Do Audio Speakers Break-in?

[Killingbeans]

....Or is it just me? Haha

Definitely not just you.

I'm always amazed when I buy a new pair of glasses. For a while I see the frame floating in front of my face, distracting me constantly. But after some time my brain filters it out. The glasses disappears completely from my field of view, and I can only see them if I consciously choose to focus on them.

It would be incredibly naive of me to think that my hearing is immune to those effects.

 

[Deleted member 48726]

As I saw PS Audio's new video where break in is the topic at hand, I dismissed the talk about electronics break in but actually tend to agree with Paul with his answer on driver suspension break in.

The reason for my agreement with him on this is based on my own experience with building subwoofers for cars many moons ago. Stiff when new (or cold) and more compliant when "broken in".
Also some driver manufacturers T&S data has an asterix showing something like "after break in" in the buttom of the sheet.

PS Audio video-->
PS Audio Break in

Video showing measurements on the same driver new vs. used-->
Woofer Break in

T&S data on a 6" driver-->
Spoiler: T&S

Link to above mentioned driver data-->

6″ SB17MFC35-4 / Polypropylene - Sbacoustics​

Vented cast aluminum chassis for optimum strength and low compression, mineral filled PP-cone made in-house.

sbacoustics.com

 

[maltux]

Why would an engineer design a driver to certain specifications if its characteristics were to change over time? I don't understand the way some people think.

 

[egellings]

Why would an engineer design a driver to certain specifications if its characteristics were to change over time? I don't understand the way some people think.

Maybe the engineer can design for a target performance; if he can predict the change in performance due to suspension component break-in, then he designs for that final result, knowing that at first, until the driver breaks in, it won't meet those specs. In time, the driver will drift into those specs as the suspension components settle into their final performance and stay there after break-in.

 

[Deleted member 48726]

Maybe the engineer can design for a target performance; if he can predict the change in performance due to suspension component break-in, then he designs for that final result, knowing that at first, until the driver breaks in, it won't meet those specs. In time, the driver will drift into those specs as the suspension components settle into their final performance and stay there after break-in.

Similar to A LOT of mechanical stuff. Let's take internal combustion engines. Not many decades ago, an engine needed break in for proper sealing between cylinder and piston rings, valves, clutches etc. Most moving parts have some settling period before the calculated properties are met. The regime reg. break in has changed but is still valid today.

 

[Speedskater]

Most speaker drivers break-in in a matter of minutes of playing loud (bass heavy) music.
if not a matter of seconds.

 

[Deleted member 48726]

Most speaker drivers break-in in a matter of minutes of playing loud (bass heavy) music.
if not a matter of seconds.

Maybe for some drivers, maybe not for others. It will logically vary depending on the used materials and the design IMO.
Edit: it would be helpful if some manufacturer has published their process in this regard. I will try to look into this driver I have linked to before.

 

[Tangband]

Most speaker drivers break-in in a matter of minutes of playing loud (bass heavy) music.
if not a matter of seconds.

Can you explain then why I always ( with about 15 different subwoofers experience at different installations ) have to lower to subs about 1,5 to 3 dB after one month of playing music ? Its not in my head, because other people who only heard the subs in the beginning and come visit after 1 month notice there is deeper and slightly to much bass…

The fs value lowers in subwoofers ( 1-4 Hz ) with break-in , the Vas changes and this make the subwoofers sound as they should after this. Different bass units behave different.

 

[Tangband]

As I saw PS Audio's new video where break in is the topic at hand, I dismissed the talk about electronics break in but actually tend to agree with Paul with his answer on driver suspension break in.

The reason for my agreement with him on this is based on my own experience with building subwoofers for cars many moons ago. Stiff when new (or cold) and more compliant when "broken in".
Also some driver manufacturers T&S data has an asterix showing something like "after break in" in the buttom of the sheet.

PS Audio video-->
PS Audio Break in

Video showing measurements on the same driver new vs. used-->
Woofer Break in

T&S data on a 6" driver-->
Spoiler: T&S

Link to above mentioned driver data-->

6″ SB17MFC35-4 / Polypropylene - Sbacoustics​

Vented cast aluminum chassis for optimum strength and low compression, mineral filled PP-cone made in-house.

sbacoustics.com

This is evidence that there IS a break in difference with different TS value before/after. Watch the last video If you are in doubt.

 

[ROOSKIE]

Why would an engineer design a driver to certain specifications if its characteristics were to change over time? I don't understand the way some people think.

Driver specs change constantly.
Heat, ambient air temp, ambient air pressure, SPL increases, air pressure build up in the enclosure.

