Groundwork 5.1.2003

Gorgeous and Gratifying Guitar Sounds (Part 2)

By David Franz

 

Hey folks. Welcome back to Groundwork. Last month I discussed how to get sweet signals from your guitar into Pro Tools. Once recorded, there's a lot more you can do with those tracks to make your audience listen in awe. This month I'm going to continue with the guitar theme, and cover several production and mixing techniques for electric guitars.

One of the simplest things you can do to fatten your guitar sound is to double your guitar track, either by recording another track of the same part or by electronically doubling the original track. Pan one track to the left and the other to the right, and you've instantly increased the apparent size of your guitar sound. I like to call this technique "adding stereo meat." (Vegetarians can substitute "stereo tofu" for an equally appealing Pro Tools mix.) Each version of doubling, or adding stereo meat, has its own flavor.

Raw Stereo Meat
The first method involves playing and recording the exact same part on another track. But don't be ashamed if you can't play your guitar part EXACTLY the same way twice; in fact, it's impossible. Just get the two tracks darn close. It's the slight differences between the two performances that make this technique sound so good.

The two almost-identical tracks, when both panned to the center (mono), will often cancel each other out with massive phasing and can sound even smaller than one track. Yet when panned out, the two tracks can sound gloriously large through your main speakers, while adding distinctive little nuances in each ear for the detail-oriented headphone tweakhead.

Processed Stereo Meat
For a tighter (i.e. totally rhythmically-aligned) sound, use a delayed copy of the original track as the panned "double" track. It's really amazing how much stereo meat your single guitar track and its clone can create. This technique is also particularly useful when recording a band with multiple guitar players who are playing similar parts. Not only is it easier and faster than recording and editing four tracks, it's often tighter rhythmically to use two electronically doubled parts than to align two double-tracked parts.

Electronic doubling is easy to do in Pro Tools. On your mono guitar track, set up a mono send (with a mono bus) to a new mono aux track. Press the "Pre" button on the send so the volume fader on the original track doesn't affect the send level. (If the term "Pre'' makes you say "huh?" see the sidebar, "Pre or Post: It's All In The Flow.") Set the input of the new aux track to the same mono bus as the send output (e.g., bus 11, as in the figure). Pan the audio track to the left and the aux track to the right. At this point, it won't sound any fatter. Why? Because the stereo image of the audio track and the aux track are playing back at almost the exact same time, yielding essentially a mono signal.



Delay plug-in with correct settings

 

   

Click to enlarge

Audio track with send and
AUX track with delay plug-in
To fatten the sound, add a short delay to the Aux track. Use the DigiRack Short Delay II plug-in and set the delay length to around 16 milliseconds. 16ms is a good number because it's enough time to separate the tracks to avoid noticeable phasing, but not really enough time for our ears to separate the rhythmic timing differences between the two tracks. Now that's using psychoacoustics to your advantage!

Most times when I do this, I don't mess with any of the other parameters in the delay plug-in because they tend to take away from the true "doubled" sound. But don't take my word for it. Experiment! Maybe you'd prefer adding some modulation and/or feedback to season your stereo meat.

Pre or Post: It's All In The Flow

"Pre" and "Post" are short for pre-fader and post-fader. Deceptively simple, these two functions are quite useful in the Pro Tools mixing environment. But to use them effectively, you need to understand the signal flow in a Pro Tools channel strip.

View pre-fader diagram

View post-fader diagram

When you click the Pre button on a send, the little "p" is highlighted in the send area of the channel strip. Pre directs a signal out of the channel strip through the send before the signal is affected by the volume fader on the track. In fact, the pre-fader signal is not affected by the solo or mute buttons on the track either. If you route a post-fader signal through a send, the signal is affected by the track's volume fader, as well as by the mute and solo buttons. Note that inserts (plug-ins and hardware inserts) affect both pre-fader and post-fader signals.

So, why do we make electronically-doubled stereo meat with pre-fader sends? Because we want the same signal going to each track, allowing us to have control over each track separately. That is, we don't want the volume, mute, and solo controls on the audio track to affect the aux track. Keep the two tracks independent and set up a group for them if you want to mute, solo or adjust their volume together.

When are Post sends useful? Here's an example. I often use post-fader sends when I send audio tracks to a reverb plug-in on an aux track. That way, if I adjust the volume on the audio track, the amount of reverb is adjusted accordingly. If I mute the track, the send has no audio to bus to the reverb, so you don't get a "ghost in the machine:" an extra reverbed track without its dry audio counterpart.

Please note that there are no hard and fast rules for using Pre and Post sends. You can use them creatively in the exact opposite way that I've mentioned here for some very cool outcomes. Experiment with them and let your ears be the judge.

 
   
Click to enlarge

Two audio tracks with two different amp models and two aux tracks with 16ms delays panned out.
Big Guitar Sounds and Onions
Big guitar sounds are like onions — they have layers. Mixing several sounds together (layering) is an effective way to improve your overall guitar sound. Like miking an amp with multiple microphones to capture and highlight specific frequencies, you can also multiply your guitar tracks within Pro Tools and put different plug-ins on each track. It's as easy as choosing "Duplicate Selected Tracks" from the File menu.

Here's an example: Plug your electric guitar directly into your Mbox, 001, or 002. No amps, mics or effects, just a guitar and a cable. Insert an amp modeler plug-in, like AmpliTube, SansAmp, or Amp Farm (TDM only), on your track and record your part. Then duplicate the dry track and add a different plug-in or plug-in setting on the duplicated track. Pan them out and you've got a new flavor of stereo meat: electronically doubled, but with different amp sounds. To really thicken it up, set up aux tracks for both the original and duplicated tracks and electronically double each one using the 16ms delay technique (as in the figure below). Now that's a HUGE sound! Using a layered approach can take you closer to finding your "signature sound."

Want an example? Download the Pro Tools session PC | Mac and check out the progression as I build the guitar sound using all the techniques described here.

Wrap Up
Wow. I've written two columns about recording and mixing guitars and I feel like I've just scratched the surface. Join me next month for the final article in the trilogy about production and mixing techniques for guitars. There's so much you can do with your guitar and Pro Tools! See you soon. Peace.

 

Like what you see in this column? Check out my book, Producing in the Home Studio with Pro Tools (2nd Edition). You can buy it online right here through Digidesign's website, or visit www.protoolsbook.com. Interested in personal instruction on Pro Tools from yours truly? Visit www.berkleemusic.com and learn about several amazing Pro Tools learning experiences available online though Berklee College of Music. Interested in hearing my band? Visit www.lipfloater.com. Wanna see my studio and hear some samples of my work? Visit www.undergroundsun.com and/or www.davidfranz.com.


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