Listening tests

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#22
As much as possible, you should make up multiple units (at the very least two), modify only one aspect at a time, and compare the modified unit against the unmodified unit. Having only one unit and modifying it can be misleading, because you really want to test the before-and-after-modified circuits under as similar conditions as you can possibly manage, and that includes your own physical and mental state.

The test audio system should also be set up as carefully as possible to make sure that the results are not masked by controllable causes such as excessive ground currents or improper speaker setup.

I have outlined my testing methodology previously in posts such as the following:

http://www.diyaudio.com/forums/showthread.php?postid=60831#post60831

http://www.diyaudio.com/forums/showthread.php?postid=62284#post62284

http://www.diyaudio.com/forums/showthread.php?postid=97797#post97797

http://www.diyaudio.com/forums/showthread.php?postid=97888#post97888

These are the same types of listening test methodologies that are conducted at the big Japanese electronics manufacturers like Technics (Panasonic/Matsushita) and Pioneer, although the test prototypes made by these companies are likely to incorporate special fixtures and structures that allow the circuits and components within each test unit to be swapped out quickly and easily.

regards, jonathan carr
 
#23
Real Time A/B Testing.

On the front panel of my solder station I have fitted a switch so that I can selectively ground connect or isolate the tip/barrel of my soldering iron.
The switch in the isolated position allows me to solder in or isolate components anywhere in the whole system, and do real time A/B comparisons on the fly.
This method is very revealling of even tiny changes in the system sonics, and one does not need the same reliance on sonics memories.
This method allows practice in discerning minor changes, and once learned this greater hearing accuity is also usefull in standard A/shutdown/B testing.
Just like learning to ride a bicycle, you don't forget.

Eric.
 
#27
Funny you should mention that Eric, as I do precisely the same trick with my setup.

I have a 20 yr old Antex iron which was made with a ceramic 'inner' shaft, so the tip is electrically isolated from the rest.

In fact it worries me that when the element finally gives out, I doubt that I will be able to replace it as I haven't seen anything like that in catalogues for years.:bawling:

They probably don't satisfy the recent safety standards, or something.

Also my power amps and (remote) speaker X'overs are always 'open', I just cover them over with an upturned carpet-covered box, and the lids of all my other gear haven't seen any fixing screws for years.
Not recommended, perhaps, if you have kids or pets around, but I don't have that problem! 🙂

Hardly a few days go by without my changing something around, as it is so easy to do it like this.:nod:

Regards,
 
#29
And You Thought Kangaroos Are Stupid

Kangaroos are also the most efficient animal regarding locomotion.
This is reliant on their leg tendons storing and returning energy, thus making them the animal able to travel with the least expendature of energy, and able to cover large distances at high speed.

Eric.

Anyway, have any of you blockheads tried springs under your speakers or electronics ?.
 
#31
Throwing Pearls To Swine....

I give up I reckon.

Among several locals, we agree that the springs are much preferrable to cones or floor mounting.
I mention this fact several times and nobody takes any notice it seems. :headbash: :headbash: :headbash:

Maybe every body is more concerned about the minor changes by fitting hugely expensive capacitors, and not the major ones that that cost the least. 🙄

My entire hifi (the one at my GF's place) has cost me less than AUS$100 including cables and tweaks, and for musicality, danceability and just plain domestic blissfull enjoyment, it whips the **** of anything else I have heard in along time.

There are some interesting tweaks (springs are one of them), and without them it reverts to a standard but still reasonably nice system, and with them it plain cranks and takes you direct to the master tape and reveals everything, and the sonics never grate.

Too bad for you guys if you have to put up with second best.

Eric / Happy as a pig in the proverbial with my sound.
 
#33
Mr. Feedback preparing to store energy so it can come back later just like the roo's tendons.
 

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#34
Thanks for all the good advice. And don't worry, I have a very long attention span!

By nature I'm more in the measurement camp, but I think for DIY audio there are good reasons to pay attention to informal listening tests. For one, there are plenty of things that can be measured in principle, just not by me given my equipment and skills.
 
