'Burn in' when there's nothing to burn
Posted by: Dave***t on 06 November 2015
Just wondered if this seemed familiar to others. Obviously some people scoff at burn in, but I've heard it with my own ears, and most here accept and embrace it.
But what if there's nothing which should be burning in? I installed a glass shelf on dome nuts underneath my 172 today, and spent a couple of hours listening afterwards. It was largely because I thought I'd like the look, but I did also hear a change, and not necessarily for the better. The details don't really matter for the point I'm making, but there seemed to be more detail higher up the frequency range, but a bit more congestion in mid-bass, and a bit of boom in the bass. This was over a few hours, so unlikely to have been to do with having switched off for 5 minutes to install the shelf.
I left Radio Paradise playing while I went out for a few hours, and when I got back, things seemed to have improved somewhat. Getting used to a new sound could be part of it, but I was away from the system in the meantime, and immediately thought it sounded better when I got back in.
So, apparent burn in from a glass shelf? Shouldn't be a factor, surely. Ridiculous, even. But if there's one thing I've learned about hifi it's to trust one's own ears. Weird. Anyone else had similar?
Could be a case of the brain taking time adjusting to a new, different and subjectively "better'' sound?
I vaguely recall Harbeth's Alan Shaw discussing this as an explanation for burning-in over on his company's HUG forum.
Having borrowed a pre-burned-in SL DIN-XLR from my Dealer and instantly loving it and ordering mine - then hating my new once it arrived for weeks while it 'burnt-in', I think there is more to it than just getting familiar with it.
DB.
One needn't assume that "burn-in" is a subjective illusion or a process of mental adjustment. But the OP has a point--while many of us can understand and accept the notion that copper wire or capacitors can "burn-in" due to electrical current passing through them, how could there be burn-in involving a metal box sitting on an inert glass shelf?
I have no firm answer, but it might involve a kind of microscopic settling in--the gravitational force generates a kind of progressive physical bonding, metaphorically equivalent to glue drying. In other words, the ongoing stabilization of mechanical isolation, which seems to be the function of Fraim and the like. This might involve the internal electrical components readjusting to different mechanical stress, force, and isolation. We have all heard "instant" results from changing shelves and the like, but that doesn't mean that no further changes will take place.
Further change after connection is all about the listener adjusting to the new sound.
Run in after 24 hours is a huge marketing hoax as is the phenomenon of low efficiency speakers ...
ATB from George
I am certain my ears (or my ears abitity) to hear degrades when I actively listen to music. This I put down to a mixture of things like lower amounts of speaking (obvious) and swallowing, small changes of pressure either side of the eardrum not compensated for by movement, a phenomenon somewhat akin within the hearing centres of the brain analogous to 'staring too long at the same bit of wall' resulting in a lowering of absolute stimulation, anticipation of known dynamic transients etc.
In short I believe you heard what you heard for a mix of ALL the reasons mentioned above, plus the fact you were not quite identical to the man who left the room!
Can anyone explain why the second cup of tea never tastes quite so good?
I find that the last cup of four of tea out of a teapot is the finest ...
I have often experience what I call "settling in" (as opposed to "burn in") from mechanical changes to my HiFi. Usually the sound improves, though it might degrade with age over time.
aht has it pretty close, I think. I believe it is micro vibration which is influencing the behavior of the system, and thus affecting the sound. Seemingly microscopic changes at mechanical interfaces or signal connectors can cause changes in the sound.
George, with all respect, there is no hoax involved. And I am pretty sure I have not been hallucinating.
After adding a glass shelf over dome nuts, I would expect the sound to settle in a bit, and likely improve. I am assuming that no electrical connections were unplugged and re-seated.
Dave***t, are you using four supports under the glass, or three?
The placebo effect is real enough ...
Homeopathy is baed on it, and it has been reported for a very long time ...
I find that the last cup of four of tea out of a teapot is the finest ...
I dread the last cup! Probably because the tea bags here in France are inferior (poncey tasteless overpriced boutique bags not included in the debate!)
Tea Leaves? Loose tea. Cannot be had in France?
