Re: given a choice between the three...
Is it Wikipedia that's changing its articles or its users? It is a wiki.
409 posts • joined 15 Apr 2010
Is it Wikipedia that's changing its articles or its users? It is a wiki.
How can one trust an organisation that we don't who what they do or who they are, the claim to operate within the laws of the land, but where former operatives claim they don't.
Don't we think it's about time the banks started using digital signatures?
DC step down difficult? Potential divider..two resistors..might have to be physically large to handle the high voltage. Not difficult.
If the security services wanted to keep anything quiet, they can. I know of an underground city in the UK which was kept quiet for 50 years, think how many people it took to dig it out, to build everything, yet they kept it quiet? How so? By classifying it at a high level and making people sign the official secrets acts with a 10 year prison sentence hanging over their heads if they discussed it with people that didn't need to know.
Forget any alarms reported by an OTDR system, the cable's been cut entirely in order to put in joints to run feeds off down new cables. If the loss of signal doesn't raise any alarms, or the loss of data transmission doesn't raise any alarms, I'd be very, very surpised.
This article is nonsense: it's objective is to rubbish the theory that sumarine cables can't be intercepted when in situ. But the fact is, fibre cables do get broken and do get repaired by specialist repair ships! It might not be easy but it is certainly done. You have to have a way to do it, you can't re-lay a 500KM cable just because of one tiny break in it.
The integration of 3D graphics processing functions, something which used to take a large circuit board, into a single chip was something that was going to happen, whether NVidia or some other company. It's a natural evolution of technology. The idea that they can patent it and stop other manufacturers from reducing their designs from say a 100 chip solution to a one chip solution is farcical. Might as well tell the entire world wide electronics industry "You can't integrate your logic onto a single chip, you have to stick with your existing architecture comprising multiple chips".
It's an unspecified glitch because they don't want to embarass themselves by describing the human cockup that was made.
First used Xilinx back in 1991, wonderful tech, albeit a bit slow then.
Migration from a logic design implemented on an FPGA to ASIC can require itself a lot of effort, even if you're starting off with behavioural level , technology independent VHDL and synthesis.
You also need to invest a lot of effort in simulations of the ASIC, both functional and ideally fault simulations.
Sounds like a waterfall development approach has been used.
All you need is some coppers reading this who lack a sense of humour, they'll be round on your doorstep next week to raid you and question you on your claims to commit mass murder of our illustrious elected officials.
You just know that in the Stalinist state we are heading towards, you just know it could happen.
I was involved in funding the Judicial Review which took place for IR35, a number of years ago.
Firstly, funding it was expensive, secondly, one of the defendant's (the government) arguments was that it's not for a Court of Law to overturn primary legislation, that's the job of Parliament.
Not sure how much consideration the judge gave to that defence, possibly some, possibly and quite likely a lot. During the week of court hearings some positive things went in our (the public's) favour, some went in favour of the government, but we didn't really have any clear sense of which way the case was going until after the hearings had been heard, But somehow, it seemed hard to imagine that the judge would rule in favour of Joe Public. He didn't. Anyway we know what happened with IR35, it was never repealed.
It will be interesting to see what happens if MP's challenge the law by way of a judicial review, do they stand a better chance at getting it repealed than the general public?
Moving the IT bods up north or out to India?
I read the judgement of the related ECJ on this matter. I don't think for one moment the MP's have read the ECJ judgement and I do not think they understand what this new law is really about and the true scope of it. It's not just a time extension to the data retention time imposed on telco's; it is far more than that.
This new law - from my non-expert unqualified reading of the ECJ judgment is illegal!
The 1995 EU directive places at its heart the idea of privacy, and that what is stored must be proportionate and the minimum necessary.
The UK government has created a definition of a telcom's communication service which is all encompassing, covering just about every traffic type you can imagine.
They have deliberately misused the ECJ ruling and created an artificial sense of urgency to enable them to create a new law and push it through rapidly without the proper scrutiny and has enabled them to create a new law (soon to be passed on to the statute) which is far more wide reaching - and I would question is illegal - than is require, than is reasonable.
