The Emporer's New Cables - Townsend Isolde speaker cable, a Rational Review (tm)

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Doomlord_uk

Well-known Member
There have been a few threads and comments recently about this extraordinary loudspeaker cable. Extraordinary in price, extraordinary in design, extraordinary in application – but not extraordinary in audio performance. Townsend are marketing this cable as offering extraordinary audio performance as a result of its design and construction. This marketing is backed by uncritical reviews online, both from individuals who don’t know how cables or hifi work, and from journalists who should, and possibly do...

The goal of this post will be to examine Townsend’s cable and the marketing claims made about it to see what they mean if there is any substance to this very expensive product. First though, it would be worthwhile to revisit just what a speaker cable is and what it does.

From a practical point of view, a speaker cable has a very simple job to do – transmit a time-varying voltage signal from an amplifer to a loudspeaker, along with as much current as the speaker draws, whilst introducing as little distortion to that voltage signal as possible. The amplifier’s job is to supply as much current as the speaker needs. The ideal cable transmits that voltage and current without any distortion. Any change to the voltage signal, or any change to the current, would be distortion. Cables can’t improve a signal.

To accomplish this, we need a speaker cable that conducts electricity – obviously – but beyond that we need it to have as low an impedance as possible whilst remaining practicable and affordable. Obviously using thick copper bus bars might be ideal electrically, but that would be neither practicable nor affordable. In fact, the job can be done well using relatively little conductor material, and this is for two reasons. One, the distances typically run are short and little attenuation will occur. Two, the net impedance of the wire remains small compared to the load; this prevents the wires acting as a filter component to the speakers, and thus altering the sound in a way the speaker designer did not intend. This also minimises power loss, although that’s not a major consideration.

The essential elements of speaker cable design are the length of conductors, the cross-sectional area of the conductors, the resistivity of the conductor material, the insulation material (dielectric) absorption value (permittivity) and the spacing (or “geometry”) of the conductors. At audio frequencies, the electrical behaviour of the cables can be fully predicted and understood from these values, and no other factors need to be considered. IOWs, it can be shown that all of the distortions introduced by a cable between one end and the other can be explained by considering these factors alone. (RFI is not a direct cause of distortion, and would be filtered out naturally by both the speakers and the amplifier’s output circuitry. “skin effect” does not produce an audible difference at audio frequencies, resulting in something like a 0.1% rolloff at 20kHz – quite inaudible).

Since we want the least distortion, we must design our cable accordingly. Quite simply, we want a high cross-sectional area to minimise DC resistance to current flow. We also want the AC reactance – or complex impedance – of the cable to be minimal too. Reactance can be simply understood as a frequency-dependent resistance. That means we want minimal capacitance and minimal inductance. These are called reactances or reactive impedance because both phenomena ‘react’ against the current, by literally pushing back against the voltage that pushes the current. If DC resistance is like ‘drag’, AC reactance is like actively pushing back – obviously we don’t want this.

Essentially, we need to understand that capacitance is a function of cable geometry but inductance is a property of the conductor itself (and is thus hard to minimise). Capacitance is a function of three properties of a cable – the distance between the conductors, the area of overlap of the conductors and the quality (“permittivity”) of the insulating material between them. To minimise capacitance then we want a big gap, a narrow overlap and a good insulator. Capacitance works by storing energy in an electric field between conductors, and inductance by storing energy in a magnetic field around a conductor.

