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Old 12th Jul 2020, 7:05 pm   #1641
GrimJosef
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Default Re: The Audiophoolery Thread.

With serious engineering effort professional speaker makers have done a fair bit better than 2%. My Yamaha NS1000s, which show what a really big corporation is capable of when it is prepared to throw enormous amounts of money at a problem, got second and third harmonics down into the 0.1% regime above 500Hz and were still only 0.3% at 100Hz (measurements taken at 90dB at 1m). The intermodulation distortion wasn't significantly higher. Not bad for 1970's technology ! Among other things the production of the beryllium domes for the mid-range driver and the tweeter made the speakers uneconomic though, and Yamaha eventually threw in the towel on them for business reasons.

Cheers,

GJ
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Old 12th Jul 2020, 7:59 pm   #1642
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Default Re: The Audiophoolery Thread.

I like Craig's suggested esoteric woods, and I really think meteorite iron is under-used in high-end audio.

We could confabulate and concoct some truly special cables., speaker magnets and whatnot. Where we would fail is in concocting the reassuring language needed to go along with them. Either our consciences would kick in, or we'd just die of laughing. It's a bit like that Monty Python sketch about that joke which was fatally funny.

I got as far as typing 'Acoustic textures' and then I needed a wee rest in a quiet room.

David
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Old 12th Jul 2020, 10:58 pm   #1643
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Default Re: The Audiophoolery Thread.

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Originally Posted by GrimJosef View Post
With serious engineering effort professional speaker makers have done a fair bit better than 2%. My Yamaha NS1000s, which show what a really big corporation is capable of when it is prepared to throw enormous amounts of money at a problem, got second and third harmonics down into the 0.1% regime above 500Hz and were still only 0.3% at 100Hz (measurements taken at 90dB at 1m). The intermodulation distortion wasn't significantly higher. Not bad for 1970's technology ! Among other things the production of the beryllium domes for the mid-range driver and the tweeter made the speakers uneconomic though, and Yamaha eventually threw in the towel on them for business reasons.

Cheers,

GJ
Sine wave harmonic distortion at 90dB (so around 1W input power at a single frequency) is a very small window into a loudspeaker's overall performance.

As soon as you use multiple tones you get doppler distortion, and with typical music delayed compression as a result of the voice coil heating up.

With healthy levels of music, at sustained higher levels the voice coil of a driver can get way above 100C. At 0.4%/C the voice coil can be 40% higher resistance, and get 3dB quieter.

That is before you start on the more esoteric distortion mechanisms which play a role in all moving coil loudspeaker drivers:

https://www.klippel.de/know-how/literature/papers.html

The thermal compression paper alone is enough to give a headache

https://www.klippel.de/fileadmin/kli...ransfer_03.pdf

Klippel's software suite is what most driver manufacturers use to optimize the performance of their units

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Old 12th Jul 2020, 11:10 pm   #1644
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Default Re: The Audiophoolery Thread.

There is also an excellent series of pages with chapter and verse on distortion mechanisms in loudspeaker drivers by Siegfried Linkwitz (RIP) here https://www.linkwitzlab.com/frontiers.htm

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Old 13th Jul 2020, 8:21 am   #1645
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Default Re: The Audiophoolery Thread.

Good info Craig, thanks.
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Old 13th Jul 2020, 9:18 am   #1646
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Default Re: The Audiophoolery Thread.

This is an interesting test on Klippel's site for audibility of distortion using real music. It is a randomised trial, and comes up with an audibility threshold.

http://www.klippel.de/listeningtest/

I did the test with a short section of Tracy Chapman (which I know) and just used the tiny and somewhat ancient Boston speakers driven from my PC with unknown distortion in themselves. My threshold in these pretty uncontrolled conditions was -36dB, or 1.5%. That apparently, of 14,000 submitted tests 13dB below the mean.

There were some whose threshold was -54dB or 0.2%. I must try it out on my main system and see what I get.

Basically it shows that audibility of harmonic distortion is not low. So sub ppm distortion in modern op amps like the LM4562 is many orders of magnitude below audibility.

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Old 15th Jul 2020, 10:32 pm   #1647
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Default Re: The Audiophoolery Thread.

ATC are regarded as being too analytical and revealing by many 'phools. They are one of the few OEMs to give a THD spec on some models. It is <0.3% - but I cannot remember frequency and amplitude. I cannot think of any cleaner sounding monitor. The best cart I have personally measured achieved 0.4 at 1KHz. But I am not sure how much of this was inherent in the groove. I can say that with the same preamp and test record, lower end MM carts often measure around 2% - and there are lots of upper order harmonics - a pretty FFT it ain't.
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Old 16th Jul 2020, 11:43 am   #1648
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Default Re: The Audiophoolery Thread.

Even just considering tracking distortion (arising from the error in tracking angle when not at one of the null points) is around 0.6% towards the inner grooves. That is kind of constant for Baerwald, Lofgren or Stevenson alignments. Parallel tracking arms get around that particular distortion mechanism, but at an eye-popping price.

