RTA420 Measurement Microphone


  • Capsule: 1/4″ Electret Condenser (10mm)
  • Polar Pattern: Omnidirectional
  • Freq Resp Characteristic: Diffuse Field (Random Incidence)
  • Freq Range: 20Hz – 20kHz
  • Nominal Sens: 7mV/Pa, +/-3dB typical
  • Operating Voltage: 9-52V DC Phantom Power
  • Max SPL: Approx 110dB (1kHz @ 1% THD)



  • 1x RTA420 Microphone
  • 1x Soft-sided dual mic carrying case
  • 1x Mic Clip
  • 1x Windscreen


RTA420 measurement microphone from Rational Acoustics.

The RTA420 measurement microphone is an ideal budget-friendly addition to your toolkit. It’s a great choice if you’re a student, just starting out with system measurement, an established pro looking for a backup mic, or putting together a “B” rig. It’s also a cost-effective solution for multi-mic measurement setups. The RTA420 offers very respectable frequency response. It has a heavy-gauge steel construction, and measurement performance to rival high-end microphones costing many times more. The RTA420 capable of generating accurate data at modest levels.

The Rational RTA420 comes with a mic clip and a bright yellow windscreen, which is great for spotting your mic in dark venues. It also includes a custom-designed soft carrying case that accommodates and organizes 2 microphones plus accessories.






The RTA420 carries a one (1) year warranty against defects in materials and workmanship. The warranty is valid from the date of original retail purchase. This is a non-transferable warranty that extends only to the original purchaser. Rational Acoustics will replace the product at no charge if the product proves to be defective upon evaluation.

Warranty does not cover or apply to (a) misuse, mishandling, and abuse, (b) products that have been modified, altered or repaired by an unauthorized party (c) normal wear and tear, (d) damage that has occurred during shipping, (e) loss or theft, (f) damage caused by accident, fire, flood, lighting or other force majeure events.

The RTA420 contains NO field-serviceable parts. If your mic stops working correctly, please do not attempt to open the mic or repair it yourself, as this will immediately void the warranty.

For warranty claims, email Rational Support with a description of your mic’s malfunction and proof of purchase (your order receipt, or order # & date of purchase).

Additional information

Weight 1 kg
Dimensions 20 × 15 × 15 cm

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