this case, I attenuated the effect to the point at which it was barely discernable. Subtlety seemed to be the best policy. On our last rehearsal day, it all started to really come together as I added more of the elements available to me on the console. The tube emulation softened the effects return to a point where the individual voices from the delay were more diffused.

Attempting to create specialized “black box” effects has put me on a good trajectory in chasing a more faithful representation of an acoustic sound. The room reverb concept and the more complex delay setup have individually and collectively produced steps in the right direction. There is more apparent life to the guitar sound than just the dry pickup output sent to a plate reverb and a stereo delay line. Using the cut-down room algorithm has definitely produced a positive result and increased the overall complexity of the output. The shimmer and chime characteristics have definitely been enhanced by the delay setup. However, I did need to experiment quite a bit with marrying the multiple delay times to the dry signal before I felt comfortable using the effect in live performance.

The Waves Vitamin plug-in offers harmonic enhancement.

‡‡         A Vitamin Can Be Good for You

The next step in this process led me to experimenting with yet another black box effect. The Waves Vitamin plug-in is a harmonic enhancement device that takes the venerable Aphex Aural Exciter concept to a new level. Waves User Guide describes the plug-in in this way:

“Waves Vitamin is a multiband harmonic enhancer and tone-shaping plug-in that can make any track sound powerful and full of spark by mixing an enriched version with the original signal.”

The words “enhancer” and “enriched” are the ones that influenced me to give it a try. I have experienced extremely good results in using the Aphex Aural Exciter plug-in to add a bit of air and achieve better definition with our background vocalists, so I was eager to give this more complex harmonic enhancer a try on the acoustic guitars. I watched a Waves demo video and became further convinced that the Vitamin plug-in might be just what the doctor ordered.

Before I added the Vitamin plug-in to the insert chain on an acoustic guitar, I ran a stereo version across a playback device and listened to some broadband music. I was then able to spend some time getting used to what the slider controls accomplished within the five factory-set pass bands as well as experimenting with the “Dry” slider and the “Punch” setting. Once I had a clearer idea of what could be done with this plug-in, I placed the Vitamin plug-in the pre-EQ insert point just after the V-Comp compressor. I then set out to customize the pass bands to best enhance each of the four acoustic guitars used in the show. For example, one of the guitars ended up with crossover settings of 150 Hz, 600 Hz, 4k Hz and 8k Hz.

In theory, I had anticipated that I would rely most heavily on the top two pass bands to add some extra air to the high frequencies. But, in practice, the bottom two bands were far more useful in reanimating and restructuring the sound from the saddle pickup. I only needed to employ very modest amounts of the upper two bands to enliven the pickup signal. But using greater amounts of the low and low-mid bands did wonders for enhancing the overall body in the guitar sound. I ended up leaving the middle band at its zero (off) setting, as this is the range in which the piezo pickup seems to produce the “boinky” output characteristic — which I am trying hard to overcome.

“Black Box” devices are extremely intriguing to me as there are no “rules” for using them. The Vitamin plug-in is immensely versatile and can be adapted to a wide variety of individual instruments or used as a mastering sweetener for a finished mix. One can even construct a sound from scratch by killing the dry signal and using the remaining five faders to build a completely new sound. I did discover that there is spot on the fader throws at which the effect changes from primarily producing harmonics to becoming fundamental tones. The trick, of course, is finding the sweet spot.

‡‡         Success!

Our tour has long been known for the quality of the acoustic guitar reproduction. We are now well on our way to making it even better. This summer’s tour will be the proving ground. If rehearsals are any indication, we have made strong progress toward the intended goal of greater realism. Each of the many tools we employ has contributed equally to the present synthesis. We are grateful to Olson, Fishman, Radial, DiGiCo and Waves for the products that make constant progress an attainable goal.

Safe Travels!