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Old 28th Aug 2020, 2:09 pm   #1761
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Default Re: The Audiophoolery Thread.

Every now and then mother nature pulls a fast one on mankind and something doesn't go the way we expect. It's called a discovery.

They are very important.

We're a bit too keen on building large towering theoretical constructs. They mostly work, but every now and then something absolutely real gets in and demolishes a chunk. Occasionally something big comes along and takes out the foundations of a large section.

Now hifi isn't 'rocket science' and its pretty much well trampled stuff, so finding something real that upsets the theories is going to be a rare event.

So if I experienced something unexpected, I would be shifting heaven and earth to investigate what it was, where it came from, why there was a real difference.

The first thing I'd check was whether a perceived effect was real or imagined. I'm right there with MM. If we really have uncovered a hole in our knowedge, then it is a prime area for exploration. I'd want to know how far it goes, and as a fully paid-up engineer, I'd want to know how I could exploit it.

Seeing something counter to normal theory seemingly being discovered, and then seeing no-one getting interested in what the mechanism may be fills me with sadness at the lack of curiosity.



In general, as far as cables and connectors go, things get progressively harder at increasing frequencies. If you want to know about imperfections in cables and connectors ask an RF/Microwave guy. He gets to see them at their worst. Audio is orders of magnitude easier.


I've operated on some signals at power levels which would boil your head if they had been sound, and others at levels of the quantum-mechanical noise floor of our universe at cryogenic temperatures. Together these represent enough to destroy the structure of ears (along with many other organs) down to less than the ear could possibly perceive, and I've worked from DC to 100GHz. Audio is definitely easier!

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Old 28th Aug 2020, 3:08 pm   #1762
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It's called a discovery.
And the whole basis of science, which, so far, works.
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Old 28th Aug 2020, 3:47 pm   #1763
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Default Re: The Audiophoolery Thread.

Many radios only have a few inches of cable between driver and amp. We could all club together to buy the 100K cable, and chop it up and give every member a few inches. I'm sure it would make all the difference

And feedback is the devil! If you haven't realised that, you haven't been paying attention (in hifi circles).Bizarrely, I have met people academically qualified who subscribe to the concept. Harold Black? Who was he? What did he know?
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Old 28th Aug 2020, 4:48 pm   #1764
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Default Re: The Audiophoolery Thread.

I suppose the aim of the cable companies is to eventually develop a cable so good that the pieces of equipment it would have connected could be dispensed with, and then there would be nothing to hold back the sound!

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Old 28th Aug 2020, 4:55 pm   #1765
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Default Re: The Audiophoolery Thread.

Ah, just go to a concert, or read a book and listen to something "no fi" enjoy the content!
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Old 28th Aug 2020, 5:29 pm   #1766
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Default Re: The Audiophoolery Thread.

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Originally Posted by merlinmaxwell View Post
Ah, just go to a concert, or read a book and listen to something "no fi" enjoy the content!
I love this thread. I went away walking in the Lake District for a week, and more whacky products have emerged!

Back to biwiring. The only time this works for sure is if you use an electronic crossover (either digital or analogue) and separate amplifiers. Meridian have been doing that for at least a couple of decades.

All their current range use DSP crossovers and multiple amps feeding each driver.

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Old 28th Aug 2020, 6:30 pm   #1767
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Default Re: The Audiophoolery Thread.

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What's the view here on bi-wiring?
Waste of copper, one bit of wire carries the bass the other the treble, a single bit will just share the task. That is current, of course in all cases have the same PD across them.
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What's the view here on bi-wiring? Or is that a no no also?
The advantage is that it allows you to use two different cables for the high and low frequency, assuming of course that you believe different cables can sound different!

I have a pair of bi-wire Heco loudspeaker cables which have four cores - two with a handful of very thick conductors and two with lots of very thin strands. If you plug them into bi-wire capable loudspeakers they sound noticeably better the "correct" way round than the "wrong" way.

However, I would agree that bi-wiring with two runs of the same cable is indeed pointless.
21 years ago, I bought a pair of B&W DM603 S2 and a bi wired them, much to the distaste of this thread.

On other cable notes, I'm looking to buy some decent cable for my UHF antenna, I think the audio people will like my quest for low loss RF cable, I don't think they'd be so bitter towards other peoples hobbies. I think nice hi fi and nice things is a treat, so I don't really understand the purpose of where this thread has gone.
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Old 28th Aug 2020, 6:59 pm   #1768
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Default Re: The Audiophoolery Thread.

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... The advantage is that it allows you to use two different cables for the high and low frequency, assuming of course that you believe different cables can sound different!

...