Actually the ECJ ruling actually states the original 1995 EC directive (which has been incorporated into UK RIPA and Data Protection Legislation) is too far reaching and doesn't recognise the privacy of individuals and their right to a private life. Only the minimum amount of data should be stored.
There's reasonable and there's excessive retention.
I think it means this:
A company located in a different country providing a telecoms service to people within the UK, and that telecoms service includes, email, instant chat, webmail, peer to peer, basically anything! - then various methods can be used to issue the warrant for interception, perhaps email for example.
It gives the government the power to monitor any form of communication either in the country or where traffic is coming in or out of the country. It's as far reaching as it gets.
No, it's not about the removal of links per se, it's about the removal of personal data (or links to that personal data). The case was brought under an EU privacy/data protection directive in year 1995, It's about individuals being able to request the removal of their own personal data.
Evidently Google have created an automated system to delist (whatever you want to call and how it is achieved, is the removal of links to the site from the search results) to enable links to be removed, believing this complies with the ECJ ruling.
But it should only be the individual themselves which are the subject of the personal data (in this Peston) that should be able to request the delist/deletion of the data, but that requires an authentication mechanism to verify the person requesting the delist really is the subject of the data.
Such an authentication mechanism is not likely to be implemented easily in an automatic form. That's the problem. How do you verify that the user requesting the removal of the data really is the subject of the data.
Google have gone for an automatic deletion, in the expection (rightly so) that they wil receive lots of personal data deletion requests and I'm not convinced they have implemented what the ECJ court requires.
The problem is, I suspect, the ECJ judges aren't technical experts (few judges are!) and they haven't really understood the implications of their decision.
The principle underlying the deletion of data is that of an individual requesting a company to delete personal data that the company holds on them. This is covered by a European directive of 1995 which I think has been enshrined in Data Protection Legislation in the UK.
The data is personal data held by the company on person A. Person A should be the only party that can request the deletion of the data. Some other random individual or organisation, party B should not be able to request the deletion of data to party A.
The only person that should be able to request and achieve the deletion of the data is Peston himself, not O'Neal and not anyone else.
I agree with you in relation to Data Protection Act, I don't think it even applies here.
Data protection act is about companies keeping private information on you and the terms under which they are allowed to do so.
But having researched a little, this court action is based on an EU directive in 1995 specifying privacy rules and data protection. As I understand it, (and I'm not an expert), EU member states have to enshrine in their own country legislation those EU directives.
I wonder if UK data protection legislation does include it?
The EU rule is to do with a company deleting personal data at the request of the individual. That seems fair and reasonable, we should be able to request a private company to delete data they hold on us, but this rule shouldn't really apply to Google, they're not actually holding the data, they're linking to it and it's held in the system of another company.
The European Court of Justice disagreed.
I can't believe the EC directive of 1995 ( or any other) forces a company to retain personal information if it is in the public interest to do do. This introduces a whole new can of worms, who decides if it is in the public interest? Google? And what if their view on a particular piece of data is different to a court of law?
The concept of being 'in the public interest' applies to organisations with the power to prosecute, such as the crown prosecution service, where they have the ability to make a decision to prosecute and the criteria for doing so is "in the public interest", but in the now case of Google, to have two parties making the determination of whether the data held is in the public interest or not, Google and the ECJ (or another court), gives rise to a difference of opinion and Google risk being prosecuted for every breach in the future where it has made a determination which is in opposition to a court of law. It's a farce.
How does a company resolve such a matter and prevent it self from being prosecuted? Is it to have every decision it is thinking of making in relation to the deletion of data reviewed by the ECJ or some other court first, so that it can then make the same decision and prevent a prosecution from occurring?
It's not practical. And I don't think the ECJ has this particularly well thought out.
The fundamental issue in this I feel is that of the actual companies publishing the personal data in the first place. If an individual doesn't want their old historic data to be viewed, they need to go to the companies and their websites which are the publishers of the data and not Google and request deletion of the data, issue take down notices.
