Ocean Way Audio RM1-B Microphone

Large-Engine, Active Ribbon Trandsucer
The magnet surrounding the ribbon motor creates a focused magnetic flux density of 10,000 Gauss (1 Tesla unit).

Ocean Way Audio’s RM1-B is the company’s latest iteration of Cliff Henricksen’s RM1 active, bi-directional ribbon microphone. The RM1-B has the RM1’s motor assembly with a 1.77-micron-thick aluminum ribbon. It uses a discrete phantom-powered preamplifier designed to Henricksen’s specifications.

With the RM1-B, the RM1’s outer peaked pop filter has beereplaced with a single flat, woven Nylon-Spandex screeframed in a stainless steel front plate. This front plate is removable/replaceable as it’s held in place magnetically by the motor assembly’s huge surrounding structure.

Looking like a small monitor speaker, the  RM1-B measure15.24 cm tall, 7.62 cm wide and 5.08 cm deep; it weighs 3.4 kilos, or about 7.5 pounds. It has an aluminum alloy body with a short, permanently attached XLR cable, and comes in a waterproof/airtight Pelican travel case. The RM1-B uses a gimbal-style yoke mount with large knurl knobs on either side to tighten the mic’s body into any tilted position. The yoke is attached to a standard 5/8-inch threaded mic stand coupler using a hex screw that tended to come loose during my evaluations. The included mount is not a shock mount, but the optional ISO1 ($170) boom shock mount is available. It uses replaceable elastic suspension bands, and I would recommend it.

Contributing in large part to the RM1-B’s heft is the massive magnet structure shaped like an elongated “O with the inside sloping walls machined into a magnetic waveguide that creates a focused magnetic flux density of 10,000 Gauss (1 Tesla unit) on both sides of the ribbon.

The magnet waveguide geometry determines the 90-degree horizontal pickup pattern lobe for high-frequency capture starting at approximately 6.5 kHz and extending far beyond audibility (67 kHz theoretically). The vertical pickup pattern is determined by the ribbon’s 5cm height, starting with a wide lobe at low/mid-frequencies and narrowing at 6.5 kHz until by 13 kHz ibecomes 45 degrees wide.


I started with a voice-over recording, and my VO talent wanted to try the RM1-B first. I used anywhere from 35 to 50 dB of mic gain from a Sunset Sound “Tutti preamp. Even though I used about 6 dB more mic gain to match recording levels with a modern condenser mic, the RM1-B had a noticeable lower noise floor.

With ribbon mics, a windscreen should always be used, and for an up-close dramatic reading, I used my Pete’s Place Blast Filter. There was the expected proximity, but the sound was open and detailed and not overly bright, with the extended high frequencies pleasing and not harsh sounding or boosted.

Positioning the RM1-B uprigh(recommended) in just the right spot required some rethinking/learning. If possible, I used regular straight-up floor stands for vocals or voiceover work.

The RM1-B’s large size, weight and the magnet’s attraction to steel stands, adapters, connectors, tools or anything ferrous can be a little problematic  when dialing in an exact placement. But I got used to pre-threading the mic to the boom end piece first, and then attachinthis to a heavy-duty stand/boom with a counter-weight and placing sandbags on the base. Do not use quick release mic adapters with this mic.


I recorded a Taylor 655C 12-string acoustic guitar with the RM1-B placed about 30 cm out front and aimed at the bridge for a bright sound. With 45 dB of preamp gain and using no HPF as a starting point, this was just what the production needed; a touch of EQ/compression during the mix brought it home. The RM1-B provided good coverage of all the sound that instrument was projecting with pure detail and all subtle nuance. Just lovely!

For louder and harder playing, I moved the mic out to about 53 cm to pull in more of the room’s ambience from the mic’s back lobe. I aimed at the 12th fret and used 40 dB of gain. When playing softer and fingerpicking, I kept the same mic location but cranked up mic gain to 50 dB. In both examples, the RM1-B produced a clear, balanced and vibrant sound with plenty of the acoustic space around the guitar included.