However, I would agree that bi-wiring with two runs of the same cable is indeed pointless.
Does this just boil down to a question of whether the cable's impedance is significant (i.e. audible) or not ? If it's not then one piece of cable will have no audible effect and multiple pieces will do nothing several times over. But if it is significant then running separate cables to the individual drivers might plausibly be audibly different from using just one cable. At the very least you could 'bi-wire' by putting two runs of the same cable simply in parallel - joining red to red and black to black both at the amp end and the speaker end. You'd have halved whatever resistive or inductive impedance they had and doubled the capacitative component and that ought to change the audible impact.

Cheers,

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Old 28th Aug 2020, 7:40 pm   #1769
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Default Re: The Audiophoolery Thread.

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I don't think they'd be so bitter towards other peoples hobbies. I think nice hi fi and nice things is a treat, so I don't really understand the purpose of where this thread has gone.
I think it is impatience with overpriced rubbish advertised with daft theories. Time was when people strove to make music in the home a better experience without fleecing the customer. Such concerns still exist, to be sure, but there are so many more which regard the customer, unfortunately with good reason, as a gullible cash cow. They have to be called out somewhere.
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Old 28th Aug 2020, 7:43 pm   #1770
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Default Re: The Audiophoolery Thread.

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I think nice hi fi and nice things is a treat, so I don't really understand the purpose of where this thread has gone.
It hasn't gone anywhere, at least not far. It's mainly highlighting some outlandish claims made about the desirability of improvements to be made to already virtually perfect apparatus, usually at far from affordable prices. Other threads are available to people of the opposite persuasion, to be taken more seriously.
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Old 28th Aug 2020, 9:19 pm   #1771
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Default Re: The Audiophoolery Thread.

I don't worry about the ultra-rich buying toys. They take no significant harm.

I worry about those for whom a length of pundit approved cable (speaker, phono, or mains) is a significant outlay. Perhaps enough money to stop the family having a holiday that year. To these people it makes a difference.

I worry about the people who can't afford the magic wire at all, and have to live with the feeling of disappointment and imagining what they are missing.

I worry about people who just accept the mysticism without seriously questioning it. Does it do harm? Yes. I once turned someone down for a job. I didn't question whether he heard the things he described. I was disappointed that he didn't A) recognise it as being counter to the normal established scientific/engineering understanding and B) find something so unexpected interesting enough to get stuck into investigating it. I felt he lacked the curiosity to make the best of an opportunity in R&D. I still feel bad about putting in a no vote, but I think it was the right decision, I just wish I hadn't had to do it.

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Old 29th Aug 2020, 4:19 am   #1772
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Default Re: The Audiophoolery Thread.

Audio reproduction is a "chain" which contains weak links. Some of the historically weak links like acoustic recording and playback, and the (relatively smaller) weaknesses of electrical analog recording have long since been addressed or superceded.

The typical weaknesses today are, and will probably continue to be, loudspeakers and rooms, but not knowing that many can spend their money on upgrading parts of the signal chain which are already excellent and dont need improvement. A classic modern one has been claiming the CD format is inadequate and insisting on only listening to "high definition" formats like SACD, DVD A and now hi def download formats.

So many problems with sound can only be addressed by actual testing of the gear, each item, and all the gear together, both listening and measurements. The room is one of those items. Since audio reproduction is a chain, we can have 9 out of 10 links performing brilliantly but one link poor. That one poor link can degrade the sound dreadfully. It might be one simple $2 switch with dirty contacts, or a loose speaker terminal screw, or a vase vibrating against a wall when a singer hits a certain note...

Last night I enjoyed a recent documentary on astronaut Neil Armstrong. Many voices spoke but the now deceased Armstrong's written reflections were spoken by Harrison Ford. Ford's deep voice came across with such exaggerated bass that I could barely understand what he was saying (there were no subtitles to switch on). At first I suspected poor mixing in the production. So I tested it. I turned off the speakers and listened through high quality headphones. Result: not a trace of boominess. So the problem has to be in parts of my system, probably the speakers in the room.
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Old 29th Aug 2020, 4:42 am   #1773
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Default Re: The Audiophoolery Thread.

One thng about bi-wiring. How do they think the high frequency components of the voltage and current from the amplifier know they're supposed to go down one wire and not the other? Ditto for the low frequency components and how do they know where to make the split to agree with the crossover?

Maybe this is what all that breaking in stuff is about, training electrons to do party tricks.

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Old 29th Aug 2020, 9:11 am   #1774
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Default Re: The Audiophoolery Thread.

I thought that speakers which are sold as 'suitable for biwiring' had some crossover elements between each set of terminals and the relevant driver. So in a two-driver arrangement the tweeter will have a circuit which filters out the bass and the woofer one that filters out the treble. The full-spectrum voltage will indeed be applied to both sets of terminals but the current in the 'wrong' part of the spectrum will either be blocked altogether or be diverted so that it bypasses the driver.

