Don't Believe Everything They Tell You

[Macca]

Good article, this: http://lampizator.eu/HERESY/heresy.html

[walpurgis]

I like that.

The bit about "stiff" speaker cabinets reminded me of a pair of remarkable sounding speakers I heard donkeys years ago. They were about three feet tall and made merely of hardboard, each sealed box containing a single largish vintage elliptical 'radiogram' type speaker, the type everybody used to sling in the bin, but are now becoming rather sought after.

Said speakers were surprisingly good at reproducing natural sounding music and even had a decent helping of clean bass. Goes to show, there are no rules!





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[Barry]

I would concur with most of what is written there – but the author is not free from personal prejudices: witness his throw-way remark in the first Heresy: “…and in non hi-fi units – the base of a transistor…”.

However there are a couple of errors in his debunking of commonly held audio beliefs. The first is again contained in the first “Heresy”, and is the error that “the whole circuit will respond instantly”. It cannot respond instantly: the response time is determined by the size of the circuit and the speed of light. Furthermore the signal passing through the circuit does not consist of a pure sine wave - it is a complex wave packet consisting of a mixture frequency components. And owing to the dispersive nature of the circuit, the various frequency components will propagate at slightly different velocities and so the shape the wave packet will distort. The delay experienced by the centre of the wave packet as it passes through the circuit is called the group delay, and for audio amplifiers is typically ~ 5ns. There will also be a group delay error, a measure of the differential delay experienced by the individual frequency components within the wave packet signal. Typically, the group delay error is ~ 1ns. Both negligible and totally inaudible, but not zero.

In Heresy 2, the author states that preamplifiers don’t amplify and uses the example of the output from a CD player. Yes true for that particular source, but obviously not so for pick-up cartridges! (This perhaps reveals another personal prejudice of the author.)

In Heresy 5, the author claims the Fourier spectrum of a square wave consist of even order components only. Wrong - the Fourier spectrum for a symmetrical square wave consists of odd-order components only. Admittedly this is probably a typo, but when one is being so dogmatic, it is best to proof read before publishing.

[jandl100]

I like that.

The bit about "stiff" speaker cabinets reminded me of a pair of remarkable sounding speakers I heard donkeys years ago. They were about three feet tall and made merely of hardboard, each sealed box containing a single largish vintage elliptical 'radiogram' type speaker, the type everybody used to sling in the bin, but are now becoming rather sought after.

Said speakers were surprisingly good at reproducing natural sounding music and even had a decent helping of clean bass. Goes to show, there are no rules!





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I recall a pair of speakers at a London hifi show, oooh must be 25+ years ago, from a cottage industry Italian maker.
Cabinets were made entirely of balsa wood of all things. I can't recall what type of driver(s).
One of the most wonderfully natural midrange presentations I have ever heard.

[southall-1998]

I'm no qualified electronics engineer. But I think his mods on most CD Players presents bullshit.

Most of those CD Players should be left well alone!!

He's just another arrogant idiot to my eyes.

S.

[Pharos]

Some of it is right, he nearly conceptualises things clearly, but his English is poor to the extent that it either exposes or masks his thinking processes.

[sq225917]

I think he's able to extract better sound from a lot of the things he mods. if valves and euphony are your flavours of course.

[jandl100]

Lampi has a clever marketing model, really quite similar to Naim.
From what I have seen, folks invest in a lower cost model and then get trapped into an upward cost spiral of upgrading.

[sq225917]

He's right about spikes, the rest of it is totally open to POV analysis. Remember it's just a sales document.

[Spectral Morn]

My experience with spikes under things like CD players, pre-amps and power-amps is that they do change the sound and improve it, but this will vary depending on where they are placed and also what material they are made from. I do think this has got something to do with vibration but not isolation, probably more like they act as a vibration drain or they effect resonances in the case work.

To dismiss spikes and by default I assume cones etc is shallow. Others mileage and views will vary.

[RothwellAudio]

I've been saying for years that "the signal path" is a myth, but most people think I'm talking rubbish so I've stopped bothering now. People believe what they want to believe and telling them they're wrong just annoys them, so why do it?

[sq225917]

My experience with spikes under things like CD players, pre-amps and power-amps is that they do change the sound and improve it, but this will vary depending on where they are placed and also what material they are made from. I do think this has got something to do with vibration but not isolation, probably more like they act as a vibration drain or they effect resonances in the case work.

