Axiom Home Page Forums General Discussion Technical Questions Equipment Burn-In -- A Scientific Test

hello everyone,

I have an idea that can help prove/dis-prove any myths about speaker or other equipment burn-in. You know how in reviews of Axiom speakers, they show us graphs showing the decibel to frequency response, well, wouldn't this graph change if the speakers did in fact change after, say, 100 hours of listening? A lot of people believe a speaker gets better after 100 hours, if not more. Some also believe the same for wires and even electronics, such as DACs and amps. Personally, I am a disbeliever, I think it has more to do with the person getting used to the sound, and not the sound getting better. This is why I want to know if there is information out there where someone or some company has done response graphs with the speakers brand, then after, say, 100 hours, then 1000 hours, and compare them to see if they are in fact different. Perhaps Axiom is up to the task? It would be the only way to scientifically conclude that break-in does or does not exist, and if it does, to what degree.

Any thoughts, suggestions?

gotta completly agree.....

well id say only a few hours are required to break in speakers, not 100 hours. two of my friends bought headphones (eyts er-6s) and they said after so many hours the bass got lower and the highs became more tame. since headphones and speakers basically use the same technology, i believe that speakers do need some time to break in. but yeah, a scientific test would be a great way to tell.

I'm all for it. I'd like to see the exact same tests done with speaker wire to see if there is an actual, audible difference. With speaker I can see there being a very slight change in lower frequency response as the surround and damper stretch out but whether or not this is audible is up to debate until we can get some real scientific numbers.

Ravi, you can find just a little bit of information on this topic near the end of an interview at the NRC with Paul Barton of PSB Speakers( soundstagelive.com/factorytours/psbnrc/ ). Paul gives his views on the matter and briefly describes tests he ran on his speakers when new and on the same speakers after 10 years( should be adequate "break-in"). No difference of audible significance was found.

amazing stuff JohnK!

thanks a lot!

now I'd like to see these tests with speaker cables, like danr suggested. However, I don't know how we could scientifically measure something like soundstange, or the transparency of the speaker. I guess that has a lot to do with off-axis performance.

Excellence article. It shows that bad speakers don't get good over time, people just get used to bad sound. The small changes noted are far too small to be audible. The brain adapts to changes or imbalances that are input by the senses. I'm also an amateur astronomer and familiar with optics and their flaws. One example of how the brain adapts is the eye. The lens of the eye isn't achromatic and actually produces a significant violet halo around the edges of bright-colored objects. The brain, however, is able to adapt to this chromatic aberration and alter how things are perceived. Do you ever see well-defined blue halos around objects? Probably not unless you wear glasses which introduce their own errors. This is the same with sound. I guess you could say that the brain has tone controls and an EQ built into it.

As for soundstage and imaging that seems to have a lot to do with baffle design and especially room acoustics (as seen in the article) and are difficult if not impossible to quantify. If we could then one could easily predict or model how one speaker design would perform and how to optimize it. Then after a while nearly all speakers would be nearly identical if one particlular design or model worked best.

Ravi and danr, on the question of speaker wire tests, these have been done on occasion in the past. Note that in Roger Russell's article on speaker wire( sundial.net/~rogerr/wire.htm )he describes the 1983 Stereo Review and 1994 Audio tests. I read these back-issues at the library and doubt that they're available online.

As JohnK mentioned, someone must have tested this out before. I would be shocked if speaker companies have not done some 'break in' testing since it is a real buzzword in the world of audio.

I just saw a customer comment the other day, on a company website, regarding his high end interconnect cables and how he talked about their 'break in' after 200h, 500h and so on. Apparently he heard quite precise changes in the mids, highs, etc. after 200h but that the real smoothness never really came about until the 500h mark. Then he went on to mention how he was using a 1500w home baseboard heater to do the break in.
One can only begin to wonder...

I completely agree with Danr on the brain perception concept.
Blind testing. It's about the best option the industry has to find out the truth.

The tests noted by Russell appear to be listening tests. I want to see graphed frequency-response tests using the same equipment they use for testing speakers. Measurements can be taken of several different speaker models using several different type of cabling in anechoic chambers.

Everybody might also want to check out http://sound.westhost.com/cables.htm

Here is a hilarious quote from a section on the link:

"What we do is kind of dirty and stinky," he said. "We say we are starting with a 12 AWG zip cord, and we position a technician behind each speaker to change the cables out." The technicians hold up fancy-looking cables before they disappear behind the speakers. The critics debate the sound characteristics of each wire. "They describe huge changes and they say, 'Oh my God, John, tell me you can hear that difference,'" Mr. Dunlavy said. The trick is the technicians never actually change the cables, he said, adding, "It's the placebo effect."

This one is the most thorough examination of cable theory I've seen yet.