There are of course other distortion mechanisms on top of that.

It is a miracle that scraping a tiny piece of gemstone across a disc of deformable plastic works at all, let along sound superb (when working correctly). It can also sound like a bag of hammers being rattled when something is not right!

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Old 16th Jul 2020, 1:52 pm   #1649
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Default Re: The Audiophoolery Thread.

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ATC are regarded as being too analytical and revealing by many 'phools.
It's pure irony isn't it when these guys are seeking to eek the last drop of micro information from a source, and they slate a component in the chain as being too analytical and revealing?!
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Old 16th Jul 2020, 2:13 pm   #1650
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Default Re: The Audiophoolery Thread.

Well, some of them are. Others want to make the music sound the way they like it to sound. Yet others feel that since stereo is a huge illusion anyway, to which there is a range of different responses, they need to set things up in the best way to trick their particular brain into recreating a 3-dimensional sound field, when all it's got to work with is a 1-dimensional (two points define a straight line) source.

Folks who don't spend time in the company of music fans are sometimes surprised at how diverse they are. There are some who are very focused on technical accuracy. There are others who have a clear view (not always correct, perhaps, but clear nonetheless) of how the music actually sounded live. There are others who are keen to experiment with all sorts of 'effects' and gizmos. These sub-groups, and others too, regard one another more critically than we regard them.

Cheers,

GJ
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Old 17th Jul 2020, 6:19 pm   #1651
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Default Re: The Audiophoolery Thread.

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Originally Posted by Radio Wrangler View Post
It seems that having any sense of proportion is an absolute impediment to anyone becoming an audiophile.

Heisenberg gets involved, too. They can clearly hear things that theoretically might be there even when they are not. They must span multiple universes.

David
I just think a lack of cash is the real problem!
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Old 4th Aug 2020, 9:37 am   #1652
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Default Re: The Audiophoolery Thread.

I've bought new hifi speakers and out of interest, and against my better judgement, I've just been looking at an audiophile forum to see the views of others. Never have I witnessed such a self identifying bunch of non-musical, non-technical, cerebrally deaf, full of audiophoolery catch phrases, bunch of phools in my life. One of the biggest things seems to be this infatuation with an amp having to 'match' a pair of speakers. Ok, basics aside like speaker impedance vs amp current capability, speaker sensitivity vs amp power capability (those are basic and a given) then what rubbish those guys talk about in terms of amps and speakers having to match. I mean, a 'bright' sounding amp needing to be paired with 'dark' speakers? most, even half decent amps have very straight frequency response curves so it's plain ridiculous. Also, if there wasn't this 'garlic to a vampire' attitude towards amps with tone controls, then many speaker and or room anomalies could at least be improved with a tad of judicious EQing. But of course, the great god 'signal' must be as pure as a mountain stream, and passing through tone controls will destroy valuable fidelity.. The fact that the signal has already passed through many and various forms of tone controls, graphic equalisers, compressors, limiters, noise reduction circuits, distorted valve amps etc etc is lost on them. And of course, no two studios have the same playback system and room acoustics, let alone the tonal and balance preference of those who mixed down the recording. So, each and every recording has a different sounding mix in terms of them being bright or dark, lacking in deep bass, whatever. What would go a long way towards sorting that out? tone controls. Most hifi speakers start to droop below, I dunno, say 100Hz. So personally, I always use a tad of bass boost to lift the low end response of the system in order for the bass to be heard as it was in the studio that had those massive monitors with their ground shaking low end capabilities. No tone controls? then you're stuck with a system that is always at the mercy of the recording studio in which a given recording was made, or the choices of the broadcaster in the case of radio.
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Old 4th Aug 2020, 9:57 am   #1653
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Default Re: The Audiophoolery Thread.

With my Dr Evil hat on, Steve, I see it as an opportunity.

I could bring out a range of amplifiers of graded frequency responses from those with an amount of HF roll-off to those with some lift. Same at the bass end, and the possibilities for ripples in the midrange are endless.

They would have no tone controls, and thereby tick that most essential box. Inside there could be no overt response shaping circuitry, it would have to be covert, done by careful choice of component values, and choice of componets to use strays.

Audiophiles could now buy amplifiers with many different types of frequency response and could while away their years working through the full lot to decide what best fits the rest of their equipment.

The replacement of equipment IS the audiophile's tone control.

I'll be rich!

David
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Old 4th Aug 2020, 10:09 am   #1654
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Default Re: The Audiophoolery Thread.

I have seen them make all that fuss and include a photo with one speaker next to a brick wall and the other by a door way.
I was once asked to fix a frequency response problem and duly sent the guy off to his HiFi dealer for a set of caps for the cross overs.
After "fixing" it I had to physically swap the speakers over to prove it was the room that was causing the problem.
This time the speakers were by a doorway and in a corner.
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Old 4th Aug 2020, 11:12 am   #1655
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Default Re: The Audiophoolery Thread.

