Suggestion for Forum Discussion Group - Audio Measurement

[alexc]

Hi All

I have a suggestion for a new forum discussion group - 'audio measurements' or something like that.

A group for threads relating to the art of measuring audio performance.

It seems like the areas of designing, building, buying, selling, using, digitising and brewering audio is all catered for.

But the art of measurement, by which we know what the hell we have built is not as much discussed.

For sure, many of folks around here are well versed in audio measurement practice and like many things freely contributed, would be happy to school us less experienced types

multimeters, signal generators, cros, power supplies, load boxes, real time audio spectral-analysis, harmonic distortions, intermodulation distortions, signal to noise ratios, noise floors, load boxes, meters, resistance-capacitance substitution boxes, transient analysis  ... the list, like the road, is long 

A group like this would really add to the lofty technical merit that this place provides.


Anyway - something to think about - it's on my mind more and more as time goes by.

'Art of Noise' (measuring audio performance)

Thnaks

 

[Ethan]

I like the idea...would there be enough interest?

 

[[silent:arts]]

Seeing many meaningless measuring results here, just because "a software can do it" (but without any reference etc), this sounds like a great idea 8)

I measure -70 with RTA, is this too noisy? 

 

[sahib]

Very beneficial. Not only from the point of of how to measure audio performance but also the mechanisms that contribute to it.

 

[Gustav]

[quote author=[silent:arts]
I measure -70 with RTA, is this too noisy? 
[/quote]

Yes, please measure your −70 with RTA somewhere else....

Sounds like a good forum, just remember, sound is also an aesthetic phenomenon, and this place is pretty geeky already

Gustav

 

[shot]

Maybe we could also do a set of "universal test files" in this section - a few wave files that all start with calibrated sinus at some level and then afterwards have some recorded signals like drums, bass or vocals, or simple square/saw waves. That way, after the unit has been built, every DIYer could run those files through his/her unit and send them back. Other users could have a taste on how their builds sound compared to other, or simply get a taste of different units so they can decide what they would like to build themselves in the future. And it would also be a great way to troubleshoot units, since it's easier to listen to the faulty unit than to describe what sounds wrong.
I am willing to prepare test files if others are cool with this idea and we have server space to host them.

 

[Rochey]

I love this idea!
A lot of audio measurements can be done with a soundcard (1K tone tests etc), however, the soundcards need to be calibrated for levels and for their own frequency response.

If anyone has already done this, I would be really interested!

/R

P.s. I thought about making a small tester based around a usb codec for quite a while. Not sure if I could convince people a 16bit codec was good enough.

 

[bernbrue]

I like this idea very much, since a lot of technical terms in measuring do not tell me anything. It´s nice when RMAA tells me, that THD is average. I want to understand why and what to do in order to improve it. I love "Art of noise" and their music but I would simply call it "audio measurements"
regards
Bernd

 

[JohnRoberts]

Accurate measurement is fundamental to empirical design (IMO).  There is a classic conflict between "golden ears" and "meter readers".

We actually live in a golden age where anybody with a computer sound card can just about replicate the test bench of a few decades ago, and actually answer for themselves if a piece of studio gear needs to get the capacitors replaced or IC's upgraded with objective measurements.

JR

 

[desol]

There is a classic conflict between "golden ears" and "meter readers".

Yes, and ears always win.

Audio measurement group....great idea!

 

[lolo-m]

+ 1 on that idea !

 

[Kingston]

There is a classic conflict between "golden ears" and "meter readers".

I would derive it further to those who understand what they are reading, and those who don't.

 

[joaquins]

I like the idea... I always measure in some way what I'm building but I wish I have a reference from somewhere else to compare with...

The other section I would like to have around is about acoustics, but I don't know if there is enogh intrest in this forum about it, I've seen a couple of topics but not so well organized.

I go with 'art of noise'!

JS

 

[JohnRoberts]

There is a classic conflict between "golden ears" and "meter readers".

Yes, and ears always win.

Audio measurement group....great idea!

As I feared....

opinions vary.

JR

 

[alexc]

Great to read that there is interest!

Your comments are exactly what I'm thinking.

Especially the part about my -120dB is better than your -70dBu

Hopefully it goes forward.

 

[joaquins]

For me measurements are necessary, measurements will help in the development process to know where and how optimize for what you are looking for, but at the end of the day if you like how it sounds is what will make you choose to use it or not...

JS

 

[alexc]

Totally agree with the aesthetic aspect of diy audio - the sound is after all what it's all about.

But like looking at a beautiful car, it is one aspect of the whole. Having the expertise to determine whether it's running right is also important.

My first couple of pieces, done before I had even a cro and signal generator, let alone a RTAS or the thest of it, sounded OK. A couple of pieces later, when I accumulated some measurent gear, I revisited those pieces and took a detailed look.

Well let's just say I was able to use the knowledge I had gained and the equipment I bought to dramatically improve performance.

When I listened to the reworked early units, I was very satisified with the effort.

Nowadays I won't listen until I know I have the basic performance where I want it.

And I'm really only now trading theory that I've known for years into actual, real world knowledge - gained only by 'doing'.

In the area of measurement, there is 'so much to do, and to know, and to have done to you'.

Once the basics are  verified, there is miles and miles of  the subtle stuff still uncharted.

And yes, the opportunity to hear from the expert practitoners and have it collected here  *FOREVER* would be just great

 

[mrclunk]

Yes, Yes Yes! (please)

 

[Brian Roth]

Count me in.

Bri

 

[nashkato]

very nice idea , like it a lot , i´m way behind on this topic