Hey can someones test speaker burn-in please?

Do drivers break in?

Of course they do, they are a mechanical object and the spyder, surround are fairly stiff when brand new. The break in lasts seconds to minutes--maybe an hour or two and mostly effects woofers or other drivers that have a long stroke. The idea that a driver "needs" hundreds of hours of break in is just paranoia or "if it needs a little, why not give it MOAR!

Now, if you are building a speaker and have the ability to check T/S parameters--why not feed them a signal free air and get the cone moving for a few hours? Check the T/S parameters the next day, plug in the readings and design your passive crossover and build around those specific readings? That is why "break in" matters to DIY'ers, to get the exact readings of the drivers they are putting together.

For instance, I was building a pair of 3-way vertical line arrays--I used 3" full ranges from the 350 Hz to 6,000 Hz band and they had a huge discount when I purchased 50 drivers. I connected 8 of them up series-parallel and ran them all day with a 20 Hz test tone to get cone movment. That night, I disconnected them and did the next 8 the next day. Basically, I took the drivers that "broke in" and tested Re and the Fs of each one and wrote it down. DON'T do this when they are "hot" as it will mess up your readings--I gave them overnight before I checked. Once all 50 of them were done, I picked the 42 of them that had the Re and Fs readings that were closest to each other. Those are the ones I used for my mids. None of them were "out" more than around 5% so no major problems noted. I was paranoid that one of the drivers would be way out of tolerances which is not good for midrange in line arrays--I slept better at night knowing they were as close as possible to each other.

As far as regular speaker builds go, I will just run them and crank the bass then point them at each other out of phase to limit SPL for an hour or two. After that, it is obvious the woofers did something because they were not as stiff with the press the cone test. I then wire them up, fire them up and enjoy. Realistically, any new speaker will sound different because it is a different speaker--and you'll notice various things over the initial listening session. I don't worry about this, at that point I'm changing the setup, playing around with toe-in, screwing around with subwoofer integration and that sort of thing. By the time I'm content, they already have a couple hours on them so all is well. Then I enter the "honeymoon phase" where they are great! Knowing that I can't make a decision because I have a new toy, I just play all sorts of different music, movies etc. to run my new toy through the paces.

As far as readings or attempting a "rule of thumb"--there is not one. Depends on what the manufacturer does with the drivers after they are built at the factory. Some companies do a sweep to verify it works properly on the line, others--like Community Sound builds the PA speakers then run them in for 24 hours in a chamber. They do this to verify they meet specifications and match speakers together in pairs. This is also done to check reliability before shipping, pro sound speakers are not thought of nicely if they fail shortly after purchase so they do this to find any duds. Pro sound stuff gets hammered in actual use so the burn in is done more for matching and reliability reasons.

Thomas Danley of Danley Sound Labs (pro sound arena type systems) he checked "burn in" and there is some, it can take seconds to minutes to get subwoofers/woofers to soften up which causes the Fs to go down, the Vas to go up and the frequency response to change a bit during the first minutes of break in. This is very important to them, they need to match multiple drivers together when building their 2 to 4 way horns with multiple mid/woofer connected to the same horn. Very important for them to have drivers that match each others when used in the same horn. He did note drivers to "break in" but it takes minutes, not days to do that. Drivers with thousands of hours on them measure very close to new drivers with an hour on them. For all practial purposes they are "the same".

If you want to check it yourself, get a basic driver that is brand new out of the box. I would avoid pro sound drivers since they are generally tested at the factory--maybe an inexpensive consumer driver and use the test rig from Dayton Audio. Check it immediately when cold out of the package and get your readings. Test it again--it will change slightly. Run it for 10 minutes, check it again--it will change again. Let it cool down for a few hours and test it again. A few hours later, test it again (rinse and repeat) and you'll notice very little change that from brand new.

Should you be OCD about it? I would not, does it really matter the first hour of use in the greater shceme of things? To me, it does not matter and it is more a mild curiosity. One time (at band camp) I purchased a new pair of PA speakers that were delayed in shipping--I picked them up off the back of the truck and 2 hours later I had to do a Christmas party. Sparked 'em up, played some background music through them for 15 minutes then it was game on. Within an hour, they were blasting full monty and ran that way for the next 5 hours. They "sounded" weak in bass inititally, most likely because I was running them at low SPL then brought them up after cocktail hour was done. As with anything electro-mechanical, I didn't want to blast them right out of the box because blown speakers never sit well at a party.

So yeah, they break in rather quickly--they break in faster than I do as I keep playing around with setup, toe-in, distance from boundries, integrating subwoofers or playing around with EQ. My failings with proper setup take longer than they do with break in so it is very hard to verify any drastic change in sound. To many variables so I don't worry about it.

