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Ningbo Alctron Electronics Co., Ltd. HRM-1

Pricing & Availability

  • MSRP: n/a


Reviews & News

HRM-1 Documentation

BidirectionalNingbo Alctron Electronics Co., Ltd. HRM-1

Bidirectional Ribbon Microphone

The HRM-1 is an inexpensive large-format ribbon microphone, modeled after AEA’s classic R84. The ribbon measures 50mm x 5mm and is 2 microns thick.

These mics are sold by Alctron and rebadged by numerous US and European vendors; the HRM-1 can be purchased as the Nady RSM-2, the T.Bone RB500 and the PPA R-1.

Most reviewers consider this mic (like all Chinese-made ribbons) a great value for the money. Further, it responds well to modification; see the sidebar for modders who will restore clarity by removing blast filtering, improve frequency range and transient response by retensioning the ribbon and upgrading the transformer.

The mic ships in a soft padded box. The mic has an integrated yoke mount. Note that the XLR cable is hardwired to the microphone.

Although Alctron does not list the HRM-1 in its catalog any more, the mic appears to be identical to the RM-21.

The Ningbo Alctron Electronics Co., Ltd. HRM-1 is also known as: HRM1, RM-21.


Frequency Response - BidirectionalClick Graph to Compare!
HRM-1 Bidirectional Frequency Response Chart
Pickup Patterns Pads & Filters
Bidirectional (1.7 mV/Pa; 30 - 18,000 Hz)
Ribbon Construction Impedance SPL/Noise
50x5mm, 2-micron aluminum ribbon 200 Ohms (Low) Max SPL: 165 dB
Self-noise: 18.0 dB(A)
Weight Length Max Diameter Interface(s)
1230g (43.39oz) 185mm (7.28'') 69mm (2.72'')
  • 3-pin XLR male (1)
Power Specifications

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