Need classic sound? Take the U 87 test below. Then have your mic re-voiced to be midrange rich & sibilance-free.

Acapella clips with LA session great Oren Waters singing
("The Waters" can be heard on over 260 gold and 100 platinum records).
Single take, both mics up, recorded by Grammy-winning engineer Bill Pearson of Mindseye Productions at an iconic Hollywood studio. A touch of reverb added - no compression, EQ or other processing in the recording or mixing. Before you crank up your monitors or headphones, please be aware the clips have extreme dynamic range.

Oren Waters testing the OktavaMod'd NT1a
and other Joly mics against a Neumann U 87

Many microphone enthusiasts familiar with my work know I have a preference for classic "Neumann-esque" midrange richness with a sibilance-free top end.

While the RODE NT1a is one of the quietest mics ever built (5 dBA) there are two aspects of this mic and the NT1 that have always troubled me - the bright voicing of the capsules used and the congested-sounding headbasket. The combination of the capsules used in these mics with their strong HF peaks (not at all like the classic K47 capsule used in the U 47 and M 49 mics) and very closed headbaskets (which causes internal reflection coloration) gives these mics a sizzly top end that tends to be sibilant while its midrange lacks the power needed for a compelling vocal track.

Headbasket Issues-

The headbasket of these mics has only about 10% open area at the bottom and along the full height of the side portions (see below). I think of headbaskets as little echo chambers defined by their dimensions and open-area percentage. After hearing lots of headbaskets with various dimensions, grille layers and wire mesh sizes - then modifying and listening to the results, I'm able to look at a headbasket and roughly imagine the extent to which it will influence the sound of the capsule.

Just take a look at the stock NT1a headbasket below - its easy to imagine how it could restrict sound and simultaneously exacerbate sibilance by allowing high frequency reflections to bounce around inside.

Stock RODE NT1a Headbasket
Note very small open area at bottom 1/3 of front and back sides

This is Michael Joly writing, founder of OktavaMod. Click "buy now" to purchase a the MJE-K47 capsule and headbasket mods for your NT1 or NT1a. Or click "contact me" below and send me your questions.

Removed NT1 / NT1a headbaskets

While some people like the various EQ curves that can be created by headbasket reflections, I prefer to hear, as much as possible, the sound of the capsule without an added layer of acoustical filtering that smears detail and lengthens transient response time as it modifies frequency response.

In fact, the influence of the multiple mesh layer cylindrical headbasket on the sound of the K47 capsule installed in the U 47 microphone led eventually to the more open, and angled M 49 headbasket (and its descendants - the angled headbaskets installed on the U 67 and U 87 microphones) as a means of reducing internal reflections and coloration.

MJE-K47 capsule inside modified Rode NT1a with new, more open headbasket
Note classic "67 / 87" shape and much greater open area percentage


Take The U 87 Test - Listen for Yourself

You'll be surprised by the similarity between the two files below - One of them is my 1970's U 87 (used by KRAMER on the Pulp Fiction soundtrack and a good number of other hits) and the other file is an OktavaMod modified RODE NT1a. Notice the authoritive lower midrange presence and smooth, sibilance-free top end.

I figured y'all could loop the short sections and A / B to your hearts content. Just think of the acoustic guitar as a "sound source" and not a piece of music. This is about all I need to make critical judgments about mics and mods, so you'll also get a sense of what I'm listening for - proximity effect amplitude / Q / F, midrange resolution and HF peakiness / integration with the midrange, sibilance levels and transient response.

Which is which? With 280+ votes cast as of 21 April 2010 there is an eight percentage point difference between the two mics - with more people choosing the mod'd NT1a file as being the U 87. Listen and cast your vote.

OktavaMod NT1a Mod (top) and '70s Neumann U 87 (bottom)

MJE-K47 - The right capsule for flat frequency response circuit mics

Actual Unsmoothed MJE-K47 Capsule Frequency Response
Note Classic "47" Timbre-Balance
(Top curve: on-axis plot, bottom curve: -180 degree response)

SDCs at 12th fret and LDCs "over the shoulder"

Award-winning Microphone Design by
Michael Joly