Dan Friedman

Recording Magazine sends out a newsletter to its subscribers every few weeks. The newsletter is (coincidentally) titled “Sound Advice“. This is the 4th installment in the series on headphones and monitors. I asked permission to reprint this newsletter (and will ask to reprint the others in the series as well) so that those of you with home studios can also benefit from the information. I want to personally thank Brent Heintz, VP/Associate Publisher for granting permission, allowing me to share this great information with you.

Please visit Recording Magazine‘s website and their Facebook Page.

Voiceover usually deals with a singular signal (your voice) and therefore it is typically mono. However, the importance of space and spatial recognition cannot be overstated. By their very nature, how you hear headphones and monitors greatly effects how you hear yourself and your ability to interpret what you hear.

So… please enjoy this installment from Recording Magazine’s Sound Advice on Acoustics.

 

Welcome back to Sound Advice on Acoustics! For the past few months, we’ve discussed the ins and outs of using headphones for critical listening and monitoring. Now Robert Auld tackles a difficult final question: How do you choose, from all the models on the market, the headphones that will work for you?

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To start with, we could try measuring headphone performance in a laboratory setting, much as any manufacturer does. This is both easy and difficult. The easy part is placing the headphones on the ears of a measuring dummy (such as the Head And Torso Simulator by Bruel & Kjaer) or onto a specially designed coupler or artificial ear (the B & K type 4153, for example). You then run test signals through the headphones, they are picked up by the microphone(s) in the dummy or coupler, and you have your test data.

The hard part is deciding what the test data mean.

One problem: the dummy ears or coupler are meant to simulate average human ears. Who is average? No one. Does it make a difference? Yes. It’s like trying to determine how a loudspeaker will perform in one room by measuring it in a different one.

Now, speaker designers do that all the time; they measure loudspeakers in anechoic chambers, where no one in their right mind listens to music. It is a useful exercise but it does not tell the whole story.

Measuring a headphone with a coupler has similar limitations. Just as the anechoic chamber will not tell you much about room effects, the coupler will not tell you much about the variable effects of real human ears interacting with headphones.

Another problem: there is not complete agreement as to what equalization curve constitutes “flat” response when a headphone is measured on a coupler or dummy. One choice is free-field (sound arriving with no reflections), another is diffuse-field (sound arriving with many random reflections).

A strong argument for diffuse-field equalization is that it better matches real-world listening conditions. Several “diffuse-field equalized” headphones have been introduced over the past decade, with models available from AKG, beyerdynamic, and Sennheiser.

They do not all sound alike. Apparently there is no consistent standard for implementing diffuse-field equalization in headphone designs. While my own attempts to locate such a standard have produced no results, that does not mean it does not exist. If anyone out there does know about, say, an ISO standard for diffuse-field equalization of headphones, feel free to email Magazine about it: [email protected]. They’ll make sure your letter gets to me.

I do not have a testing laboratory, but I still need to evaluate headphones. So I use my ears. I listen to test signals and to music. First, the test signals. I listen to two types of signals: warble tones and pink noise.

The warble tones are sine waves that continually vary in frequency over a range of about 1/3rd octave. This prevents resonances from building up at any one frequency in the test environment (usually listening rooms, but it works for ears covered by headphones too). I use the warble tones to get some idea of the bass extension of the phones under test. At some point it becomes necessary to dramatically boost the signal to hear anything at all, and this is usually a good indication of the useful limit of bass response.

Pink noise is good for assessing overall tonal balance and showing up colorations—midrange humps, upper bass dips, or whatever. These show up as tonal changes in the pink noise.

The real test, though, is music. It is important to pick music recordings that have the right characteristics. Most commercial recordings, especially those of pop music, are disqualified from this test because we do not know what was done to them during recording and post-production.

We can listen to two different monitors with a given recording and say, for example, that one sounds brighter than the other. But which one is the more accurate monitor? What does an AKG C12 tube microphone, nine inches on axis from a particular singer, put through a compressor, a parametric eq, and a Studer analog multitrack tape machine, really sound like? You tell me.

There are a couple of ways around this situation. One is to use recordings that you make yourself with simple techniques, no processing, and microphones considered to be accurate. I do this myself using the Crown SASS stereo microphone. I do not think the SASS is a perfect microphone, but its deviations from accuracy occur mostly at the frequency extremes. It also helps that it is a quasi-binaural array. So if I listen to a recording made with the SASS through particular headphones and it sounds more like I’m actually there, I figure I’m on the right track.

