Let’s talk about… How we test equipment


Burn in, measurements and other routes to optimal readiness

I do like putting systems together, after all that’s essentially what we all do to a point. System synergy is a given for me and it’s not just a case of setting a budget, apportioning it across the system components and buying ‘award winners’ from magazines, unless you get lucky of course…

As far as possible I like to fully test components before deciding to add them to our sales portfolio – or not. It can take significant time, but then, that’s part the journey. 

The other point to make here is that we all like certain sound styles and I’m no different, or perhaps I am? The industry appears to be on a technical excellence path and I’m very much into relaxation and sound that has ‘soul’ – two ends of the audio spectrum perhaps?

I’m also not one for measurements, I like to trust in my ears – that’s what I’ll be using every day to gauge enjoyment and not a measurement variation.

I point you at some (old) reviews of valve amplifiers that ‘measured poorly but sounded great’. However if you need a guide, and plenty of manufacturers rely heavily on measurements in design, then cool – whatever works for you.

I heard an amusing story presented by the wonderful Prof. Hannah Fry on the equally informative ‘Maths of LIfe feature’ (BBC 6 Music 12/03/24, paraphrased below) to back up my point… to a point.

It seems mathematicians got their digits in a twist back in the early 1900’s arguing about the small stuff, essentially the atoms of maths. Here’s the thing – how do we know for sure that 1+1=2? In other terms how do we define 2, or ‘twoness’? Is it visibility like Noah’s Ark? How do we know we are thinking about the same thing? How do we prove logical things?

Confused? Don’t worry. Bertrand Russell wrote a book just to define 1+1=2. However, it’s 700 pages long and even then at the end he added a caveat saying it only works once arithmetic addition has been defined – how are you feeling about ears right now?

The other problem I have with measurement is consistency. My pedometer that I use for recording my daily 5000 steps is inaccurate. I know that because I have tested it, but it doesn’t matter as long as it’s consistently inaccurate and I can record comparable data. 

Can you judge the performance of a system from a component measured in isolation? What if you hook up a component with different input/output parameters? And, what if your listening space isn’t an anechoic chamber… I could go on. And yes I know my ears aren’t perfect, but I know what I hear and that’s my constant – wax permitting…

So, ears then.

I was told once that there’s a difference between hearing and listening and that you can learn how to listen. Of course plenty of practice in a consistent environment helps. Also some companies like COS Engineering employ a ‘golden ear’ whose final word determines what goes out to the customer. I’d like to think I am at ‘silver ear’ level with room for improvement.

The flip side is that we (think we) know that hearing deteriorates as you get older but then the stereotypical audiophile is in a small group within a narrow age bandwidth, so no issues there then?? Plus, we’re all different – happy days!

For me, I have both the time, and enjoy listening so that is how I test equipment. The majority of time spent is on burn in and I use internet radio for that, it’s relatively consistent. After that, like a lot of reviewers, I have a set playlist of songs that I know very well so I can hear variations in sound. It’s not perfect but if you actually analysed the recording, it’s not pitch perfect either.

To cover the theory of burn in I do notice some (fairly) consistent changes in relation to elapsed time. The first 10-15 hours are usually a write-off (apart from power cables for some reason). I get dips around 30-40 and 60-70 hours and a noticeable peak after 90 hours improving through 120 to 150 hours. Some products can take up to 300 hours to fully bed in, but it’s unusual.

So that’s the method I use and I am meticulous about keeping notes and spend many hours actually ‘in the chair’. After the initial time period it’s mainly about swapping in/out different equipment and re-assessing to see what works for system synergy.

Then, just to blow everything out of the water (again), I read in a review recently a loudspeaker manufacturer saying that the first 10 hours are indeed irrelevant, but after that it’s just the brain learning about the sound.

Great! Thanks for that. So again we are talking about the brain. Something we know little about (that we can prove…)

Back to the library for something to read whilst I am testing! It’s a never ending journey after all.