If that were to be enforced, the legal mechanisms put in place to allow that to happen (not saying it's easy with the original information can be distributed across web servers in different countries and there then becomes a problem of jurasdiction) then these conflicts about data being in the public interest and courts of law trying to dictate to private companies what data they should retain go away.
I can't see how any law can specify that an internet search provider has to provide links or not provide links to other sites.
I can accept the BBC has a public interest obligation, and therefore have to provide educational articles and undertake certain activities: they're funded by the tax payer!
"I am the government and YOU WILL provide links to my pages on the Taxation".
DSPs in speakers are doing two things:
1) Making up for poor analogue design
2) Attempting to correct for the buggering up of the frequency response of the system caused by room acoustics.
I have some sympathy for 2 because not everyone can accoustically treat their rooms. But 1, do the job the right!
Similar things have been said to me by colleagues in the recording business, that the speakers used in studio setups are not suited to home use because speakers for use in a studio have different design goals, to have a totally flat response, to show every thing wrong with the sound so it can be corrected by the studio engineer.
I eventually opted at home for some active monitors from Dynaudio, and have found very, very little that can beat them. And I can listen for many hours at a time, and they compare to a separate amp and speaker configuration of home hi-fi costing many times more.
They are revealling, very revealing and if the original source CD hasn't been mixed very well they do show it up.
A classic example of this is an album by Garbage called 'Garbage' is just that, it's garbage.
The quality of recording and mixing is terrible.
But fortunately, few albums are this poorly produced, and whilst one or two may p**ss me off, on the whole, the very revealing nature of those monitors does give a greatly increased pleasure to the listening experience of much of the music I have.
An album by Tori Amos, with a conventional consumer grade equipment hi-fi, I wasn't particularly keen on her, play her album Under the Pink through my active monitors andy my opinion changed, and ever squeek of every piano key can be heard, the short intakes of breath heard, the detail that's there on the original recording will blow you away.
So, I think you can do a home setup with studio monitors, if you select the right studio monitors.
If you sample, such as what happens with D to A conversion, then you always get aliasing taking place, (if we're talking about the same kind of aliasing!). Increasing the sampling rate, results in those images being more greatly spaced out in frequency, allowing for anti-aliasing low pass filters to be made of lower order, = fewer components and cheaper cost.
What's more important is the stability of the clock in the system, feeding data to the DAC's as this will effect the linearity of the output.
It's not just about timing, it's also about amplitude.
When a sound source is in front of you, not only do yuo get a small timing difference as the wavefronts of the sound hit your ears, but the amplitude is slightly different too.
As someone that's gone down the professional equipment route, using active monitors, I have to agree with you DaemonProcess.
Why can we have a sine wave of a finite number of cycles then?
Yeah, did that fourier analysis of a square wave at university, and various other waveforms, going through the maths and the integration.
I'm using the word 'active' in in the way professional audio manufacturers use it.That is: mains power input, balanced (differential) analogue audio input, power amplifier, cross over and speaker drivers all contained in the same unit. Crossover filters comprising active filter circuits using operational amplifiers.
You may call it powered, but it's both powered and active.
Cell phones which don't yield their own number. Must be O2 network then.
They're the only carrier I've come across so far where you can't use the phone to interrogate the network to find out the phone number (phone number is held on the network not in the SIM or phone).
Cue my little problem a little while ago: was sent a phone and SIM on O2. But SIM hadn't been properly activated, emergency calls only. Couldn't dial a number to call someone for them to give me the number from the CLI. Couldn't look up the phone number because O2 network doesn't provide that facility.
Tried to get it resolved (not using O2 but via someone else, long story to go into):
they wanted the mobile phone number in order to resolve it! Duh!
Gave them SIM serial, IMEI, IMSI number (now f**ng go look up the mobile num from the IMSI number please!).
Two weeks to resolve...couldn't make this s*t up.
The issue is, there are armchair engineers out there, then there are proper degree qualified electronic engineers that have spent three or four years studying this subject (along with a load of other stuff) at university, that understand the concepts of: frequency response, phase response, impulse response, Fourier analysis. The author is the latter, quite evidently so. Some people on this forum are the former, clearly so.