With all this in mind, let us now look at Townsend’s Isolde cable. Townsend make some interesting claims about their Isolde cable. The most prominent is that the conducting material is made from “EDCT” oxygen-free copper. EDCT stands for ‘enhanced deep cryogenically treated’. The DCT part refers to a process of cold-annealing the copper. The enhancement to this process is not specified, and is apparently a trade secret. DCT is used to minimise grain boundaries between adjacent crystals of copper in the wire. This is done in industry to improve the physical strength of the copper, to maximise its working life in a variety of industrial applications – eg welding. From a basic electrical point of view, DCT leads to a minor drop in copper’s resistivity – its resistance to electrical current. This reduction is tiny and given the expense of deep-cryogenic treatment, it would make far more sense to just use a little bit more copper in the cable to achieve the same result. Copper isn’t that expensive, after all... DCT is. By employing EDCT, Townshend have priced their product right out of contention for all but a few privileged audiophiles with budgets in inverse proportion to their knowledge of basic electrical theory. Changing the resistivity of copper makes no qualitative difference to how a cable distorts the voltage signal, other than a tiny proportionate drop in DC resistance. Level matched, and in reality, you will not hear this, much less attribute complex audible characteristics to the EDCT copper.

A second claim is that it is designed deliberately as a high-capacitance cable! Given that we want a cable with as low as capacitance as possible, why on earth would Townsend do this? It’s a good question. Now, typically, amplifier outputs include a capacitor in series with the output but one or two manufacturers - *cough*Naim*cough* - omit this, compensating with their own high-capacitance speaker cables to match. The rest of the industry just does things normally. Are Townsend targeting owners of Naim amps? Not according to their marketing materials. Instead, what they are doing is offering us pseudoscience – claiming that their high-capacitance cable enables it to be “impedance matched” with an “8 ohm” speaker. In short, they’re making the extraordinary claim that their speaker cables act as transmission lines, and that you’ll get better performance because of this.

To understand the pseudoscience being touted here, we first need to understand what a transmission line is. In short, it’s any wire or conductor carrying an AC (time-varying) voltage signal where the length of the cable is at least a quarter as long as the wavelength of the highest frequency of the signal. (lower frequencies have longer wavelengths – it’s only those wavelengths that approach ¼ or more of the length of the cable that are affected). In simple terms, it’s a really long wire! The classic example is of course the long-distance telephone circuit, and the most extreme of those were the old copper undersea phone cables, some of which ran for literally thousands of miles in length. Not really comparable to speaker wires at home, or in a studio! Indeed, at 20kHz – the highest frequency with the shortest wavelength in the audio passband – a speaker cable would have to be over 15 kms long, yet very few audio cables exceed one thousandth of that length! Clearly, speaker cables are not transmission lines.

What does it matter? Well, transmission lines (ie long cables) suffer from signal reflections that cause signal cancellation, and from significant power loss. Neither is a problem for speaker cables though, and here’s why. Firstly signal cancellations are microscopic at audio frequencies in short cables, the effect is essentially non-existant and would be hard to measure with scientific apparatus, much less hear as distortion. Power loss is also not an issue – the load impedance is far higher than the line impedance and the amplifier is more than capable of supplying the required power despite the attenuation of the line.

Now, these problems are solved in transmission lines by matching the load impedance (the speaker's impedance) to the “characteristic impedance” of the cable, to prevent reflections, and by matching load and source impedance (the amplifier's output impedance) – to maximise power transfer. But to do this, you need the right characteristic impedance, and you need a high source impedance – neither of which is desirable or needed in audio. In order to obtain a good damping factor, source impedances are typically kept very low compared to the load impedance. And an 8ohm characteristic impedance requires a very high capacitance cable... which as I explained above, we don’t want!

EVEN IF a speaker cable were to act as a transmission line, we also have to consider the final error in Townsend’s pseudoscientific marketing – that a speaker is an 8-ohm load. Few if any speakers are 8-ohm loads. In actual transmission lines, the loads are purely resistive (with good reason) yet in speakers the load is often highly reactive, which is bad for transmission lines! Whilst speakers are often described as ‘8 ohm nominal’ this is just an averaged value – impedance curves can vary wildly between minimum and maximum values across the desired frequency range. This is because drive units and crossover components have high reactances (by design, of course). So in fact even if you wanted to buy 15,000m of Isolde to run a pair of speakers in the next county... it STILL wouldn’t work as a transmission line! Incidentally, such a cable run would cost you £3.9m – before discount, of course! You can bet the telcos don't pay that much for their wiring...