A second solution is to seek out commercial recordings made with simple techniques, relatively accurate microphones, and no processing. These do exist. Next month I’ll give you a short list of some of my favorites, but until then, one hint: almost any of Jack Renner’s recordings for Telarc would qualify.

Listen to such a recording on, say, two different headphones. If with one pair you hear midrange colorations or boomy bass while the other pair sounds open and well balanced, it is likely that the better sounding headphones really are better.

Next time, we’ll wrap up this article with a list of some CDs I personally find useful for testing headphones. See you then.

Recording Magazinesends out a newsletter to its subscribers every few weeks. The newsletter is (coincidentally) titled “Sound Advice” and this month it features a new series on headphones and monitors. I asked permission to reprint this newsletter (and will ask to reprint the others in the series as well) so that those of you with home studios can also benefit from the information. I want to personally thank Brent Heintz, VP/Associate Publisher for granting permission, allowing me to share this great information with you.

Please visit Recording Magazine‘s website and their Facebook Page.

Voiceover usually deals with a singular signal (your voice) and therefore it is typically mono. However, the importance of space and spatial recognition cannot be overstated. By their very nature, how you hear headphones and monitors greatly effects how you hear yourself and your ability to interpret what you hear.

So… please enjoy this installment from Recording Magazine’s Sound Advice on Acoustics.

Welcome back to Sound Advice on Acoustics! We’ve been discussing how to use headphones as critical listening monitors, but author Robert Auld warned us way back at the start that his answer to “Can we do it?” is “Yes, but.” In this month’s installment, it’s time to look at a really big ‘but’, if you’ll excuse the expression…

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I said that my ‘yes’ to using headphones as critical monitors was qualified. Jerry Bruck explains one small but important problem that can happen when editing stereo program material:

“I love using headphones for editing because of the precision. If there’s some vestige of something you don’t want in a splice that’s, say, coming in or going out, the headphones will nail it in a way that loudspeakers never do.

“But—and this is a big but—a real danger exists, because I have many times had the experience, as others have had, of making a splice in music, and on headphones it is totally inaudible. You sit there congratulating yourself on what a wonderful splice you have just made, and then take the headphones off and turn up the speakers, and suddenly it’s glaring. It’s there, and you can hear it, and you go, ‘How can that be? Why can I hear it on speakers and not on headphones?’

“I don’t really have an explanation, but I will venture one: that it has to do with the phase relationships between the channels. Again, it’s the interaural mixture that occurs with speakers and doesn’t occur with headphones. Once that happens the two channels have phase relationships that are a giveaway that something has happened here that could never happen in real life.”

“So I would more than caution anyone, I would actually warn anyone who attempts editing in headphones: check your work on speakers. It doesn’t happen every time; it happens like one time out of twenty… but that one time will really amaze you when it occurs, and you’ll have to go back and redo it. Otherwise everyone is going to hear it.”

A good case can be made for always using both headphones and loudspeakers to monitor our work. The two different monitoring methods each tell us different, useful things—stuff that we really need to know. (There is also the issue of the increasing use of headphones by our listeners with all those millions of portable music players out there.)

Once we decide to work this way we can reap some real advantages from it. For example, if I have really good headphones I have less need for big, expensive loudspeakers. The things I need speakers for—checking the stereo image, the direct to reflected sound balance, etc.—can be reproduced just fine by smaller, less expensive loudspeakers (provided their basic sound quality is adequate). Other things—fine balances between instruments in the mix, little details of performance, tonal colorations, etc.—are better checked on top quality headphones.

Jerry Bruck has taken this idea to its logical conclusion for some of his location monitoring. On some of his smaller scale jobs, where he doesn’t want to lug around a whole van-full of equipment, he brings along the Cambridge SoundWorks Model Twelve speaker system.

You’ve probably seen the ads for it: “stereo in a suitcase.” Two small satellite speakers and a small 3-channel amp fit into a medium sized carrying case that also has a built-in woofer. Unpack the amp and the satellites and the case becomes the subwoofer of a powered 3-piece system. According to Jerry, the sound quality of the Model Twelve is quite good—certainly accurate enough to tell him what he needs to know. Then for the fine details, on go the headphones.