I feel rather sorry for the uninformed but genuinely interested in better audio reproduction who end up resorting to reading through such hi-fi comics- a long time ago, there would have been genuinely useful and cost-effective advice to sift through, now they are just another arm of the all-pervading "conspicuous consumption through social intimidation" marketing strategy- and it has plenty of "useful lackeys".
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Old 4th Aug 2020, 12:07 pm   #1656
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Default Re: The Audiophoolery Thread.

Quote:
Originally Posted by GrimJosef View Post
Well, some of them are. Others want to make the music sound the way they like it to sound. Yet others feel that since stereo is a huge illusion anyway, to which there is a range of different responses, they need to set things up in the best way to trick their particular brain into recreating a 3-dimensional sound field, when all it's got to work with is a 1-dimensional (two points define a straight line) source.

Folks who don't spend time in the company of music fans are sometimes surprised at how diverse they are. There are some who are very focused on technical accuracy. There are others who have a clear view (not always correct, perhaps, but clear nonetheless) of how the music actually sounded live. There are others who are keen to experiment with all sorts of 'effects' and gizmos. These sub-groups, and others too, regard one another more critically than we regard them.

Cheers,

GJ
I think this is a fair assessment. I would add that it's not necessary to know about the science of nutrition or the chemistry involved in cooking to have tremendous fun preparing and eating your dinner. Many audio enthusiasts are similarly blind to the science but are having fun. If anything irks me it is when those folk who know little or nothing of science or electronics start using technical language to explain whats going on, that's overstepping the mark in my world!

Steve.

Steve.
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Old 4th Aug 2020, 12:33 pm   #1657
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Default Re: The Audiophoolery Thread.

Quote:
I've bought new hifi speakers and out of interest, and against my better judgement, I've just been looking at an audiophile forum to see the views of others. Never have I witnessed such a self identifying bunch of non-musical, non-technical, cerebrally deaf, full of audiophoolery catch phrases, bunch of phools in my life.

Oh dear Steve, your re-education is going to prove a challenge....


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Old 4th Aug 2020, 1:00 pm   #1658
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Default Re: The Audiophoolery Thread.

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I've bought new hifi speakers and out of interest, and against my better judgement, I've just been looking at an audiophile forum to see the views of others.
Well, come on then, what are they? Let us know so we can take the mickey!

I'll start with:

- Ooh, I wouldn't have bought them if I were you.
- They won't match your amplifier.
- Your cables aren't good enough for them/are too good for them
- They're too small/too big/the wrong colour for your room

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Old 4th Aug 2020, 1:05 pm   #1659
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Default Re: The Audiophoolery Thread.

Stuck in an airport, wandering around, looking at a magazine rack, amongst all the other interests, there are hifi magazines.

Do I buy one?

If I did, would it make me feel smugly happy that I could see through all the verbose crap? Or would it make me feel saddened for them (and that I have to share the same planet with them)?

Decisions, decisions...

There's a magazine on pigeon racing.... I know nothing about that... yes, that could be interesting... Oh, the history of the napoleonic wars in 27 parts with a free cardboard cutout brigantine in this issue! Part number 11. Um, no scissors on the plane... the Pigeons it is, then.

David
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Old 4th Aug 2020, 1:13 pm   #1660
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Default Re: The Audiophoolery Thread.

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Originally Posted by stevehertz View Post
What would go a long way towards sorting that out? tone controls. Most hifi speakers start to droop below, I dunno, say 100Hz. So personally, I always use a tad of bass boost to lift the low end response of the system in order for the bass to be heard as it was in the studio that had those massive monitors with their ground shaking low end capabilities. No tone controls? then you're stuck with a system that is always at the mercy of the recording studio in which a given recording was made, or the choices of the broadcaster in the case of radio.
Most good amps have facilities to correct for that sort of thing. At least good in my books. The real audio gem was the Quad 34 and 44. That had a tilt control to gently shelve the response in 1dB calibrated steps - 3dB each way. It had a bass boost control to compensate for smaller speaker's shortcomings, and a step control to tame speakers placed too close to an end wall.

Interestingly, in their new Artera pre https://www.quad-hifi.co.uk/artera-pre/ they have included their tilt control for the first time in decades.

Seigfried Linkwitz, whose speaker designs in recent yeards are all active dipoles and have significant EQ, has a section on EQ of closed box subwoofers. The idea is that you cancel out the second order two pole response with two zeros, and then apply new poles with optimum Q. The intention is to extend the low frequency output (within the limitations of cone excursion of course).

Known as the Linkwitz transform, it is a biquad filter around a single opamp. Partway down this page (which is interesting insight in its entirety) https://www.linkwitzlab.com/filters.htm

Heaven knows what the great unwashed trolls on the audio fora would make of real physics and electronics in loudspeaker design!

Craig
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