SO.103 Cardioid Microphone Now Available! All Products In Stock and Available to Order. Free Shipping within the Contiguous U.S. on all orders over $100!

SO.103 Cardioid Microphone

Regular price $99.99

Shipping calculated at checkout.

Featuring a new and improved cardioid capsule! Housed in a 20mm die cast zinc enclosure with a male XLR termination, the SO.103 is compatible with the typical industry standard XLR cable. The SO.103 Cardioid Microphone is currently the only Primo EM423 based microphone available in a standard 20mm housing!

The SO.103 is a cardioid microphone with incredibly high sensitivity, a rich full-bodied sound, and a high end response characterized by a natural and airy presence. All of this packaged in a small form factor designed to be compatible with all of the Sonorous Objects Standard series accessories. When used in near field scenarios, the SO.103 provides excellent environmental noise rejection allowing you to fully focus on your subject without distraction while hearing every micro nuance and detail presented to you in the process. In further field scenarios, the SO.103 captures beautifully spacious and realistic sound fields.

Our favorite applications for the SO.103 are Sound Design & Effects, Foley, and Instrument & Musical Recording. The SO.103 utilizes Primo’s recommended cardioid capsule, the Primo EM423 capsule, known by recordists and sound designers for its directionality, detail, and its effortlessly natural frequency response.

We’re excited to be able to provide a frequency response graph and response data table that is specific to the unique microphone capsule used in the SO.103

The SO.103 capsule enclosure is fabricated in-house and the SO.103 Microphone assembled by hand in NYC.

*The SO.103 microphone is back in stock with a new & improved Primo Cardioid Capsule and is now available to order!! Please note all SO.103 orders will begin shipping in mid April

What's Included

(1) SO.103 Microphone

(1) Frequency Response Graph that is specific to the unique microphone capsule that you will receive.

*x2 above quantity amounts when ordering a matched stereo pair. 

*x4 above quantity amounts when ordering a matched quad set. 


- Exceptionally low self noise

-Utilizes Primo’s new and improved cardioid capsule, the EM423, delivering an additional 10dB of dynamic range over the EM204 capsule.

- Wide dynamic range and frequency response for accurate sound reproduction across the audio spectrum

-Balanced, transformerless output for increased immunity to noise over long cable runs

- Fantastic level of detail and clarity on-axis. High level of performance at rejecting rear sounds.

- Excels in studio and controlled environments. Ideal for Sound Design/Effects, Foley, and Instrument Recording. Performs well in the field with high level of wind protection. The SO.103 is sensitive and prone to wind and plosives.

- Can be used individually or as a matched pair. Stereo miking techniques yield spacious and accurate stereo fields.

- Universal form factor. 20mm diameter is compatible with many housings and accessories

- Frequency Response Graph and Data unique to the specific capsule used in the mic that you receive. 

-Industry Standard High Quality Components and Parts used. Neutrik Gold Pin Connector

- Fabricated in house by hand in NYC.



Capsule | Primo EM423

Polar Pattern | Cardioid

Frequency Response 20hz - 20khz. (Spectrograms show extended range)

Signal to Noise Ratio | 76dB

Self Noise | 16dBA

Maximum Input SPL | 135dB

Dynamic Range | 119dB

Sensitivity | -42dB (+/- 3.0dB @ 1kHz) | Stereo Pairs are matched within 0.3dB @


Operating Voltage | 48V Phantom Power (IEC61938 Standard)

Enclosure | Zinc Diecast Metal with Black Chromium Plating & Black PLA Plastic

Physical Dimensions  | 52mm Length x 20mm Diameter

Polarity | Positive pressure on the diaphragm produces positive voltage on XLR Pin 2

Operating Temperature Range | -10°C ~ +50°C

Storage Temperature Range | -20°C ~ +70°C

Connection | Three-pin industry standard XLR male connector, Gold Plated


SO.103 Microphone Product Manual PDF


Audio Recordings


*all recordings made with the SO.3/SO.103 plugged into a Sound Devices Mix Pre-6 II. The recordings contain no post-processing

*any subsequent modifications to the information above will be recorded on the SO.103 Microphone Change Log in the Sonorous Objects Resource Wiki.

*recordings above made with the previous version of the SO.103 containing the EM204 capsule. The current SO.103 contains a capsule with a similar frequency response & performance.

Be sure to check out our resource wiki for additional information, contents and downloads. 

Sonorous Objects Resource Wiki