Analog or Digital?

One of the biggest debates among audio engineers is between analog and digital processing. Devout believers on both sides can be found at every step — performance, recording, mixing, mastering, even the end listener. Some insist that only a fully analog chain can keep music sounding good, while others prefer the transparency and control of a properly maintained digital signal path. As with many issues, the "right answer" may lie somewhere in the middle.

Analog: Pros and Cons

Originally, there was no argument. Music was made with analog equipment because that's the only equipment that existed. Microphones used transistors and tubes, as did their preamps. Audio then went into an analog recording console and was sent through various outboard equalizers, compressors, and other processors. Mixing, mastering, and even the final delivery medium were all analog — remember records? Vinyl records are analog; the sound that comes out depends on the vertical and horizontal space inside the tiny grooves. For the most part, analog gear will never expire, become incompatible with other gear, or grow dependent on a specific platform or environment. However, they can be costly (in time and/or money) to maintain, and if the parts are very old, may be impossible to fix.

While analog audio can be said to have "infinite resolution", some of that resolution is taken up by noise. Analog devices hum and hiss. Vinyl may scratch, and even the dust that settles on the record causes crackles, pops, and additional hiss. Why, then, would anyone think analog sounds better? Well, in terms of processors, the added noise may not necessarily be undesirable noise. In fact, it is commonly stated that gently driven tubes produce "2nd harmonic distortion," and that this distortion sounds good to the human ear. In fact, tubes and transistors provide many degrees of distortion at the same time, but the loudest harmonics tend to be the 2nd or 3rd. These overtones can make the music sound bigger and fuller. Harmonics can make lower-frequency sounds warmer, and higher-frequency sounds brighter. While pleasant distortion is still distortion, this musical color is something many people love.

Digital: Pros and Cons

It is getting harder and harder to find new music released on vinyl. Rock often goes only to CD, and even clubs that spin hip-hop and trance have begun to mix CDs. The Compact Disc is a digital medium. No matter how many times you play a CD, it cannot wear out. Dust is easier to remove from CDs than from records, and the plastic discs are considerably harder to scratch or break. Digital audio is very precise — you can send a signal through any number of quality digital devices, and the end result will be indistinguishable from the original file. Compare this with the inherent noise added by a chain of several hardware boxes, or the generational quality loss in copying analog tapes.

The other major benefits of digital engineering are control and flexibility. Many DAWs (digital audio workstations) have virtually unlimited undo, which would be prohibitively expensive to emulate with analog tape. Instant recall is another benefit. Decide you want to try a new equalizer plugin on a project you mixed last year? No problem, all of the previous settings are stored when you reopen the project file. Digital processing can even simulate the mild distortion and noise inherent in its analog counterparts, to some degree.

One issue many people have with an all-digital system is reliability. If your hard drive crashes for any reason (major virus, physical failure, etc.), you may lose everything — your sequencing and arranging software, plugin instruments and effects, all of your project files, and all of your finished mixes! It would be exceedingly rare to lose the same amount of work at one time with an all-analog system.

Another aspect of reliability has to do with upgrades and compatibility. If a software company releases a new version of your favorite effect, you may find that they no longer support the old version. When you upgrade your computer, some of your old software may no longer work. Hardware does not have the same kind of obsolescence.

A Hybrid Solution

Musical preference is simply opinion, so each person's answer to this debate is correct for that one person. However, to please both sides it may be necessary to adopt a hybrid solution. A CD mastering engineer's goal is to make the most of a piece of audio while maintaining the integrity of the original sound. This may require any combination of digital transparency and analog warmth. Mixing Engineer Dave Pensado (Christina Aguilera, Mary J. Blige, Beyoncé, The Black Eyed Peas, Ice Cube, countless other modern pop, r&b, and hip-hop hits) has proudly declared his love of plug-ins, but certainly has not abandoned analog entirely. Zero 7 epitomizes the newer breed of musician who embraces both analog and digital techniques to produce the best possible result. Craig "Hutch" Hutchinson (Chief Designer for Manley Labs) has designed analog gear found in countless mastering houses — including the Massive Passive equalizer and Vari-Mu compressor/limiter — yet even he has documented and encouraged the widespread use of quality plugins during mastering. Chi-Squared Mastering supports the hybrid method of CD mastering, keeping an open mind and open ears to find the best of both analog and digital worlds.