I know the French coffee is alway a pleasure!
Best wishes from George
Tea Leaves? Loose tea. Cannot be had in France?
Dust can be had by the kilo. As for coffee, we have a machine more expensive and daunting than some Naim boxes, which I never go near, as I don't want to be scalded, burdened or blamed!
My favourite ground coffee is “Lazy Italian” produced in Harrogate [Yorkshire] by Taylors and all you need in is a cafitierre
Less than £10 to buy a cafitierre for coffee almost as good the magic they make in France ...
ATB from George
So, apparent burn in from a glass shelf? Shouldn't be a factor, surely. Ridiculous, even. But if there's one thing I've learned about hifi it's to trust one's own ears. Weird. Anyone else had similar?
Your own ears can be fooled, as can other senses. One very obvious example is playing at extreme loudness, which dulls your hearing for a while. It is doubtful whether you can hold an exact sound in your head for long - I mean precisely, all aspects of it. And if you have either been in the room with music playing, or elsewhere with other sounds - or silence - they all affect your brain's perception of the next sound you hear. Just as with your eyes, if you've been in a bright place, or dark, or have been looking at something coloured.
Certain components may change with use, so subtle effects over time are possible, however in many of cases I believe it more often is simply getting used to the new sound - sometimes aided by a modicum of post-purchase justification helping convince.
Glass shelf? Over a few centuries maybe, as it very gradually 'flows', but otherwise the only possibility would be if vibration has caused something to move and either reduce, or increase, a subtly audible resonance: not burning in!
Racking burn in, utter crap.
Even with electrical components, it depends how sensitive they are in the first place. Something like Naim is quite revealing so it is noticable. A cheap 300 quid system is probably not revealing enough. The exception is speakers because the have moving parts and need to be flexed. I always find speakers take some burn in and it is always very noticeable. Electronics depends. I don't think this this is consistent among brands or components. I heard a lot of change on my UQ2, 250.2 and 282; not so much on the SCdr despite being advised it would take a month to come on song.
Cabling is something that I understand the stabilising effect of applying current will subtly change the properties but I've never heard a difference from a new cable vs. a run in cable.
Having borrowed a pre-burned-in SL DIN-XLR from my Dealer and instantly loving it and ordering mine - then hating my new once it arrived for weeks while it 'burnt-in', I think there is more to it than just getting familiar with it.
DB.
I would agree that is undeniably true for cables because I've experienced the same thing. However that doesn't mean that it has to apply to glass shelves. Maybe that was familiarity with the system, or different mental attitude, or different type of music, or mains feed being cleaner later in day etc etc.
Personally I have never understood why adding a glass shelf would be a good idea.
People talk about isolation, but surly most vibration your 172 will see will be airborne from the loudspeakers. Adding glass plate on dome nuts will, I would have thought, only add to the problem as this plate will now also vibrate.
It will certainly not damp any vibrations from the floor, for which you would need rubber AV mounts.
If the plate is not for isolation, apart from looking nice, what is its purpose?
I had exactly this thought as I drove my FraimLite home earlier this year - might a rack exhibit some sort of settling in process? It wasn't difficult to envisage some possible mechanisms, such as vibrations gradually making the various parts settle in/bed in/run in (take your pick). Such processes are well known in mechanical engineering, for example, not just in the more ethereal levels of hi-fi tweakery.
Anyway, after all that, it turned out I couldn't hear any changes over the ensuing months. Sounded great out of the box, and still does now. For the reasons above, though, I don't find it impossible to believe that others may well be hearing some sort of bedding in process happen in their racks.
Mark
I had exactly this thought as I drove my FraimLite home earlier this year - might a rack exhibit some sort of settling in process? It wasn't difficult to envisage some possible mechanisms, such as vibrations gradually making the various parts settle in/bed in/run in (take your pick). Such processes are well known in mechanical engineering, for example, not just in the more ethereal levels of hi-fi tweakery.
