[DaveC113]

This has always been a controversial topic...   

In the few years I've been running ZenWave Audio I've got a lot of feedback from folks on burn-in. The first several months I sent out totally fresh, unused cables. This wasn't a great idea, especially with the litz-wire cables as the burn-in is very pronounced. I got a lot of comments about how bad the litz-wire cables sounded at first, but at least some folks who never thought burn-in was real got to experience it themselves   After I purchased my AudioDharma Cable Cooker I never got another comment. Semi-anecdotal but something that could be used to form a hypothesis.

My ideas about burn in involve the interface between the conductor and the dielectric, and that this is where burn-in happens. The litz wire I use has a lot of surface area here, and burn-in is very obvious. So obvious in fact that I figured it should be measurable with a simple frequency response test. I finally got around to doing the test and the results are below.

Pioneer S-1EX speakers used with 5" magnesium midrange and coaxial beryllium dome tweeter. Omnimic software, mic placed about 2" from dome tweeter, centered on tweeter. Mic was not moved while cable was being burned in for 5 days on an AudioDharma Cable Cooker.

Cable used was ZenWave Audio SL17 speaker cable which uses an aggregate 17g of UPOCC copper litz wire.

IMO, frequency response is one of the more subtle aspects of burn-in, but the test shows unmistakable and relatively large changes in frequency response. It's fair to say a lot more is going on besides frequency response changes during burn-in.

1/6 octave smoothing

[Tone Depth]

From the plot, it looks like about a 2 dB frequency response increase between 9 and 12 kHz following burn in? I can imagine making the signal seem relatively somewhat brighter in the mid-high frequencies.

[OzarkTom]

What? There is a difference in cables?

Just kidding.

[DaveC113]

From the plot, it looks like about a 2 dB frequency response increase between 9 and 12 kHz following burn in? I can imagine making the signal seem relatively somewhat brighter in the mid-high frequencies.

One phone call I got before I started burning in said "It sounds like I put a muzzle on my system!" and I think that's a great description...   

Before burn in overall SPL seems lower, highs are muted, detail is covered by grain and harshness, just an overall congested poor sound. This particular cable has a more dramatic burn-in vs most others as discussed earlier and I'm not surprised the burn-in is easily measurable. The changes in SPL and frequency response are minor compared to the other effects.

What? There is a difference in cables?

Just kidding.

Lol

[DaveC113]

Zoomed In:

[DaveC113]

Actual proof of wire burn-in and no comments?   

I've seen huge debates on this topic many times on almost every audio forum and AFAIK this is the only measurement that's been posted that supports the fact that wire actually does burn-in...

[SteveFord]

Stop bothering us with the facts and let's get on with the debate about how bad so and so's hearing must be!

I seldom join in on these debates but everything else breaks in so why wouldn't cables do the same?

[Folsom]

You really want the dogs out? I know where to post a link...

[paul79]

[jtwrace]

Actual proof of wire burn-in and no comments?   

That's far from proof, I'm sorry to say. 

[paul79]

How bout a bit more than a blank accusation there Jason?   

[OzarkTom]

You really want the dogs out? I know where to post a link...

 
Hmmm....

AVS forum?

[Folsom]

OMG, I'm not that evil... and I won't post there anymore. It's almost as bad as a forum that once tried to Lynch me by posting personal information solely for the fact I disagreed with a design feature of the product the forum was for... and still loved the product.

[*Scotty*]

The key thing to remember is when you have change in SPL of even 1dB that covers over 2 octaves it is very audible. That fact that there is any measurable change in frequency response at all due to applying a  very small voltage to the cable over a period of time is fascinating.
Scotty

[RDavidson]

While I'm not a believer that science can explain EVERYTHING (nor does it need to), your experiment points out that there is phenomena that can be observed through at least one scientific method. Very interesting stuff.

[DaveC113]

That's far from proof, I'm sorry to say. 

True, but it's an indication, a bit of evidence.... maybe others can replicate it? I might be willing to supply some wire...

You really want the dogs out? I know where to post a link...

No, not looking for a fight, it's just a simple test... I figured it would generate some interest as I've never seen evidence that wire burn-in has audible effects before. Most of us know it's true through experience, but this is a real indication that we're not just imagining things.

[Speedskater]

I would think that the loudspeaker, mic and/or room environment were much more likely responsible for the measurement difference than the cable.
Why not repeat the test using an AC voltmeter on the speaker terminals?
Or better yet, make a RLC dummy load loudspeaker.

[Salectric]

Very interesting!  Even though I don't need measurements to confirm that burn-in is real, it's nice to see a test that shows there is a measurable change.  I do agree with Speedskater though---there are environmental issues associated with mic measurements of a speaker such as room temperature and humidity.  A simple electrical voltage reading on the speaker terminals should reveal the same measurement differences, if the cable break-in is truly responsible, without being subject to environmental variables. 

[Peter J]

I'm really in no position to confirm or condemn burn-in theory. I am a skeptic at heart but try to leave the door open to things unknown.

I do find it curious, however, that when reading various threads about it, I don't think I've ever known anyone to say something like "it sounds shitty now that it's broken in". Seems it always audibly improves things, which doesn't make sense to me. Statistically, wouldn't there be as much chance for it (whatever it is) to sound worse?

[TJHUB]

I'm really in no position to confirm or condemn burn-in theory. I am a skeptic at heart but try to leave the door open to things unknown.

I do find it curious, however, that when reading various threads about it, I don't think I've ever known anyone to say something like "it sounds shitty now that it's broken in". Seems it always audibly improves things, which doesn't make sense to me. Statistically, wouldn't there be as much chance for it (whatever it is) to sound worse?

I see comments like this often, but the answer is very simple.  No cable designer would ever design a cable for what it sounds like in the first couple hundred hours.  I'm certain they take a lot of time to sort out the sonic signature, so it seems obvious any cable design would be settled on far after the cable is fully broken in.  So when a new cable is built and requires break-in, wouldn't or shouldn't it always get better with break-in?

I just spent a week waiting for some new power cables to settle in.  It was a rough ride.  Just this past Saturday, I was thinking about a selling strategy.  Today, I think they're damn near perfect.