Sound Investment?

[Guest]

I normally see these audio "improvements" as snake oil, happy that my periodic cleanings with Kontak, biwiring, biamping etc provide the ideal listening experience. However, following a tipoff, the statmat has been the best 30 quid spent on improving the soundstage on my equipment. Anyone else got any other low price audio solutions which have audibly improved the performance of their systems?

[johnb]

My concern with be whether any eccentricity in the mat caused the CD Rom bearings accelerated wear (because of the high spin rate).

[rauschwerk]

If the explanation of how this device supposedly works contained a reference to a paper published in a reputable journal, complete with blind testing, I might take it more seriously. Sadly, I can only regard it as mumbo-jumbo. If the digital signal were corrupted in the way that is claimed, then either the error-correction circuits would sort it out or there would be very noticeable distortion.

[Panjandrum]

If the explanation of how this device supposedly works contained a reference to a paper published in a reputable journal, complete with blind testing, I might take it more seriously. Sadly, I can only regard it as mumbo-jumbo. If the digital signal were corrupted in the way that is claimed, then either the error-correction circuits would sort it out or there would be very noticeable distortion.

Well, it was What Hi-Fi Choice of the Year, but maybe you don't consider that a reputable journal? However, its more the build-up of electrostatic fields which can distort the phase of the signal from the CD to the speakers which is the issue and can result in a degradation of the sound quality. This obviously varies in extent.
Believe me I was sceptical too but I can only go on the evidence of one's own tests, all of which have demonstrated a noticeable and notable audible improvement.

[MrGongGong]

Out of Phase and Distortion are hardly the same things at all
I'll have to consult a geek wizard on the physics
I suspect a "homeopathic" effect

Just reading some of their blurb and they say

"These phase anomalies can affect the timing of the music, with disastrous consequences on the quality of the reproduction. The timing of notes is crucial to the experience of music. To our ear, timing represents texture, dynamics and distance. It is the signature which musicians put on their music and which allows us to recognise a piece as being performed by them. During playback, certain knowledge of a piece of music leads to expectation of what comes next. If it is slightly out of time, our musical experience is compromised. An accurate, phase- coherent signal is therefore essential for musical enjoyment and appreciation of the performance."

Timing might "represent" texture and dynamics and "distance" (?????? Vague or what ) to YOU matey but not to my ears
I think the key word is REPRESENT , is that as in the "REPRESENT yourself innit sarf london big up my maaaaan jayzeee" style or "the wine represents the blood of Christ (expect to the high folks of course !)........

enough there for a whole Bad Science column
we are talking fractions of a millisecond , "out of time" which is not perceivable as "timing" but might (MIGHT ) affect phasing

See Sloboda, Seashore et al on the psychology of perception of timing errors ........... etc

[rauschwerk]

Well, it was What Hi-Fi Choice of the Year, but maybe you don't consider that a reputable journal?

No I don't. I meant the Journal of the Audio Engineering Society or similar. The only proper ways to test a device like this are (i) a rigorous peer-reviewed scientific analysis of the alleged effect (has an electrostatic field been detected and how precisely might it affect the audio signal?), (ii) accurate measurement of that effect and (iii) blind (preferably double blind) listening tests with a sufficiently large panel to avoid statistical anomalies. All else is wishful thinking.

[Ferretfancy]

Many years ago a team of BBC engineers at Television Centre invited a number of "magic" cable manufacturers to submit their wares for a carefully designed blind testing.
They all refused. The days when audio equipment was rigorously tested are long gone, I'm afraid. Subjectivity reigns.

[Dave2002]

I suspect a "homeopathic" effect

Well there is mention of a water test. That fits - surely we've all heard of the beneficial effects of homeopathic water. I am tempted to use a word beginning with 'b', followed by a number of asterisks (7) - with a double 'l' somewhere in the middle.

What happens if I rip my CDs to hard drive - as I have been doing, and then play back later? The timing in that case will be determined by other factors than the CD or the CD drive unit, assuming the data has been ripped correctly, which is often the case.

[gradus]

Homeopathy and its extraordinary dilutions are unscientific, something like adding a single drop to the Pacific ocean ...... but are they unscientific?
In the world of theoretical physics almost anything seems possible, see for example item 4 in Prof Alkhalili's list of the Top 5 Weird Physics Facts:

http://www.jimal-khalili.com/

So maybe there is a reason why Statmat works, its just that the prof hasn't yet got round to discovering the explanation.

[barber olly]

Well there is mention of a water test. That fits - surely we've all heard of the beneficial effects of homeopathic water. I am tempted to use a word beginning with 'b', followed by a number of asterisks (7) - with a double 'l' somewhere in the middle.

What happens if I rip my CDs to hard drive - as I have been doing, and then play back later? The timing in that case will be determined by other factors than the CD or the CD drive unit, assuming the data has been ripped correctly, which is often the case.

You mean some are pdq and others finish eventually or for some reason don't at all.

[umslopogaas]

panjandrum (#1), you asked if anyone knew of other cheap audio equipment extras that made a difference. I can offer one that doesnt. My amplifier is much too powerful for the rest of the system, and I only ever use very low settings, anything louder would blow out the speakers. I bought a pair of Rothwell In-Line Attenuators for £39. These are supposed to weaken the input signal so that you can use a bit more amplifier power and run rather less risk of accidentally overloading the speakers. If they worked it would be thirty nine quid well spent to safeguard a thousand quids worth of speakers, but they dont: I cant detect any difference.

