Break-in. Best Practice or BS?

[Ian Mackenzie]

As to break in I was thinking more along the lines of the actual diaphragm structure but this would tend to depend on its construction. ie soft or hard, density and construction and in the case of cones whether they are blended with carbon/paper/fibreglass and other compounds.

In the case of a cone, there are several key properties, stiffness and self damping, profile and the termination but this also applies the mid and HF devices.

As such some cone / diaphrapm may give a bit after initial use and so may the termination, possibly those that are semi rigid and designed to operate in break up mode more so than those that are the lossy damped variety.

Odd that many Hi End manufacturers suggest 100 hours playing to break in their systems.

[4313B]

such change would continue with further use

It does, it's a mechanical object. It will wear out. That's why we recone them. Recones aren't just for cones and domes little kids decide to kick in. JBL has new designs that reduce excessive suspension wear.

I also fully agree with your designer's standpoint issues, but most of us aren't on that end of the food chain. Remember, this is in General Audio, not DIY..

Good clarification.

I'm seeking the best answer for the masses

That would be "plug and play". Can't think of much else to say except maybe .

I suspect that drivers are being damaged by inappropriate methods used by the uninformed.

I neither suspect it nor care. In fact, I don't give any thought to what anyone else is doing to their drivers at all. I'm busy with my own crop of drivers.

woofer testing for box design is a wank?

No. You do what you need to do to implement your specific intended application.

So, my box tuning varies significantly depending upon how long it's been idle?

Box tuning is largely independent of what transducer is mounted in it. If you want to get picky, a box tuning might measure slightly different with a 2235H in it instead of a D130 if only because of specific drivers loses (e.g. center dome and surround porosity) and potential volume displacement differences. Environmental factors can also affect box tuning due to changes in the density of air.

If you use eBay at all you will know that none of this matters anyway. If the surrounds are rotted out of your drivers, the domes are kicked in, and the spiders are shot to hell it will not affect the sound.

*****

Here's some old data on a fresh LE14H-1 recone:

I don't have a problem with pulling the driver from it's box tonight and measuring it again. It's been in a 240Ti box for quite some time now.

[moldyoldy]

I'm busy with my own crop of drivers.

Glad you weren't too busy to share your POV, it's always welcome!

If you think I'm stoopid, you should meet my brother. (Now that there's funny!)

[4313B]

Glad you weren't too busy to share your POV, it's always welcome!

I was specifically asked to for some reason. I'll pull the driver tonight, measure it and post the results.

*****

I haven't used this LE14H-1 since this past Wednesday night. Here are the numbers as of right now:

Fs = 24.2 Hz
Qes = 0.24
Qms = 7.5
Qts = 0.23

So we can see there's been a permanent change in the suspension losses of this LE14H-1 from a "fresh" state.
Nothing too radical I don't think and this is just one set of data and just one driver.

[moldyoldy]

Odd that many Hi End manufacturers suggest 100 hours playing to break in their systems.

Not if you think about it, after 100 hours, you've reached the Point of No Return.

[Ian Mackenzie]

Moving parts.

Yeah but how long does it take to run a Yankee car in? The perception is is at least they are a little stiff to start with! Trust your ears.

[moldyoldy]

Now, THERE'S a good question for an OT thread;

How come it's considered OK for a jolly swagman to say "Yankee", but when us lazy hillbillies say it, we get shot at?

Semantics....Sheeesh!

(sorry Ian, Yankees only exist in the Northern US........except when they go on vacation.....)

[Ian Mackenzie]

No kidding? or should I say apparently..but don't let me spoil the Bush Howard love affair.

Actually, in my last important life I worked with Du Pont and 3M for quite a long while and we did all sorts of tests in the name of materials research at the serious end of the market with al sorts of materials incl woven and non woven..coated and uncoated.

People like JBL and their hangers on are quite a bit further down in the food chain than they'd like to think they are.

[4313B]

People like JBL and their hangers on are quite a bit further down in the food chain than they'd like to think they are.

I highly doubt that A.) They think about it. B.) They care. C.) It's relevant.

[Mr. Widget]

So, at this point, (though I'll keep an open mind to be convinced otherwise), I'll conclude;

BREAK-IN IS BS. (Edit; verdict in temporary suspension)

I assume you mean that no particular break-in regime is required... you aren't ignoring easily quantifiable results and claiming that speakers do not change with time are you?

Along with what Giskard posted about speakers wearing out... since they are mechanical systems like a spring in your car's suspension... their properties change with time. With loudspeakers they operate in their "sweet spot" for a number of years after the initial break in and then slowly degrade. Obviously if you play them hard for many hours a day they will change more rapidly than if you play them a few hours a week at low levels... actually in the later case they will most likely deteriorate from environmental conditions more than actually wear out.


Widget

[moldyoldy]

I assume you mean that no particular break-in regime is required... you aren't ignoring easily quantifiable results and claiming that speakers do not change with time are you?

Along with what Giskard posted about speakers wearing out... since they are mechanical systems like a spring in your car's suspension... their properties change with time. With loudspeakers they operate in their "sweet spot" for a number of years after the initial break in and then slowly degrade. Obviously if you play them hard for many hours a day they will change more rapidly than if you play them a few hours a week at low levels... actually in the later case they will most likely deteriorate from environmental conditions more than actually wear out.


Widget

Yes, Widget, your assumption is correct. I understand and agree (thank you for giving me a little credit). My intent was to give pause to the "they didn't sound right until after I ran 48 hours of looped 1812 cannon at 600 watts" crowd. After re-reading my initial post, I realize that (again) I didn't select my wording carefully enough. Bear with me, I'll learn the technique sooner or later....if I live through this one.

[4313B]

My intent was to give pause to the "they didn't sound right until after I ran 48 hours of looped 1812 cannon at 600 watts" crowd.

The Internet lives for that kind of posting though!

And for me personally it was more like 37 hours without sleep and three six packs before it all sounded right...

Usenet is like a herd of performing elephants with diarrhea - massive,
difficult to redirect, awe-inspiring, entertaining, and a source of
mind-boggling amounts of excrement when you least expect it.
- Gene Spafford

[Robh3606]

It really surprises me what some people will do to break-in a speaker. You guys missed a post on AA from a guy who asked if the changes in X-Max with some JBL drivers were real or not. After a couple of posts we find out that he tore the suspension on a new E-145 recone by running it to it's rated X-Max to break it in. Now why on earth would you drive a speaker that hard on purpose to begin with. Under normal conditions it should be very rare to push a driver that hard. If you need too get two.

Rob

[moldyoldy]

The Internet lives for that kind of posting though!

And for me personally it was more like 37 hours without sleep and three six packs before it all sounded right...

Usenet is like a herd of performing elephants with diarrhea - massive,
difficult to redirect, awe-inspiring, entertaining, and a source of
mind-boggling amounts of excrement when you least expect it.
- Gene Spafford

Which is exactly why I continue to dive headfirst the wrong way down a one-way street. They may not say much, but those 4,000+ lurkers are still here, and I have to assume that it's not just to look at our pretty pictures. (sorry Northwood).

Yeah, I'm running without sleep too. Does that mean you've got a six-pack left?

[spkrman57]

That is about the time frame for my 2226/2242 drivers.

During that time they exhibited a "midbass" hump and then they settle down to a flatter response.

I usually break speakers in just playing them at average volumes. Much less than their rated power for sure.

Ron