Nothing In Particular

[steve s]

Great news Steve..

[Ray P]

My daughter gave birth to baby girl Evie last night.11;55 pm, 7lb 15oz.
I'm a grandad again.

How's everyone doing Steve? You and Mrs Cressy have a frequent visitor pass I imagine?

[Cressy Snr]

Everyone is fine. We are leaving them until Saturday so they can come to terms with the happy event.

[jack]

Not done this for a while, however it's iconic...

https://en.m.wikipedia.org/wiki/EF50

EF50.jpg (27.32 KiB) Viewed 1729 times

[Nick]

Very interesting. I didn't know that history.

[jack]

Very interesting. I didn't know that history.

Ronald Dekker, he of uTracer fame, is a Senior Researcher at Philips and a Professor at TU Delft.

Using his access to Philips' archives, he has put together a great page on the EF50 aka CV1091 (SWIDT) which is also referenced on the Wikipedia page:

https://www.dos4ever.com/EF50/EF50.html

Frankly, everything on his site is worth reading!

[jack]

Speaker cable thoughts from Mark Hennessy, 20-odd years as Engineering Lecturer at BBC Academy, Wood Norton...

https://golbornevintageradio.co.uk/foru ... 8#pid98758

What's the panel's opinion? I should say that I know Mark (a bit) and he is the owner of that forum and I'm the other moderator.

[pre65]

I thought I knew about most V8 petrol engines ever manufactured in bulk.

I recently came across an 1100 cu in (18Ltr) all aluminium flat plane crank DOHC 32valve V8 petrol engine from the 1940s.

Seems Ford USA got hold of some RR Merlin drawings and built their own V12 version, but for reasons it was not accepted by USA aircraft manufacturers.

Eventually Ford did a V8 version for use in tanks.

Wiki page.

https://en.wikipedia.org/wiki/Ford_GAA_engine

You tube video.

[simon]

Speaker cable thoughts from Mark Hennessy, 20-odd years as Engineering Lecturer at BBC Academy, Wood Norton...

https://golbornevintageradio.co.uk/foru ... 8#pid98758

What's the panel's opinion? I should say that I know Mark (a bit) and he is the owner of that forum and I'm the other moderator.

Looks like you've got to logged in to read it

[jack]

Speaker cable thoughts from Mark Hennessy, 20-odd years as Engineering Lecturer at BBC Academy, Wood Norton...

https://golbornevintageradio.co.uk/foru ... 8#pid98758

What's the panel's opinion? I should say that I know Mark (a bit) and he is the owner of that forum and I'm the other moderator.

Looks like you've got to logged in to read it

Balls. It's in the "members' section", so yes.

These sorts of threads are always difficult.

Rob clearly believes he is hearing a difference. The trouble is, we don't just hear with our ears. If, based on reading lots of reviews, we spend money on new cables, we will hear a difference.

Expectancy effect is extremely powerful when it comes to audio. And many hi-fi fans are very suggestible. That's why the marketing material implies (very carefully, without actually promising) audio nirvana. That, combined with the reviews, builds expectation. And having spent the money, only the bravest will admit to themselves that they were wrong and there is no difference in what they hear.

The thing is, audio memory is notoriously short. To be able to hear the microscopic differences that might exist between two electrically similar cables, you need an instant switchover. The amount of the time needed to swap the cables over is too long.

it is possible to arrange for this using a relay switchbox. Then, with the help of a patient assistant, you're in a position to start a blind AB comparison that should produce statistically significant results. That means conducting dozens of tests, and correctly identify the new cable most of the time.

But hi-fi enthusiasts never submit themselves to this sort of testing. Partly because it's too technical to set up, partly because they have no interest in the cold, hard truth. Those that do are never able to identify the special cable under investigation. But rather than accept that and learn from it, the usual response is to blame the stress of the test situation. Or claim that the relay box is degrading the sound quality so much that you can no longer identify the subtle qualities of the special cable.

In professional audio circles, this sort of stuff rarely comes up. Audio engineers are far more interested in the subtleties of the recording process. Microphone choice and placement, channel gain, phase, delay, EQ, compressor settings. The dozens of parameters you can adjust on a reverb unit, etc. We are listening for real, identifiable and repeatable changes. Every parameter we can change comes with a bypass switch so you can instantly compare the difference you're making. Why? Because of that thing I said about audio memory being extremely short.

It's a lot of fun to put an audiophile in front of the studio monitors to find out what they really can hear. Of course they struggle because they don't have any training, and don't know what to listen to. But with a bit of help, it's easy to tune into the elements of a mix, and hear right into the recording process. And when you start doing that, you listen the system a lot less. In fact, you find it's surprising what you can hear on really quite modest equipment - and how some very expensive equipment can mask a lot of detail. Price is no indication!

There is a lot of content on YouTube for anyone who wishes to train their hearing to get the best out of their music collection. Forget about hi-fi channels and investigate music production and live sound channels.

Once you've spent a bit of time in the space, you start to understand the numbers a bit better. For example, it's accepted that the smallest change we can reliably hear with a reference is 1dB. Under some circumstances we can hear smaller changes, but under others, we might need a much larger change.

But to keep it simple, let's go with 1dB.

What is that, as a voltage change?

About 10%, give or take. Again, let's keep the numbers simple...