Now for "audiophile" speakers--I do find it odd that something so expensive requires hunreds of hours of break in and so on. If the drivers are so "special" that they need that--why don't they break them in at the factory? They sure charge enough money to do that! So the better the driver is, the worse it is in that it takes hundreds of hours to meet specs? Uhhh.... really? As we well know, marketing will exploit anything and if they can keep the product in your hands longer--the more likely you won't send it back comes into play. The top dogs of snake oil, the cable people have even jumped in on this that a piece of wire needs "break in" or electronics need to be "broken in" for hundreds of hours also. Never mind that nothing else that uses the same electonic parts require break in at all--now Mr. Smith, we replaced the computer module in your car so don't go over 3,000 RPM for the next 5,000 miles so the board can "break in". Gee Bob, we replaced this board in this fighter aircraft so it will not be usuable until it "breaks in" for the next few weeks. Mrs. Jones, your new fridge should be plugged in and run for a month or two without food so the control board can "break in"...don't just load it up, plug it in and go. Geez, my phone really needs a month of use to get up to speed... FN break in time!

Be careful with audio dogma, compare it to things like it (other things that use electronics/wires etc.) Think about why nuclear missles go back online immediately after board, cable replacement. Ponder "smart" missiles that uare used once, those electronics don't require "break in" periods of hundreds of hours or "warm up" time--sorry, the anti-missile system won't be ready to respond until it "warms up" for a few hours since it must be deadly accurate--said nobody ever.

As far as the mythology about speaker break in goes, sure it will sound different if you have new speakers--I'd hope it would! Relax, breath and give them a go for an hour but concentrate on setup and playing around with them. By the time you have run your favorite movie clips, musical favorites and getting the setup correct--basically you are at the bend of the break in period. At that point, it is more a novelty, something to ponder than an actual "problem". Personally, if a speaker supposedly takes hundreds of hours to "break in"--that does not make it better quality, that makes it much worse.

If you are worried about it, just crank up the bass for the first hour and let them rip. After that, play more signals through them and worry about proper setup more than their sound changing. It is just something that happens with initial use, you really can't do anything about it unless you have the measurement gear and built the crossovers yourself. If you are the OCD type, don't get into building your own speakers--you will never get to "perfect" but you will learn quickly what counts, what does not count and gain the wisdom to know the difference.

In the real world, the T/S specs change when the voice coils heat up--the sound changes depending on how hot your voice coils are and it will cause passive crossovers to "slip". Generally speaking, the woofer will get hotter, the impedance goes up which willl cause a dip in the frequency response at the crossover point. At higher poeer outputs, your frequency response changes when using passive crossovers and it can get weird when the woofer is cooking but the tweeter/mid is not--or vice versa. Plenty of things to worry about! Relax--it is how the game is played so no worries. To avoid power compression and passive crossover points slipping, either turn it down, use more efficient speakers or both--or use active crossovers and water cool the magnets (people actually do that)

In summation, electro-mechanical devices to break in--but it does not take too long and the effect after the first hour is slight. Get REW, measure them out and find out for yourself--or, look at technical papers published by Danely Sound Labs, JBL and others if you really want to know what changes and it's effects. Good info to know but nothing to worry about. All part of the hobby--more important to a DIY'er using multiple drivers but just a curiosity if you purchase speakers off the shelf. The manufacturer knows it changes initially so they design the crossovers to work their best after they break in. Break in happens but it does not drastically change and is over rather quickly. No need to worry about it.

buggers said:

You can believe whatever you want, it does not change reality.

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That doesn't make getting more data a bad thing, does it? That's what science is, trying to get to the bottom of phenomena by controlled experimentation. For instance, when CD came out, some people were bothered by the sound. Others thought that was nonsense. Investigation showed that several mechanisms-jitter, noise modulation, pre-ringing-could possibly be affecting the sound adversely.

buggers said:

...My ears and brain do not ever get used to new sounds...

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Ah, but how do you know that? That is the point, to try and see if "burn-in" is actually something physical, or something psychological. I wouldn't expect broken/not broken to sound "good" or "bad"-just different perhaps. Come to think of the reverse side of the coin, I'm not sure how we could ever PROVE we get used to the sound. But that still doesn't make collecting more data a bad thing, unless one fears the data for some reason.

The human ear is capable of sensing insanely small forces, like nano-newtons in an sterile anechoic chamber type setting. (and that is the type of setting you'd have to have access to, in order to conduct such precise measurements.)

I'm afraid you'd also need to use a very expensive mic, at least $1000. I don't think a UMIK-1 with a 35dbA noisefloor is gonna cut it (the human ear has a 1dba noisefloor, when young).

I can tell you that when I first bought my HD800 headphones (thousands of dollars), they sounded absolutely horrible.
They sounded like $5 yellow sony walkman headphones from the 80's. They sounded worse than bose or a $20 headset from walmart. They sounded "broken". I literally almost cried on the spot.
I told myself: I'm gonna push pink-noise through these things 24hours a day until they improve; and if they didn't sound awesome by Monday I'd return them for a full refund. I was devastated.

I immediately took them off and started that processes and went to bed, then work. By 6pm the next day I put them back on my head and they were already sounding like $90 headphones.
I was like... "ok" well at least there is still "hope", put them back on the noise generator and continued that process for another 48 hours.

