REWIRE YOURSELF

REWIRE YOURSELF

ROCK WITHOUT NOISE

by

Richard Robinson

In electronic parlance noise is any sound produced by machinery which is not part of the signal passing through that machinery. Noise occurs in both audio and video electronics, and equipment manufacturers go to great lengths to eliminate or at least limit the amount of noise present to the eye and ear of the equipment user.

To experience pure electronic noise, turn on your stereo and without putting on a record or a tape, turn up the volume control to its maximum setting. Unless you have an absolutely perfect system, you’ll hear a certain amount of hiss coming from the stereo speakers. The hiss is electronic noise, produced by your stereo components as they do their job.

Normally, the listener doesn’t hear much of the noise present in an electronic system because the signal (record, audio tape, videotape, radio or TV broadcast) is stronger (louder) than the noise. So while the noise is still there, it goes undetected. This phenomenon is described in terms of signal to noise ratios. If the signal is stronger than the noise, has a good signal to noise ratio, then the noise will not be apparent.

The better the stereo system design, the better the signal to noise ratio. The same is true for the signal source. High quality audio and video tapes, strong radio and TV broadcasts, well pressed records—all have very acceptable signal to noise ratios. But noise is still present, and in certain circumstances it can become an annoying element in the overall sound (hiss, rumble, distortion of the music you’re listening to) or picture (streaky, snowy, blurry pictures).

Noise is particularly a problem with audio tape recordings. The very mechanics, of the tape recorder produce noise as the tape rubs across the recording and playback heads, not to mention noise that is produced in the recording process by microphones, mixing boards, and amplifiers; noise is also generated by the process of transferring the master tape recording to tape copies or to records.

Audio noise is something that engineers and consumers lived with for years as part of the overall sound produced. But as narrow cassette tapes running at very slow speeds were introduced, the signal to noise ratio fell to the point where the noise was gaining over the signal.

In order to combat the noise, manufacturers turned to several systems which processed the signal to reduce the noise without affecting the signal. First came the Dolby system, then dbx, and most recently CX. All of these systems encoded and then decoded the recorded signal at various points in the recording and playback process to suppress the tape hiss and other unattractive noise factors while allowing the signal to maintain its integrity from guitar in the studio to listeners’ ears at home.

As a record producer I’ve worked with both Dolby and dbx (both trademarked, highly original systems) and frankly found both of them ultimately let me down when it came to recording and reproducing high energy rock ’n’ roll music. I personally think the tape hiss is part of the record energy, that when creating electric music all the electronics (be they guitar, amplifiers; tape recorders, or stereo systems) are part and parcel of the act of making rock music. So eventually the first thing one did on a session was tell the engineer to take the noise reduction units out of the studio, because no matter what the technical claims of the system manufacturers, I felt that the noise reducers took the heart and soul out of the sound along with the hiss.

Recently CBS Records introduced a new noise reduction system which they’ve named CX. According to Dick Asher, chief operating offers of the CBS Records Group, CX is “...An important aspect of our quality drive...to reduce the surface noise of LPs and to increase the dynamic range of recorded music.”

That is all very well in theory, and may work as well as Dolby and dbx in practice, but CX, like its competitors, faces one problem: what does it do to the music while it’s busy getting rid of noise? Now in theory, all noise reduction systems do nothing to the music. And that may be true on Donny Osmond and Up With People records as well. But, as I say, when it goes to driving, full blast rock music, I have yet to hear (or should I say ‘not hear’?) a noise reduction system that didn’t take the edge off along with the hiss.

The amusing thing about all this is that there is a recording process that has theoretically no noise at all: digital recording. The very nature of digital recording (converting the audio signal to computer pulses) is noiseless. And if any work should be done in getting rid of noise, it should be in making advancements in this area.

But the funny thing about digital recordings is that the lack of noise is apparent. In their own way digital recordings are like noise reduction processed recordings: some of the essential electricity of the recording is missing.

Unfortunately, consumers are often not given a choice as to whether they want to live with energetic hiss or filtered noise free recordings. Because all noise reduction systems are claimed to be compatible with normal stereo systems (meaning you can play a Dolbyed tape on a machine without a Dolby decoder), the public is often presented with noise reduced records and tapes without a chance to hear what the original recording sounded like. Frankly, I’d like a choice, or at best I could do without the noise reduction at all. But the advent of CBS’s CX system as the third major noise reduction system suggests that the time has arrived when all records and tapes will have some sort of processing to achieve theoretical signal to noise levels.

The real problem is that the people in the laboratories developing the patents don’t seem to spend a lot of time out in the world listening to rock music. Or maybe it’s just that their eardrums are different than mine...