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Audio reproduction is a "chain" which contains weak links ... The typical weaknesses today are, and will probably continue to be, loudspeakers and rooms ...
This is certainly an area which can give bigger improvements for less money than almost any other. However it is hard work - it involves getting up and down from your seat, moving the speakers in a near-random way (I've never seen a detailed description of precisely how to position speakers for best effect) and then trying to judge the effects, which might be subtle, of those actions. Here is just part of the instructions Peter Walker wrote into the manual for the Quad II/22 system back in 1959 ! (My bold):

The standard of reproduction obtained from any loudspeaker is influenced by both its position in the room and its position in relation to the listening area. The optimum position can only be found by experiment and this cannot be carried out quickly or in a perfunctory manner, if long term non-fatiguing listening is to be obtained.

With the advent of an additional speaker for stereo the difficulties are enormously increased ...

The quality of the results obtained will depend on the following:

Single Channel -

a) The position of the loudspeakers with respect to the room boundaries (and sometimes floor joists).
b) The direction of the loudspeaker axis.
c) The position of large pieces of furniture.

With stereo the following may be added -

d) The distance apart.
e) The point of intersection of the loudspeaker axes.
f) The relation of the base line (an imaginary straight line joining the two speakers) to the room boundaries.
g) The position of the listeners.

This list is formidable ... Few people can successfully complete these experiments at a single session ...

The ... loudspeaker should be tried in the various room positions which appear physically possible, in order to ascertain which positions are likely to be worth further investigation.

The loudspeaker should now be used in each of these positions for normal day to day listening. Normal attention should be given to the programme itself with no conscious concentration on the quality. In this way the optimum position for most satisfactory listening will become apparent ...


Phew, I'm tired out already ! We live these days in a society where many people who can afford hi-fi are likely to be cash-rich but time-poor. Sadly it's not hard to see that they'd sooner buy their way to a better sound than spend what little and precious free time they have working their way through the above list. That doesn't mean they're right, but it might explain the phenomenon known in hi-fi circles as 'box-swapping'.

Cheers,

GJ
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Old 29th Aug 2020, 10:57 am   #1775
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Default Re: The Audiophoolery Thread.

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I thought that speakers which are sold as 'suitable for biwiring' had some crossover elements between each set of terminals and the relevant driver. So in a two-driver arrangement the tweeter will have a circuit which filters out the bass and the woofer one that filters out the treble. The full-spectrum voltage will indeed be applied to both sets of terminals but the current in the 'wrong' part of the spectrum will either be blocked altogether or be diverted so that it bypasses the driver.
I know that, you know that, everyone round here knows it, but the grossly simplified explanations for bi-wiring usually say that the treble frequencies travel down one wire and the bass down the other.

It makes sense that the filter networks in the crossover present a high Z in their stopbands, but with the wires commoned at the amplifier both sets of cable get the same voltage even if different currents are taken. Both those writing the twaddle and those reading it don't understand transmission line effects.

There are two techniques which blow the whole biwiring thing out of the water.

1) Why not locate power amps right at the speaker? The best speaker cable has to be no speaker cable (except from the point of view of the cable manufacturer's accountants)

2) Do crossovers at low level and have individual amplifiers for each driver. This avoids all the imperfections of power inductors.

For the price of some of those cables, the job could be done properly, and still have a lot of change.

David
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Old 29th Aug 2020, 11:31 am   #1776
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Default Re: The Audiophoolery Thread.

Indeed room placement significantly impacts on overall sound balance. And it is very tricky with a box-style loudspeaker. The problem is that at low frequencies, where the wavelength is significantly longer than the dimensions of the speaker, it is omnidirectional. So it excites all room modes equally. As the frequency increases, the speaker becomes more and more directional.

Even leaving aside the problems of a joisted floor and plasterboard vibration, getting an even frequency response is difficult. There are various recipes of course that can be easily found on the web for initial placement, toe in and listening position - but seemingly trivial movement in any of those can cause surprising changes in tonal balance and imaging.

The problems are different with dipoles, of whatever technology. These have zero output in the plane of the speaker, so they only excite longitudinal modes in the room. Of course they need to be placed more than a metre from the end wall (mine are 1.5m away), but are by their nature non-boomy since there isn't a box, and mode excitation is much less at low frequencies.

As for imaging - whenever I am at a classical concert or opera, I try the trick of closing my eyes and imagining I'm listening to my audio system. And often it sounds surprisingly muffled and with pretty poor imaging (particularly from an orchestra pit). In fact Wagner specified the orchestra pit at Beyreuth to produce a non-localised wash of sound, through a slot-like aperture, as Wagner put it emerging from a "mystical abyss".