To dismiss spikes and by default I assume cones etc is shallow. Others mileage and views will vary.

Maybe I read it wrong, he's not dismissing them, he just said they don't isolate, which they don't, they couple.

Some people have these crazy ideas that spikes have some diodic effect, they don't. They pass vibration equally in either direction.

[Barry]

Maybe I read it wrong, he's not dismissing them, he just said they don't isolate, which they don't, they couple.

Some people have these crazy ideas that spikes have some diodic effect, they don't. They pass vibration equally in either direction.

I was discussing this with a mechanical engineer some years ago, who at the time made the curious statement that you can't transmit vibrations through a point.

But then neither do I believe the acoustic pressure from a speaker driver can cause the dead weight of the speaker to rock, or move, on a 'spongy' carpet. I haven't done the calculations however.

[Macca]

But then neither do I believe the acoustic pressure from a speaker driver can cause the dead weight of the speaker to rock, or move, on a 'spongy' carpet. I haven't done the calculations however.

Yes, I've always thought that was an odd claim. Seems to me that the speaker would need to be very light for the motion of the drivers to make it move even minutely.

[Arkless Electronics]

I've been saying for years that "the signal path" is a myth, but most people think I'm talking rubbish so I've stopped bothering now. People believe what they want to believe and telling them they're wrong just annoys them, so why do it?

Because the truth must out! No matter how much it pisses off the people who are wrong... Galileo didn't give up just 'cos everyone else thought the earth was flat!!

[Joe]

Because the truth must out! No matter how much it pisses off the people who are wrong... Galileo didn't give up just 'cos everyone else thought the earth was flat!!

I don't think that Galileo was claiming the earth was round, which was pretty well accepted knowledge at the time. What got him (and others) into trouble was claiming that the earth revolved around the sun, rather than vice-versa. I can imagine the subjectivists of the time saying 'I don't care what Galileo says, my eyes tell me that the sun goes round the earth. These scientists don't know everything'.

[anthonyTD]

I think the main issue is that the term; "Signal path" means diffrent things to diffrent people!
Because the truth must out! No matter how much it pisses off the people who are wrong... Galileo didn't give up just 'cos everyone else thought the earth was flat!!

[Arkless Electronics]

I don't think that Galileo was claiming the earth was round, which was pretty well accepted knowledge at the time. What got him (and others) into trouble was claiming that the earth revolved around the sun, rather than vice-versa. I can imagine the subjectivists of the time saying 'I don't care what Galileo says, my eyes tell me that the sun goes round the earth. These scientists don't know everything'.

Ah yes that it's:)

[sq225917]

I was discussing this with a mechanical engineer some years ago, who at the time made the curious statement that you can't transmit vibrations through a point.

But then neither do I believe the acoustic pressure from a speaker driver can cause the dead weight of the speaker to rock, or move, on a 'spongy' carpet. I haven't done the calculations however.

He was a real engineer? That's a really stupid statement, without qualification.

I can't imagine any speaker other than big panels with high excursion, and sloppy framed Quads where instability caused by driver movement would ever be an issue. ( or even measurable)

[swampy]

I've been saying for years that "the signal path" is a myth, but most people think I'm talking rubbish so I've stopped bothering now. People believe what they want to believe and telling them they're wrong just annoys them, so why do it?

Signal paths are taught in electronics since it helps to understand a circuit, that is all. The same is for synth programming for eg. Start at the oscillator and the signal passes to the filter etc, etc. Its the same for many engineering or science points. i.e. we think of electrons as point particles that orbit a nucleus but really they are a 'cloud'. We simplify concepts for our minds that's all. I think some points in the article are just nit picky re use of language and terminology but some are sound.

[Pharos]

I have a link to an article on spikes which asks how they can decouple, given that in running shoes they do the opposite, and also that nails are used to fix things - DC coupling in effect.

My ADAMs have their own spikes, which no doubt do stop rocking, but I am concerned that they may conduct vibration through the floorboards.

[sq225917]

His bit on silicon only being a semi conductor is also crap. Yeh, sure it's a semi conductor, and obviously integrated circuits are no good, that's why lighter, smaller, faster, more accurate and stable silicon computer chips failed so badly at replacing valve based computers. Oh. Hang on a minute.....