Now, while a change of 1dB is quite hard to detect, a voltage change of 10% is very, very easy to measure. Even the cheapest, nastiest sub-£5 multimeter can do that.

So that gives us a bit of an idea about how poor our ears really are. Of course, that's very simplistic, but there isn't space to get into the wide range of audio tests available. It's worth saying that new tests are being devised all the time, and also the amount of research into the human hearing systems is huge. That's because there's money to be made in better understanding how we hear, because that feeds into improved date-rate reduction systems, and that saves broadcasters money. MPEG, etc, are getting better all the time...

Here's a site I frequently recommend to audio fans:

https://www.npr.org/sections/therecord/2...io-quality

This is a chance to see how well you hear MP3 artefacts. That might seem a bit tangential, but the MP3 process will alter the signal grossly compared to how a speaker cable might. It also gives you a bit of insight into blind testing.

There are a number of short extracts, and you have to listen to them and pick what you believe to be the best version.

For each extract, you have the original file straight off the CD, and two MP3 versions. One of these is at 320 kb/s, and the other is 128 kb/s. You can listen as often as you like before making your choice. And don't feel bad if you pick the 320 MP3 - it's very hard to tell that from the WAV at first. To begin with, just concentrate on separating out the 128 MP3 from the others.

If you refresh the page, the order of the samples are randomised, so that makes the test blind. You need to do it at least a dozen times to be sure you're really hearing what you think you're hearing. If you get lucky at first, have the courage to keep going!

To be fair, they have used a good quality MP3 encoder (it's not just about bit rate and type - a modern MP3 encoder will do a better job than an older one, even if all the settings are the same).

If you find this a difficult test, this might be a better place to start:

https://www.soundonsound.com/techniques/...your-music

The good thing about this article is that it tells you specifically what to listen for. For someone with no studio training, this is really useful. Also they're using a less good MP3 encoder, so it's easier to hear the changes. The files can be downloaded from here:

https://www.soundonsound.com/sound-advic...usic-media

There's also a lot of background into how all this works. It's worth putting the effort into understanding it all. There's far too much ignorance in the hi-fi world, too much reliance on faith. I don't know why. I have many hobbies, and taking the time to learn about them is part of the joy of it - why would anyone be incurious about something that absorbs free time and money?

So that's my challenge to Rob. Rob, you made the initial claim about the cables. So I'm asking you to see how good you are at hearing MP3 artefacts - and to be honest with us and - crucially - yourself about this. You stand to learn a lot about audio from this, and that will increase your enjoyment of your system and music collection. What's not to like?

Of course, you're happy, and we all get that - people are just taking issue here with your claims. Remember, this is a technical forum, so if you make the assertion that a cable is "excellent all round compared to other cables that I've spend 2 and 3 times the price of this cable!" (sic), you need to expect engineers to challenge that. Note, by the way, that I haven't. Instead, I'm trying to educate. Remember what my day job is

[Nick]

I don't have a dog in the race, but there are a couple of things in that post I would point to:

Now, while a change of 1dB is quite hard to detect

It depends on just what sort of 1dB change you are talking about, if its a overall gain change, then yes, it will be hard to notice, but if (for instance) it was a 1dB shelf between 50Hz and 300Hz, and then back down to 0dB above that, I would bet it would be a lot easier to hear.

So I'm asking you to see how good you are at hearing MP3 artifacts

The unsaid assumption there is that MP3 artifacts are equally as audible or inaudible than the change (if any) between speaker cables. That is a claim that would need some proof.

There are some examples out there of reviewers being able to distinguish between cables with results that seem statistically valid. And there are certainly speaker cables that make obvious and repeatable changes to sound, that even in my most skeptical frame of mind find hard to ignore. Also, I would argue strongly that A/B are very flawed when it comes to listening tests, for reasons that are directly related to the way hearing and listening takes place. Just because there may not be a better test available, doesn't mean you have to accept its results are valid by default.

I posted some wav files many years ago of a sine wave with added harmonics. The only difference between them was the phase relation of the fundamental and the harmonics. They were clearly audibly different, but most (not all, I agree, they would look different on a scope) audio test sets would measure them the same.

[andrew Ivimey]

Yeah but ..... zzzzzzz, zzzzzzz, zzzzzzzzzzzx. Unfortunately Life's too short. and.... sub 5quid multimeter - from where!?

Even scientists get bored with .... have their own biases...I'm just about to take a chainsaw to my Tannoys 'cos I don't care any longggggggerrrrrrrrrrrrrrrrr.

Oh and 1dB... in the world I come from 1dB is the place where there is, in any environment, where the patient/ individual can tell the difference between silence and something. As the amplitude increases, I'm sure you will agree, this difference gets more and more difficult to differentiate. Interested? There's plenty more ( that's a pun but as I never understand 'swidt' I don't expect anyone to get 'more' -> Moore as in Brian at Univ.Cambridge -lovely funny chap - he even produced a CD showing different amounts, kinds of sensori neural hearing loss.... but I dont think many people were listening. Its interesting how few people are interested until they have a hearing loss - it's not too late but denial kicks in. The high correlation between hearing loss and dementia is scarey....

[Ray P]

The high correlation between hearing loss and dementia is scarey....

Sorry, what were you saying?

[andrew Ivimey]

Snigger. But no laughing matter.

[Daniel Quinn]

That’s the first time I’ve heard that correlation , is it science based ?