[handsomefortune]

beginning with 'b', followed by a number of asterisks (7) - with a double 'l' somewhere in the middle.

yes, the sound from my pc (and ipod) speakers are the same make, with the double 'l' dave2002.

Anyone else got any other low price audio solutions

i've always enjoy humming.

[Simon B]

...My amplifier is much too powerful for the rest of the system, and I only ever use very low settings, anything louder would blow out the speakers. I bought a pair of Rothwell In-Line Attenuators for £39. These are supposed to weaken the input signal so that you can use a bit more amplifier power and run rather less risk of accidentally overloading the speakers. If they worked it would be thirty nine quid well spent to safeguard a thousand quids worth of speakers, but they dont: I cant detect any difference.

Umslopogaas - have you tried contacting the supplier/manufacturer? Unlike most hi-fi esoterica, e.g. that which was the original impetus for this thread, there's no room for subjectivity in the performance of these devices.

When used correctly they either attenuate the signal by 10 dB or they don't. If they don't, either:
(a) They're not fit for purpose which seems unlikely, or
(b) The circuit into which they're being inserted doesn't have the expected "line" properties.

Bear in mind that 10 dB really isn't very much, a 1 dB change in speaker output power is on the threshold of human discernibility in carefully controlled experiments. I can adjust the input gain on my amplifier and just tried reducing it by 6 dB as an experiment. I can tell, but the effect is pretty subtle.

If your system has an amplifier with far too much gain (do you have exceptionally sensitive speakers or something?) and really is only operable at "very low" settings you probably need a lot more than 10 dB of attenuation.

[Gordon]

Like others here I am deeply sceptical of these claims. However PJ seems to hear a difference so I am tempted to ask him what is it about the "soundstage" that is improved? Soundstage suggests stereo imaging - so in what way was it improved?

We all know from cassette tape experience what soundstage defects can be heard with gross phase and amplitude errors between channels arising from that medium. Apart from the noise level, audible instabilities in location of sources is a classic result of dynamic phase shifts between the channels in this case. Is this the kind of thing that is heard?

As regards HiFi Choice being reputable source of authority on matters audio I beg to differ - they are journalists and have magazines to sell and also need adverts of products like this to help keep the sub down. I'd take more seriously a paper in the AES journal written by recognised workers.

I also have a similar experience to Ferret - many years ago we were working on surround sound and brought some golden ears for some blind tests [no one, including the presenters and engineers, in the listening room knew what they were listening to]. None of them showed anything other than random performance in correctly identifying the various processing that we had done. For example, every one of them failed to identify phase reversals which they had claimed to be able to do.

As for this latest stuff - how does an electrostatic field around a CD playing affect the decoder chain? What are the physics? Is there any explanation for this thing that actually addresses how it is supposed to work - other than the quoted mumbo jumbo. If a static charge builds up on the spinning disc playing side isn't it earthed, at least near the centre, in the player via the platter? If so shouldn’t the effect be minimal at the start and get worse at the end of the disc? Without this mat does anyone notice a worse “soundstage” at the end of discs? By the way there is a layer of conducting aluminium over the whole surface of the disc under the label which will at least tend to equalise any static over the disc but it isn’t necessarily earthed. Have any of you experienced your CDs with charge after playing? Do they crackle like old LPs as you get them out of the player?

How does this static mat earth any charge if it is not itself earthed to something, eg the platter? It has to be placed on the label side of the disc for obvious reasons unless one of its features is that it is perfectly transparent to laser light AND remains stuck rigidly to the disc surface so as not to interfere with the laser my moving about. Furthermore the laser lens has to be very close to the disc because of the optical aperture and depth of focus needed so is there room for a mat there? So, given that the disc is made of non-conducting plastic, how does it remove charge from the other side of this disc where the reading laser spot is given the aluminium screen? The near presence of the reading head, which is almost certainly earthed, will tend to diminish any field around itself anyway. How does an electrostatic field affect the laser beam reading the pits remembering that this is a single stream of bits with the “soundstage” locked into them?

There is talk of "timing" effects – what does this mean? During decode the bits are stored while the error correction is done before being read out to the DACs under control of a crystal oscillator which, in a decent piece of HiFi, will be extremely stable and accurate to at least 1 part in a million, possibly better. Remembering that audio samples of both stereo channels are decoded together using the same phase of clock, a dynamic phase shift between them that might affect "soundstage" is virtually impossible to generate except in the following analogue circuitry.

[umslopogaas]

Simon B, thanks for those comments, I think you have probably hit the nail on the head by pointing out that 10 db attenuation isnt very much: I hadnt really appreciated this, but you are right. I havent contacted the manufacturers, but I might have a word with the friendly local hifi man who supplied them.

The amp is a Musical Fidelity Dual Mono A308. Normally their stuff would be way out of my price range, but the hifi shop in question (not my current local one) had one in stock they couldnt sell, so they put it in a sale at half price. I still couldnt really afford it, but it seemed such a bargain I couldnt resist. Its massive, so heavy I can hardly lift it, and has enough power output to roast the Sunday lunch. So my attenuators probably are working, but I need a lot more attenuation! However, I believe that its best to use an amplifier with plenty of output left in reserve, because if you drive them flat out you are more likely to get distortion. I know I have to be careful, I think I should just stick a label by a mark on the front saying "DO NOT EXCEED THIS SETTING!" in case anyone else gets their hands on it.