Tech junk: On radio interference...

I know there's a lot of text below, but the upshot is that I'm trying to save folks money -- or at least hopefully keep people from spending money on 'solutions' that probably won't be effective, money that can be put to more effective use inother ways, so it may be worth at least glancing over...

Quote:

Originally Posted by -------- Yes, we  have Monster cables going from mics to our interface. I'll try Mogami cables.   I heard from a friend that buying a power conditioner can also help reduce interference. However I'm reluctant to buy a $100 power strip...

First, regarding radio interference specifically -- if the problem is related to cabling -- it's not so much that you don't have high enough quality cabling -- it's that you have a defective cable.

Radio interference typically comes from a connection that should be solid but which, for some reason, has become reduced to something like a strand or two of wire (which may even be intermittent). That can form something that acts like the cat's whisker capacitors that were at the heart of early, very simple radio receivers.

That usually means a bad connection at a solder or other connection point or, as sometimes happens, a broken solid wire lead that is being held together in intermittent or minimal contact by insulation. You found that last in older gear with point to point wiring.

In modern gear it's usually found where wire leads or other components contact the circuit board. Stress points around connectors are another place to look (particularly where there are external connectors mounted in a case that are also mounted on the circuit board -- as in many laptops and other pieces of modern, low production cost gear). In such cases, a circuit board often becomes broken and can be held together -- such as it is -- by the actual conductor substrate, potentially tearing and stressing micro-thin printed circuit conductors which then may begin acting like cat's whisker capacitors.

So, your problem could be cable-related (a defective cable -- likely a bad connetion at the connector), but it could also be from a large piece of gear.

On radio interference in general: I think you said you were a mile and a half from a transmitter. If it's the source of your problem, my guess is it's a 50 KW AM station. At that distance, interference is likely only if there is a problem in your gear -- ie, a defective piece of gear/connection.

But, if such a transmitter is in your backyard, it may so thoroughly saturate the area with transmitted power that signal is jumping everywhere, and interference is not limited to gear made vulnerable by defect or poor design. Nearby illegally high powered CB or ham radio transmitters may also cause problems.

When dealing with radio interference issues, remember this: radio power from a non-directional antenna, like sound from a single point sound source, diminishes with the square of the distance from the source -- in other words, a radio signal will be 9 times weaker at 3 feet from the source than it is at 1 foot; 16 times weaker at 4 feet compared to 1 foot, etc.

Because FM radio is not amplitude modulated, it does not typically present the same sorts of contamination issues.



With regard to premium cable, quality and expectations...

Mogami makes good cables but they're very expensive.

You can also buy good cables very inexpensively. It's not that Monster is too cheap. Many would say they tend to be overpriced, by many measures, even when they are of adequate quality.

If there's a respected pro shop oriented to commercial recording and sound reinforcement in your community and they make their own cables, as many do, I would suggest that, since they will very likely be competitively priced and will likely provide a solid bargain, since the shop will likely stand behind them.

Paying premium prices for good cable (like Mogami) is OK if you're willing to shell out as much as 3 or 4 times the commodity rate for equal quality cables for the 'assurance' that the reputation provides.

But the job of wire is very simple. As long as the cable is made of standard materials and appropriate configuration for your purpose, has insulation of an appropriate material (which is not necessarily expensive and that will not build up static charge and so produce the crackling microphonics associated with improper insulation choice) and has well made connectors attached appropriately, it should perform fine and last a long time.

And with regard to the outlandish claims of the "magic cable" people -- fuggedaboutit. Paying hundreds or even thousands of dollars for short runs of cable, whether it's speaker leads, power cables, digital signal cables, whatever -- is hooey. Nonsense. Nonsense bordering on fraud.



With regard to power conditioning and people's expectations...

Power conditioners are largely not effective for most of the purposes people want to put them with regard to improved sound quality.  There are a lot of reasons for that that others can explain better.*

Uninterruptible power supplies can provide protection for your power failure, allowing you to shut down your gear within a safety window. But they are often not effective at other uses people want to put them to (like 'conditioning' the power for better sound). The ability to provide protection against power surges/spikes may not be nearly as effective as one might like; I suggest further reading on that subject.

Some people do buy into the notion that power conditioning is likely to improve the sound of their gear's operation. Suffice it to say that there's little chance of that with modern gear, which tends to have its own internal regulators, for the most part -- unless one is spending serious money (not talking mere hundreds here) for a system which essentially provides a regulated supply from a bank of continually recharging batteries, completely isolating the power supplied from that coming into the building from the power company.

