Monday, October 28, 2013

ARTICLE: Cheap and Dirty Microphones

(Originally published in Recording Magazine, September 1999. It was considerably shorter in RM, but this is the whole submission with warts and all.)

(NOTE: The flaw in this article was that we didn't organize high priced spread comparisons and went ahead with what we had.  With that flaw, the article doesn't really make sense.  I've done the comparison in the past, and since, and the cheap stuff stood up really well.  Nuts.)

All Rights Reserved © 1998 Thomas W. Day

So, why should I care about cheap microphones?

Over the years I've owned a fairly wide price range of microphones, from $5 high impedance desk mikes to $1,500 tube condensers. When I was billing for studio time, I could justify a few high-end mikes. Now that my recording habit has settled into something more resembling a hobby, I buy what works and sell what doesn't.

In visiting several small studios over the last year or two, I've noticed that owners seem to be investing a lot of money in their board, recording system (digital or analog), their effects rack, and their studio furniture. But, when they get around to buying microphones, those tools seem to be at the tail-end of the studio budget and planning. At that point, the popular tactic appears to be to buy one or two really trendy and expensive mikes and enough throw-aways to cover a drum kit.  At an extreme, one studio owned only SM57s and 58s because they "are industry standards." 

Most recording engineers have a group of standard microphones they use because every other engineer claims to use those mikes in particular situations. "U87 on voice, 421 on the kick, a 57 on the snare, and a pair of 451's spaced over the drum kit" . . . and so on. If you can get that same guy behind a couple of beers and in a conversation mood, you might get a look at and a chance to listen to some of their personal favorites. Often you'll find those favorites are low cost beauties that they stumbled into when they were getting into the business and still experimenting with equipment and instruments. (An activity that often stops when the passion becomes a profession and that profession has to pay the bills.)

The expensive gear is important as part of the process of selling studio time and in creating the studio's image as the all-knowing source of everything technical and aural. Marketing is marketing and perception is everything in that strange world. But when it's your money and your recording, you don't have to be so manipulative or cost ineffective. The fact is that a lot of mikes will do the job and getting a professional sound it doesn't take any where near as much money as some people (marketing types, for example) might want you to believe.

I'm a natural born skeptic. I can't help think that the phrase "popular wisdom" is an oxymoron.

If you're doing your own music or working on projects where the cost of your equipment won't impress the clients, I think there is a better way to spend your money. Instead of blowing the budget on one or two expensive and trendy mikes, I recommend that you collect a dozen good, but cheap, microphones. For the purpose of this article, I'm going to define "cheap" as less than $250. Sometimes, a lot less than $250.

Fifteen years ago, I attended a recording engineering seminar at the University of Iowa. This seminar was put on by the university's music department and the lecturer was a well known and respected engineer who was also the importer of an expensive German microphone manufacturer. The class was made up of, primarily, studio-owning recording engineers with a lot of recording experience.

At the end of the week-long course, the university's house engineer and I recorded several pieces of music with some of my favorite cheap mikes, some of the university's mikes, and some of the instructors' high-budget pieces. We did a decent job of presenting the microphones with a fair collection of recording situations and holding the levels and positions reasonably consistent.

The next day, we did a listening test with the rest of the class. The results were not predictable. Fifteen years ago, mid-priced microphones sold for barely above $100. Expensive mikes were about the same price as they are today. Time after time, in our single blindfolded test, the cheap microphones were picked as the class favorites over the gold-plated models.

When the listening test was over, the lecturer asked to borrow some of my mikes for a few weeks and took them back to his office for further testing. I got the mikes back a month later, but never heard what they learned from those tests.

What do you get for your money?

Ever since my first experiment in microphone comparisons, I've had strong suspicions that the adage "you get what you pay for" doesn't tell much of the story. In the competitive world of professional recording studios, perception is everything; another adage that isn't particularly informative. At $75 an hour (and up, way up), musicians and producers want to see equipment that looks more expensive than the stuff they own. As any experimenting will tell you, though, looks expensive and sounds expensive are not closely related.

All this is not to say that the cheap spread and the "gold standards" are created equal. At the most expensive end of the scale, some of what you pay for is in the hardware. Building a product with the finest switches, connectors, wiring, machine work, and components used in the electronics (condenser amplification, for example) adds a lot to the unit's manufacturing cost. That cost will be reflected in the manufacturer's retail price. Sometimes all that precision and refinement results in a more reliable product. Some companies put a lot of effort into product consistency. B&K, for example, makes precision engineering tools that just happen to be microphones. But for the majority of users, a lot of that effort doesn't provide a lot of bang for the buck. Like musical instruments, the inconsistencies in individual microphones can result in occasional gems among the rocks.

