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Sound generators for breaking in speakers
- Thread starter Stephen
- Start date
Yes, they do. That's the entire point of breaking them in. I do so with every driver that passes through my hands because if not broken in the speaker will not work as intended. By all rights it should be done at the driver factory, and if not there by the speaker manufacturer, but break-in takes time, time takes money, and so...
There is a difference between manufacturing inconsistencies in T.S. Parameters between same model drivers and the differences that happen in one driver after a break in period.
These are two different things.
The type of mechanical compliance changes (though some individual parameters may be as much as 5-10%) basically equal out as far as performance goes. Box resonance and compliance has a great influence on the overall result too.
Not to say there is no noticable difference. There IS such a thing as break in from an unused driver. And over long periods of time I think there can be more change. I'm sure you have come across extremely compliant very old or "pounded" drivers. Especially certain surround, cone an spider types. Actually, I always thought that my foam surround Lowthers always sounded better just before they died. But this is not really relevant to the original context.
They actually never stop "breaking in" throughout their entire life cycle. It suspension, like shock absorbers in a car, it's continue to get more compliant..."softer"....as it keeps getting worked. Your speakers that sounded best just before they died were at their softest.
I don't have a bunch of test equipment, I can't tell you exactly how far some drift. I have modeling programs and ears, but I only make speakers for myself. I look at it like this....I'm going to be playing this thing for years, I don't care if takes some hours of playing to break it in. I just don't glue the ports in permanent until I've played and messed with it for a while and reach a point where I'm satisfied. That leaves room for adjustment, etc. as the driver gets the new wore off. Were I making these for the public, yes, I'd run test tones and break them all in, so I know the design is complete and when I take somebody's money for it, they're going to get what I tell them they're going to get.
billfitzmaurice
Commercial User
- Sep 15, 2004
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- Owner, Bill Fitzmaurice Loudspeaker Design
On average woofers come through with Fs about 10% higher than spec, but 20% isn't unusual. I've got an EV DL10x that specs at 60 (and EV says right on the data sheet that's a 'broken in' figure) that came through at 75, and never went below 70, so in the box it still sits 9 years later.
I got an EVM12L in 1975, spec Fs was 55. It came through at 62, went down to 55 after a normal break in. I used that driver until 1999, at which point Fs had dropped to 48Hz.
I would have to guess that after settling by 10% to 20%, further changes in Fs aren't going to make a huge performance difference for a bass guitar speaker. My rationale is simply that most bass speakers go into boxes that are equal to or smaller than Vas, thus the box itself contributes half or more of the effective restoring force on the cone. If the box is small enough, then the box is the suspension. And the air in the box doesn't break in.
I suppose that changing the stiffness of the suspension might alter the distribution of cone breakup modes. But I don't know if that's a noticeable effect in a bass speaker.
I suppose that changing the stiffness of the suspension might alter the distribution of cone breakup modes. But I don't know if that's a noticeable effect in a bass speaker.
The differences in amplitude response between pre & post-break in in speaker systems are negligible. If one is a Hi-Fi nut designing super stereo systems, then worry more about consistency of specs out of the package, and maybe further about matching pairs.
Just a reminder for some out there, we are talking here about differences in the same units after break-in, not manufacturing inconsistencies between units. And we already established that is common. The effect on final performance from any particular differences from published spec is another subject.
Anyone designing musical instrument speakers, I would suggest just using decent quality speakers from a decent manufacturer (There can always be a bad woofer, even with the best manufacturers, but thats a whole different story. And maybe a speaker significantly enough off sample spec). Even if you don't do initial break in, by the first day of incessently tweaking your samples, for all intents and purposes, they will be burnt in. If not initially.
All you end users out there. Just play on your cabs. No need to worry about it. Your cabs may sound "warmer". They may not either. They will sound how they sound--If not already.
Next we will be talking about burning in cables...
Broken in and running in for a short period may be two different things. One suggests ongoing permanent mechanical compliance changes. The other is temporary. It took me a while to distinguish between these two things (after bitching to a high end manufacturer). There is a different degree of effect with some materials. For instance, rubber surrounds. Previously I assumed working temperatures had to be much higher and mainly in the coil to make any adjusments to parameters.
bongomania
Commercial User
billfitzmaurice
Commercial User
- Sep 15, 2004
- 16,860
- 278
- 76
- Disclosures
- Owner, Bill Fitzmaurice Loudspeaker Design
Both are present. Even after the driver has been broken in the suspension will stiffen up after a period of non-use, even one as short as overnight. It has to be flexed for a bit to get it back to normal, though that 'waking up' process takes only a few seconds.
To lump breaking in of cables with breaking in of drivers does a great disservice to those who don't understand why drivers do break in, and cables don't, and serves no positive purpose.
I have been playing but not easy with a moaning wife in the house
If you can hear her moaning, you are not practicing loud enough.
Different fs = different spec = acts different in the box. At the point after breakin, I'll sometimes try a couple tunings adjustments, sometimes not depending on how it sounds. All done by ear at that point really. I think what usually happens is as Bill says. They come new a little higher than the target and settle in. To my ear anyway, the first go 'round with the cab on a gig sounds slightly different than expected, but as they smooth out it sounds more like I was imagining it was going to looking at the charts. Of course, in my case this isn't hard measurements, rather just listening, so some human error is at play, getting used to how the particular speaker sounds and plays after spending some time with it, etc. Boxes done for speakers that aren't brand new I don't take all that time, they sound how they're going to sound so a quicker listening test, any adjustments done, then the glue, usually all in one afternoon.
