Zu Loudspeaker Burn-In - Part One of Two

Zu loudspeakers require abundant break-in and burn-in to sound their best. The changes in performance they undergo is remarkable. While there is significant heavy-handed factory break/burn-in, more is required once they are in your home. The factory break-in phase is engineered to target the full-range driver’s cone—a process that is out of reach for the vast majority of users­­. Breaking in the membrane requires extreme levels of shear force to set the membrane into its performance profile, and there’s a fine line between membrane break-in and permanent deformation. During this time other aspects are also breaking in, the drivers’ suspension and also the dielectrics and electronics, but these, particularly the electronic, will continue to burn-in within typical home playback levels.

Break-in is a fairly simple, straightforward, once-and-done thing (sarcasm eyes). Not funny? Likely not. The humor assumes you like audio-dad jokes and that this is not your first set of new Zu loudspeakers. Unless specified otherwise, what follows are generalizations about burn-in specifically relating to home audio direct radiating Zu loudspeakers.

The majority of potential Zu owners that we talk to feel that burn-in is a thing, but that its not all that pronounced. We agree when applied to other brands­—the vast majority of loudspeakers change very little, some so little that you wouldn’t even know burn-in was a thing. But Zu loudspeakers are not like normal speakers and the burn/break-in changes they go through is an interesting and not subtle phenomenon.

In casual conversation, Zu use the terms burn-in and break-in interchangeably, to generally refer to the changes a loudspeaker goes through on its way to reach its long-term performance profile. Technically however there is a difference between them. Burn-in is the domain of the electric and break-in is the domain of the mechanical. Understanding each is interesting and might help with expectations of the loudspeaker when new, and when returning them to service after not being used for a while.

Effecting the speaker’s transition from sounding new to sounding full and engaging include:

- The length of time played.
- Power levels and program material played.
- Temperatures they might have been subject to in shipping or storage.

During the burn-in phase we don’t recommend swapping of components without reason and method as burn-in is heavily impacting the sound. If you have amps and other components that are burned in and near-to-hand maybe give them a try. But for the first three weeks or so we would advise against purchasing new gear to solve problems that might soon evaporate. New gear is going to also go through burn-in, and listening through burn-in on top of burn-in is rarely worth anything. If you do change an amp and notice a change for the better, you should also switch back to confirm that it is in fact the amp the made the difference. It could also be that the change was coincident with a burn-in related improvement, or some other change.

Disconnecting and connecting gear can clean a dirty connection and improve sound—even a clean contact that is not snug will reduce fidelity.

Your brain is a component of the playback system. The act of swapping gear or feeling like you are doing work on your system has a powerful psychoacoustic effect and is likely to allow you to hear deeper into the sound.

Burn-in changes during the initial ten to forty hours of in-your-home play will very likely be linear. Burn-in changes at this point will appear to plateau, but additional changes maybe on the horizon.

Once they have made that very noticeable transition to sounding good, you may need to revisit how you have them placed in your room.

If Zu speakers lay dormant for three months or more, even if fully burned-in prior, they will not sound just as they did and will go through a shorter phase of the burn-in phenomenon.

The life of a loudspeaker can be profiled in three phases: burn-in/break-in, performance, and aging-out. Next week we’ll explore the burn-in profile curves of the Dirty Weekend and Union loudspeakers.