John Curl's Blowtorch preamplifier part II

[fas42]

Originally Posted by Esperado

My measurements, fas42... But you can go to the JBL site as well, they provide distortion measurements of their speakers, not the worse of the market.

Or here: NRC Measurements: Vivid Audio Giya G2 Loudspeakers

Frank

[Esperado]

At lower spl level, but same order, between 40 and 50 (it is easy to cut the sheet where it look nicer :-)

[fas42]

Originally Posted by scott wurcer

BTW I disagree, due to the "voice in a crowd effect" I would expect one to be more sensitive to a totally different piece buried in the mix.

Depending on what the primary sound "message" is, -60dB can be a long, long way down in the sound landscape. From my own investigations, AC/DC at significantly less than maximum volume can make it impossible to understand what someone is saying in the room, while a classical track attenuated by -60dB is only just decipherable at maximum volume with my ear jammed up against the speaker driver ...

Frank

[Esperado]

All that to conclude that evil resistances are just very discrete components.
(Did this poor joke works in English ?)

[VladimirK]

Originally Posted by Esperado

Make yourself a favor. Take an audio signal (X), clip-it awfully. Divide-it by a 1/100 resistance's bridge. Add this distorted signal (Y) to the original signal with a potentiometer. Stop when you can hear-it. Measure the level.
Do the calculation: Result in dB= 20 log(Y/X)

What do you think, what is the level of distortions added by interconnect cable?
If I replace my standard Analysis Plus Silver Oval In 1m silver interconnect cables by more cheap Nordost Blue Heaven 1m, sound difference is very easily notable in my system. Could you measure the difference?
In less detailed system, the difference will hardly be notable.

[fas42]

Originally Posted by Esperado

At lower spl level, but same order, between 40 and 50 (it is easy to cut the sheet where it look nicer :-)

Not quite ... the results is mostly lying in the range 50-55dB down. This is a particularly fine performing speaker, whose distortion largely falls below their normal limits, if you look at other examples on that site they give a clearer picture of how ragged the curves are for speakers in general.

Also note, these are for outputs measured at 2 metres, not 1, so we are talking about extremely intense SPLs in room: I have a miserable battery operated smoke alarm detector rated at 85dB, and when it goes off from the toast burning it just about rips my head off.

Years ago, in HiFi News they did decent 2nd and 3rd harmonic measurements of mostly very average bookshelf speakers, and a good'un would hit -60dB over quite respectable areas of the spectrum ...

Frank

[Esperado]

Originally Posted by VladimirK

What do you think, what is the level of distortions added by interconnect cable?.

0
But little changes in response curves or dynamic behavior of the previous stage, mainly due to capacitance of the cable.
The same cables will surely present no differences in my system, because i can drive high capacitances. Or so small that it is not worth talking about
No need to turn round and round.

[VladimirK]

Originally Posted by Esperado

0
But little changes in response curves or dynamic behavior of the previous stage, mainly due to capacitance of the cable.
The same cables will surely present no differences in my system, because i can drive high capacitances. Or so small that it is not worth talking about
No need to turn round and round.

Please, do not oversimplify. If it would be simple cable capacitance, every cable manufacturer would have reliable receipe how to make best cable in the world.

In my system I distinguish, whether a single gold contact of OMRON relay (input selector in integrated tube amp) is present in the signal chain, or it is shorted by silver wire.
Therefore, I mentioned above, that 99% of listeners have no idea what the "micro sound picture" could be. These tiny effects of a single contact, as also reported Ed Simon, has around -140 - 160dB level.

[DF96]

Originally Posted by VladimirK

In less detailed system, the difference will hardly be notable.

Cables differences are noticeable in poorly engineered systems, such as bad grounding or high source impedances.

[john curl]

Ed Simon gave us something important, because he actually MEASURED what others just ignored. Serious hi end designers have 'listened' to the sound quality of various resistor types for the last 35 years. Many of us came up with similar results from different paths.
Same with caps.