That's not a criticism of the former, but they need to know which category in which they reside, and be able to recognise which posters on this forum fall into the latter category.
Knowing a little about frequency response and 3db points and 6db per octave cut-offs doesn't make you a qualified electronics engineer.
Rubbish. To recreate a perfect square wave does require an infinite frequency response.
We have function generators which generate square waves, which are an important piece of test equipment, Sure, there is capacitance in the cables, capacitance in the load to which the function generator connects, and as a consequence, the square wave isn't an 'ideal' perfect square wave, but that doesn't actually matter. The less than perfect square wave is still extensively used and with good reason.
You seem to be adopting the attitude of "It's not a perfect square wave so it's useless". I don't honestly think you've even done any electronics experimentation at all with function generators, audio equipment at all.
Do you understand what a square wave is, and how to do a Fourier analysis (by hand on paper) on it? I'm not convinced you do. I'm not convinced you understand the importance of square waves and how and why they are used.
Dave, you are correct.
Audio design engineers with whom I have worked, very much do concentrate on timing, as well as frequency response. But they were not desigining speakers, they were designing mixing consoles with all the analogue (and digital) electronics in that, from active filtering using literally hundreds of operational amplifiers and many different types of active filtering circuits.
I haven't worked for any speaker manfacturers, so I can only assume the author is right when he says speaker manufacturers are not focussing on the timing.
But from discussions I had with colleagues (design engineers and recording studio engineers), there is something missing from all the specifications of audio systems, two systems can look the same on paper, in frequency response, in phase response, but yet still sound different. Generally speaking, our system of measurement, what we are measuring is incomplete.
>How likely is it that group/phase delay passes through unchanged at all these points ? Only if all >these components have zero group/phase delay is it worth redesigning your loudspeaker crossover >unit, and even them only if you think that the effect is gross enough to be audible.
First point: manufacturers of equipment (and certainly output stages of DACs) go to great lengths to design an active filter of high order, which buggers up the phase of the frequencies, and correct those phase errors using other types of active filter circuits. I know, because I've seen the circuit diagrams and spoke to the analogue design engineers undertaking the design.
Second point: You're making the assertion that because a system may not be of zero group delay up to the speakers that you don't need to design the speaker elements for minimal group delay. It's a flawed way of thinking. What matters is the total group delay of the entire system and if minimising it only in the speakers helps reduce the total delay for the system, then that's a good thing.
And by the way, from ex-recording turned electronic audio design engineers with whom I have worked, the author is entirely correct in his analysis.
No, I think you're jumping to the wrong conclusion about what you think the author believes.
He clearly is focussing on time delay has being a very important consideration, but that does not mean he believes that nothing else is important.
He does mention in the article about how the brain processes frequencies after the brain processes the transient information.
There is no doubt (without doing any research into his background), he's an electronics engineer, and being a fellow of the audio engineering society, I am highly confident he does understand about frequency spectrums, the representation of signals in both time and frequency domains and the transformation from one to the other.
I think he is focussing on one key aspect of audio design which is vitally important which he perceives (and possibly rightly so) is present in amplifier, filter design but which is missing from the last element of the chain in speaker design.
But this doesn't mean he doesn't understand that frequency response isn't important. I'm highly confident he does know it is.
I grew up in the era of CDs, the 1980's. Lossless compressed music came about as a result of the internet as download speeds were relatively low (by today's standards).
The youth of today has rarely heard uncompressed music fed through a decent sound system.
Some years later, after graduation from university I spent a small spell working in a company which made large format mixing consoles used in recording studios and there I learned what music is!
We had a couple of demo rooms in which we could demo the equipment to our customers (including some big name artists but more often demo'd to studios).
I got off the bandwagon which I had been on since a teenager, repeatedly upgrading hif-fi, replacing individual units, I went out and bought a pair of active speakers, - professional grade for use in studios- with XLR balanced inputs. I bought the best. I don't need to upgrade (unless I get a bigger house and have a much bigger room).