#35
Hi Eric,

Knowing from my own trials that what you generally say works well, I would be tempted to have a go at the springs you mention.
(Boing, boing, boing, boing) :nod:

However (nearly) all of my gear is supported on Townshend (an ex-countryman of yours) Stands, which I guess will be very similar in effect, except perhaps rather better damped.

Max's 'Seismic Sinks' entirely support the gear on air bladders, and were it not for hearing a demo of them at a show, I would never have expected that they could be so effective.

Over the years I have had many proprietary and DIY stands of differing types, but nothing comes even close to these Townshends.

At the demo, Max played some music for a while, and then gradually let the air out of the bladders, and everyone in the room was amazed at the change which took place.

I would hate to have to do without them now, and they are one of the very few bits of audio I have *purchased* in many, many years.

Regards,🙂
 
#37
Rob M said:
Thanks for all the good advice. And don't worry, I have a very long attention span!

By nature I'm more in the measurement camp, but I think for DIY audio there are good reasons to pay attention to informal listening tests. For one, there are plenty of things that can be measured in principle, just not by me given my equipment and skills.
Click to expand...

Hi Rob,

I am glad to see that your stamina is greater than the Thread Monitor's, whose contribution so far has not only covered policing what I said, but he's branched out into unsolicited literary advice, and ultimately into explaining what another poster means in his postings! :goodbad:

When I did some technical authorship for a japanese semi-conductor manufacturer a while ago, of course I did many drafts and carefully checked everything for order and continuity, repetitions, superfluous text, grammar, and spelling etc., but I was commissioned to do that work, and I was very well paid for it too!

However, when I first saw your post on this topic late one night, and that there were (at that stage) no other replies, I checked back to your 'inaugural' post, realised that you were new to the Forum, and, from your request, assumed that you were not already very experienced in this field.

Far too many times on the Forum I see rather vague comments/advice dispensed in an apparently authoritative manner, and, regrettably, quite a few times when I have tried to subsequently get a further 'working' explanation, it has not been forthcoming, which suggests to me it is more likely to be assumptions or hearsay, rather than experience 'talking'.

I therefore tend to do some 'hand-holding' and provide step-by-step 'instructions', which if followed will be effective (not necessarily the *most* effective, though!), perfectly safe as far as the experimenter and equipment is concerned, and generally will use readily available equipment etc.

So far, I have had ( a few!) more 'accolades' than 'brickbats', so I don't feel inclined to change just yet! :bigeyes:

Accordingly, I did my best to show you some encouragement and share some of what has taken me 30 years to pick up, and as usual, my style in these threads is to write simply what comes into my head, as it does.:goodbad:

Returning to the subject, there are certain artifacts which will probably never be satisfactorily quantified or measurable (IMO), to give but one example, the subtle differences in the 'front to back soundfield' which probably relates far more to phase than much else, but this can readily be 'adjusted' by the carefull (or careless!) choice of certain components in the audio equipment. Before some 'expert' tells me here that phase can be measured, I am (just about!) aware of this, but what I mean is measuring the relationship between say changing from one capacitor to another, and the consequent difference in this perceived 'depth'.

Until some 30 years ago, when I accidentally discovered 'the error of my ways', I also believed in the 'LCR Rules' approach, and that all components of nominally similar specs will sound the same.

This 'discovery' was a very awkward and uncomfortable thing to find out about, as it added a whole raft of complication to my audio beliefs and tinkerings, and initially I tried to convince myself that I was mistaken as I don't enjoy wasting hard-earned money, nor indulging in any more hard work than is necessary to get by in life.

However, self-deceit, whichever way (either in a positve or negative fashion) is not my way of going on, and as I am also very patient and determined, and not to mention incredibly inquisitive, I just had to look further into this subject.

It has occupied perhaps half of all of my spare time during these past 30 years, and has given me just as many heartaches as pleasure, but I don't regret doing it, nor what I learned along the way, at all.

