Tech's Files: Do You Hear What I Hear?

Oct 1, 2009 12:00 PM, By Eddie Ciletti

OPTIMIZING THE LISTENING POSITION IN YOUR RECORDING STUDIO

Polls


Mix Regional

The Mix Regional section for Mix's September 2014 issue focuses on Miami. Send us your studio news: updates, sessions, new rooms, plus club performances and installations. Let the Mix audience know what is going on! Send photos and descriptions to mixeditorial@nbmedia.com.

Fig. 2: PMC’s orientation instructions for its MB1-XBD dual-woofer, three-way system. Notice the downward 10-degree angle: The engineer sits below the midrange driver by “x” distance, the listening position is just forward of “D” and the console edge is 500 mm forward of “D.” PMC’s Golden Rule for this system is that when standing, the listener should be no higher than the midrange driver.

Fig. 2: PMC’s orientation instructions for its MB1-XBD dual-woofer, three-way system. Notice the downward 10-degree angle: The engineer sits below the midrange driver by “x” distance, the listening position is just forward of “D” and the console edge is 500 mm forward of “D.” PMC’s Golden Rule for this system is that when standing, the listener should be no higher than the midrange driver.

The low-frequency response seems to benefit most from the bookshelf orientation (tweeters on the outside and offset high, rather than low). The NS-10M is bass shy below 200 Hz, emphasizing the familiar midrange honkyness. Now I know why horizontal placement works for so many.

Reading the Manual

I don't review or buy monitors with any regularity, so I'm not sure how many manufacturers take the time to power-assist their customers. That said, a trip to a local mastering house was yet another educational diversion. Greg Reierson, at Minneapolis-based Rare Form Mastering, has a pair of PMC MB1-XBD main monitors. By itself, the MB-1 is a three-way system, but is augmented for larger spaces by a duplicate low-frequency driver in a separate cabinet. This rather tall system puts the midrange driver at ear height when standing — the tweeter is above that — contrary to what you might think of as optimum when sitting.

As shown in Fig. 2, PMC provides very specific details to optimize its monitor for your listening pleasure. It is a teachable moment that can be extrapolated to other monitors. At minimum, we should all go back to our monitor manuals to see if, in our unpacking haste, we missed something. If no information was provided, then you now know how pink can work for you.

The Alt-Universe Tape Measure

Genelec's Acoustic Tape Measure is another example of a manufacturer's effort to improve the monitor-listener experience, especially in smaller control rooms where nearby wall reflections can hurt bass and low-mid response. It outwardly resembles a standard measuring tape, but the tape's top side is calibrated in quarter- and full-wavelengths between 115 and 10k Hz. The bottom side is a centimeter/inch rule. The instructions are written on the tape with an example.

Consider the first two bass guitar octaves. Open E-1 = 41.2 Hz; E-2 = 82.4 Hz (also open E on guitar); and E-3 = 164.8 Hz. Small rooms and small monitors don't support low frequencies very well; the low-frequency limit on Genelec's 6010A monitor is 74 Hz (hence its companion 5040A sub). Thankfully, bass is a harmonically rich instrument, especially when the cabinet is miked, so let's consider E-3, the end of the second octave at 164.8 Hz.

A monitor's “face” is 659.24 Hz away from the wall behind it — that's 20.57 inches = 0.522 meters = 1/4-wavelength of 164.81 Hz. The round-trip, with reflection off the wall, is 329.62 Hz, now the half-wavelength and the reverse polarity of 164.81 Hz. For those without the tape, there's a useful wavelength/distance calculator at www.mcsquared.com/wavelength.htm.

Two waves of opposite polarity will cancel rather than combine. This is why the distance between the monitor and the wall behind it can interact in a negative way, messing up the bass response. If you play bass (or want to hear all the bass notes), those two octaves are critical. The small-room rule of thumb is that monitors should be as close to the wall as possible; the distances to avoid are 17 inches (around 200 Hz) to 43 inches (78.75 Hz).

Tweak Party, Anyone?

Like any social relationship, getting accurate sounds from your monitors requires an investment in thought and time. This can result in a more focused and 3-D sound, reduced ear fatigue and an improved end result with less guesswork. So why not invite a few friends over tonight and tweak away?

For more Eddie Ciletti, visit www.tangible-technology.com.






Acceptable Use Policy
blog comments powered by Disqus

Mix Books

Modern Recording and Mixing

This 2-DVD set will show you how the best in the music industry set up a studio to make world-class records. Regardless of what gear you are using, the information you'll find here will allow you to take advantage of decades of expert knowledge. Order now $39.95

Mastering Cubase 4

Electronic Musician magazine and Thomson Course Technology PTR have joined forces again to create the second volume in their Personal Studio Series, Mastering Steinberg's Cubase(tm). Edited and produced by the staff of Electronic Musician, this special issue is not only a must-read for users of Cubase(tm) software, but it also delivers essential information for anyone recording/producing music in a personal-studio. Order now $12.95

Newsletters

MixLine

Delivered straight to your inbox every other week, MixLine takes you straight into the studio, with new product announcements, industry news, upcoming events, recent recording/post projects and much more. Click here to read the latest edition; sign up here.

MixLine Live

Delivered straight to your inbox every other week, MixLine Live takes you on the road with today's hottest tours, new sound reinforcement professional products, recent installs, industry news and much more. Click here to read the latest edition; sign up here.

[an error occurred while processing this directive]

The Wire, a virtual press conference offering postings of the latest gear and music news, direct from the source. Visit the The Wire for the latest press postings.