Too many users pay for image or possible resale value. They don't know enough about the equipment to get the most out of it and they often grossly misuse their equipment. One thing that's common among all fine instruments is that a little abuse will go a long way toward major damage. Using a large element condenser, for example, as a kick drum mike can be a terrific way to find out what happens when those micro-thin gold plates (charged with a couple hundred volts) make contact. I've seen it done and, since it wasn't my money, it was pretty fun to watch.

Putting ears to the test

With all of this in mind, I asked Michael McKern of Minneapolis' Music Tech if he'd be willing to put up some of the school's high-end microphones against a collection of cheap stuff. Michael took the bait, readily. He'd been thinking about doing something similar and was looking for an excuse to do a test just like this. I became an excuse.

Michael promoted the "The Cheap Mike Shootout" at the school and the local AES chapter. We hoped for as many ears as possible, but only a few hard core students made it to the event. This isn't unusual. In my experience, a blind test will send most of the self-proclaimed golden ears running for cover. Something about not knowing the answer in advance changes a lot of attitudes towards listening tests.

It must be close to impossible to do a truly scientific microphone test. Setting all things equal is incredibly difficult. There are a variety of test protocols that you can use to do your testing and we had to pick one for our experiments.

What we decided to do was to drive four microphones at a time with the same source material. For comparison, we had an acoustic guitar, an acoustic violin, a grand piano, and male and female vocalists. We placed the microphones in a tight pattern (see picture), far enough from the sound sources that proximity variations wouldn't affect the microphones significantly. We included at least one expensive microphone in each batch of four mikes under test, as our "reference standard." We matched the volumes of the instruments by placing a tone generator where the instrument/voice would be. With the tone source, we calibrated the output of each microphone with a meter (sometimes to within 0.05 dBV, thanks to Michael's persistence with the faders). After swapping out the signal generator for the musician, we recorded a few minutes of each instrument.

The following is the equipment used in our test:

Monitors (far field): JBL4312

Monitors (near field): Yamaha NS-10

Console: TAC Magnum (used for playback only)

Mike Preamp: Focusrite #1 (red)

Recording System: Sony JH-24 (analog) 24 track deck using Quantegy 456/2" tape

After recording all of the instruments and vocals, we played it all back. Comparing each of the four microphones on each performance, we voted as to which mike we thought sounded best on each performance. The actual microphone ID's were randomized during the listening tests. Michael was the only one of us who knew which channel we were listening to and he didn't know which mikes were where. It was a mild flavor of double blind testing.

We made no effort to compare microphones on similar performances. I'm not much of a believer in "aural memories." The fairly quick comparisons we were able to make on each of our test microphones, sometimes, made it easy to determine which microphones had the best characteristics for that instrument or voice. Other times, it was incredibly difficult to make a decision.

Because of the distances we maintained from our sound sources, we were sometimes forced to choose the best out of four compromised sounds. None of the piano recordings were ideal, for example. In our effort to make sure that the four mikes got, essentially, the same source material, this seemed like a necessary sacrifice. However, some of the mikes produced such a dramatically inferior sound from the position we were in that something useful was pulled even from the least perfect experiments.

Michael's experience is at the other end of the recording spectrum from mine. He's done 20-plus years of high budget work with name artists and studios. Most of his work has been in the pop world (rock and blues and commercials). Most of my work has been on low budget acoustic recordings, most of it on instrumental jazz with very little post-production processing. The other listeners involved in the test had a variety of musical experience and tastes, but they all had young (undamaged by professional audio abuse) ears and their choices were more often similar to Michael's or mine than they were different. I think we ended up with a very discriminating group. Even when I disagreed with them, I couldn't fault the justifications for their choices.

As far as which microphones "won" most often or which microphones sounded "best" on which instruments, the results of our test are unimportant. What I believe is important is that we picked the low cost mikes as "best of group" as often, or more often, than we picked the expensive units. On some tests, there were clear "winners" and "losers." Often, though, there were one or two mikes that were so close together than it was difficult to chose which sounded "best." Just as often, those two mikes would be at the opposite ends of the cost spectrum.

Only for the purposes of giving you an idea of the range of microphones we used, here are the microphones we used in our test:

  • AKG 414ULS
  • Neumann U87
  • AKG C1000S
  • Sennheiser 421
  • Teac M120
  • Audio Technica ATM813
  • Shure SM57
  • Electrovoice RE18
  • Electrovoice PL6
  • Audio Technica (unidentified model) Lavaliere

It might appear that we abused on AKG as or our high-end references. High-end AKG units were what was available at the time. The two models we selected as "reference standards" are respected, quality units and have been used in thousands of excellent recordings. I've done this test with the other expensive German brand name and had the same results. Nothing about this test tells us that the times we preferred a $100 mike to a $1,000 mike proved that the low cost instrument was "better" than the expensive mike. It just means that the cheap mike was "different" than the expensive mike in a way that contributed to a musical sound that we liked better at that time on that instrument. Your mileage may vary.

