DIYers... Do You Measure?

[Thad E Ginathom]

Most of us buyers are never going to measure, unless we are seriously interested in room correction, followed by room treatment, etc etc --- and, frankly, to me, that is high-end listening, regardless of the equipment cost, because it takes investment in equipment, learning and time and effort to do it. Which I don't.

Most of us will do the single most important (even for those of us with deficient ears) thing: try to buy something that we are happy with, enjoy, or even love listening to. Faults or no faults.

Makers may choose to do the same: please themselves. But, established designs or kits aside, how would they do even that without measurement?

One of the things in watching the John Atkinson presentation is a reminder that the world is not divided into just two sorts of people: engineers who wear ear plugs and digest numbers, and music lovers that listen.

 

[hydrovac]

So, we love to have a good discussion/argument/rant here about the many claims (Objective and Subjective) audiophiles make that others dismiss as myths. The arguments go round in circles; I hear a difference - but there cannot be a difference, it is all in your mind - have you tried different this and that? - I dont need to, it is all in your mind etc., and we all know how it goes.
But sometimes I have the impression that these wonderful people are emphasizing the technical rather than the non-technical issues, like: how a unit really sounds? This is a prelude to a very controversial issue that I want to discuss: are the audio-techno-philes who are measuring and DIY'ing things more concerned with measurement data and circuit topologies rather than with how the equipment really sounds?

At least in my case DIY is very much driven by the quest for better sound within a given budget. The DIY audiophiles I know build and then listen. It is 100% about how things sound and nobody really cares that much how it measures. Measurements may come later and are used to analyze when things go wrong, but if it sounds good the measurements dont matter.

In the case of speakers, many were designed entirely by ear, with never a measurement (era BC). Nowadays we have the benefit of much research into the behavior of drivers in boxes, and detailed specs for drivers, but this only means fewer iterations of the design because the starting point will be OK. The final evaluation and design tweaking is always done by ear. That isn't to discredit all the necessary knowledge in acoustics, electronics, and algebra one must understand and use to design a loudspeaker. To believe that one could even design a speaker without these scientific and mathematical concepts is very ignorant. (Although I was "ignorant" myself, many years ago, I admit it.)

You realize that DIY can be fun (or not, depends on the person). Note it is possible to design and build your own amplifier and spend thousands on parts and labor, which could exceed the cost of another branded amplifier which may be suitable for one's needs. The point is doing it yourself may be motivated by quality of sound rather than economics, and that the diy hobbyist may be no different than the non diy audiophile.

 

[keith_correa]

<snip>...Measurements are simply a human construct that we overlay on reality in order to help analyze it using narrow interpretations. Our ears do an impressive job of that already. It's more about the method than anything and I find that there is a method in common amongst most people responding here.<snip>

Dumb that I am, I don't think I understood most of your post [hyeah:] but the above is very clearly understood and your POV appreciated. Well put!

 

[keith_correa]

<snip>The DIY audiophiles I know build and then listen. It is 100% about how things sound and nobody really cares that much how it measures.

"build and then listen"? Is there any other way? I doubt you intended saying what you wrote but are you saying that these folks build without simulations or measurements? Simming is also based on basic data which is derived out of measurements. Are you saying that these folks don't sim at all?

<snip>Measurements may come later and are used to analyze when things go wrong, but if it sounds good the measurements dont matter.<snip>

That seems to be a wrong way of going about doing things. IMO, sim [based on measurements], build and then tweak based on the room/ear. At least that seems logical to do - to me.

 

[hydrovac]

Are you saying that these folks don't sim at all?

This is about some DIYers not using any kind of simulation software to validate their designs before committing to prototypes.
Secondly I am referring to measurements, evaluating the performance of the designed systems.

 

[keith_correa]

This is about some DIYers not using any kind of simulation software to validate their designs before committing to prototypes.
Secondly I am referring to measurements, evaluating the performance of the designed systems.

I forgot to ask one basic question: Are you talking speakers here?

 

[tcpip]

i prefer to build something which measures well. I cannot comprehend why anyone would treat listening tests and measurements as an either-or divide. I do both.

What would I do if something "sounds good" but measures poorly? I would keep working. I would not accept something which merely "sounds good". It must measure well too.

In my limited experience, each and every piece of audio gear I have worked with or studied has sounded more "neutral" when it measured well. There are well-known examples of systems which sound good but measure poorly, e.g. significant quantities of lower-order even harmonics. I find such sound not to my taste -- it's like a cup of coffee with too much sugar. I prefer my single malt straight, no chocolate please. This is not a comment about those who like their sweeteners -- more power to them.

My last experience was with the Asawari Mark II. After I built it, the first few days were great, and then I began to notice problems. After listening tests and tweaking, the sound became considerably more "flat", more neutral. It became more "ordinary" compared to the decidedly "hi-fi" character it had earlier. I realised that it was now more real-sounding. But this sound may not be to everyone's tastes.

I have studied in detail a lot of the blog posts from NwAvGuy, the designer of the O2 and ODAC. I have yet to find any divergence in our views (in spite of a million-mile gap in our knowledge levels ). He uses measurements and sets very high standards for measured performance. The outcome is an amazingly neutral sounding DAC and amp. I have purchased the O2+ODAC combo, and it is the most accurate and neutral sound reproduction component I have. I use it with my ER4P IEM -- this too is an IEM which is too neutral for some people's tastes.

On the topic of evaluating by ear: I think the ear is a wonderfully sensitive instrument, but it is also easily deceived. Listener expectancy is a very real problem. A lot of audiophile tweaks would never survive a proper double-blind listening test. I presume you all know about this fantastic experiment? This does not mean that I recommend that you stop listening and go by measurement alone. In fact I recommend that you understand the (severe) limitations of both sorts of evaluation, be they instruments or be they your ears. Only then can you get good results out of them. For instance, some left-brained engineers believe that a single all-encompassing THD+N figure, expressed as a single percentage, is adequate to tell you how an amp will sound. This is immature -- you need a whole slew of measurements, with different loads and at different frequencies. For instance, see the set of measurements in this review of a humdrum amplifier. The subtle differences in measured performance under different conditions tell their own story. In many cases, these differences make two amplifiers sound audibly different even when they have identical single-reading THD+N figures. I guess we all know how Peter Aczel evaluates power amplifiers by using a special device which applies different complex loads on it. People who thought that measurements began and ended with a single THD measure gave measurements a bad name, and that continues till today.

 

[Thad E Ginathom]

That is very interesting, and I enjoyed browsing through your speaker DIY experiences. Although most of the technical terms, abbreviations, values, etc etc did not have much meaning to me, it was a window into the process, theory, technicality, practicality, of designing and building a speaker.

(Your link "review of a humdrum amplifier" needs mending it is a link to this thread)

 

[tcpip]

(Your link "review of a humdrum amplifier" needs mending it is a link to this thread)

This link is the one I wanted to post. It is a review by Ken Rockwell. Is the link working now? Sorry about any earlier mistake.

I have also edited my earlier post and fixed the error now. Thanks for pointing it out.