*For further reading, try Googling something like power conditioning myths.


PS... you can probably expect people who have a large investment in supposedly high end cables or in power condtioning (and likely both) to pop in here with some strident defenses of their belief system. Since the claims they often make are extraordinary, I would suggest asking them for empirical evidence to support any extraordinary claims. (Expect to get the ol' Well, if you can't hear the difference, you must be deaf! routine. )

Tech Time: Signal Phase vs. Signal Polarity

 Someone elsewhere asked about double miking snare drums, it raised (but) one of my pet issues --  proper terminology when talking about issues of signal phase and signal polarity...


You reverse polarity in order to get the two signals from mics on opposite sides of a drum head to reinforce each other instead of (potentially) partially canceling each other out.

By contrast, when someone suggests moving the mic to change the relative distances from the drum head of the mics, he is talking about changing the relative phase relationships of the two signals, vis a vis the sound emanating from the head.

But phase is a term strictly relative to the frequency of a wave. Since the cycle period of every frequency is different, those phase relationships are strictly related to the frequency of any given wave component of the aggregate sound. And that is something a lot of folks who spend a lot of time talking about recording either don't get -- or simply are too lazy to address correctly.

With a single skin drum, by moving one mic far enough away from the struck skin so that the signal reaching the mic is now delayed by precisely 1/2 the wavelength of the fundamental, we achieve a change in that phase relationship equivalent -- in a sense -- to reversing the polarity -- but only at that fundamental. Other frequencies will have varying amounts of cancellation or reinforcement when the two signals are summed, often leading to the familiar 'comb filter' effect.


So, under that latter scenario (moving one mic), if we consider the fundamental of the drum to be our primary concern with regard to phase (assumptions are often dangerous in audio) and the fundamental to be 800 Hz (to pick a number I've heard a few times, though, of course, the fundamental tone of a drum, and the concentration of energy at a specific frequency depends in large part on how -- and how well -- it's tuned. (Info on snare drum physics: The Snare Drum)

Here's a (simple) wavelength calculator (it assumes 'standard' values for temperature and altitude/air pressure): Wavelength

From that we get a ballpark figure of ~17 inches for the WL of our 800 Hz fundamental. So, to change the phase of that signal in such a way as to invert an 800 Hz tone 180 degrees, you would move that mic ~ 8.5 inches farther (or nearer) the drumhead, vis a vis the other mic.


But it's important to remember that that snare sound is not only comprised of its fundamental pitch -- drums -- and particularly snares -- have a tendency to produce extremely complex waveforms with a lot of different frequency components. There are the myriad of issues revolving around the complex character of the snare drum, particularly the fact that (while many drummers remove the bottom skins from most of the drums in their recording kits) the drum will generally have two skins. At lower frequencies, the skins will tend to move in the same direction. But at the higher mode formed by the enclosed space, the skins will actually be moving apart, making the sound quite complex. And then there is the snare 'spring' itself.

So, in all likelihood, moving one of the snare mics may produce pleasing results in the sum of the signals but it will not be that much like what would be accomplished by having both mics equidistant from the drum head and reversing signal polarity of one of them.



The 3:1 relative distance rule of thumb will help save your sanity. Keep in mind it's a relative guideline ballparking the relative levels of a given signal reaching each mic. (You're basically trying to get the level of a given drum loud enough in its own mic that it will dominate when that mic is summed with other mics, and relative effects of cacellation are minimized.)

When considering phase relationships in complex drum miking scenaria, another sanity-saver is to focus on one drum and its relationship with its mic vis a vis the other mics around the kit at a time.

Since sound radiating in a free space is basically inversely proportional to the square of the distance, we know that if mic X is one unit of measure away from a single point sound source and mic Y is three units away, the level of the signal reaching mic Y will be nine times (3 squared) less than that reaching mic X. (However, there is a lot more chaos there, though, since a drum head is certainly not a single point source.)

What mastering is for...

Talk about a bad penny topic...

Someone was asking recently about a problem he was having with his mixes sounding good in his studio -- but falling apart in the car or on other playback systems. He asked if that was a problem or if that could be fixed in mastering -- and someone helpfully answered, Yes, that's what mastering is for.

In today's paradigm, I'd make that a highly qualified maybe.

Even the best ME can't turn a sow's ear into the proverbial silk purse. If a track is mixed badly or has fundamental flaws, you can try to put sonic band-aids on it, but it's always going to be fundamentally compromised -- and it will be likely to cost you more money as the ME struggles to overcome problems with tracking or mix.