At another session for a vocal/acoustic guitar demo, I used the RM1-B for the singer and a Røde NTR ribbon (also figure-of-eight) on his 12-string guitar. I had the singer close in at about 5 to 10cm. This produced some proximity, and I had no problem with overloading with this experienced singer who used appropriate mic technique for the louder bits. I liked the intimate sound this microphone brought to the singer’s performance.


Next I tried recording both clean and distorted electric guitar amp sounds. I used my Fender Strat plugged into a littl5-watt Class-A amp connected to a 12- inch speaker/cab.

I used a desktop stand and elevated the amp on an isolation platform. This allowed the mic’s gimbal mount to swing the direction of the mic’s pickup up or down anywhere from straight on the dust cover to anposition on the speaker’s cone. At no closer than 61cm from the grille cloth, the gimbal mount allowed for dialing in the exact ratio of edge-to-tone sound mix.

The RM1-B revealed every detail—good and bad—about the amps sound. It is an honest and warm sound with a mellowing effect like older ribbon microphones produce. But the RM1-B has more accuracy, clarity and depth. This was an overdub, so I was free to move the mic further away for less proximity and more of the rear lobe in the sound. But I was careful not to get too close in and added the Blast Filter to prevent speaker chuffing or port air blasts from damaging or distorting the ribbon.


I set up a pair of RM1-Bs as a Blumlein coincidence stereo pair array. I wanted to capture an ambient-realistic recording of a drum kit positioned at one end of a large drum recording room. The drum kit projected sound lengthwise down the room’s 7.7-meter length. (The room is 3.5 meters high and 6.4 meters wide.) My laser-measuring device indicated that the Blumlein pair was positioned 3.34 meters out in front of the kit and centered within the room’s width.

I used two stands so that the bottom RM1-B was 1.41 meters above the floor with the second boom stand holding the upper RM1-B so that it was nearly touching the top of the bottom mic. Both mics were turned 90 degrees (right angles) from each other so that both of the mic’s front sides were aimed left and right towards the drum kit. It took some time to get the two mics positionedthat’s 15 pounds of microphones—so they didn’t magnetically “stick to each other.

Listening to the pair panned L/R in an audience’s perspective, I could easily hear the left side of the kit—ride cymbal, crash and floor tom—and the right side with rack tom, crash and hi-hat cymbals easily located and heard in the stereo field. The transients were clear but not harsh, and the cymbals were in balance relative to the rest of the kit.This setup produced one of the best room sounds I’ve ever heard. I got a complete drum sound with loads of low frequencies—much more tha using a condenser The 24-inckick sounded like it did in the room, and the toms and snare were all in balance and present.

There was a slight tendency toward a “boxy flavor, but when mixed with the close drum mics, it produced a very or- ganic overall drum sound. The RM1-B was remarkably true to the source, as my drummer, kit and room were top-notch.

The company cautions: “excellent for just about any instrument except nearfield kick drum and near-field bass guitaspeaker pickup (LF will harm the ribbon). I quickly found this true for twRM1-Bs as overhead mics located abou1.5 meters above a drum kitthe toms and kick overloaded the ribbon.

I was impressed by the ultra-realistic capture provided by Ocean Way Audios RM1-B Active Ribbon microphone. It is excellent for instruments or vocals—close in for medium to soft sources or for the ambient pickup of distant loud instruments such as drum kits or guitar/bass cabinets.


COMPANY: Ocean Way Audio PRODUCT: RM1-B Active Ribbon Microphone
PRICE: $2,600 MSRP
PROS: Silky, realistic and rich-sounding
CONS: Heavy and a little unwieldy to set up


For acoustic guitar and vocal recording, I arranged the mics so that the side null of the RM1-B vocal mic was aimed at the side null of the Røde NTR I used on the acoustic guitar. The side nulls of the two figure-of-eight mics working together produces an amazing amount of total isolation! Soloing either the guitar or the vocal, I could barely hear the guitar leakage into the RM1-B and minimal vocal leakage into the Røde.

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