Does Equipment Break In, or Does Our Hearing Adjust?

I’ve read many comments about how the sound quality of equipment improves after so many hours of use.  I don’t doubt what people are saying.

About a year ago, my wife and I were tired of not being able to hear dialog while watching TV.  Especially when there was background music or noise, we had a hard time hearing dialog.  Turning up the sound helped, but not very much.  The sound of the TV sounded normal to other people visiting us.

We bought a Zvox sound bar.  Setting it up, we could hear the dialog, but it sounded very tinny, almost irritating.  But that disadvantage was outweighed by being able to watch TV and hear what was being said.

Now, a year later, we can still hear the dialog, BUT, it doesn’t sound tinny anymore.  The voices sound normal, like people we talk to in real life.  It’s not irritating in the slightest.  This happened gradually over a year, so we didn’t notice it until we thought back to what it first sounded like.

My impression is that our hearing adjusted or became used to the new tinny sound.    Or, maybe the sound bar broke in to sound normal. But if it broke in to sound more like normal, I would have thought that it would lose the special effects that enabled us to hear it better.

Or even, maybe it was a bit of both?  Any thoughts?


While it does not sound like your experience necessarily has anything to do with breakin. With high end equipment breakin is very real and completely reproducible.

I wonder how one would know?  I went and heard my old Klipsh Heresy's that I sold to a friend and it was an odd sound but after an hour I started to sound better. The speakers have been played long enough to pass any break in but for sure my ears needed to adjust so that is a real thing!


Some equipment clearly "burns in".  Tubes are the best example.  They are metal glowing red hot so it makes sense they need time to reach equilibrium.  Electronics are very small circuit paths in semiconductors and so I can see them rearranging some atoms along the way.  But the time needed to burn it is greatly exaggerated.

It is very convenient for a manufacturer when a customer calls up and says "I don't like the sound, I want to return" and the manufacturere can respond "How long have you listened.  This ___________needs 300-400 hours to burn in."  So the customer hangs up, keeps listening, gets used to it, and figures out 400 hours will take 6 months and after 6 months it is much less likely he will return...oops, lost the box if nothing else.

And I'm skeptical about many things burning in--copper wires for one.  speaker wires, interconnects, and power cords.  The atomic structure of copper doesn't change with low level signals running through it.  Some of these same manufacturers try to tell us they have found directional copper. 

 OTOH, sometimes "burn in" can include the consumption of some alcoholic beverages and on that 10th night of listening with just the right blood alcohol level, this _____________ is now starting to really burn in and sound great.




Does Equipment Break In, or Does Our Hearing Adjust?


Both, yes.

No simple clarity for the linear minded who project the idea of being safe via the filter of the animal mind's demands, I'm afraid.

Like Jung said, "Thinking is difficult, that's why most people judge.

Which is how we ended up with 'negative proofers' getting involved in science and polluting it with powerful mental demands for certainty. Where certainty does not exist in things that have unknowns and things not yet well understood.

The argument is not about logic, it's about mental design/function and projections. It's not about science, it's about how some minds project science to be, via fiat of desire, via projection of unthinking force. That problem child (literally!) is the animal in the human, making safety and surety demands.

Sorry, science does not work that way.

But engineering does!... as engineering was designed from the ground up to deal with this mass problem of the bulk of how humans filter/color through/via their minds.

So when you find someone demanding that it's all junk and people are just hearing things and break in and so on is not real, it's an 'animal level anti-science human animal wants to be safe' projection.

One has to wrestle that projection to the ground, openly, and in enough completeness... that it begins to actually shut up and let the rest of us get on with explorations in science.

Both, yes. Though for my part, I’ll say I’ve previously underestimated the effect of phycological / hearing adjustment. Over the years now I’ve had two of the same item (one old, one new) several times, which sometimes shows perceived "large" burn-in changes as illusory. Of course this is greatly complicated by the fact that some manufacturers DON’T produce the exact same quality item from unit to unit - even when they’re supposed to be the same version. And then there are products where the maker silently works in minor changes over time (no explicit version change). And then some products - like headphone pads - really do change their acoustics from wear & conditioning.