[Editor’s note: at the time of this writing, the Cambridge Soundworks system was, if not unique, unusual and worthy of mention in the industry. Nowadays there are a lot of fairly portable 2.1 speaker systems with tiny satellites and a reasonably portable subwoofer that might serve as alternatives to headphones, or even stereo coaxial systems with optional or no subwoofer that can do the job. Recently reviewed speakers of this type include the Equator Audio D5, reviewed December 2011, and the Pelonis M42, reviewed April 2012.]

I’ll leave you with this thought before we consider how to evaluate different headphones:

“It is an axiom of any recording technique that the final result is only as good as the monitoring system used when making the recording. The more accurately the recording engineer can hear throughout the process, the better the final result will be.” —Streicher and Everest

See you next month as we go into the home stretch with testing criteria and suggested listening material!

Part 1

Part 2

Recording Magazine sends out a newsletter to its subscribers every few weeks. The newsletter is (coincidentally) titled “Sound Advice” and this month it features a new series on headphones and monitors. I asked permission to reprint this newsletter (and will ask to reprint the others in the series as well) so that those of you with home studios can also benefit from the information. I want to personally thank Brent Heintz, VP/Associate Publisher for granting permission, allowing me to share this great information with you.

Please visit Recording Magazine‘s website and their Facebook Page.

Voiceover usually deals with a singular signal (your voice) and therefore it is typically mono. However, the importance of space and spatial recognition cannot be overstated. By their very nature, how you hear headphones and monitors greatly effects how you hear yourself and your ability to interpret what you hear.

So… please enjoy this installment from Recording Magazine’s Sound Advice on Acoustics.

Welcome back to Sound Advice on Acoustics! We’ve been discussing the question of whether headphones can serve as adequate replacements for studio monitors, and at the end of our last installment, author Robert Auld said the answer to that question is “Yes, but.” It’s time to find out what he means, starting with the “Yes” part…

***

There are many situations where headphones have the potential to offer a higher quality of sound than loudspeakers:

~ They are not dependent on room acoustics, which can vary tremendously. As a sound reference that is consistent from venue to venue, headphones are a uniquely practical solution.

~ Most practical high-quality loudspeakers use more than one driver for each channel and need a crossover network of some sort. The potential for sonic problems with this arrangement has always been a challenge for speaker designers. Headphones can bypass such problems entirely by using a single driver for each channel.

~ There is no agreement as to the ideal polar radiation pattern for a loudspeaker. A variety of approaches are found in both consumer and professional settings, and they all interact with the listening room in different ways. With headphones this is not even a consideration, let alone a problem.

~ The very characteristic that makes the most difference in the way headphones sound—the lack of interaural crosstalk—makes them revealing of details in a recording to a degree that no conventional loudspeaker setup can match. This is one reason why many classical music engineers use them: if you need to catch things like that smudged entrance in the second violins or a fluffed note by the bassoonist, headphones will tell you about it much quicker than loudspeakers will.

~This same precision in rendering detail makes headphones superior for editing stereo program material. They reveal what is really going on at the splice point much more readily than loudspeakers—most of the time. (I’ll let Jerry Bruck tell you about the exceptions in a future installment of this newsletter.)

There are many practical advantages to using headphones as well:

~ They are lightweight and portable.

~ Dynamic-element phones have no need for large, powerful, expensive amplifiers. Suitable headphone amps are already built into a lot of recording equipment, and separate headphone amps are usually small and cheap compared to speaker amplifiers.

~ Closed-back headphones provide some isolation from your surroundings, making it possible to monitor where it would otherwise be difficult or impossible.

~ Some headphones are capable of deep bass response normally found only in very large full-range loudspeakers or in subwoofers. If you record pipe organs for a living—or, which is a lot more likely in this day and age, you record dance music or other bass-heavy musical genres like hip hop—you may find this useful.

~ Did I mention that they are lightweight and portable?

Even the more expensive top quality headphones offer more “bang for the buck” than loudspeakers. For example, the Sennheiser HD 580 has a street price of about $250. This gets you dynamic element headphones that are considered to be near-equivalent to the most esoteric electrostatic models. Loudspeakers with equivalent sonic performance could easily cost five times as much, or more.

But if it was really that easy, all the time, for everyone, there wouldn’t be loudspeakers in professional studios any more, would there? Tune in next time, when I reveal a subtle, annoying, even fatal fly in the ointment that more than adequately explains why even the smallest budget studio must have speakers as well as headphones. See you then.

Part 1