[mummer]

There IS a question at the end of this.

I really thought the idea that you need to burn in new IEMs was......poop! An affectation or fetish with, perhaps, some placebo effect. Well, after being really disappointed with the muddy "there's a lot of flatulent bass and nothing else" out of the box sound of my Atrios, I decided to plug them into a radio and play the local modern rock station into them for three days. Son of a gun if they don't sound clearer. Maybe I'm just falling for a placebo effect myself, but I don't think so. I approached it with intense skepticism. I'm going to do the same thing to my Klipsch S4s now.

My question: can anyone speak to the specific principals of physics (or whatever) behind this phenomenon? I get the general idea that at first the drivers are stiff (or something?), but I'm really curious as to how burning these things in clears up the sound. Thank you for your kind professorial responses.

 

[semisight]

You probably just got accustomed to their sound. Going without them for a few days allowed you to appreciate them again. Happened to me with my RE0s. That said, I still haven't made up my mind about burn in. People have pretty sensitive ears here towards sound signature differences, so maybe the sound did change a bit. I doubt that's where most of the improvement came from anyway.

 

[Napilopez]

While there are plenty of factors that affect your impressions, I do believe burn in has some physical basis in truth, esp for dynamics. I mean, it almost seems odd to me that it wouldn't. there are plenty of objects that are stiff upon first use, but get better with time. Some say its residue or something on the drivers. I've heard other stuff too. And then why are there so few people talking about burn in for electrostatic or balanced armature phones?

Also, how do you account for discrepancy for the need of burn in between headphones? I don't think all headphones or even all dynamics need burn in to sound better, but some it seems definitely do. I mean, check out the RX700/RX900 thread on the full size forum. Pretty much everyone, or at least a heck of a lot of people agree that they start off sucky and get alot better after a good deal of burn in. There is at least one person I remember who A/Bed one model without burn-in and one with, and the latter clearly came out superior.

Even if it is psychological, which I seriously doubt for many of not most headphones, I think the point is that you need to give the headphones some time before you judge them.

 

[brendon]

Burn-in is very real IMO. However it depends largely on the type of earphone/headphone. Most people here agree that the maximum change happens withing the first 10 - 20 hours of burn-in for dynamic IEMs.

This 'maximum change' is the bone of contention as to the magnitude of change. Mostly its a decent noticeable change which can really come down to a placebo effect. However in a few headphones (like the above mentioned JVC RX900) it has a huge effect which is really difficult to put down as a mass placebo effect. So my take is that burn-in happens with some phones (maybe all) and some phones really benefit from burn-in while in many others phones its a subtle effect which can even be argued to be a placebo effect.

The Atrios are balanced armature IEMs and theoretically they would benefit very slightly (if at all) with a burn in. So its a bit surprising to hear that the sound has changed especially since you are a skeptic and was not expecting the sound to change.

 

[ljokerl]

Quote:

Originally Posted by brendon /img/forum/go_quote.gif The Atrios are balanced armature IEMs and theoretically they would benefit very slightly (if at all) with a burn in. So its a bit surprising to hear that the sound has changed especially since you are a skeptic and was not expecting the sound to change.

???

 

[jyle_t]

He sure knows his stuff.

 

[Modifiedz]

If the sound has in fact changed or not, its the fact that you believe they changed which is whats important. If you asked me if my IE-40 changed with 100hrs of white and pink noise, I would say that they changed, audible or not, they wear-in. In balanced Armatures there is a thin piece that is being flexed constantly as the springs on your new car, then after many miles your springs feel slightly different when driving (if you pay attention).

 

[mummer]

I'm pretty sure that's not true. They're dynamic drivers. Unless Futuresonics is pulling the weirdest scam ever by saying they use a dynamic driver and really selling people an armature design.

As for the earlier poster that suggested I had just gotten used to them, I don't think that would explain it, because I only listened to them for about 3 minutes the first time (when I thought they sounds muffled and murky) so there was no initial conditioning of my ears (or psyche) to the sound.

Wasn't really looking for people to naysay. I was hoping someone could go into the specific technical concept behind the break-in theory. What specifically is supposedly happening to what components, and how does this process affect the way the IEM reproduces sound.

 

[Real Maximus]

Nay sayers are everywhere, in every forum, in almost every thread in hi-fi and audio. I am relatively new to portable audio, but for many years have had numerous receivers, speakers, cables, powercords, etc. I CAN hear the difference with virtually every piece of equipment I have ever owned. Its not only myself, but others I know that also witnessed and experienced MY equipment changing its tonality, textures, its fingerprint if you will. I currently own the monster turbines and hated them at first. I burned them in for about 40 hours and they sounded much better, but still quite shy of what I was looking for. I burned them in for a total of 100 hours before my next listening and that is what polished them for me. They sound great now and I am very happy with them.