So I’ll just be satisfied with the fact that BOTH apply, but that actual large changes from burn-in are exceedingly rare.

I once had a guy install new output caps in a custom tube headphone amp. When I listened, it sounded like complete sh*t with no bass and most of the midrange missing. He said: `don’t worry, these caps just take a long time to break in! Get a few hundred hours on them.` Well I got fed up with that quickly, because it was truly unlistenable. So I cracked the amp open and see that he’d put the 0.47uF "bypass" cap in SERIES with the main cap. So even with 300 ohm headphones the high-pass rolloff effect was starting at something like 1 kHz. That’s my best example of "burn in mythos run wild".

I’ve heard interconnects break in.  I had a pair that started out with very tizzy high frequencies and they slowly changed to a more acceptable natural sound over 100 hours.  They didn’t get entirely to where I wanted them but I heard the change, there is no doubt.  I was playing the same song for a week. I knew what to listen for. 

@mward so if you move them around do you have to wait for them to break in again?

You get used to the sound there is very little "breaking in" after a few seconds to minutes even with speakers.  

IMO, the more I listen to a song, the more I take in.  At first listen, it is a guitar string sound, but after a few more listens, I am picking up the vibration of the string, and a few more, I am focused in on the decay of the string to silence.  Or, I listen past the string and hear the drum brush in the background.  In my life, this is what I think is often referred to or mistaken as equipment break in because the sound, for me, becomes more detailed the more I listen.  Similarly, if I watch a complex movie once, I understand it and enjoy it.  But if I watch it 3 times, I really pick up a lot more of the plot and character nuances.  Clearly not the same thing, but similar.  

I have experienced and struggled with break-in of audio components for fifty years. It is a pain in the butt… especially when upgrading. Typically high quality components take 600 hours… although the largest portion is done by ~ 200 hours. Typically I don’t hear much change in wires beyond 200 hours, but if I move them in a big way or take them out for a long time and they will need ten or twenty hours to settle down.

All this is completely reproducible and easy to detect for the experienced listener.


I had the experience of breaking in three identical Audio Research Reference 160s amplifiers. I was absolutely amazed at how each followed exactly the same very complicated change in sound. In particular in the 120 hour range after the amps sounded better than at the start, would suddenly sound terrible for a session, then great, then terrible. This flip flop lasted for around 20 hours.


The mind becomes more sensitive to a component at the beginning as you subconscious becomes aware of the sound characteristics. It does’t perceive the sound differently, it becomes able to sense deeper into the nuance.

The Audio Research Reference 5SE preamp required about ten minutes of actual music playing through it each time before it sounded right, even if it had been warmed up for an hour. I thought there was something was wrong with my head. It was absolutely repeatable. I went to a audiophile forum where all the users own high end audio systems (Audio Afficianado) only to find a number of users discussing this peculiarity. The newer Audio Research Reference 6SE does not do this. In fact it needs little warm up to sound perfect.


Anyway, for the experienced audiophile these changes are easy to hear and must be taken into account when creating, upgrading or changing your system. There is no controversy on this subject among audiophiles.



I had the experience of breaking in three identical Audio Research Reference 160s amplifiers.

Great amps. How did you happen to have three 160s?  Did you buy the 160 stereo version and then decided to buy the monos, or vice versa?

Agreeing with what other have said here, it is true that for some of us at least it’s our ears that do the vast majority of the breaking in. I’ve bought identical amps new and listened to them both at the start, and judged them to sound identical - equally bad. Then burned one in for a few hundred hours and noticed it sounding dramatically better. Comparing them again at the end of the burn-in I discovered to my delight that they still both sounded the same but dramatically better than they did at the beginning. I’m not going to insist that some people may not notice real equipment changes over time. But it is fascinating that the burn-in almost always seems to improve the sound rather than degrade it. You’d think there’d be occasional components that go the wrong way. Or perhaps reach their peak sound quality mid-way through the burn in but then slide back a little before stabilizing. Also it seems rare for equipment to brighten its sound signature as it breaks in.