There is no one set of driver 'specs'

Every driver has an operating range in which the specs are changing. That is not exactly the same as break in and not the same as changing due to beak in over time but it is a reality.

I am not a huge fan of long driver break in times, more like long ear adaptation time. That said anecdotally, I have had a few drivers that did seem to break in. I don't think it took very long. It seems like a few minutes or a few songs at an SPl that streches the parts out is enough. Who knows. It is nearly impossible for a listener to determine if it is break in for the speaker or ear adaptation.

There is often a stifness to the spider and perhaps some stiffness with surrounds especially paper coated accordian surrounds. Proabily a good idea to use drivers that have been played and would be broken in if need be when designing a speaker just to be safe.

Can you explain then why I always ( with about 15 different subwoofers experience at different installations ) have to lower to subs about 1,5 to 3 dB after one month of playing music ? Its not in my head, because other people who only heard the subs in the beginning and come visit after 1 month notice there is deeper and slightly to much bass…

The fs value lowers in subwoofers ( 1-5 Hz ) with break-in and this make the subwoofers sound as they should after this. Different bass units behave different.

This is evidence that there IS a break in difference with different TS value before/after. Watch the last video If you are in doubt.

Yes compliance changes so the whole slew of parameters change a bit but it isn't that much in terms of how it will model and perform.
3db increase with one subwoofer?
That is alot.
That is strong and unusual claim that you should measure and post said measurements.
What type of installs are these?

 

[Deleted member 48726]

This is SB Acoustics protocol for T&S testing-->

https://sbacoustics.com/wp-content/uploads/2021/01/Measuring-Thiele-Small-parameters.pdf

"Prior to measuring T/S parameters, the drive unit should be broken in – for two reasons. If the suspension of the drive unit is not broken in, its compliance will slightly increase during the measurement, thus affecting/distorting the results. Furthermore, eventually the drive unit will end up being broken in (it actually does not take that long), which is why it is recommended to use T/S parameters that apply for a broken-in drive unit when calculating box volumes and tuning frequencies. The free air resonance frequency typically drops about 10-15% during break-in, as the suspension compliance increases. This directly affects the Q-factors and the equivalent volume. To break in a drive unit, you are going to need a sine wave or a noise generator with adjustable output voltage (the former is recommendable) and a power amplifier. Using a sine wave generator, adjust the frequency somewhere below the expected free air resonance frequency of the drive unit (typically about 80% of this value). Slowly turn up the voltage until the suspension reaches maximum displacement. Keep it below clipping level. Usually you can hear when the suspension goes into clipping mode - there will be some kind of mechanical noise. Adjust the voltage slightly below this level. During the process of breaking in the drive unit, it might be necessary to turn down the voltage a little to keep it from clipping, as the suspension softens. It needs to run for about ten minutes. Before measuring, let the drive unit cool to ambient temperature."

 

[Deleted member 48726]

...



Yes compliance changes so the whole slew of parameters change a bit but it isn't that much in terms of how it will model and perform.
3db increase with one subwoofer?
That is alot.
That is strong and unusual claim that you should measure and post said measurements.
What type of installs are these?

Tangband may want to answer for him self, but if several parameters change AND impedance it may be exaggerated when the driver is mounted in an enclosure. Especially if there is impedance change around the resonant frequency in either the enclosure or the room itself.

 

[GXAlan]

As I saw PS Audio's new video where break in is the topic at hand, I dismissed the talk about electronics break in but actually tend to agree with Paul with his answer on driver suspension break in.

Driver break in is real, but it probably happens in a few hours of first use.

Perhaps most importantly, if it is real and you aren’t dealing with a budget speaker, why doesn’t the manufacturer do the break in for you?

Turns out that Diatone in Japan does. They believe there is break in for the drivers in their exotic bookshelf speaker so they say the do the break in before assigning a serial number to the unit, to ensure that customers can enjoy the product immediately.

This is important for electronics too. If it does exist, do the burn in for me.

Right now, a lot of burn in talk is just to get you to decide it is too much trouble to return the unit than keep it.

 

[delta76]

Maybe for some drivers, maybe not for others. It will logically vary depending on the used materials and the design IMO.
Edit: it would be helpful if some manufacturer has published their process in this regard. I will try to look into this driver I have linked to before.

Many manufacturers even say that speakers need a few hundred hours of breaking in.

Running-in period for hifi speakers

The loudspeakers used in speakers are complex mechanical parts which require a running in period in order to work to the best of their ability

www.focal.com

Most reputable manufacturers however, will test the drivers as part of their QA process. that is enough for breaking in

 

[valve_integrator]

Similar to A LOT of mechanical stuff. Let's take internal combustion engines.

