What is Conditioning (break‐in)?
Conditioning, what some people call “break-in” or “blossoming,” describes the process whereby sound of a new loudspeaker undergoes a noticeable improvement in performance after it has been played for many hours. People differ in their ability to perceive the change, but it is very real. This improvement is due to the suspension of the speaker reaching its optimum stiffness range.
One important parameter that affects the sound of a loudspeaker is the suspension stiffness. The suspension is made up of a combination of flexible parts that allow the speaker diaphragm (cone/dome, etc.) to move in and out to generate the sound you hear.
The suspension becomes softer over time. This is a natural consequence of the suspension material properties. Materials commonly used are synthetic rubber polymers and impregnated Nomex cloth. Fresh from the factory, these materials are stiff and crisp, like a new pair of jeans or leather boots. As they are used, small predictable irreversible changes take place in the microstructure of the material, leading to the materials becoming softer. The initial change is quite rapid - just as with boots and jeans. The rapid initial change is called break-in or conditioning. As the suspension breaks in, the changes slow and become imperceptible, this is now aging. With proper design, materials, and use, aging proceeds very slowly and the speaker will provide many years of enjoyment.
When Definitive designs a speaker, the effects of break-in are taken into account. How? Well, we use industry standard life tests such as CEA-426B. This test requires a high power pre-conditioning before the test begins. The speaker parameters are measured after the pre-conditioning and after the life test. There can be no significant changes in the parameters measured after the life test.
Why doesn't Definitive pre-condition all speakers? It would drive the price of the speakers drastically upwards. Like your car, your boots, and your jeans, your speakers are tested just long enough to ensure that they are built correctly. You probably wouldn't want your new car to come with 500 miles on the odometer, or your new boots or jeans to be pre-worn (yuck).
How to Condition New Speakers
You may be wondering how much conditioning a typical speaker needs and how to go about doing it. In most cases people are so happy with the sound of their brand new speakers that they don’t feel the need to do anything special. They just come to find that the speakers improve over a few weeks of normal use. There’s nothing wrong with that. But if you want to get to peak performance faster we can help. Since you probably don’t have access to the measurement equipment and test signals here are some easy home brew pre-conditioning tips for the next time you buy new speakers.
In conclusion, break-in is a natural process of initial change inherent to all loudspeakers. The changes are easily measured, but are not audible by all people. Definitive speakers are designed to have a rapid initial change to reach a consistent predictable performance point, which will then remain stable throughout the life of the speaker.
Reference: 1 Klippel, Wolfgang: Mechanical Fatigue and Load-Induced Aging of Loudspeaker Suspension, 131st Convention of the AES. New York, 2011 October 20-23, paper no. 8474.