This test was different in a lot of important ways from the kind of selection process that goes on in a studio. In the studio, you set up a mike, record a track or listen to a few minutes of real-time music, and decide to keep or change the mike. Then, you go through the same process, again. The performance is different. The position of the mike might be different. You have time invested in the change, which tends to make you want to stick with the result of that investment.

Or, you're trying to prove how much better your favorite mike sounds and you find a way to do that by doctoring the comparison. You EQ to bring out whatever you think needs to be brought out. You add a little processing to the favorite to show how it "could sound" when it's prepared properly. We intentionally worked at confusing such biases with our test design.

A side lesson that was learned from this four hour test was that "listening fatigue" is a real and vicious malady. I think re-listening to what we recorded over a series of days would change some of the results, but not necessarily the gist of the outcome. Some of the really close matchups might swing one way or the other, but that wouldn't necessarily be to the advantage of the more expensive units in the test. Several of the most obvious "best mike" comparisons left out the expensive models entirely. However, by the end of the four hour marathon a lot of us were happy to have it over with, regardless of the results. That's another thing to take into account when you're trying to record the best possible sound; when you're doing the final mixdown, stay fresh. Your ability to make quality judgments is inversely proportional to the time spent at the board.

How do you pick a good cheap microphone?

If you accept the premise that it's possible to get a professional quality sound from a semi-pro priced microphone, the next step is to start looking for those hidden gems. The first thing to think about when you set out to buy a microphone (or a bunch of them) is "what do you want to do with a mike?" That probably sounds like a dumb question, but microphones have a lot of purposes and your application may be a lot different from mine. There are as many microphone personalities as there are model numbers.

For example, if you're doing a Techno record, you might be happy with just about anything that gets sound onto hard disk. I don't mean that as a knock on Tech. If you're going to process the voice or instrument into something completely different than the original acoustic sound, it doesn't make a lot of difference what it sounded like in the first place. Your microphone choices are practically unlimited.

On the other hand, if you are recording traditional instruments in a well designed acoustical environment, you will be very demanding about the accuracy of the microphones you use. You choices are more critical and limited.

While a lot of audio techies egotistically argue about the small nuances they believe they hear throughout the audio chain, just about anyone can pick out one mike from another. Like loudspeakers and other electro-mechanical devices, the "errors" in microphones are huge compared to the electronic chain.

You can look at this as a bad thing or a good thing. Since we go out of our way to buy equalization and distortion enhancing equipment, later in the signal path, I vote "good thing." In fact, I prefer to view those characteristics of microphones as pre-conditioning for the instrument, voice, or noise I'm recording.

Now, you only have to decide what kind of pre-conditioning you're trying to buy.

Because, in a recording environment, we're not worried about feedback we can pick from a lot wider variety of microphones than those used by live performers. Omnidirectional microphones, for instance, have almost no purpose in live music but they are often the perfect mike for recording situations. If you're recording voice or acoustic instruments in a really terrific sounding room, you can often get an incredible sound with a well placed omni. For that purpose, I like the EV 635. Back when I first discovered this mike, they sold, new, for as little as $50. Now, it's a popular TV mike and the price is higher, but it's still a valuable tool for a reasonable price. My old Teac ME120's have an omni capsule that does the same job with a little flatter frequency response. Adding omnis to your toolbox opens up a huge number of options for possible killer buys in great microphones.

Of course, omni's are not ideal for situations where you need to get some isolation from other instruments. That's exactly what omnis don't do well. Cardioid and super-cardioid patterns are the hot setup for those kinds of situations. Point-and-shoot mikes, you might say. In real life, that heart-shaped polar pattern only exists for certain frequencies and that's a big part of what makes up the characteristics of these microphones. Weirdly enough, with all the bad PR this mike gets, Shure's SM-57 gets used in a lot of drum kits because of the consistent (meaning, "we know what to expect") directional response the mike provides. That can't be said for many of the high-priced, condenser standards. In my opinion, one of the silliest drum kit sounds I ever heard was produced with six microphones worth a total of about $11,000.

The other consideration you have to make is the microphone electronics. Dynamic microphones are often nearly indestructible (which is why Shure SM-57s end up in almost everyone's collection). The down side to this durability is often a lack of sensitivity. The design of the element of a dynamic microphone can limit the mike's ability to react accurately to high frequency, fast transient, or low amplitude sounds.

