# Speaker break-in data



## hrpschrd (Sep 16, 2008)

As I posted four months ago, I am measuring the "break-in" progress of a set of new speakers. 

I have heard many ideas of how to accelerate the break-in period by running bass through your new speakers (or even electronics!) on 24/7 and other aggressive methods. While I do believe that some components do "loosen up" over time, I wondered just how long it would take if you just played music through the system as you would normally do. So every month I do an analysis and once in a while I will post it here and at the Planar Speaker Asylum. The speakers are planar stretched Mylar films so I would expect them to stretch and soften with use. This should produce more bass excursion it would seem.

As you can see below there appears to be a noticeable increase over time each month. I must qualify that with other changes that have been made to the room and to the data.
- the listening room had significant renovation (parquet wood floor replaced carpet, one whole wall is now a hollow light box, changes to bass traps, etc.)
- June included a three week vacation with no music played at all
- per suggestion here, I have smoothed with 1/6th and matched peaks at a relatively flat area (109Hz). Blue=Mar, Red=Apr, Cyan=May, Black=July, Green=Aug

FWIW: the speakers are Magnepan 3.7R and the music played is mostly classical and not very bass intensive (instrumental and choral) with occasional pipe organ. This is not a very good recipe for breaking-in bass, I admit. I have a subwoofer (REL Strata III) in use for listening but not for these measurements.


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## 94vg30de (May 16, 2012)

Interesting. When were the different elements changed? Looking at the data, it seems like significant diff between March/Apr, big jump between Apr/May, then nothing significant happens. Cool test though!


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## hrpschrd (Sep 16, 2008)

Yes, there were significant changes. Between April and May was a remodel job so the floors went from carpet to rug on hardwood; the left wall became a "light-wall"; different furniture, etc. The result is clearly different.

Then there were three weeks of vacation during June.

I'm a scientist so I don't look at this data as proving anything but there might be a trend with the bass energy increasing slowly (around 30 Hz) over the last few months. That is what everyone expects when they say "break-in". I am not doing what some recommend by playing bass 24/7 to hurry up the process. I just wondered how long it would take under normal conditions.

Also note that I play mostly classical music without much low bass which will make it take even longer. Most of the other changes should stop now, although I am constantly tinkering with the acoustics of the room (moving bass traps; and first reflection traps; and speaker positions; and listening positions). And I let a little Bach organ music rip sometimes too.

I will keep posting progress in case anyone cares. Most experiments take much longer than a couple of months.


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## Wayne A. Pflughaupt (Apr 13, 2006)

I remember the “back in the day” stereo mags used to say all you needed to do to break in new speakers was to play a low-level signal through them for 24 hours or so. It looks like you saw the biggest change between March and April, so perhaps speakers do need more than 24 hours to break in (assuming your room changes aren’t accounting for the difference). However, things have been consistent since then (May, July) so I’d be surprised if you see much change from here on out.

Regards, 
Wayne


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## hrpschrd (Sep 16, 2008)

My guess is that I don't have enough hours on the panels yet to tell. Remember, I have only played a little bass on them for a short time. I am thinking they may still change for about six more months but that is the point of the experiment - to find out where it stops.


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## Barleywater (Dec 11, 2011)

Changes that have been made to room are huge factors. Speaker position, microphone position, room furnishings and treatments really need to remain static. If room opens into other spaces these need to be static too. Temperature and humidity should at least be tracked. Electrostatic membrane is highly sensitive to temperature and humidity, likewise important with microphone when trying to track small changes.

Yes, it will take quite some time to get statistically significant data.

Best regards,

Andrew


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## hrpschrd (Sep 16, 2008)

Graph above is updated for August.

Wayne; still wondering why smoothing is acceptable vs. missing possible instrumental (or vocal) fundamentals?


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## Dual-500 (Aug 1, 2010)

I would be interested in measurements next year, comparing month to month readings between each year. I've maintained high end club systems, active multi-amped systems. They would be checked out on a quarterly schedule. EQ settings flattened and 1/3 octave RTA utilized in addition to scope, signal generator, VOM, etc.

Most, not all times they would require a little tweak here and there. Mainly in the LF and low-mid frequency bands. I always attributed it to seasonal weather and humidity changes and not driver compliance changes. Reading this thread got me thinking about it. Depending upon speaker cone materials, humidity could be a definite factor. It would affect enclosure damping materials, and even the wood itself to some extent as well as the environment. Wood floors, walls and so on.

I never really considered it in this regard.

What are you using to take the measurements posted above? Nice plots BTW.


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## hrpschrd (Sep 16, 2008)

I am using REW software (as this site suggests) on a laptop with a RadioShack mic/meter and a Creative SoundBlaster generator. Simple setup but gives very reproducible results. Using only two channel (without sub bass) but for music listening I adjust the sub frequency and volume according to REW measurements not shown.


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## flatfinger (Jul 27, 2011)

Just as a side note from a speaker building hobbyist;...



Speakers ( drivers) that are designed to end up in an acoustic suspension ( SEALED) box are going to have looser suspension and spider construction ; the sealed box is providing a control on the drivers excursions.

A driver that ends up in a ported box ( 9 out of 10 these days ) is going to have stiffer suspension and spider so that it can operate in a purposely less dampened way ( resonation to extend lower frequency levels) . There isn't the "spring" or countering force to excessive excursion like in sealed .....

It also protects the driver from destruction ( a little while longer !) should it be operated below the tuned frequency ( unloaded ) .

Ported boxes should , in theory , take longer to "Break in ":hsd::devil:


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## hrpschrd (Sep 16, 2008)

I should have mentioned that these speakers (from Magnepan) are open planars (bipolar) with no box at all. Interesting observation though.


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