Apart from these two major aspects of Isolde cable, the speaker wire is also offered with ‘biwiring’ links, and these are remarkable in themselves. Across the rest of the audio industry, bi-wiring means running two sets of wires from the amplifier to the speakers – with a separate crossover filter on the end of each wire. One driving the bass, the other the mid/treble. When – as is the case most of the time – speakers are not biwired, little shorting straps or cables are used to connect the bass and mid/treble crossover sections, allowing a single run of cable to be used (and saving money and mess for everyone concerned). These are typically provided by the speaker manufacturer (so that they fit properly and neatly). SOME speaker cable manufacturers make their own, and at a remarkable markup for what are rarely more than 6” of cable. Townsend though – apparently having no idea what bi-wiring is for – do something else entirely. They offer ‘bi-wiring terminals’!! What are those you wonder, and well you might! It turns out that these are speaker cable terminations that can stack on top of each other, just like the connectors on multimeters and oscilloscopes do! How extraordinary!!! So you can plug two Isolde cables into the SAME crossover terminal! Aside from the fact this is NOT biwiring, it’s just insane – you double the cost and double the reactance of your cabling. It also nullifies another putative benefit of the Isolde geometry – RFI resistance (which Townsend claim is minimal up to 60GHz due to the closenss of the gap between the cables). Like all cable manufacturers, Townsend stand to profit mightily (literally, doubling profits) from biwiring so its understandable they’d support biwiring, but to do it with these stackable terminating plugs is incredibly cynical.

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It’s also worth remarking on the construction of these cables. Cables, once in place, rarely find themselves moved about or damaged from heavy contact, but it’s always possible and where such contact or impacts can damage the cable and (somehow...) affect its operation, it is important to anticipate this and design appropriately. Unfortunately, by their own admission, Townshend have not done this with their super-expensive cable. Instead, they warn against excessive bending or treading on the wire ‘end on’ unless they’re under the carpet... and in high-wear areas, even under carpet. They offer to supply ‘at cost’ a machined metal cover for the cable. The thing is, it would not have been hard to construct the cable in a more robust manner, with thick, strong insulation that would also protect the conductors and their geometry. This has not been done, leaving the customer to worry about protection instead. For such an expensive product, this is simply not acceptable, especially considering the cheapness of a tough cable shroud.

In fact, it pays to have a close look at the page-length ‘instructions’ for these cables. Speaker cables are just plug and play you’d think, sure, but... just have a look. Away from the website, and in the hands of the customer, we see even more claims made about these cables. They are well worth examining.

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Addressing these points in turn:

1) The cable requires delicate handling to avoid kinks and bends. Oddly, at least one reviewer claimed the cables could be bent over at 45 degrees (to create a right-angled bend) when installing. He didn’t report any issues. Call me a cynic, but I suspect Townsend are creating a ritualistic manner of handling, to further imply the value of these cables (as if the sticker price was not enough of a clue!) and create a nice feeling of ‘value’ in the hands of the customer.

2) Don’t tread on the cable! Especially on edge. The site’s FAQ specifically mentions heels, and warns that damaging pressure on the cable, with its thin insulation, could cause an amplifier-destroying short. Really, what kind of cable can’t be stood on? Guess where almost all cables end up – on the floor!

3) Luckily, if you have carpets and run the cable under them (no explanation of how to get the cable round corners etc...) that’s OK though, as long as its not a high-traffic area. The customer is advised to consult with the manufacturer, and Max Townshend himself has said that a machined metal cover can be supplied ‘at cost’ which sounds very generous, at least. Better to make a tough cable, though, really... at the Isolde’s price, proper engineering is a reasonable expectation.