One way to know for sure with your sound bar would be to do before and after measurements. The apparent tonality change should readily show up on a frequency response graph if it was actually caused by physical changes in the sound bar’s performance. Or another option is to go buy another one just like it that’s new in the box and see if it sound bright and tinny.

Now that I think about it there are other possibilities besides just burn-in. Some components could conceivably change sound quality for better or worse over time whether used or not. Some could conceivably sound better after a burn in period, but then lose the burn in effect if not used regularly enough so that another burn in period is required. Some could even start to degrade from excess use but then recover if left unused for a period of time. These all sound like nightmare scenarios to me. I’m glad that the changes most equipment go through due to burn-in have negligible effect on my enjoyment of music. My ears are not hyper discerning so there’s a lot of serviceable equipment that seems stable over long periods of time to my perceptions.


New speaker drivers need to move and the capacitors in their crossovers need to be “charged” My KEF’s were noticeably better sounding after about a week of leaving them playing 24/7 after I got them!

So I also have a pair of Acoustat Model X speakers with the Servo amps on another system and if I don’t fire them up for a while, they sound awful, thin and lifeless, but once the caps are recharged (about 90 minutes) the system sounds fantastic! After that, the system sounds great with only waiting for the tubes to warm up, maybe ten minutes.


As to three REF 160s’s. My dealer got one and thought I would like it… so he brought it over. I instantly loved it and asked him to order me one. He left the first until I received my copy. So, a couple months later, my unit shows up. We swap it. My new one was great… but one of the meters was weak… not a big deal, no hurry… several months go by. My dealer drops by and asked what I want to do… have him replace the meter or get a new one. I say, I don’t care, what would you do? He says, “get a replacement”. He calls ARC, and a couple minutes later a new one is on its way. So, in a couple weeks, I get a new one.

I can’t remember why, but at the beginning of this year my dealer (who has become a friend over the last twenty years) brought over the reference 160m monoblocks… for me to compare. I love them, so he has been nice enough to leave them. So, I currently have both.

These mono-blocks were early copies… not long after they came out. I went down to his store to hear Bruce from Audio Research introduce them. I immediately realized it was finally time to get a tube amp. I decided then to get the stereo version when it came out. It took a couple years or so, but they did, and I did. But having these monoblocks in my system is really gratifying, not only because of how amazing they sound, but because these were the very ones that I heard that caused the pivot in amplification for me… so, important for how my system sounds today. This very amp probably caused one of the most important pivots in my system of all time. My system is now all ARC and exceeds all expectations I have ever had in owning an audio system.

Hello tcotruvo.  Equipment, cables, speakers, etc do "break in."  While Nordost uses 8 or 9 conductors for each leg of a cable to a speaker, you can buy 50 conductor ribbon cable ($0.65/foot) and have 25 silver plated conductors in each leg of "speaker cable" and enjoy excellent performance (use every other wire for + and the others for -). I mention this because the cable is used to carry very high frequency data betwen mainframe computer cabinets and uses an insulating plastic we would consider "ordinary." This material is the cause of the "break in" effect. It takes between 30 and 120 MINUTES to break in and you can hear the effect quite easily.  A friend with Martin Logan electrostats says they are the best cables he has ever used. At $65 for 100 feet, you can't go wrong. Surplus outits sell the stuff. I think Amazon lists it too. "Look for 50 conductor flat cable."


Thank you for that explanation of your history with the AR160 amplifiers, that is very interesting. You have a great dealer.

Truth be told it would be great to hear your system.  Of course the fact I live in Vermont puts the dampers on that idea.

Have a great day/night.




😊👍 Thanks. I have an in incredible dealer. 

If you ever get out this way, give me a holler. Would be great to have you over.

Would be really interesting to make a recording of a new piece of gear on day 1 and then after 400 hours.

I feel it's a combination of both. I've audibly heard brand new components change significantly as they broke in (most audible of which were speakers), but also have bought used components that are well broken in and the sound settles which I credit more to your ears adjusting than the component.