About Reviewed.com
Reviewed.com, part of the USA Today network, carries out quantitative reviews on a wide range of products including appliances, headphones, cameras, televisions and more. Since the beginning, their reviews have been built on the principle of using standardized scientific testing procedures to examine the performance of products, and a proprietary scoring method to ensure a level playing field amongst all manufacturers. Recently, I met with senior scientist Julia MacDougall, and received a tour of the facility and some insight into their headphone test methods, as well as a demonstration of their recently upgraded SoundCheck system.
The large brick building in Central Square, Cambridge, is in a part of town renowned for its young start up culture and unconventional work environments, so it’s no surprise to see a ping pong table next to the large, glass-walled conference room. However, once you get beyond the main lobby it is a labyrinth of test labs, each designed for testing a specific product. A room dedicated to camera testing features various test pictures on the walls, as well as 3d models with many moving and rotating parts to evaluate the camera’s capture of movement. Another lab was filled with massive flat screen televisions that were being tested for display performance, color measurement, luminance, contrast and more. Perhaps the most impressive was the appliance lab, where staff get to do their laundry while they work (in the interests of testing the washers), as well as working their way through many loads of white towels and stain strips that are marked with red wine, chocolate, sweat and more to scientifically evaluate the performance of the washing machines. Dishwashers, dryers, microwaves and ovens are also tested here, and a dedicated temperature and humidity controlled room contains many refrigerators filled with ‘dummy food’, the temperature of which is continuously monitored. The floor above the test labs is where their testers retreat to write up product reviews for their website, away from the whirr of tumble driers, swishing of dishwashers and stepped sine waves from the audio test lab.
The Audio Test Lab
The area that interested me the most was the smallest test area – the audio lab. Headphones are small and the test equipment is also compact, so a large room is unnecessary. Reviewed.com has been using Listen’s SoundCheck software since they first started looking for an objective way to test audio products back in 2007. Back then SoundCheck was being used for measuring mobile phones – smartphones were in their infancy, the next ‘hot product’, and Reviewed.com was the first review website to measure sound quality of a wide range of phones.
Full Story
This test sequence demonstrates SoundCheck’s Triggered Record – Chirp Trigger function for open loop testing of devices without analog inputs such as smart speakers, wearables, smart home devices, tablets and cellphones. A stimulus WAV file is created in SoundCheck and transferred to the device under test, where it is played back and the response recorded in SoundCheck as if the stimulus were played directly from SoundCheck. The Acquisition step is triggered by the chirp in the stimulus file. Chirp triggers are more robust than level and frequency triggers which are susceptible to false triggering due to background noise.