Settling in and running in aren't the same thing. For non moving objects like buildings and bridges, there is a settling period where they adjust to their own weight and the surrounding bedrock - this is why the safety inspections approving super structures for use cannot happen for several months after the structure is completed. The same is true with a rack in that once assembled and loaded with gear, it may need to be tightened up again in several months. But this is purely a function of a time and mass load causing compression and not the same as burning in. These aspects of settling are also going to depend on what, if any, components (rubber gromets, springs, MDF) have a minimum compression threshold lower than the mass they support. You can play music whatever you like through your system for weeks with a new rack, it won't change the sound.
On their hand if you want to settle in a rack; a bunch of Naim boxes, or bags of sand - given enough time they have the same effect. Not all racks have components that can be altered by the mass load the average consumer will put on them anyway. A glass shelf would be a good example.
My favourite ground coffee is “Lazy Italian” produced in Harrogate [Yorkshire] by Taylors and all you need in is a cafitierre
Less than £10 to buy a cafitierre for coffee almost as good the magic they make in France ...
ATB from George
George,
Is that a 50/50 mixture of Taylor's 'Lazy Sunday' and Taylor's 'Rich Italian'?
I had exactly this thought as I drove my FraimLite home earlier this year - might a rack exhibit some sort of settling in process? It wasn't difficult to envisage some possible mechanisms, such as vibrations gradually making the various parts settle in/bed in/run in (take your pick). Such processes are well known in mechanical engineering, for example, not just in the more ethereal levels of hi-fi tweakery.
Settling in and running in aren't the same thing. For non moving objects like buildings and bridges, there is a settling period where they adjust to their own weight and the surrounding bedrock - this is why the safety inspections approving super structures for use cannot happen for several months after the structure is completed. The same is true with a rack in that once assembled and loaded with gear, it may need to be tightened up again in several months. But this is purely a function of a time and mass load causing compression and not the same as burning in. These aspects of settling are also going to depend on what, if any, components (rubber gromets, springs, MDF) have a minimum compression threshold lower than the mass they support. You can play music whatever you like through your system for weeks with a new rack, it won't change the sound.
On their hand if you want to settle in a rack; a bunch of Naim boxes, or bags of sand - given enough time they have the same effect. Not all racks have components that can be altered by the mass load the average consumer will put on them anyway. A glass shelf would be a good example.
The settling in process of a mechanical system will also be influenced by the introduction of energy into the system (typically thermal or mechanical). There may be an argument that a rack therefore is subject to "running in" if the "settling in" is accelerated by vibration from, for example, a pair of speakers.
Regards,
Willy.
Personally I have never understood why adding a glass shelf would be a good idea.
People talk about isolation, but surly most vibration your 172 will see will be airborne from the loudspeakers. Adding glass plate on dome nuts will, I would have thought, only add to the problem as this plate will now also vibrate.
It will certainly not damp any vibrations from the floor, for which you would need rubber AV mounts.
If the plate is not for isolation, apart from looking nice, what is its purpose?
Hi Morton,
A toughened glass plate supported on ball bearings or dome nuts can act as an isolation system, but the method of operation of this isn't obvious.
Vibration transmitted into the stand finds it's way into the shelf (which is relatively soft compared to the steel supports). From there it's transmitted fairly efficiently into the steel supports as the small compliance of the shelf couples them at audio frequencies. From the steel supports to the glass there's little compliance (they are both very rigid materials - hence using toughened glass); however the velocity of sound is different in the two materials and this results in reflection of the sound waves at the interface. Acting together with the very small contact patch (typically a few square microns) this limits the amount of energy transferred into the glass.
However, personally I don't see a mechanism by which this can significantly change in hours or days time-scales. Perhaps someone else can suggest something?
...
The settling in process of a mechanical system will also be influenced by the introduction of energy into the system (typically thermal or mechanical). There may be an argument that a rack therefore is subject to "running in" if the "settling in" is accelerated by vibration from, for example, a pair of speakers.
Regards,
Willy.
Hi, Are you suggesting that it's not the rack settling in, but the electronics settling in again, because of a change in the vibration characteristics of their environment?
That's a very interesting idea, and quite a plausible mechanism.
