Seriously. Have you ever tried doing physics with non cgs units. It takes 12 of this to equal 1 of these which takes 3 of to equal one of those which takes 1725 (don't even remember the right number) to equal a mile. May as well use hands for distance and stone for weight.
And comparing one countries standards to the rest of the world is pointless and is a very American isolationist point of view. Can you answer me one question. Why don't you have Robertson screws?
If the kack-EMF is high, the impedance of the loudspeaker is high. For the same output voltage, the amp delivers less current and distorts less then.
If an amplifier is good enough - it's rather immune to the impedance change, including some rather low-value complex loads.
At some point during the NS OPS testing sessions, I did abuse it with 2.2uF capacitor in parallel with 8R resistor at the output, increasing the swing ant the frequency.
At some point, one of the capacitor's leads had just melted, disconnecting the capacitor, demonstrating its capability to draw a rather substantial amount of current at the output when required.
Spectrum measurements also showed rather "immaterial" distortion increase with 2 ohm load, comparing to the "normal" 8 ohm load.
Recent measurements, presented in this thread, performed with the Tribute-3000 amplifier, also showed a rather low increase of distortion at the amplifier's output, comparing to what we see at the speaker terminals in the same conditions (especially at 200Hz resonance frequency).
The longer cable - the higher the difference (divider exercise again
).
At some point during the NS OPS testing sessions, I did abuse it with 2.2uF capacitor in parallel with 8R resistor at the output, increasing the swing ant the frequency.
At some point, one of the capacitor's leads had just melted, disconnecting the capacitor, demonstrating its capability to draw a rather substantial amount of current at the output when required.
Spectrum measurements also showed rather "immaterial" distortion increase with 2 ohm load, comparing to the "normal" 8 ohm load.
Recent measurements, presented in this thread, performed with the Tribute-3000 amplifier, also showed a rather low increase of distortion at the amplifier's output, comparing to what we see at the speaker terminals in the same conditions (especially at 200Hz resonance frequency).
The longer cable - the higher the difference (divider exercise again
).Quote from OBL-15 (4/17/2018)
OBL-15 Copyright 2015-16 © Troels Gravesen
Quote:
Measurements may give us an idea of tonal balance of a system, i.e. too much or too little energy in certain areas. Measurements may tell us about bass extension if far-field measurements are merged with near-field measurements. In addition to this, ports may contribute to bass extension. Most of us diy'ers do not have access to an anechoic room for full-range measurements from 20-20000 Hz, nor do manufacturers for that matter.
What cannot be seen is what kind of bass performance we get in a given room. Bass performance is highly dependent on in-room placement of your speaker and the same speaker can be boomy in one place and lean in another.
Actual SPL level at 1 meter distance and 2.8V input is useful for en estimate of system sensitivity and combined with the impedance profile may give an idea of how powerful an amplifier is needed to drive the speaker to adequate levels.
What measurements do not tell is the very sound of the speaker unless displaying serious linear distortion. The level of transparency, the ability to resolve micro-details, the "speed" of the bass, etc., cannot be derived from these data. Distortion measurements rarely tell much unless seriously bad, and most modern drivers display low distortion within their specified operating range.
Many people put way too much into these graphs and my comments here are only meant as warning against over-interpretation. There are more to good sound than what can be extracted from a few graphs. Every graph needs interpretation in terms of what it means sonically and how it impacts our choice of mating drivers, cabinet and crossover design.
What measurements certainly do not tell is the sonic signature of the drivers, because cones made from polyprop, alu, Kevlar, paper, glass fiber, carbon fiber, magnesium, ceramics or even diamonds all have their way of colouring the sound.
The choice of crossover topology has a huge impact on the sound we get. We may produce the same frequency response from 1st, 2nd or 4th order filters and they may be Butterworth, Linkwitz-Riley, Bessel and others and they all sound different, very different indeed, so take care!
OBL-15 Copyright 2015-16 © Troels Gravesen
Quote:
Measurements may give us an idea of tonal balance of a system, i.e. too much or too little energy in certain areas. Measurements may tell us about bass extension if far-field measurements are merged with near-field measurements. In addition to this, ports may contribute to bass extension. Most of us diy'ers do not have access to an anechoic room for full-range measurements from 20-20000 Hz, nor do manufacturers for that matter.
What cannot be seen is what kind of bass performance we get in a given room. Bass performance is highly dependent on in-room placement of your speaker and the same speaker can be boomy in one place and lean in another.
Actual SPL level at 1 meter distance and 2.8V input is useful for en estimate of system sensitivity and combined with the impedance profile may give an idea of how powerful an amplifier is needed to drive the speaker to adequate levels.