4) Yup – these cables are directional, AC theory notwithstanding... They come with a ‘terminating block’ and the end with the block is to be attached to the amplifier. Connect these cables the wrong way and, according to Max Townshend “unstable amplifiers may overheat”. Not sure why that might be, but it sounds like a huge flaw in a cable design if mis-use can cause unstable amplifiers (which ones are unstable???) to overheat! Most wires don’t do this, so it doesn’t really recommend these ones to have this design flaw. What’s in the ‘terminating block’? A filter network (crossover components – in a cable!) to “ensure optimum performance with all amplifiers”. It would be interesting to know what this filter network does, exactly, but for sure you don’t want to add filter networks to cables, because speakers already have filter networks and altering how those works will affect the sound balance of the speaker adversely. OTOH, it’s possible this filter network is there specifically to impart distortions to the voltage signal to fool customers into thinking the cable has an identifiable sound. Just in case you think this is a good thing, remember that the ideal cable does not distort the signal – and any filtering does distort the signal!

5) See above about Townsend’s unique take on biwiring! Note that the CSA for these cables is 4mm square – that’s quite high, but perfectly good, but it means there’s no point in going to 8mm square CSA, with double the reactance. Non at all. Even before we remember that biwiring is mean to be about... (and no, biwiring isn’t useful anyway).

6) Don’t touch the cable, and after a while – presumably after being installed – it will sound even better. Just leave it and do nothing – and it improves all by itself! Extraordinary!! Further, unlike other cables that do need ‘burning in’ (another example of pseudoscience) these cables don’t. Supposedly the (E)DCT has already had the same effect. OTOH, constant bending would lead to ‘work hardening’ (um, that’s what annealing – DCT – does) which apparently makes the sound worse...

7) Stating the obvious for once, the cable can be safely installed next to masonry and metal (phew...) so no need for cable elevators (yet another audio pseudoscience concept!) etc. Also claims the cables are immune to RFI inherently due to the close gap (not true... a gap is a gap, and you need a twist to prevent RFI) whilst the network blocks also have RF filtering (ie inductors) anyway. Maybe that’s what ensures ‘optimum’ amplifier operation???

8) Much like point (1) above, more feelgood ritual to appreciate the delicacy and value of your new investment. Actually, an interesting point, is that the two flat ribbons of copper in the wire are free to move across each other, which implies the dielectric between them is not bonded, and there must also be air in there. This would imply that these cables are actually microphonic! Whilst in practise a minor concern if it is one at all, it doesn’t sound like a good idea!


Altogether, Townsend Isolde represent a remarkably difficult, fragile, inappropriate and expensive way of accomplishing a very very simple engineering task – getting an audio-frequency signal voltage from amplifier to speaker with minimal distortion. Isolde deliberately adds distortions through faulty understanding of electrical theory, bad design, filter networks, potential microphony and advice on how to double reactances, in a high-reactance cable that is fragile and easily damaged. All at an eye-watering, wallet-reaming price...

Even if you wanted what Isolde does in a cable, there’s simply no need to do what Townsend did. You can add your own (high-power) capacitors and inductors on the end(s) of your normal, cheap, robust, low-reactance speaker cable and – electrically – the result would be no different to Isolde. Except the price and practicality – which would be vastly superior to the Townsend product. What Townsend are selling in effect is a product that comes with an aura of belief, but no substance to justify it. Like the emporer’s new clothes, the benefits are all in your mind, they just don't exist in reality. If you like the aesthetics, can accept the impracticalities and don’t care about money (or sound, or physics...), then these expensive audio baubles may well be for you. There is nothing wrong with decorating your hifi, after all :)
 

HeadBanger

Well-known Member
Doomlord I think most people here will actually agree with you. However, many of them probably won't admit it or are on the fence because they don't want to be the one that can't hear any difference. These guys who can hear all these wonderful difference can't be wrong......can they?
 

Doomlord_uk

Well-known Member
Well, hopefully after reading this, they will feel more confidant in admitting there isn't a difference to be heard.

Btw, I'm planning a more general post on audio cables that will cover this issue more widely and fully. And one particularly on the issue of audibility in hifi. Stay tuned - but don't hold your breath!
 