Personally I have never understood why adding a glass shelf would be a good idea.
People talk about isolation, but surly most vibration your 172 will see will be airborne from the loudspeakers. Adding glass plate on dome nuts will, I would have thought, only add to the problem as this plate will now also vibrate.
It will certainly not damp any vibrations from the floor, for which you would need rubber AV mounts.
If the plate is not for isolation, apart from looking nice, what is its purpose?
Hi Morton,
A toughened glass plate supported on ball bearings or dome nuts can act as an isolation system, but the method of operation of this isn't obvious.
Vibration transmitted into the stand finds it's way into the shelf (which is relatively soft compared to the steel supports). From there it's transmitted fairly efficiently into the steel supports as the small compliance of the shelf couples them at audio frequencies. From the steel supports to the glass there's little compliance (they are both very rigid materials - hence using toughened glass); however the velocity of sound is different in the two materials and this results in reflection of the sound waves at the interface. Coupled with the very small contact patch (typically a few square microns) this limits the amount of energy transferred into the glass.
However, personally I don't see a mechanism by which this can significantly change in hours or days time-scales. Perhaps someone else can suggest something?
The small contact area between glass and ball bearings results in a very high loading(N/m**2) at the contact point. Over time this will cause deformation of both materials and a gradual increase in the contact area. Maybe that breaking these contacts and resetting to a smaller contact area with higher loading accounts for the perceived benefits of a periodic Fraim build?
Regards,
Willy.
...
The settling in process of a mechanical system will also be influenced by the introduction of energy into the system (typically thermal or mechanical). There may be an argument that a rack therefore is subject to "running in" if the "settling in" is accelerated by vibration from, for example, a pair of speakers.
Regards,
Willy.
Hi, Are you suggesting that it's not the rack settling in, but the electronics settling in again, because of a change in the vibration characteristics of their environment?
That's a very interesting idea, and quite a plausible mechanism.
I'm suggesting that the "settling in" that would occur naturally over time due to the loading of the glass at the interface with the ball bearings would be accelerated by introducing additional energy into the system as mechanical vibration. Purely a mechanical effect. It would of course apply to any other stressed mechanical system/component.
Would also be influenced by the introduction of thermal energy into the system, especially thermal cycling.
Regards,
Willy.
Personally I have never understood why adding a glass shelf would be a good idea.
People talk about isolation, but surly most vibration your 172 will see will be airborne from the loudspeakers. Adding glass plate on dome nuts will, I would have thought, only add to the problem as this plate will now also vibrate.
It will certainly not damp any vibrations from the floor, for which you would need rubber AV mounts.
If the plate is not for isolation, apart from looking nice, what is its purpose?
Depending on the shelf dimensions and other physical characteristics it can pick up airborne vibrations more so than the equipment sitting on it, and so transmit through the equipment feet to the equipment! acting as a 'sounding board'. Meanwhile vibrations via the floor can be significant especially with a suspended wooden floor.
in laboratories, three different approaches apply to isolating sensitive equipment such as balances from vibration from different source: very solid (typically stone or concrete) table tied to to solid building foundations foundations, where that isn't possible, solid high mass table or slab on resilient vibration absorbing isolating material (eg feet), and an enclosure to protect from draughts, which may be an acoustic enclosure where airborne noise is a possible source of vibration.
When end I had a turntable, clearly the item most susceptible to vibration, I used it on a concrete slab on a metal frame spiked to the (solid) floor, inside a cupboard lined with damping pads on all panes to minimise their vibration and hence transition into the cupboard, and I acoustic absorbent material inside as well to minimise reflections. Clearly not a full sound isolation booth, but I believe it is an effective supplementary approach - and wonder why others don't do likewise if concerned that vibration is a significant issue for any or all of their equipment, or is it just that no-one else has thought of it?
Whilst ventilation holes can be judiciously arranged to provide adequate airflow for low powered components while still providing a fair degree of acoustic isolation, the same is unlikely to be true for power amps so serious consideration of ventilation would be necessary if they are contemplated - but as signal levels are higher the power amp should be the item of least vibration concern anyway.