Audio Quality

Unparalleled audio quality

Cortex delivers audio quality beyond any other VHF.  We spent countless hours testing, trialing, and refining five different elements to create the ultimate VHF audio experience. Each element is critical to delivering crisp, clear, and loud audio that is as loud as a train, but clear as a bell.

Fast sampling rates

Unlike most VHF’s Cortex samples at 44 kHz. There are two benefits from this. Firstly, it is the starting point for audio clarity, providing sharp detail for signal processing. Secondly, it enables processing gain to drop the noise floor to further enhance the signal clarity

44khz processing-2

Snapdragon Processor for filtering algorithms

Used in billions of mobile devices, the Qualcomm Snapdragon in Cortex handsets provides raw processing power. This enables complex filtering algorithms to run in real-time, providing a clearer audio signal to the power amp.


Capt. Scott Goodwin

BD Outdoors

"I bought a simple and sufficient VHF and after some use was not thrilled with the volume of the radio.

Visiting one of the boat shows a while back, I learned about the Vesper Cortex V1 VHF,  I thought it very cool and kept going, but later read comments from actual users about how loud and clear the speaker was for the VHF.

The installation was pretty simple.  The Cortex speaker is nice and clear with plenty of volume; problem solved."

A powerful power amp

Cortex handsets include a Class D power amplifier to deliver loud volume with low battery drain. This amp was selected to deliver maximum power for the specific speaker and cavity in Cortex, without wasting battery consumption.


via Feedback Portal

Case #16515826

"Still love the sound quality! VHF is now usable in an open cockpit, a big improvement. Most of my customers have old school VHF and the difference is remarkable. A bit like using professional wood working tools and going back to leisure quality."


Speaker quality

Every speaker outputs a different frequency response. A good speaker delivers high pitch sound and low pitch sound at the same volume (an even frequency response). Without that, the speaker will distort some pitches, while others will be too quiet. The Cortex waterproof speaker works in harmony with the cavity it sits in to deliver a flat frequency response, providing up to 85 dBA with a total harmonic distortion of less than 1%.

Cavities count

The speaker cavity works in harmony with the speaker and impacts the final frequency response. Our acoustic engineers sloped the angle of the speaker to increase cavity size, ribbed the back panel to prevent vibration, and refined the number and positioning of holes in the back panel to ensure maximum volume at all pitches, even when the handset is lying on a flat surface. All this was achieved in a completely waterproof (IPX8) enclosure.

Audio Quality

Loud as a train, clear as a bell

All five elements must work in harmony to deliver quality audio. When we created Cortex, we ensured every aspect was considered, tested, and refined so we could deliver a product we were proud of.