Member 116841

Distinguished Member
I tried the Isolda cable about 10 years ago, when I had some QED Silver Twelve (I think it was called) feeding KEF Reference Model 4.2s. This was about £12/m if I remember rightly, and I bought it mainly because I needed something flat at the time to run under the carpet. The Isolda cropped up, which I'd heard good things about, so thought I'd try it. I was expecting to hear a fair difference given the price of the Isolda. It didn't wow. It didn't give me anything over and above what the QED was giving me, so I stuck with the QED.

A more costly cable has to produce something pretty special to justify itself, which unfortunately the Isolda didn't.
 

BlueWizard

Distinguished Member
Though there is a lot of wisdom to absorb in this thread, it is not actually a review of the Townshend cable, but rather a review of the Townshend design concept.

As to the design concept, you may be right.

As to the cable, only a Double Blind A/B/X test performed with the highest quality equipment and the most revealing speakers can be considered a test or a review of the cable.

Steve/bluewizard
 

Doomlord_uk

Well-known Member
You're right this is a review of their Isolde cable design. But then that's all there is to review in a cable. The measurements - albeit not independently taken - are already there.

There's no need for listening tests - but I'll address why in other threads. You need to forget the idea that an equipment test needs to involve your ears - unless it's speakers, of course.
 

Doomlord_uk

Well-known Member
I'm hardly 'bringing this forum down to the level of What Hifi' - a magazine notorious for its breathless tabloidese as well as its endorsement of listening tests - by suggesting people don't use their ears. Cables DO NOT make an audible difference. If they did, they're badly designed or made, and should be rejected - that's the point. They're wires, they really do not do anything audibly detrimental to the sound. OTOH speakers actually do produce sound so are worth listening to, to evaluate, not least in your own listening enviroment.

My goal, apart from addressing Isolde in particular, is to illustrate that expensive, complicated engineering solutions to non-existent problems are silly. You don't need your ears to tell you that. And as I pointed out, the electrical properties of Isolda - the whole point of its design - can be accurately replicated for a tenner in parts. You don't need a pair of ears to get that...
 

Welwynnick

Distinguished Member
Cables DO NOT make an audible difference.
That's a very black and white opinion masquerading as a fact. Since you challenge eveyone else whose opinion you disagree with, can you produce some facts to back up that opinion?

Nick
 

Member 116841

Distinguished Member
I'm hardly 'bringing this forum down to the level of What Hifi' - a magazine notorious for its breathless tabloidese as well as its endorsement of listening tests - by suggesting people don't use their ears. Cables DO NOT make an audible difference. If they did, they're badly designed or made, and should be rejected - that's the point. They're wires, they really do not do anything audibly detrimental to the sound. OTOH speakers actually do produce sound so are worth listening to, to evaluate, not least in your own listening
I'm not talking about the magazine itself. I'm talking about the forum. Nowadays, amplifiers don't make a difference, cables don't make a difference, streamers don't make a difference, DACs don't make a difference etc etc. Apparently the only difference is the speakers and the room. Anyone who asks a question about any of these products that supposedly don't make a difference get pounced upon, linked to some "favourable" website making bold claims, and the OP either disappears because of the way he's been treated or thinks everyone on the forum is nuts.

I'm not going into the cable thing, it's been done a zillion times.

Why do people try and label "quality" cables as the ones that make a difference because they're badly designed or made? Cheap cables can be too!

My goal, apart from addressing Isolde in particular, is to illustrate that expensive, complicated engineering solutions to non-existent problems are silly. You don't need your ears to tell you that. And as I pointed out, the electrical properties of Isolda - the whole point of its design - can be accurately replicated for a tenner in parts. You don't need a pair of ears to get that...
Point taken, but that doesn't automatically mean that NO cables make a difference. Just because science can't measure any difference, it doesn't mean there can't be one. I'm open to the idea, as opposed to a point blank refusal there can possibly be any difference.
 

mattkhan

Distinguished Member
Nowadays, amplifiers don't make a difference, cables don't make a difference, streamers don't make a difference, DACs don't make a difference etc etc. Apparently the only difference is the speakers and the room.
I don't read that site but avs has a similar approach in many parts. However it is not an unreasonable argument even if it is often made unreasonably.