After a total of 72 hours of moderately-loud pink-noise they were already sounding like the best headphones I had ever heard/owned. Exceeding my previous reference headphones which were $150 upper-500 series headphones.
(My other references being my B&W 803's and SEOS's, all 3 of which I had owned for MANY years by this point. 10 years for the 500's, 5 years for the 803's and 3 years for the SEOS's back then.)

At that point I stopped the pink-noise and just used music.
They slowly became better and better over a period of like a month. But 98% had been accomplished in the first 72 hours using pink-noise.

They sounded bright, distorted, colored and overly tight. Pretty much the opposite of anything HiFi, no where close to transparent. There is zero chance I could ever adjust to it.
I can hear flaws in the DSP implementation of Adobe Audition 12.1.3 vs 12.0.0.
I'd never "get used to the sound", I just abandon it if it sounds bad. I'd rather have all that money back, I ain't got time to bleed!

If you've ever heard a freshly plucked B&W 800 vs one that has been at a dealer for months/years, there is a huge difference there too. They sound very bright and plasticy when new, those FST mids take multiple-100's of hours to break-in.

My LMS-18's and SAB-24 was tight as hell too when I first got them. I've always used infrasonic sinewaves free-air to accelerate the softening up of subwoofer drivers. It took like a year of use even after a solid 30 mins of sinewaves before they fully softened up. Playing like ~4hours of bass every day for ~300days.

They all played flat and distortion free. To me it just makes them sound excessively overdamped and inefficient, you can see it in the excursion for an applied-amount of power.
Once you put some juice to them it usually doesn't take very long to reach >85% ROI (minutes).

Some drivers it made zero difference to, such as my SEOS's, Fostex's, and Beyma's.
They were great sounding out-of-the-box.

I've never bothered or tried to measure it.

For many people there IS a factor of them getting used to the new sound as well. If they only had a Bose sub and just deployed a 24, their head is gonna be blown off and they'll be hella-impressed by the new lows and louds.

I don't CARE how many hours a Bose headphone or subwoofer HAS on it (or any other HTIB system).
They all sound like the... POOP, that they ARE. (You can't fix broken...)

and Adobe Audition 12.1.3 is definitely broken (but still WAY better sounding than any Bose. hehe! )
No amount of time or quantity of bits inputted will fix it.

Unless your testing is performed blind and back to back, it is virtually irrelevant.

Actual science incoming, since this thread lacks it.

I've measured before and after. The only thing that will really change is a woofer's compliance increasing, which in turns lowers fs by a few hz. Break in of this nature can be accomplished in under a minute by running a driver free air at high excursion levels to loosen up the suspension, as spiders can be a bit stiff after being pressed.

This is the impedance plot of a new 21ds115-4 before/after break in mounted in an enclosure tuned to around 17hz.



Here's a graph of compliance vs accumulated work of 4 woofers, which shows the majority of break in occurs right away



Here's an excerpt from Sound Reproduction by Floyd Toole on break in, which sums it up well and is backed up by measurements and blind testing.

In parts of the audio industry, there is a belief that all components
from wires to electronics to loudspeakers need to
“break in.” Out of the box, it is assumed that they will not
be performing at their best. Proponents vehemently deny
that this process has anything to do with adaptation, writing
extensively about changes in performance that they claim
are easily audible in several aspects of device performance.
Yet, the author is not aware of any controlled test in which
any consequential audible differences were found, even in
loudspeakers, where there would seem to be some opportunities
for material changes. A few years ago, to satisfy a
determined marketing person, the research group performed
a test using samples of a loudspeaker that was
claimed to benefi t from “breaking in.” Measurements
before and after the recommended break-in showed no
differences in frequency response, except a very tiny
change around 30–40 Hz in the one area where break-in
effects could be expected: woofer compliance. Careful listening
tests revealed no audible differences. None of this
was surprising to the engineering staff. It is not clear whether
the marketing person was satisfi ed by the fi nding. To all of
us, this has to be very reassuring because it means that the
performance of loudspeakers is stable, except for the known
small change in woofer compliance caused by exercising
the suspension and the deterioration—breaking down—of
foam surrounds and some diaphragm materials with time,
moisture, and atmospheric pollutants. It is fascinating to
note that “breaking-in” seems always to result in an
improvement in performance. Why? Do all mechanical and
electrical devices and materials acquire a musical aptitude
that is missing in their virgin state? Why is it never reversed,
getting worse with use? The reality is that engineers seek
out materials, components, and construction methods that
do not change with time. Suppose that the sound did
improve over time as something broke in. What then? Would
it eventually decline, just as wine goes “over the hill”? One
can imagine an advertisement for a vintage loudspeaker:
“An audiophile dream. Model XX, manufactured 2004,
broken in with Mozart, Schubert, and acoustic jazz. Has
never played anything more aggressive than the Beatles.
Originally $1700/pair. Now at their performance peak—a
steal at $3200!”

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