In the old days of then-high tech, computer controlled cutting lathes, creating a master for pressing disks required very expensive gear and a lot of skill and knowledge to use -- making the process quite expensive -- fixes at the cutting lab were for last minute and emergency fixes.

Also, in those days, mastering labs were seldom outfitted as high quality mixing rooms. Not only was it wildly expensive to do a fix there, but it was entirely likely that if you tried to make decisions there, they would be compromised by far less than ideal monitoring.

That's why mastering jobs were, by accepted practice, submitted with an edit list of any EQ or other fixes one wanted imposed. The ME might change the sound (say rolling off bass) in order optimize the signal for the rigid requirements of vinyl (narrow dynamic range, limits on bass levels) but there were other things like phase content that he typically had little control over (unless it was simply a polarity error).

In those days, the ME was expected to not make aesthetic decisions but only apply the requested changes or those absolutely necessary for the format.

But mastering changed with digital -- but the cost of entry was even higher at first. But as CD-R masters became acceptable at rep houses, it became entirely possible for the average home recordist to prepare his own replication masters.

And at that point, mastering houses -- and those who had simply noticed that mastering houses had traditionally commanded hourly rates sometimes 5-10 times higher than studios -- realized there was a challenge but also an opportunity -- to expand on the traditional last-minute-fix aspect into something oriented to corrections few would have made -- or wanted made -- in the old days and to plant the idea that was 'normal practice' and that a mix was not 'finished' unless it had been 'fixed again' by an ME.

So is recording history rewritten to help shore up demand for what is often an unnecessary -- and sometimes aesthetically disastrous -- step.

Now there is another aspect to mastering for those putting together album packages. It's also one where the traditional role of the ME has been expanded. That is in last minute fixes to help try to give some consistency in timbre as well as level to album tracks that may have been recorded in different times and places by different production staff, as so often is the case these days.

When one is putting together a package for replication and commercial release, it may well make perfect sense to use an ME in order to assist in producing a package that fits together well.

And in an era when many of those recording do not have long experience, necessarily the greatest gear (and likely not the knowledge of how to get the most of it), that court of last resort at the ME's may well make some kind of sense. Do make sure that you have chosen an ME that is not just experienced but thinks like you do. There are a lot of different approaches. Validity of approach is contingent on the nature of the project/genre.

But when there is no budget, when you are releasing the music for free or as one-off sales through online stores, I recommend at least trying to do it oneself.

Really, the right place to get things right is in tracking and mixdown. Learn to get that right and, even if you always have everything externally mastered, you'll still be helping to make sure that things end up sounding  as close as possible to what you want and that the ME has to make as few of his own aesthetic/corrective decisions as possible.

An ocean of music...

To paraphrase some poet or prophet -- or maybe I lifted it from a standard funeral homily:

People make oceans of music and only a tiny, tiny amount ever rises up for a few moments like a wave, visible from the shore.

And then it's gone, too, back into the bottomless sea of forgotten music.

The right set of barbarians...

Someone, elsewhere, was despairing that a new musical revolution like the rock and roll, Brit Invasion, pyschedelic, or punk waves of decades past had become all but impossible...

I'd say the 'last' music revolution (arguably the grunge thing -- unless you want to count the so-called 'modern metal'/screamo thing) was pretty much pre-owned by the establishment. I was really excited going in but the boring/retread angle there for most of the bands (grunge, seems to me, needed a few more Nirvanas with their pop hooks or Alice in Chains with their adventurousness). I went up to Seattle in '89 looking to connect up with grunge. I walked away decidedly unimpressed.

Look, revolution is far from impossible. But the palace guard want you to think it is.

They've been quite scientific -- and even somewhat flexible -- in maintaining -- with the assistance of the cohort of bought-and-paid for shills who have the overweening gall to call themselves "music journalists" -- the current commercial music Pax Romana.

But all it takes is the right set of conditions -- and the right set of barabarians -- to topple the empire once again.

Lining up for the Big Cookie Cutter

This article spawned this discussion elsewhere, in which I (more or less) wrote:

The distressingly boring, stamped out, streamed out, spewed out product of today's music business is the culmination of trends that have been in the works since I was a kid...

Demographic analysis and targeting of radio audiences really started kicking in in the mid-60s, with the formulation of Boss 30 Radio (from the old RKO General radio network). Before that, choices about programming were largely informal and based on hunches, word of mouth, charts from other stations and cities, and, oddly enough, the tastes of the DJs.

