Top of the Charts

A U D I O F I L E S ~ By Benjamin Hunting

The songs sound engineers use when designing your car stereo.

What’s blasting from your car speakers, and more important, how does it sound? For sound-system engineers at the audio-equipment manufacturer Bose, a playlist is more than tracks that slap. To test stereos, they need songs representing a variety of sounds and recording techniques to make sure new systems can re-create a song with the depth of the original recording.

To have a common reference point, Bose engineers all over the globe share a master playlist. “Every system engineer knows these tracks inside and out,” says Mark Armitage, head of the acoustical-engineering team at the company’s Michigan field office. “It makes for a universal language we can use when testing and tuning.”

Armitage says the 54-track Bose playlist is updated periodically, and engineers can use it alongside a smattering of their personal favorites or recent Grammy winners. He walked us through a few selections from his test list.

mono pin k noise “The least fun track [Literally noise—Ed.] and also the one we use most. It shows you where your center image [the imaginary center stage of the recording] is, and it’s full bandwidth, so you can hear frequencies that aren’t aligned properly.”

Hol ly Col e T rio, ” I Ca n Se e Cl e a rly Now ” “This track is quite centered, and the first part of it is very mono channel. The deep-malevocal equivalent is Johnny Cash’s ‘Bird on a Wire.’ ”

Bru no M a rs , “ 2 4K M agic ” “Features a lot of instruments that are spread wide across the soundstage, from the high tweeter notes all the way down. It’s very full.”

Win t e rp l ay, “ Bi l l i e J e a n ” “It’s a simple, clean female vocal accompanied by an upright bass. A lot of times the simpler things show soundstage details that are harder to hear in something that’s super-busy.”

Tom P e t t y, “ L e a rn ing to F ly ( L i v e ) ” “The crowd starts singing along, Petty’s voice drops out, and if the system is done right, you get a real sense of how big that auditorium is. If not, it tends to collapse and you lose that giant space.”

Dav e Bru b eck Q ua r t e t, “ Ta k e F i v e ” “Listen for the hi-hat and the cymbals from the intro. Cymbals are hard to record and reproduce, and this has a nice, natural sound with excellent instrument spacing.”

S t e e ly Da n , “ H e y N in e t e e n ” “Has a lot of detail and sharp, clean hits that show how well the music’s temporal alignment is coming to you. With each speaker a different distance from the listener, tuning a system involves making sure all sounds arrive to ears at the same time to sound clear and natural.”

S t r a igh t No Ch ase r , “ Hom e wa rd Bou n d” “All a cappella, the vocals span all the way across the stage, and you can independently hear each person singing.”