By that I mean the idea that modern manufacturing and design processes are good enough and cheap enough to mean the differences between components are extremely small, quite possibly (probably?) inaudibly so. Whereas there are undoubtedly large differences between mechanical devices, between different uses of DSP, and different room designs.

The unreasonable bit is just people being keyboard warriors really, various people on both sides of the fence are thoroughly ignorant after all.
 
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Doomlord_uk

Well-known Member
That's a very black and white opinion masquerading as a fact. Since you challenge eveyone else whose opinion you disagree with, can you produce some facts to back up that opinion?
It's not an opinion, in my opinion... but fact. There ARE facts in the world and we shouldn't be afraid to state them bluntly. Why pussyfoot around an issue? As for what makes it a fact, that is something I will address in another thread (as I noted above).

I'm not talking about the magazine itself. I'm talking about the forum.
I'm sorry, I had no idea there was a forum! It doesn't surprise me now you mention it, though.

Why do people try and label "quality" cables as the ones that make a difference because they're badly designed or made? Cheap cables can be too!
I think because 'badly designed' and 'badly made' are the ONLY reasons a cable could possibly cause an audible level of distortion. I don't agree only expensive cables can be like that, of course. If you made the £10 version of Isolde, it would still be a bad cable (why would you add reactance to cable???).

Point taken, but that doesn't automatically mean that NO cables make a difference. Just because science can't measure any difference, it doesn't mean there can't be one. I'm open to the idea, as opposed to a point blank refusal there can possibly be any difference.
If there IS a difference, it would be trivial to measure it - simply record two signals and subtract one from the other - if there's any difference, you'd see it. More importantly, you can (by the same method) measure the distortions made by a particular cable. This can be done digitally too, permitting any amount of analysis to understand the nature of the distortion. Of course, we can accurately predict what distortion a cable introduces, because the physics of electrical conduction in cables is completely understood. Now, if you can show me measurements that don't follow from the predictions, then that would be interesting - and will probably land you a Nobel prize.

To be able to observe is to be able to measure - the idea we can experience things that can't be measured (or, perhaps what people mean is, can't be defined...) remains unsupported conjecture, and IMO doesn't make any sense quite honestly. With all due respect, you have to be prepared to dismiss bad ideas at some point. This isn't a battle of opinions, it's a battle of facts. There is nothing mysterious about how hifi works.
 

mattkhan

Distinguished Member
There is nothing mysterious about how hifi works.
one letter makes a big difference here, do you mean there is nothing mysterious about "how *A* hifi works" or "about how hifi works"? You wrote the latter but context says the former. Which is it?

After all there's plenty that could be called "mysterious" about the way your brain perceives what a hifi produces, both in terms of your own experience in its entirety (whether it's the emotion induced from certain tracks to the more analytical, but still subjective, "critical listening" through to a purely objective assessment of system performance) and in terms of the physiological/neurological processes that even enable you to hear in the first place.

I am using mysterious here as a synonym for not completely and utterly described by science btw

NB: for the avoidance of doubt, I'm not referring to cables in the above. Cables are a subject that baffle me as to why people spend so much time arguing about it, I'm perfectly happy that they either work or don't so I buy on function alone. If someone else wants to buy specific cables at whatever cost then it's a free world. Fortunately the world of audio is large and there are much more interesting subjects, to me at least, to spend my time on :)
 
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Doomlord_uk

Well-known Member
I'm not seeing the difference? I was saying that there is nothing mysterious about hifi equipment works. If I said, 'a hifi works' then that would be the same thing, to me.

What a hifi produces is sound. But HOW it produces sound, and how it distorts that sound, is not mysterious.

Now, how the brain turns continuously varying air pressure into a conscious understanding of what is producing that sound - a voice, an instrument, an echo, whatever... THAT is not fully understood, although it is well enough understood. But that process is going on in your head, not in your hifi.

