Burn in and peer reviewed brain research
Not to broach a religious topic, but I know burn in discussions happen all the time in audio circles. Until today, I had not found any scientific research from the brain side.
This article was interesting: https://pmc.ncbi.nlm.nih.gov/articles/PMC10898501/
It is a 2024 review in Cureus (Kalchev, PMC10898501) that surveyed the physiological, psychological, and social dimensions of audio burn-in. It found no substantial evidence for mechanical changes producing audible differences, and instead identified several well-documented mechanisms — ear fatigue, confirmation bias, placebo effects, and neural acclimatization — that adequately explain perceived changes without requiring the equipment to have changed at all.
Has anyone found other literature of this type – physiological, psychoacoustic, rather than engineering/mechanical? I'd be curious to learn about it.
Of course, anyone who wants to put their hand on a bible and swear that burn in is real based on personal experience is welcome to do so, but I'm hoping to find things beyond the anecdotal.
I can't say that I've noticed differences after burn-in for electronics or cables. I do, however, believe that other people are hearing it. I would never buy gear that didn't sound good out of the box with hopes that it would get better.
I have heard differences in tubes after break in. In one case, the sound did not get better. |
Interestingly, a tubes sound does not change over time. Once you apply power, a tube comes up to operating temperature in a few minutes and you're good to go. What might account for small, if at all noticeable changes in a preamp's or amplifier's sound are minute changes in the characteristics of all the other components in the device primarily from the heat they're generating. In addition, the gaps in the windings of chokes and transformers get smaller as they warm and their transfer function becomes more efficient. |
Interesting comment – the price/value/sonic-quality conflation is real, as is the sunk-cost psychology. I like the "audio jewelry" framing — if someone is buying for visual aesthetics and symbolic value, they’re explicitly *not* making a *sonic* claim and empirical criticism that they don’t care about sound doesn’t touch them. As we know, the audiophile market sells visual looks and sonic performance, and most buyers want both. For the buyer, visual, symbolic, and sonic justifications tend to collapse into each other — especially after an expensive purchase, when motivated perception kicks in hardest. The behavioral psychology literature, including Kalchev, would predict exactly that. So if a buyer is using the "audio jewelry" rationale, they’re intellectually honest when it’s a genuine, prior motivation. Often, though, it functions as a retroactive justification — which puts it back inside the trap the study accurately describes. None of this is really blameworthy on a human level. The issue on an audio forum is that many assertions are offered as if they were straightforward testimony about sound — meant to advise others about sound — so if someone is arguing from mixed motives, it will come across as bad advice, possibly wasting others’ time and resources, and advancing falsehoods about sound. There are worse falsehoods to tell, of course, but on an audio forum, it gets singled out. Regarding tubes, I understand that a tube reaches operating condition within minutes of applying power is true — thermal stabilization is quick. But I thought that tubes do change over time in ways unrelated to thermal equilibrium. For example, cathode emission stabilizes over the first hours of use as oxide layers settle; getter activity can shift; mechanical components (the internal structure is surprisingly delicate) may take time to fully stabilize under repeated thermal cycling. These are acknowledged in tube manufacturers’ documentation and in electrical engineering literature. The expected degradation curve over a tube’s lifespan is also well established, which presupposes that tubes change with use by definition. How much of this is audible? That’s a harder question! But I’ve heard my tubes sound worse before they failed. On tubes: https://www.effectrode.com/knowledge-base/secrets-of-the-tube-alchemists/ |
Got my speakers 6 weeks ago. Created a new PEQ setting with a umik-1 mic and REW. A few days ago, got a vintage turntable and created a new PEQ profile to use when playing vinyl. Since I had the umik-1 setup, I remeasured the speakers. In same position, song, volume....zero difference on the REW graphs before & after. Wouldn’t care if there was, just sharing my recent experience. Note: I work from home, speakers are on 12-18hrs per day, ~700hrs of use. To add, these are active speakers, so measurements were on speakers, internal amps, DSP and new xlr cables. |