What Eric said is very true, it is easy to get so carried away with these sometimes very intense experiments (if you are really fussy about getting the best results, rather than just making some 'interesting' changes to the sound) that the joy can go out of listening at all, and you do need to be able to change back to 'normal' mode, and forget the testing and just sit back and enjoy the music.

I am not a crank, and the accuity of my hearing was appreciated by John Linsley Hood, whom you may have heard of as being a well-respected audio designer/writer in the UK, as, before he retired, he would sometimes sent me a new prototype design for an independent 'sonic' opinion before he finally published the circuit.

As we all (nearly all!) appear to agree, this 'listening' ability is very much an acquired 'skill', and it does improve a great deal over time, but everyone has to start somewhere.

My rather 'laborious' suggested set-up will be the easiest way (IMHO) for you to get a foot on the first rung of the ladder, and shouldn't be too hard or costly to set up.

I urge you to set aside perhaps a day or weekend sometime, and do some of this 'immediate' A/B testing, since, as I said, you can keep on switching back and forth over and over again, until you start to appreciate where any differences are between the two different components under test.

It is better when there is no-one else around, because they will get fed up with the repetitious sounds, and always take a break from time to time, so that you avoid getting too tired or fed-up and frustrated with it.🙁

Unless your system is very poor (and I am sure if it was, you wouldn't be interested in trying this, anyway) if you persevere sufficiently, you are virtually bound to succeed like this, especially if you try to pick a 'bad' or exaggerated case to begin with.

Once you spot the kind of differences which can be heard, it is then, like someone else said, just like riding a bicycle, and your accuity will improve so you need not, perhaps, go to so much trouble with future set-ups.
All unneccessary additional switches (no matter how good) or extra connections will tend to mask the *full extent* of any sonic differences, but in general, the kind of artifacts you are attempting to identify will still be quite apparent.

With the passage of time, familiarity with your system will grow, and this is also very helpful.

I openly admit that I have grave doubts about hearing half of what I do in my own system, when I am somewhere else and listening to unfamiliar equipment, but my hearing still does pick up some differences in 'foreign' environments as well.

Finally, I hope this is of some help to you, and if anyone else wishes to comment on what I have said, which is very welcome, I trust they do at least show the same consideration which most of the other members of the Forum do, rather than just being impolite.

Regards,
 
#38
Eric:

>The switch in the isolated position allows me to solder in or isolate components anywhere in the whole system, and do real time A/B comparisons on the fly.<

I did this years ago, and I assure you that this is _much_ less trustworthy than having multiple units that are identical in all particulars except the test item(s).

You must be able to revisit your starting point as well as all steps in between.

And also, you need to be able to judge the sound of each change without any knowledge of what it physically entails. Although I have not observed the power of suggestion (or placebos) to be absolute and insurmountable, it can undoubtedly exert a powerful influence on our subjective reactions.

Much of my listening test methodologies are precautionary measures designed to keep the reactions of everyone in my listening panel "honest", and that includes myself.

>Just like learning to ride a bicycle, you don't forget.<

Maybe you don't forget, but you _do_ become inattentive and lazy. I have witnessed too many situations where listeners who are trained and should know better allow their listening methodology to lapse for the simple reason that no controls were imposed on them externally (i.e., supervision). The result was that their listening data was useless.

Electrically, I wouldn't recommend keeping a soldering iron on in the listening room, because when the tip temperature is running low, the thermostat elements will pull power from the wall in a long-continuous surge, and this can affect other power supplies near by.

And besides, with complex circuits using multi-layer circuit boards, there is very, very little that you can change unless you first take the test unit to pieces!

regards, jonathan carr
 
#39
Edmond Stuart said:
>"euphonic distortion"
😀
Click to expand...

No doubt - if you hear a difference then there is coloration or distortion at work.

Most people know when they compare live sound of music to amps can tell which one is more accurate to the music. In the case here, people seem to think the CFA is closer to 'real' or live music instruments.

Now, if both amps being compared have thd/IM below .001% then what parameters are contributing to the percieved (euphonic distortion) difference. In fact, this question has not been answered here but is a central point of wonder. What characteristic of CFA/VFA make for this difference?


Thx-RNMarsh
 
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