I'm lucky enough to have Leo Beranek's book Concert Halls and Opera Houses (Music, Acoustics and Archtecture) throughout the world, signed by Beranek. There are all sorts of parameters which influence audience perception and enjoyment of music. All the many factors of Interaural Correlation Coefficient, Mid Frequency Strength factor, Distinctness etc etc are defined by equations and measured in practice with hall empty and filled with audience.

There is nothing that is not defined formally and measurable in a performance venue. Whereas in our room absolutely nothing is known formally and we fiddle around until we get an acceptible result.

Craig
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Old 29th Aug 2020, 11:48 am   #1777
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Default Re: The Audiophoolery Thread.

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. All the many factors of Interaural Correlation Coefficient, Mid Frequency Strength factor, Distinctness etc etc are defined by equations and measured in practice with hall empty and filled with audience.

There is nothing that is not defined formally and measurable in a performance venue. Whereas in our room absolutely nothing is known formally and we fiddle around until we get an acceptible result.
Humans use different sound location techniques across different frequency ranges.

When the 'Trimphone' came out with its warbler instead of a bell, the tones it warbled between were in bands where different location processes worked, and it didn't stay long enough for either to get located before it changed.

This is why no-one could locate which bl**dy phone was ringing in a trendy office!

David
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Old 29th Aug 2020, 11:56 am   #1778
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It makes sense that the filter networks in the crossover present a high Z in their stopbands, but with the wires commoned at the amplifier both sets of cable get the same voltage even if different currents are taken. Both those writing the twaddle and those reading it don't understand transmission line effects.

There are two techniques which blow the whole biwiring thing out of the water.

1) Why not locate power amps right at the speaker? The best speaker cable has to be no speaker cable (except from the point of view of the cable manufacturer's accountants)

2) Do crossovers at low level and have individual amplifiers for each driver. This avoids all the imperfections of power inductors.

For the price of some of those cables, the job could be done properly, and still have a lot of change.

David
Absolutely. And it is a darn sight easier to design an electronic crossover, where all the crossover filters, time delays, notch filters etc are done either with op-amps or in a DSP, than to design a passive crossover in the speaker itself.

In fact, because of the sheer physical volume of my (class B) power amps, siting them behind the dipole speakers would modify the polar response. So I have them sited centrally between the speakers in the null plane.

Meridian put their DSP engine and class D amps within each speaker, however, given a clean sheet of paper that is clearly the better way to do it.

Given an amp system redesign I'd probably use the Hypex N-core class D modules https://www.diyclassd.com/product/nc400/11 which would be a good power match with +/-40V rails. These have sub-5ppm distortion at <20W (and sub 10ppm at 200W!). And site them on the platform underneath the LF drivers.

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Old 29th Aug 2020, 1:06 pm   #1779
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Default Re: The Audiophoolery Thread.

I've just had a thought.... Electricity is noisy! Just stand somewhere where electricity is around in the raw.... the barking buzz from the substation in the town that can be heard a full block away, the fizz of the discharge across the insulators of a pylon in the mists of a morning. The window rattling crack of nearby lightning.

Obviously those speaker cables are going to produce improper sounds in competition with your loudspeakers.

WAP! ..... Wrangler Audio Products will shortly announce acoustic attenuator sleeves for your high-end speaker cables. Cut to length to match your individual installation and available in several grades to price-match your cables. Starting from only $7000 per yard (Metres are modern and harsh-sounding.)

David
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Old 29th Aug 2020, 5:12 pm   #1780
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... There are two techniques which blow the whole biwiring thing out of the water.

1) Why not locate power amps right at the speaker? The best speaker cable has to be no speaker cable (except from the point of view of the cable manufacturer's accountants)

2) Do crossovers at low level and have individual amplifiers for each driver. This avoids all the imperfections of power inductors ...
As Craig says, hi-fi people are aware of this and some of them do do it. They call it bi-amping (or tri-amping, if appropriate). There are (at least) two reasons why it's less common than we might hope:

1) Those of us who have to share our listening space with someone else are either lucky (the someone else indulges us) or not (the someone else grumbles even about the speakers cluttering up 'their' living room and would not tolerate a mess of electronics with all the cabling etc plonked in full view, or the someone else is a cat and will sooner or later burn themselves on it),

2) If hi-fi is your hobby (as opposed to, and very distinct from, listening to music) then every so often your curiosity might drive you to try changing something - in much the same way that if wireless is your hobby you might find that you end up owning more than one set . If you've built an active hi-fi system, with the crossovers before the power stages, then your freedom to make such changes is more limited. Active systems aren't so popular with hi-fi manufacturers either, for the same reason (I note Craig's counter-example with Meridian though, and there are others).

Cheers,

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