Driver Break in - Fact or Fiction?

[Kal Rubinson]

Mike P. wrote:

Yes it is, for those who are familiar with the subject. But it's "new" news for someone who is just learning.

Unfortunately for them. There's little to learn from such reports but they do create a bias.

Fact: it's a mechanical system.

To the OP, solid post. Sometimes it is indeed best to steer clear of an audibility argument because you know where that goes.

[loupy31]

Guitar amp speakers, you will notice a "........HUGE......." diference in tone quality as the speaker is broken in

[1Michael]

To answer the original post. I have no way to measure such things but having built 3 sets of main speakers and half a dozen subs, in every case the speakers when finished all sounded like trash to the point that I wanted to take a sledge hammer to them. After about 100 hours they become listenable and after a couple hundered hours they all start to sound decent. Now some uninformed individuals may tell you it is because I have "gotten accustomed to them" but that is nonsense. The sound changes and my wife has heard it also. There is a break in for drivers. Now subs dont seem to sound much different do to the lower freq's but I still run my 0-100Hz CD on those as well.

[Anthony]

I wish I had saved the plots, but I did not:

I ran an impedance test of a Dayton RS 8" driver new out of the box.
I ran one three weeks later after a lot of testing and breaking in.

Completely different animals. The impedance peak shifted down about a half octave and the high end rise tapered off considerably.

To me it's that simple, if the measurement showed a difference (and a big one at that), then break-in is important. It did and the speaker I built with it sounds much better after 100 hours now than it did after first assembly.

[drf]

How come noone hears a change in sound quality for the worse after a driver has been "broken in"?

it just seems a little confusing to me that "ALL" speakers sound better after breakin, yet none sound worse.

[Geoff St. Germain]

drf wrote:

How come noone hears a change in sound quality for the worse after a driver has been "broken in"?

it just seems a little confusing to me that "ALL" speakers sound better after breakin, yet none sound worse.

I would think that in some cases the driver may sound worse, but one thing to consider is that if the driver is being crossed over, such as a woofer or mid in a two or three way speaker, the crossover is likely designed for the "broken-in" parameters. In this case, I would expect that for a well designed crossover, the driver will sound best when it's parameters are closest to the parameters for which the crossover was designed.

Also, if the change in sound is small, then people may either not be able to detect it, and simply feel it sounds better because they are becoming used to the sound, or they may not be able to perceive the change as being either good or bad and simply say it is good. I thought my WMTW center sounded great as soon as I put it together. It still sounds great and I can't say that I've noticed any change in the sound of the speaker even though the drivers' parameters may have changed slightly.

Of course, I could be wrong, these are just my thoughts on the issue.

[tonyvdb]

drf wrote:

How come noone hears a change in sound quality for the worse after a driver has been "broken in"?

This is simply because manufacturers break in their test speakers before making any final adjustments to the tuning of the cabinet or crossovers and then sell to the public that design knowing that the speaker will sound the way they want it to after the so called break in period.

[Anthony]

Oh, I was simply referring to raw drivers for DIY projects. With manuf. speakers, many times they are partially broken in to test for bad drivers, make sure the crossover is performing correctly, that sound actually comes out

For raw drivers, with few exceptions (from what I've read and experienced), the drivers are straight off the manufacturing line. Parts Express even recommends you run a break-in / test right away to make sure the drivers are in good shape so they can send you replacements if you got a bad one (I guess some people shelve them for a while and then the return/warranty period has expired).

I wouldn't think the low frequency drivers would "break-in" very quickly once installed in a damped enclosure.
Mine hardly move at all with normal program material.

Also, the suspensions are just that; they simply suspend the cones and domes and really should not be a significant part of the overall resistive load.
In any event, countering or altering the electromotive forces from the motors would be analogous to a kitten trying to impede the movement of an elephant.
If anything happens to "loosen" the compliance of the suspensions, I would think that those effects would degrade sound quality, not improve it. Similar to a new shock absorber becoming more compliant over time, resulting in reduced damping of vertical shocks to the car suspension.

Any effects that cold storage and shipping has on driver compliance probably constitutes the bulk of the effects of break-in, and should clear up, with or without music being played through the speakers, once the air within the speaker cabinets warms up to the temperature of the listening environment.