You don't need to spend a huge amount of money, you just need to know what you are doing.
And key to that, is having heard a very high quality sound and getting used to it, hearing it every day, that then becomes your reference level of sound quality which you then use for comparison when you go out shopping for speakers and equipment.
Prior to that 're-education', my reference level was the existing hi-fi I had, and I was comparing prospective purchases with that as the reference. That resulted in incremental steps up each time.
I met one guy (the salesman) in a well known upscale audio shop who said to me upon hearing what I had purchased "They're the cheaper ones", implying that they can't sound particulary good because they weren't £6K ! Little did he know.
Don't assume that because it's expensive it must sound good. Don't assume that you need to spend £10K on speakers and amp to get anything decent.
Once bought some line level phono-to-phono cables a metre long costing £200. Then I started doing some experimentation using cables of the type used in studios, with cables purchased from the same vendor the studios used, the end result? I made my own interconnect cables (not exactly rocket science if you can solder!), which sounded equally good for something like £20, with the gold plated phono connectors costing way more than the cable itself! But I guess that company had to make a living.
But that's where the marketing BS comes in, sell the cables for £30 and people won't buy them, too cheap you see, they can't be any good.
I presume the capacitor is being used as an anti-alias filter? So all you've got here is a single order 20db per decade roll off filter. Depending on the sampling rate of the DAC, it doesn't have a high enough cut-off rate to deal with the images higher up in frequency, (the image spacing in frequency is determined by the sampling rate). I'm sure it would work, but it perhaps wouldn't sound too good.
The THD on decent audio quality op. amps such as the NE5534 is considerably lower than 1%. It seems that when we get to the power amps that we allow THD levels to increase.
I think this shows a failure to understand the definition of the word digital. The class D amplifier does not contain any digitial electronics and it does not represent information or signals using numbers.
The class D amplifier contains only analogue electronic devices. There isn't a logic gate, a flipflop in sight.
But then that is not an amplifier! That's a high current output DAC.
It's a solution which obviates the need for an amplifier. But I go back to my original statement. An amplfier is an analogue circuit. It is. It has to be. An amplifier takes an analogue current or voltage and makes it bigger ( a simple class A amplifier with a simple transistor *is* an analogue circuit. There's nothing digital about it).
It's akin to saying "digital aerial for FreeView". It's not a digitial aerial, it's an analogue aerial.
You obviously haven't worked in a recording studio. If you listen to music with all the equalisation being flat, the sound sounds pretty awful. Some equilisation *is* necessary.
Within a few lines of reading the article it became clear to me that the author is a professional engineer, almost certainly educated to degree level in Electronics I would suggest. I have spent a short period of my career working for a very well known professional audio company designing and building mixing consoles sold to very famous recording studios around the world (including the likes of Abbey Road, Air Lyndhurst, LucasFilm). Trust me, he knows exactly what he is talking about, and his conclusion that time delay is a key factor is absolutely correct.
But you can't design an audio system to handle only odd harmonics or even harmonics! Or have notably better performance on one or the other.
So what do you use as a baseline during design if not a square wave? That is, if you create a design, test it, and then set about improving that design, and then re test it? How do you know if you have improved your design? You need a reference set of signals to apply to your design, measure the output, modify, re test with the same set of reference input signals. You have to use some sort of standard input signal which you can re-apply in order to determine if you have actually improved your design. That's where square waves come in (and frequency swept sine waves).
Your statement that square waves are F** all use is incorrect.
Valve amplifier = analogue. Digital amplifer? Never heard of a digital amplifier. Amps have to be analogue.
If you buy active speakers, then the problem goes away!
I have a pair of Dynaudio accoustics professional active speakers, all analogue, and I can assure you, even at your age, you *would* hear the difference. The industry rips people off with incredibly expensive consumer range speakers and amplifiers and Joe Public is lead to believe they need to spend £10K on a good system.
Most people haven't got a club what decent sounds sounds like, and it doesn't have to cost the earth, you just need to know what you're doing.