With that said, I cannot speak to the physics side of things, however there is plenty of information all over the web that speaks to the physics of sound changing in cables, let alone equipment. Manufacturers sell various cables that are directional. The reason for this, is so that the electricity flows through the natural flow of the crystaline structure. I have read that over time, when electricity continues to flow through a specific cable (break in period), that the grains of the cable gell together, and to some degree meld as a single crystal providing a less coarse, but more natural, effortless tone. This is an exaggeration, the grains will never become one, but over time, the sound changes, as if that were were the case. Again, more natural, effortless nuances. I DO hear the difference with burn in. Regarding my ability to "enjoy" my current IEMs, burn in made all the difference for me.

 

[mvw2]

Burn in is required to get drivers into a state where they stop changing. It's required for dynamic drivers, not really by BAs, although some may argue. A BA burn in is more like seconds. A dynamic burn in varies by method. You could take the same earphone and full burn it in after one hour or 5 days. It depends partly on how you do it and partly on the driver itself. I heavily feel no driver in existence needs more then a day of burn in as long as you are efficient with it's progression. The 500 hour kind of deal blows my mind frankly. I could take any earphone out there brand new and hand it back to you the next day done. Now if you only listen to it lightly the entire time, sure, it will never really be broken in. Break in requires you to ramp it up to its eventual limits and simply stretch everything out and get parts to a point where they will not change from there on out.

If you want a simile, it's like stretching a balloon. You can do it very slowly if you like, but it can be done very quickly too, your choice.

Here's an example of something I do. I'll run a pink noise test or perhaps something with a lot of drum and bass. I'll start by increasing the volume until I get a tonal change or any sign of harshness or strain, and I'll back off to slightly below this. Then I'll let it play for 10 minutes. I'll put the earphones back on and readjust the volume to the new limit and repeat. As it loosens up, it will let you get louder each time. At some point in relatively few cycles of this you will find a point where you will no longer adjust the volume any further without inducing some form of tonal change/harshness/strain. This is effectively the limit of the earphone. You may repeat a couple times to verify, but you will find yourself never adjusting the volume any higher then before. It may change very slightly more over a much longer time after this, but this also at levels that you will 99% never listen at. You have already broken in the earphones way past the mechanical movement at quieter levels, so you will never hear any further appreciable change during any type of normal listening.

I would say adequate amperage is important too. If you can never fully push the driver, you can never fully break it in.

It is also important to understand what to listen for. You could very well damage an earphone by overworking it. In essence, when you increase the volume, the sound should increase very linearly and effortlessly across the spectrum. At some point, you will get a change in tone. This is when the driver starts to reach its max linear range and you begin to get compression in the sensitivity in the low frequencies. This is a mechanical limitation. Strain and harshness can point to other types of mechanical limitation then linear diaphragm movement. You'll always want to back off from this point. A simple rule of thumb is any change in sound is a bad change in sound. Volume gains should be effortless and quite linear. The sound should get louder, but it should not change characteristics. If you can learn to stay below the functional limits of the hardware, you will never damage it.

 

[brendon]

Oops ! Sorry for some strange reason I was under the impression (for a good year actually) that the M5 were using balanced armature technology !

I was most surprised seeing strange reactions to my post as I was dead sure they were BA drivers. A quick google search however showed that Future sonics use dynamic drivers only.

So since they are dynamic drivers then it makes sense if they exhibited burn-in.

 

[scrane]

Not Jesus. Just the Shroud of Turin.

 

[theKraken11]

I think your mindset has less to do with a placebo effect than you think. Intense skepticism can cause more than just one reaction: suppose you were so doubtful that burn-in would do anything, that when you went to reevaluate the phones you ended up impressing yourself. In other words, your expectations were so low the phones could only have sounded better.

I don't say that because I disbelieve in burn-in... I do believe it for dynamic drivers. Just getting at what might cause an unrealistic reaction to the whole process.

 

[average_joe]

I recently discussed burn in with a friend that has been an electronics technician for many many years. Simply put, he thought the burn in changes are a result of changes to the magnetic field of the permanent magnet in reaction to the opposing magnetic field/current flow.

 

[iponderous]

I don't mean to sound unkind or unprofessional, oops, I meant anti-professorial but for the love of God, not another burn-in thread.