In deciding between two similar interfaces, the often hard-to-decipher performance specifications play an integral role for the clued-up engineer. And here’s the problem – you would be fooled if you thought that these performance figures were reliable.

Because companies do not adhere to the same measurement standards, their performance figures often misrepresent the true performance of a product. Digital dynamic range figures are a classic example of this. There is a standard - the AES17 standard. Focusrite measure to this standard, but many interface companies do not.

Worse than this, some companies in the pro-recording industry quote figures from the datasheets they receive from the manufacturers of the silicon devices they’ve selected for their product. These figures are extremely misleading, since once placed in the environment of a product, with essential circuitry around the chip, performance figures change for the worse. Herein lies the real talent of good product design – to get the most out the chips used.

Our trusted R’n’D department have found that this difference can be as much as 12 dB dynamic range, with a chip's DAC performance measured at 114 dB outside of the box, and 102dB inside the box. That difference of 12dB is equivalent to a reduction from 19bits to 17bits – essentially, the studio is being short-changed by two bits! 

So, in summary, unless it says that it has been measured to AES 17 standards, you cannot trust the figures. When you’re told that a product does ‘exactly what is says on the tin’, treat these words with caution – appearances can be deceiving.