In the 70s, the labels got involved in targeting the format requirements of Boss Radio, similar formats, and the album oriented rock format that evolved (many would say devolved) from the late 60s underground radio scene. In the early 60s and again at the end of the decade, there were explosions of interest in making music instead of just consuming it (first, the folk revival and then the hippie/alternative culture movement). Many learned a few chords and lost interest, but more than a few maintained music as a hobby, often supporting that often expensive hobby with day jobs.

As amateur musicians matured and their earning potential increased, they spent more money on gear and music production expenses, mostly subsidized by those precious day jobs. Periodicals -- supported mostly by adverts for "pro" gear used overwhelmingly by non-pros or moonlighters -- sprang up and were often packed with glossy ads for gear and services. There had to be something between the sexy pictures of guitars, amps and keyboards and all those ads... Articles on 'honing one's professionalism' an shaping one's career came to the fore. Some of the people writing those pieces were actually journalists (could happen) and actually managed to start digging up pertinent educational info.

Meanwhile, by the late 70s, a tiny handful of community colleges had begun to experiment with offering courses of instruction in video and audio work and expanding commercial music programs (themselves quite new at the time) to cover the technical sides of music production, as well as career aspects. (I'm a product of that era and two of those programs, both at then-nearly-free community colleges. I'd do anything for 'free' studio time.) Often, even in those early days, the emphasis was on best practices and how to deliver the kind of product that labels and radio (and the then growing field of music video) wanted to see.


As a consequence, bands got very good at following all these highly specific recipes for "success." But, of course, not everyone can be successful... and the convergence of all those trends had created veritable armies of well trained wannabes, their heads all filled up with nearly identical cookie cutter personal styles and musical approaches...

The damnedest thing from my point of view?

The musicians mostly seemed fine being just like all the other wannabes. It never seemed to occur to them that in a crowded marketplace, you really, really don't stand out by being just like all the other market dross waiting forlornly for Joe and Mary Consumer to walk by, clucking their tongues in disdain. "Look at that hair. What is it with these musicians that they all have to dress the same and have the same haircuts. How lame."

Changing Recording Roles

A newb somewhere was hazy on the actual duties and roles of engineer, producer, and mastering engineer...

Traditional roles have broke down as the biz has been flooded by newbs but here are the traditional roles:

• Producer -- he's the chief executive officer of the project; he's the one with the purse strings; he's often the one who picks the talent and material. In the traditional biz, he worked for a label, typically, often working hand in hand with label A&R (artists and repertoire). He's the chief talent and tech wrangler.

• Engineer -- he's a technician, tasked with keeping the studio running and fulfilling the producer's instructions. He's usually the one with his hands on the controls. In recent years, new roles have developed around specialized editing that was not possible in earlier days, so that you end up with people now who specialize in vocal editing (retuning and re-timing) and drum editing (re-timing).
  
  [Obviously there are many in the industry, particularly in Nashville, who are incredibly bad vocal editors. It's one thing to T-Pain a vocal if the artist and producer want it -- but if the singer wants it to sound natural, I shouldn't think there could be any excuses left for the utterly clumsy and obvious vocal retuning that 'graces' the recordings of many big stars.]

• Mastering Engineer -- traditionally, this was the highly trained technician who did the very difficult task of trying to squeeze as much fidelity (and in the case of singles, particularly in the 50s and 60s, when singles had to compete with each other in jukeboxes and on the radio -- loudness) into the narrow grooves as possible. The variable groove spacing lathes these guys operated were complex, and very tricky to run well. In those days, a mastering house really earned its money.
  
  At first, the bar for mastering in the digital era was very high -- meaning that established mastering houses still had a valuable franchise. But then the advent of the CD-R and other new technological approaches meant that virtually anyone could prepare a CD master for replication -- crisis time in the mastering biz!
  
  But musicians are a gullible and mostly clueless lot. They turned out to be quite easy to gull into continuing to pay as much as hundreds of dollars an hour -- not for the highly technically demanding craft of a disk cutting engineer -- but rather for an extension of the last-emergency-fix-it stop repairs that had long been a possible adjunct to the grooved disk mastering process.
  
  And, with the explosion of inexperienced recordists and shoestring studios there really were problems to be fixed, no question.
  
  Problem was that the right place to fix many of them was back in the mix.
  
  But many in the music biz don't like to let cold-headed reality get in the way to make a buck.
  
  So we had a group of vested interests promoting the quite new idea that tracks had to be "mastered" -- but now, by that misused term, people actually meant a sort of post-facto final sweetening, typically focusing on adding more compression and then trying to fix the dullness that results from overcompression, often by aggressive use of finite impulse response (linear or 'mastering') or other EQ.