Saturday, March 19th, 2011 | by matthew mcglynn
Vintage mics are always better!
In this episode of The Microphone Show, we put a vintage Neumann U87i against the current production version of the mic, the Neumann U87Ai. Our U87-vs-U87 shootout included sung vocals, voiceover, and acoustic guitar.
What’s the difference between the mics?
In short, the original U87 had no DC-DC converter, and so the capsule was polarized at about 46V, which is all the 48V phantom power (or onboard battery pack) would provide. The ‘A’ revision replaced the battery pack with a DC-DC converter, allowing the mic to generate the 60V that the K67 capsule was designed for.
The voltage change raised the microphone’s sensitivity significantly — from 8mV/Pa to 28mV/Pa (in Cardioid mode), which is worth about 10dB of output level. It also increased the signal-to-noise ratio by 3dB.
Because the U87Ai’s output level is ~10dB hotter than the U87i’s, any comparison of these two mics requires a sonically neutral preamp. Otherwise you’d be hearing 10dB of color from the preamp on the U87i track, which would likely mask the subtle difference in the sound of the two microphones.
For this reason we sought a high-fidelity, neutral preamp. Typically we’d reach for a Millennia Media pre, as the sonics of the HV series gear are well-regarded. For this test, however, we wanted a preamp with a transformer on the input, due to the widespread conviction that “Neumanns love transformers.”
(Perhaps we’ll test that notion in a future episode.)
We went with the Hardy M-1, a 4-channel pre that meets all the required specifications:
- Transformer input (using Jensen JT-16-B transformers)
- Neutral sonics
- High fidelity
- 4 channels of awesome
The pads and filters on both mics were disabled. Both were set to Cardioid for all tests.
The M-1 was run directly into the studio’s HD converters. We adjusted preamp gain to produce equal signal levels from both mics in Pro Tools.
We output 24-bit, 48 kHz AIFF files from Pro Tools. Downsampling (to 44.1 kHz), bit-reduction (to 16-bit), and format conversion (to MP3) were done in Bias Peak.
Voiceover – Mark Keller
|U 87 i||AIFF||Male voiceover: U87|
|U 87 Ai||AIFF||Male voiceover: U87 Ai|
Sung vocals – George Merrill
George sang a chorus from “Waiting for a Star to Fall,” a 1988 Billboard hit from George’s duo, Boy Meets Girl. (See the original video here.)
The Vocal samples are RMS matched to within 1/10 dB — and yet phrase-for-phrase there are audible level differences. If you want to analyse these closely, open the AIFF files in your DAW, select a short phrase from each, gain-match them, and then compare. (See below for one such excerpt.)
|U 87 i||AIFF||Male vocals: U87|
|U 87 Ai||AIFF||Male vocals: U87 Ai|
Acoustic Guitar – Mark Keller
|U 87 i||AIFF||Acoustic guitar: U87|
|U 87 Ai||AIFF||Acoustic guitar: U87 Ai|
The Listening Test
I found it interesting that the members of the listening panel had such different perceptions of these two mics. And yet, in the end, everyone agreed that the differences were so subtle that a mismatched pair of U87i/U87Ai could be used for stereo recording without problems.
Listening closely with headphones, I can hear a difference in the vocal tracks between these two microphones. The Ai has ever so slightly more air. It sounds more “open” at the very top end. The older mic, in comparison, sounds a tiny, tiny bit more compressed. The effect is most noticeable on the voiceover tracks, but I can hear it on the phrase “be what you” in the sung vocal line too.
I’ve isolated some excerpts to make this easier to hear. In both the tracks below, you’ll hear the U87Ai, then the U87i, and then the whole thing repeats:
Taking a Stand
In the video, I stated a preference for the newer mic, without going into detail. What I hear from the Ai that I prefer is its additional “air” on the vocal samples. On acoustic guitar, I don’t hear enough difference to identify either mic in a blind test.
Couple the slightly more appealing sense of air with the higher output level and lower noise of the U87Ai, and the choice is clear. For my money, the U87Ai beats the vintage model. I am no longer holding out for a U87i. The new model delivers the characteristic Neumann U87 magic with superior performance specifications.
We owe a great deal to the people who contributed valuable gear for this test:
Kenny Evans of Mesa Recording for the loan U87Ai and the Hardy M-1.
Mike Pappas, Chief Engineer of Denver’s KUVO Jazz Public Radio for the loan of his personal U87i, which was serviced by the Neumann factory immediately prior to our shooting date.
Christopher Currier of Sennheiser USA for arranging the loan of Mike’s U87i.
Thanks also to the artists who contributed to the session:
Mark Keller of Loudvile Studios for his guitar and voiceover work
Composer George Merrill for amazing first-take a cappella vocals. See George’s full discography via AllMusic.com.
And finally, thanks to the cast and crew!
Jody Banks, Technical Director
Josh Petersen, Technical Engineer
Nissa Brehmer, Photography & Camera Operator
Alphonso Suerte, the masked announcer guy
Paul Simmans, Audio Engineer
Stephen Hart, Audio Engineer
Ana Sophia Dunham, Audio Engineer
Mathew Trogner is the Producer and my partner in crime. Mathew handles the engineering, the direction, all the video editing, and another hundred details I don’t even know about. If you like what you see, it’s largely due to his work. Thank you, Mat!
A word from our sponsor
The production costs of The Microphone Show are nontrivial, so I am pleased to say that Episode #2 is sponsored by Front End Audio. I’ve worked with the Front End Audio guys for a while, and I can say they have some of the best prices in the industry, and their service is second to none. If you’re in the market for a U87Ai (as I am!), your first stop should be Front End Audio’s Neumann product listing.
What’s your preference? Which U87 did you prefer?
By the way, within a week after the filming of this video, Paul Simmans bought a brand-new U87Ai. And I’ll be next, unless Mathew beats me to it.