We really need to get away from treating hifi as something that works by magic. It isn't magic, it's simple science, we figured it out a long time ago.
 

mattkhan

Distinguished Member
You' seem to be focusing on the electronics not the system, not an unreasonable approach given the context of the thread mind you :)

Nevertheless the transfer function of (dsp-)speaker-room-ear is one in which there are almost infinite possibilities as to how that performs. This is the distinction I was drawing; "a hifi" is source-amp-speaker whereas "hifi" is source-amp-speaker-room-ears. The former is relatively straightforward, the latter not so much.

I agree there are simple components in the chain and I agree there are certain components that are just conduits that move things from A to B. However I absolutely don't agree, if you are arguing this and I'm not sure you are, that the entire chain is simple and completely understood.

To give a trivial example, have you experimented with target curves? and analysed your perception of system performance (aka optimising for your preference) given different target curves and/or different methods to hit that target curve? I find that exercise continues to surprise.
 

Doomlord_uk

Well-known Member
Ears aren't part of hifi. No-one manufactures or sells you ears, you come with your own. Likewise your brain (hopefully...). I'm talking about hifi EQUIPMENT. That is what we design, manufacture, sell, buy, install and use. It's getting a signal off a recording and to the air next to your ear with the least distortion. Once it enters your ear, the hifi's job is done. I really don't share your view that the ear is part of the hifi system. The "signal chain" perhaps... but I'm not talking about a system or flowchart, but solid material goods governed by the laws of physics. Well, we are too, but i mean the manufactured parts. The *hifi* components. There's no mystery to how they work.

I think room acoustics, whilst hard to predict in real-world situations (without a lot of computer power?) is not hard to understand in principle and at least to optimise, if not perfect. I think (although I admit I do not know this point for sure) that we have a very good idea of how direct reflections, general reverberation, room modes etc all affect how the sound gets from speaker to ear. Certainly it's my understanding that we can design acoustically ideal spaces and this is a routine form of engineering in the professional world (studio design) and in commercial spaces (concert halls, etc). Homes are problematic because almost always they are simply not designed, constructed, fitted, finished or furnished with good acoustics in mind - save for the very few wealthy enough to dedicate a room to this. For everyone else, typically it's a case of 'try before you buy' and see what works. I wonder how many people - even dealers who OUGHT to know - understand room interaction and acoustics well enough to recommend the right equipment and placement for each different room... and then, how many people are truly prepared to fit a room around a hifi system. I would think for many, myself certainly included, that's simply not a possibility.

The reason I called this a "rational review" was to suggest that I was NOT going to rely on subjective impressions; rather I'd look at the design and engineering and ask whether these Isolde cables make any sense, given their purpose.
 

Doomlord_uk

Well-known Member
Btw I have no idea what you are referring to when you say "target curves"
 

mattkhan

Distinguished Member
apologies for the blow by blow reply!

I'm talking about hifi EQUIPMENT.
this is what I thought you were talking about, "a hifi" in my terms not "hifi"

I think room acoustics, whilst hard to predict in real-world situations (without a lot of computer power?) is not hard to understand in principle and at least to optimise, if not perfect
it's turtles all the way down, simple on many levels but with an almost fractal like complexity IMV. Possibly peeling an onion is a better analogy.

I think (although I admit I do not know this point for sure) that we have a very good idea of how direct reflections, general reverberation, room modes etc all affect how the sound gets from speaker to ear
yes and no, the simple mechanics of it yes, the effect of this on the nebulous concept of SQ (aka preference) is a much more grey area.

I wonder how many people - even dealers who OUGHT to know - understand room interaction and acoustics well enough to recommend the right equipment and placement for each different room
I would expect a good dealer to have a good appreciation of what they sell and the ability to be able to decipher what a customer says, I wouldn't expect them to have a detailed understanding of acoustics.

I have no idea what you are referring to when you say "target curves"
as in using DSP to shape the response to your preference
 

Doomlord_uk

Well-known Member
I've still no idea why your definition of 'hifi' is different... =/

No idea why room acoustics is fractal in nature, or 'turtles all the way down', either.