One attempt to modify the lack of sensitivity problem is the ribbon element. There are a few ribbon "studio standards" and their characteristics are worth experimenting with. They are not, however, particularly durable.

This is where condenser microphones come into our collections. Condensers are usually more sensitive and more fragile than dynamic microphones. They are often considerably more durable than ribbons. Condenser microphones need a power supply (either phantom or battery) and they have active electronics (this is where the tube vs. transistor argument begins and I go find a good cup of coffee). I'm particularly fond of condenser mikes because they specialize in doing what I like to do. It's possible to find a reasonably priced condenser mike that can do a wide variety of jobs, either through removable capsules or switchable polarity patterns. At their best, condenser microphones can be very sensitive, accurate, and versatile.

With all the technical stuff behind us, the way to "find" a good cheap microphone is to follow your ears. Listen to it. Bring some favorite mikes along and your best headphones or near field monitors and do your own mini comparison testing. Bring a DAT or a good pro portable deck along to record your test. Don't trust the headphones for isolation from the live sound. Don't trust your aural memory for comparisons. If you are looking for an instrument mike, bring the instrument.

Where do you find good buys on cheap microphones?

The best place to find a rare deal on a great mike is at a great music or pro equipment store. I mean this. No sucking up intended. If you know a store that will let you go into a quiet room to do your testing or take the mike home for an evening, don't worry about saving a few bucks on the price. These guys are your best friends. I will almost guarantee that, if you can spend the time to do quality comparison shopping, you'll save major money with your choices.

If we're talking going the cheap route, no one who knows me would expect me to pass up buying used. Sometimes, you can save incredible chunks of money by picking up a little known gem through the want ads or in a pawn shop. You may not find any monster bargains on Neumann's, AKGs, Telefunkens, B&Ks, or even Sennheisers, but you might escape with a killer deal on a Sony or some other lesser noticed manufacturer. Pawn shop guys must have a network that provides them with the highest possible price that a trendy mike might bring, on the best day in uptown NYC. It can be easier to get a good deal on new stuff than a beater that the dealer thinks is a collector's item.

Most music stores don't seem to carry used mikes. I've heard at least one store owner say "used microphones are a lot like used harmonicas." While there might be some kind of health issue involved, there are lots of ways to decontaminate materials and I think it's worth the effort. However, this route has major drawbacks. You probably won't get to do any kind of comparison testing until you get home. You won't know if the unit even works, most likely. You might not get a guarantee that will last beyond the doors of the shop. So keep all that in mind and include possible repair costs in your offer.

For example, I paid $25 for a beater EV RE-18. It worked, but something was loose in the case. I sent it back to EV, paid another $40 for repairs and ended up with one of my favorite general purpose (live or recording) mikes for $65. The dealer wanted to tell me the mike was a $300 list price mike and ought to be worth at least $150 used, but I passed. He hung on to it for a couple of months and, finally, dumped it on me in a moment of weakness. It happens.

A few sterling examples

Without naming names and condemning the innocent, here is a short list of low-to-mid-priced microphones that I've found in a variety of studios:

  • EV N/D57, N/D408A, N/D408B, 635, RE-20, RE-10, RE-16, RE-15, RE-18, RE-27N/D, PL6
  • Audio Technica AT4050, AT4033, ATM15a, ATM10a, ATM31a, ATM813, ATM63
  • Sony C-535P
  • Carvin CM67, 68
  • Peavey PVM380N
  • Crown PZM, PCC-160, PCC-200
  • Realistic Various PZMs (often modified for pro use)
  • Shure SM-57/58, SM-33, SM-53, BETA 56, BETA 52, SM-7, SM-5B545
  • Beyer M500, M160, M260. M88

This isn't a recommendation list. It's just a list of mikes I found on the equipment sheets of several well respected studios. There are a lot more models to choose from and nothing should keep you from making your own list. [In more recent years, some of these mics, especially the Beyers and Sonys, have made a price-comeback and are no longer “cheap.” In fact, I just sold my Teac ME120’s for $400 for the pair, about 4X what they cost new and 10X what they would have cost used when I wrote this article.]

For me, all this is one of the most interesting things about recording. Microphones are musical instruments. They're fun to own, play with, and use. Microphone technique is a vanishing art, especially as we all go into our basements and bedrooms and leave professionally designed rooms. Learn how to pick 'em and use 'em and you will have a talent that will be reflected in your recordings.

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Wirebender Audio Rants

Over the dozen years I taught audio engineering at Musictech College and McNally Smith College of Music, I accumulated a lot of material that might be useful to all sorts of budding audio techs and musicians. This site will include comments and questions about professional audio standards, practices, and equipment. I will add occasional product reviews with as many objective and irrational opinions as possible.