History of Double Tracking
- 1966 -
Artificial Double Tracking
invented by Ken Townsend
The practice of doubling recorded tracks started to emerge as a powerful post-production technique as early as the 1950's. By the 1960's it has become so influential that leading musicians started to demand an outboard double-tracking device that they could use in the studio.
During The Beatles' recording sessions John Lennon pressed their sound engineers to come up with a technical solution that could replace the oh-so tedious art of double-tracking. This is the point when Ken Townsend heroically enters the scene!
As a super-talented audio engineer at Abbey Road Studios he makes a discovery that firmly etches itself into the thick walls of music history. Using tape-recorders Ken builds a genius signal chain that caters for the needs of The Beatles, thus the very first technological solution for double-tracking is born:
'Artificial Double-Tracking'
Ken Townsend's original invention gained so much popularity that not only the Beatles but other visionary artists like Eric Clapton, Pink Floyd and Jimmy Hendrix started to incorporate this new form of double-tracking effect into their music.
Even though today's standards have rendered it obsolete, Artificial Double-Tracking has left a permanent mark on audio engineering. It is still in use, but only as a special effect that conjures the warm vintage vibes of the 1960's.
- 2016 -
Mimiq Doubler Pedal
invented by TC Electronic
The 50th anniversary of the invention of 'Artificial Double-Tracking' marks the release of TC Electronic's brand new doubler pedal called:
'The Mimiq Doubler'
This stomp-box houses a unique digital algorithm specifically designed for double-tracking electric guitars. TC's engineers have definitely made some serious steps towards achieving double-tracking with more realistic results. Their purpose-built circuitry approximates the effect of recording two instances of the same guitar part a lot better than Ken Townsend's analogue tape-based technique does.
The Mimiq shines by combining pitch, modulation, and delay micro-variations into a cohesive doubling effect. However, for those who are looking for an authentic reproduction of double-tracking it has some serious disadvantages. It achieves stereo separation, but does it at the cost of introducing unwanted side-effects. These side effects are specific 'audio artifacts' that human ears register as unnatural sounds.
- 2024 -
Realistic Double Tracking
invented by Gábor Bagó
As we can see it from its long history 'double-tracking' is one of the most fundamental staples of modern music production, especially when it comes to recording electric guitars. In spite of its ubiquity it is still the only audio effect category for which pedal manufacturers have not been able to come up with a truly realistic sounding solution.
Double tracking guitars manually gives a song a very natural sense of stereo separation that is extremely difficult to reproduce in the digital domain. The most fundamental challenges arise when engineers try to replicate the actual sound of double-tracking with modulation- & time-based algorithms. This approach always fails to produce natural results.
The underlying problem is caused by an inherent characteristic of modulation/time-based effects that is 'delay'. The introduction of even the slightest amount of time-delay between two signals causes a special kind of audio artifact called 'comb-filtering'. It is a highly intrusive audio artifact that basically cancels out the guitar's sound.
'Comb-filtering' is very annoying in stereo and even more distracting in mono because it causes phase cancellation across the entire audio spectrum. This basically results in the original audio loosing its character. The end result is a muffled and quiet sounding guitar tone. And this is the point where I enter the scene by inventing:
'Realistic Double Tracking'
which is here to put an end to an over half-century-long quest for a realistic sounding double-tracking device. It stands right out from the crowd by providing comprehensive solutions for the most important challenges that have been plaguing doublers for almost 60 years now! These challenges are connected to issues with:
1. Mono compatibility
2. Unrealistic sound
3. Audio artifacts
4. Latency
(1) One of the main objectives during the development of Realistic Double Tracking was keeping the effect as 'mono-compatible' as possible. My research made it crystal clear that the only way to prevent the stereo double from collapsing in mono was to break with the tradition of using time-based effects, because they always introduce 'comb-filtering' which weakens the signal. Realistic Double Tracking provides a strong full-spectrum guitar sound even in mono simply by avoiding the use of time-based effects.
(2/3) Another very important - although less technical - priority was making sure that the doubling effect actually sounds realistic. My experiments quickly taught me that a doubler's sense of realism is fragile and the easiest way to lose it is through using modulation effects (like chorus, flanger or phaser). These are great for enhancing stereo separation, but only at the expense of adding audible 'chorusing' or 'sweeping' sound-artifacts to the original signal. By leaving these destructive elements out of the equation Realistic Double Tracking keeps the guitar's sound realistic-sounding and artifact-free.
(4) The last great challenge to overcome during the developmental stages was latency. Today's fast-paced world is an absolute safe haven for ridiculously fast rhythm-based musical genres. The average modern listener's ears are so used to hearing tempo-corrected songs that they can easily detect even the most subtle rhythmic imperfections. It is easy to understand that if the audience is hyper-aware of temporal changes then musicians have to pay even more attention to eliminating delay from their rig. Realistic Double Tracking is carefully engineered to provide the lowest possible latency for guitar players.
But why is Double-Tracking so special?
If I had to answer logically I would say that because it is the most special effect category of all! Audio engineering is so far advanced in its technical solutions that we have many specialty effects previous generations could only fantasize about. Take auto-tune for example, or polyphonic pitch shifting. We are at such an advanced stage of technological development that for all the major effect categories we have at least one realistic-sounding solution; except for doubling! This makes Realistic Double Tracking the 'last missing puzzle piece' in the grand multi-colored picture of guitar effect typology.
If I also had the chance to answer from my heart I would definitely say that turning 'RDT' on gives me a very specific feeling that is hard to describe. It is similar to experiencing some exotic sensation for the very first time in your life: 'The uniqueness of Realistic Double Tracking is hearing yourself play your guitar and hearing it doubled right away as if someone has already double-tracked it for you before, but it all happens instantly!'
It kind of feels like meeting your identical clone in real life ...
🤯
... and this is the feeling I want to share with my fellow musicians!
⬇️