Though I’ve worked with digital audio equipment for more than 30 years, I’ll confess to keeping a great collection of black vinyl at home and on occasion still cue up some great old album to enjoy some warm, if worn, tones off the turntable.
But honestly, I haven’t bought or recorded anything in analog for a very, very long time. And come to think of it, I really can’t remember the last time I acquired any kind of content â€“ music, pictures, movies, games â€“ that didn’t come to me digitally. (Though there’s recently been a modest resurgence in sales of vinyl LPs and turntables, analog audio accounts for less than 1 percent of all music sales.) The convenience, quality, portability, durability, reliability, and economy of digital content â€“ and the utility of the web for sharing that content â€“ have all but squeezed out any role for analog in entertainment. For all but a small number of analog “purists,” the superiority of digital is indisputable.
So, here’s the $64,000 question: With all the trends in content and technology already headed for a full-digital future, why is it that most multi-room home a/v systems still use analog to distribute audio and video content? Even more ludicrous, all of these systems are starting with content that’s in digital format and converting it to analog in order to route it around the home.
Is that really such a terrible thing, you ask? Well, frankly, yes, and here are a few reasons why. First and foremost, distributing in analog instantly increases the noise and distortion levels in the music or video signals, even with best equipment and cabling. And the greater the distance the signals travel, the more noise and distortion that’s likely to be introduced. As we all know from watching digital telecasts (not to mention DVD and Blu-ray), the remarkable clarity and vividness of digitally delivered audio and video offers a quantum leap in quality over the analog technology it replaced. Why go backward by installing an analog distribution system in your home?
Secondly, in addition to more noise, analog distribution suffers from signal loss, which also degrades content quality on its way to the playback device. For audio, this can mean less clarity in delicate musical passages and more distortion in louder ones; for video, it can mean picture degradation that affects image quality and stability, color, and other elements.
Using digital distribution offers other advantages. For example, bringing digital signals all the way to the loudspeaker not only eliminates sources of noise and signal loss, it allows frequency cross-over, equalization, and other signal processing or conditioning to be conducted in a digital domain â€“ and to be changed and controlled remotely. For multi-room audio and home theater systems, this degree of control helps installers in setting up great sounding systems that are tailored to customers’ needs and personal preferences. This isn’t science-fiction: two companies, Polk and Mid-Atlantic, already make critically-acclaimed IP (Internet Protocol)-capable and IP-ready loudspeakers that allow a digital, IP-based audio signal to be delivered the speaker so that the audio is not covered to analog until it’s conveyed to the speaker’s voice coil (the final step in audio playback).
While these limitations may be obvious, here’s one that isn’t: analog distribution involves separate cabling for audio, video, and control signals, so that, in moderate or large systems, the installation and management of cabling becomes a project â€“ and cost center â€“ unto itself. Analog control solutions â€“ typically a patchwork of IR, RF, RS-232, relays, etc. â€“ are notoriously difficult to document, maintain, and troubleshoot. And, depending on the variety of source and playback equipment used, redundant cabling (e.g. component and S-video) may be needed to provide all the functionality a homeowner wants. In a digital system, everything â€“ bi-directional control and content â€“ can move over one (inexpensive, highly reliable) CAT5 cable.
While there are many more performance and feature-related benefits to opting for full-digital distribution systems â€“ power efficiency, system expandability, home systems integration, to name a few â€“ there’s another more fundamental reason to rethink choosing analog distribution. Today, both source and playback equipment is designed and optimized for native digital content â€“ which is great, since as I’ve already pointed out, nearly all the content we acquire or obtain is originally captured or produced in digital format. However, distributing in analog undermines both the quality and functionality of operating in a pure digital domain, and makes the distribution network, which should be the backbone and foundation of great a home entertainment system, the weak link in the chain from the standpoint of performance and connectivity. If your gear is optimized for digital, shouldn’t your distribution network be, too?
While full-digital a/v distribution and control systems do exist â€“ ClearOne’s NetStreams DigiLinX being a quintessential example, with all a/v and control signals carried on just one CAT5 cable â€“ it’s clear that their cost is still one factor that has restrained sales. Also, the issues surrounding HDMI have confused many consumers (and installers, for that matter) about how best to manage digital a/v distribution for multi-room and whole home systems. Nevertheless, the writing is on the wall and the message should be clear: analog is your father’s Oldsmobile: great in its day but doomed for obsolescence. Digital distribution is the domain of the future. Why even consider another option?