Not many decades ago, an engine needed break in for proper sealing between cylinder and piston rings, valves, clutches etc. Most moving parts have some settling period before the calculated properties are met. The regime reg. break in has changed but is still valid today.

sorry that's nonsense, and the comparison is totally spurious.
I have made race engines for years.
If you have to break anything in on such an engine you have built it wrong, no matter if it's a mid 60s Aston Martin engine or a mid 90s supercharged or V12 unit.

I can understand some of those low tech 1950s Yankee V8s might need TLC, but NAH, I believe break in on a properly made race engine about as much as break-in on properly engineered speakers.

All entirely imaginary.

 

[Rottmannash]

sorry that's nonsense, and the comparison is totally spurious.
I have made race engines for years.
If you have to break anything in on such an engine you have built it wrong, no matter if it's a mid 60s Aston Martin engine or a mid 90s supercharged or V12 unit.

I can understand some of those low tech 1950s Yankee V8s might need TLC, but NAH, I believe break in on a properly made race engine about as much as break-in on properly engineered speakers.

All entirely imaginary.

Why does Chevy recommend limiting RPM's for a certain # of miles on the new Corvette?

When a new owner takes delivery of the Corvette Z06, the tachometer will have a redline of 6600 RPM for the first 500 miles and then will reset to its 8600 RPM redline afterward.Feb 22, 2022

 

[krabapple]

Tangband may want to answer for him self, but if several parameters change AND impedance it may be exaggerated when the driver is mounted in an enclosure. Especially if there is impedance change around the resonant frequency in either the enclosure or the room itself.

If you and he are talking about the Hexibase video on youtube, AFAICT it fails in two stunning respects:

1) no measure of unit to unit variation when new --- i..e the true baseline
2) no measure of unit change at timepoints between 'new' and '3 years of use'

 

[Keith_W]

Why does Chevy recommend limiting RPM's for a certain # of miles on the new Corvette?

When a new owner takes delivery of the Corvette Z06, the tachometer will have a redline of 6600 RPM for the first 500 miles and then will reset to its 8600 RPM redline afterward.Feb 22, 2022

Manufacturing tolerances, perhaps. Mass produced engines are not the same as carefully manufactured racing engines. In F1 cars, the tolerances are so tight that the engines seize when they are cold. Only when the engine is heated do the cylinders expand, and the pistons are able to move freely. Before F1 cars are started, they have to circulate hot oil through the engine.

Since we are talking about cars, I was told that tyres also have "burn in". Every time I get new tyres fitted, I am told to be careful for a few hundred km because new tyres do not grip as well. I assumed it was to do with compounds in the rubber that need to be worn off by the road. I don't know if this is true.

 

[Rottmannash]

Manufacturing tolerances, perhaps. Mass produced engines are not the same as carefully manufactured racing engines. In F1 cars, the tolerances are so tight that the engines seize when they are cold. Only when the engine is heated do the cylinders expand, and the pistons are able to move freely. Before F1 cars are started, they have to circulate hot oil through the engine.

Interesting. I believe the new Corvette's engines is hand built.

 

[Tangband]

Driver specs change constantly.
Heat, ambient air temp, ambient air pressure, SPL increases, air pressure build up in the enclosure.

There is no one set of driver 'specs'

Every driver has an operating range in which the specs are changing. That is not exactly the same as break in and not the same as changing due to beak in over time but it is a reality.

I am not a huge fan of long driver break in times, more like long ear adaptation time. That said anecdotally, I have had a few drivers that did seem to break in. I don't think it took very long. It seems like a few minutes or a few songs at an SPl that streches the parts out is enough. Who knows. It is nearly impossible for a listener to determine if it is break in for the speaker or ear adaptation.

There is often a stifness to the spider and perhaps some stiffness with surrounds especially paper coated accordian surrounds. Proabily a good idea to use drivers that have been played and would be broken in if need be when designing a speaker just to be safe.




Yes compliance changes so the whole slew of parameters change a bit but it isn't that much in terms of how it will model and perform.
3db increase with one subwoofer?
That is alot.
That is strong and unusual claim that you should measure and post said measurements.
What type of installs are these?

Always 2 subwoofers . Thats about 1,5 dB each. This was Rel S5 , but also Genelec 7360 and SVS 2000 behaved slightly different after some use.

An other example : if the break-in change is only about 1 dB in the bass tuning for a standmounter, you always listen to two speakers = 2 dB = audible.