"sound quality" can mean either of two distinct things, and they shouldn't be confused. The first is the effect of hifi equipment on signal (not 'sound') quality. Specifically, the level and nature of distortion imposed on the voltage signal. High sound quality here means no audible distortion IMO. Pretty much achievable everywhere from recording medium to speaker drivers. Second, is the question of conscious perception of external "sounds". The second is fundamentally different from the first because it is so profoundly shaped by the brain's internal state (memories, learning, experiences, state of mind etc) and also because the brain doesn't interpret waveforms the way we imagine, or the way a hifi component does, but instead is engaged in the transformation, at an unconscious level, of continuous neural impulses from the ear into conscious concepts such as 'drum' and 'voice' and 'echo' and things like identity, position, movement, etc So a waveform enters the ear, and the conscious mind thinks "Katie Melua" or "car crash" or "a conductor tapping his baton on his stand" or "leaves rustling in the wind" or "car moving away from me" - symbolic concepts that, being consciously experienced, trigger further responses from the mind, all quite independently of what's entering the ear. Ie from context.

I think a dealer should have a good basic understanding of acoustics, since room-speaker interaction is quite important. It's no good a customer ordering a pair of electrostatic speakers to hang on the wall(!) or some horns to be put in the middle of the room. Likewise if a speaker is quite directional, the dealer should know this. He ought to be able to adjust his demo room to some aproximation of a customer's own room too - adjusting from a hard, bare room with a very live sound, to something much less reverberant and quieter, with soft furnishings, etc. I've never heard of a dealer doing this... but I think they should.

OK, I think I get what you mean about DSP 'curves' - I assume you mean room EQ? Or 'sound field' processing (aka what Yamaha was into for many years).
 

mattkhan

Distinguished Member
No idea why room acoustics is fractal in nature, or 'turtles all the way down', either.
synonym for "there are lots of variables that interact in often confusing ways & where there is lots and lots of detail to uncover about the way things work". I don't think it's an obvious & simple subject at all.

High sound quality here means no audible distortion IMO. Pretty much achievable everywhere from recording medium to speaker drivers. Second, is the question of conscious perception of external "sounds".
I don't think the perception of sound as an experience is really that relevant to this discussion & there is much more to sound quality than just distortion and "distortion" is not one thing anyway as it comes in many shapes and forms. I don't think it's true to say that a "good speaker" is easily achieved either.

I recommend reading Sound Reproduction: The Acoustics and Psychoacoustics of Loudspeakers and Rooms: Amazon.co.uk: Floyd Toole: 9780240520094: Books (there are PDFs of it to be found online) which should give you a decent primer into small room acoustics and designing a room.
 

Doomlord_uk

Well-known Member
I don't think the perception of sound as an experience is really that relevant to this discussion
Neither do I, but you brought it up by suggesting the ear and brain were part of hifi (and hence my confusion...).

there is much more to sound quality than just distortion and "distortion" is not one thing anyway
I disagree here. There is a signal, which we must treat as ideal, that exists in the recording medium. The goal of a hifi system is to get that signal out of the medium, amplify and process it as desired, and get it to your ears - all with the least possible change (distortion) to the original. Distortion is any and all change to the signal that was not intended and desired by the listener. Yes, of course there are many causes of distortion, and different types of distortion, but the sum of it all can still be referred to collectively as distortion. The goal, in realistic terms, is to keep that distortion inaudible (ie below a certain level), since we can't keep it to zero. I don't believe there is any other aspect of or to 'sound quality'.

Thanks for the book-ref, I'll get a copy!
 

mattkhan

Distinguished Member
Neither do I, but you brought it up by suggesting the ear and brain were part of hifi (and hence my confusion...).
just to be clear, I was really referring to the impact of small room acoustics (and how the speaker interacts with that room) on how we hear NOT the physical process involved in sound -> brain as a mechanism.
 

martimu

Well-known Member
Whatever your POV/belief/premise, seems rather rude to single out one manufacturer rather than do a generic post stating your opinions/points
 
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