Καλωδια, r l c - crosstalk κλπ.

[ln()]

Ακόμα και το ένα με τη μεγάλη διαφορά, στα 3 μέτρα έχει -0,5 db. Και οι ίδιοι δεν πιστεύουν ότι είναι ακουστή (may..). Στα 15 μέτρα (-3db) μάλλον (highly likely).

Ναι, 0,5dB είναι λίγα. Αλλά:

• 0,5dB διαφορά στην ένταση ανάμεσα στα δυο κανάλια είναι εύκολα ακουστή διαφορά αφού προκαλεί μετατόπιση της εικόνας δεξιά ή αριστερά.
• 1% αρμονική παραμόρφωση είναι, αν δεν απατώμαι, -32dB από το σήμα. Κι όμως θεωρείται ήδη αρκετή.

Συνεπώς 0,5dB μπορεί να είναι λίγο, αλλά μπορεί να κάνει τη διαφορά.

 

[Κωνσταντίνος Τυροβολάς]

Προσωπικά δεν ακούω διαφορά 0,5db στα 20 κΗζ, γιατί δεν ακούω τόσο ψηλά. Γενικά, στις μεσαίες συχνότητες, το 1 db θεωρείται το όριο που αντιλαμβανόμαστε διαφορά στην ένταση (το έχω και σε δημοσιευμένες εργασίες, δεσμεύομαι να το βρω μέχρι το τέλος της εβδ.)

Αυτό όμως αφορούσε 1 και μοναδικό καλώδιο. Πολύ φοβάμαι πως απάντηση δεν..
Διαφορές ακούγονται, γιατί όμως??

 

[vas silis]

Το μόνο κατασκευαστή που ξέρω να έκανε σοβαρή έρευνα γύρω από το θέμα, νομίζω πριν καν ξεκινήσει η εταιρεία είναι η QED η οποία υπηρξε μια προσπάθεια μετά την έρευνα. Ας το βάλουμε και αυτό εδω να υπάρχει


"The Genesis Report"

During 1994 we conducted the most extensive ever scientific investigation into the effects of speaker cable on hi-fi system performance. Read the results in "The Genesis Report"

http://www.qed.co.uk/downloads/qed/brochures/genreprt.pdf

I n t r o d u c t i o n
The listening sessions were vital: QED engineers are all too aware that measurements alone are not the whole story. It would be tempting to claim that they tell you everything, though this is clearly not the case. On the other hand, if any cable introduces measurable errors and distortions as a result of being inserted between the amplifier and loudspeaker, it obviously cannot reproduce music accurately.

Genesis - the outcome

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As summarised in (1,2,3,4 and 5) the most accurate and consistent- sounding loudspeaker cable will have minimal DC resistance, inductance and capacitance combined with low dielectric losses. All our re s e a rch findings confirm this simple conclusion. Conductors designed with small cross- sectional area in an attempt to avoid skin effect (which is not an issue anyway at audio frequencies) have higher DC resistance, with obvious harmful consequences.

Through Genesis, QED's engineers have bucked the over- simplified 'rule' relating inductance to capacitance. Capacitance and dielectric losses have been reduced by choosing a suitable high-quality insulation material (low-density Polyethelene). In addition, minimising the insulation wall thickness and designing narrow webs (consistent with mechanical integrity) the ratio of air to solid dielectric has been improved, thus further reducing capacitance and dielectric losses. By optimally orientating multiple parallel stranded conductors, QED has been able to reduce both inductance and capacitance below that p redicted from a single pair of the same DC resistance. The use of stranded conductors of good total cross section has kept DC resistance low. The result is a range of low-loss transparent - sounding loudspeaker cables of superior perf o rmance. The correlation between insulation and sound quality has also influenced the design of QED's interconnects, which use foamed LDPE to increase the air/solid dielectric ratio and maximise sound quality.​

 

[vas silis]

Ελπίζω μόνο με αυτά και με αυτά (άρθρα, μελέτες κλπ) το θέμα να μην ξεπέφτει τόσο πολύ που να φτάνει να είναι μόνο για «λαϊκή κατανάλωση» όπως διάβασα κάπου.

Όχι ότι έχω τίποτα με το «λαϊκό», το αντίθετο μάλιστα μου κάνει και πολύ μάλιστα.

Απλά θέλω να πω ότι τη «λαϊκή κατανάλωση» τη βλέπω σε κούφια λόγια που δεν στοιχειοθετούν και τελικά δεν προσφέρουν τίποτα.

http://www.youtube.com/watch?v=5G2LtPvPemw&feature=related

http://www.youtube.com/watch?v=FuRYoz5jRW8

 

[vas silis]

Ξεχάσαμε το άρθρο του δάσκαλου και δεν ήταν σωστό, οπότε το ρίχνω τώρα να υπάρχει και αυτό .

I have listened to these cables on a variety of amplifiers (mostly
my own) and loudspeakers, including Magneplanar Tympani 1 D's, MG
II A's, modified Dayton Wright XG 8 MK III's (as shown in Fig. 6)
Cabasses; I have also heard some examples on Dahlquist and Snell
loudspeakers.

Frankly, I found it difficult to assess the results except at the extremes of
performance. For 10 foot lengths with properly terminated cables and
speakers with inductive high frequency characteristics, the differences
between low inductance cable and twin conductor are extremely subtle
and subject to question. With a low output inductance amplifier and a
Heil tweeter (whose impedance is a nearly perfect 6ohm resistive) the
difference was discernible as a slightly but not unpleasant softening of
the highest frequencies. Fulton or Monster cables were a clear
improvement over 24 or even 18 gauge, though a little less subtle than
I would have expected, leading me to believe that the effort associated
with heavier cables pays off in bass response and in apparent midrange
definition, especially at crossover frequencies. The worst case load, the
modified Dayton Wright electrostatics, presented some interesting
paradoxes: the extremely low impedance involved showed the greatest
differences between all the types of cables. However, the best sound
cables were not necessarily electrically the best because several
amplifiers preferred the highest resistance cable. In one case, I had to
use 24 gauge cable to prevent tripping the amplifier's protection circuitry.​

With this much information, we might think we have the subject nailed
down. However, we could easily install the finest amplifiers, cables, and
terminating impedances and achieve 100 times the distortion of the
amplifier alone. Loose, dirty, or oxidized connections can, while
measuring well with an ohmmeter, cause high amounts of harmonic and
intermodulation distortion. When high distortion occurs during an
amplifier checkout at Threshold one of the first things we do is replace
or tighten the cable from the amplifier to the load; we have thus cured
many "defective" amplifiers.


A few guidelines have emerged here, but the final judgment belongs to the user. All the special cables mentioned worked well on the test bench and, given the assumption that series impedance should be minimized, all of them work better than 16 gauge wire. If, like many audiophiles, you have
spent a small (or large) fortune on your hi-fi system, money spent for
high quality cables and connectors is a reasonable investment.
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http://passlabs.com/pdf/articles/spkrcabl.pdf
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Πάντως εντύπωση μου έκάνε αυτό :​

However, the best sound cables were not necessarily electrically the best because several amplifiers preferred the highest resistance cable. In one case, I had to use 24 gauge cable to prevent tripping the amplifier's protection circuitry.​