What measurements do not tell is the very sound of the speaker unless displaying serious linear distortion. The level of transparency, the ability to resolve micro-details, the "speed" of the bass, etc., cannot be derived from these data. Distortion measurements rarely tell much unless seriously bad, and most modern drivers display low distortion within their specified operating range.
Many people put way too much into these graphs and my comments here are only meant as warning against over-interpretation. There are more to good sound than what can be extracted from a few graphs. Every graph needs interpretation in terms of what it means sonically and how it impacts our choice of mating drivers, cabinet and crossover design.
What measurements certainly do not tell is the sonic signature of the drivers, because cones made from polyprop, alu, Kevlar, paper, glass fiber, carbon fiber, magnesium, ceramics or even diamonds all have their way of colouring the sound.
The choice of crossover topology has a huge impact on the sound we get. We may produce the same frequency response from 1st, 2nd or 4th order filters and they may be Butterworth, Linkwitz-Riley, Bessel and others and they all sound different, very different indeed, so take care!
are you saying that what Troels Gravesen is talking about is irrelevant?
as a system tech and repair person i've learned that what others are attempting to communicate often fails because of the discontinuity between meaning and definition and worse yet when asked to qualify/quantify things that are complex or nebulous.
the divide that exists between objectivist's and subjectivists is made worse when either side fails to attempt to see the others point of view and disqualifies the other with false rationalizations like "if you can't explain it to me in my terms then it was no validity".
in reading the statement i get and appreciate that Troels is acknowledging both the validity of objective measurements yet lends credence to the subjective side when saying that interpretation of a graph does not adequately translate to how things sound.
as a system tech and repair person i've learned that what others are attempting to communicate often fails because of the discontinuity between meaning and definition and worse yet when asked to qualify/quantify things that are complex or nebulous.
the divide that exists between objectivist's and subjectivists is made worse when either side fails to attempt to see the others point of view and disqualifies the other with false rationalizations like "if you can't explain it to me in my terms then it was no validity".
in reading the statement i get and appreciate that Troels is acknowledging both the validity of objective measurements yet lends credence to the subjective side when saying that interpretation of a graph does not adequately translate to how things sound.
Regards 'the "speed" of the bass' that's difficult to define since it does seem to have multiple meanings, and it's going to be harder too when the author uses inverted commas. It's just about on topic due to the effect cable resistance has on damping factor (in one of it's definitions {probably}).
No, I said IME people will not always agree on what are micro-details/transparency. For the record I think this "fast" bass thing could yield to a proper set of measurements if someone put their mind to it. For that matter as proposed years ago by Dean Jensen multi-tone signals or real music with empty notched out zones can reveal the true total grunge + noise floor, who knows maybe that's a start on this micro-detail/transparency stuff.
Of course it´s important to match/synchronize vocabulary if you would like to talk with others in a way that minimizes misunderstandings.
Wrt measurements it is a bit more complicated as perception like "fast" or "tight" bass are descriptions that reflect multidimensional evaluation results.
Furthermore the same or similar perception might be triggered by differenct physical events.
It is not an easy task to find correlations (and hopefully cause and effect relations) between perceptions and measurements.
Not an exactly new insight, but i thought it could help.
Wrt measurements it is a bit more complicated as perception like "fast" or "tight" bass are descriptions that reflect multidimensional evaluation results.
Furthermore the same or similar perception might be triggered by differenct physical events.
It is not an easy task to find correlations (and hopefully cause and effect relations) between perceptions and measurements.
Not an exactly new insight, but i thought it could help.
there's an easy answer to that question but in a forum where "politics" are taboo the remainder of the answer is that Henry Ford was a cheap bastard and refused to pay PL Robertson for the patent rights and definitely was not going to allow any one else to...that's when it goes back into politics.
back to distortion... thus far while it seems that keeping cable and gauge size in the right proportions reduces measurable quantities is there any way of determining a scale that quantifies when it's an audible consequence?
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sorry i could not resist...
closer to topic if cable resistance worsens damping and produces distortion can we use the subjective terms "loose" to describe inadequate damping (?) and "sloppy" as additional distortion(?)
i know that currently there are no one to one or, accepted definitions of "terms to effects" and a better correlation needs to be made.
with respect to bass speed i do think much can be learned examining transient response.
closer to topic if cable resistance worsens damping and produces distortion can we use the subjective terms "loose" to describe inadequate damping (?) and "sloppy" as additional distortion(?)
i know that currently there are no one to one or, accepted definitions of "terms to effects" and a better correlation needs to be made.
with respect to bass speed i do think much can be learned examining transient response.
As usual Jakob hits a number of nails squarely on the head with such force they are each driven all the way home with a single strikeOf course it´s important to match/synchronize vocabulary if you would like to talk with others in a way that minimizes misunderstandings.
Wrt measurements it is a bit more complicated as perception like "fast" or "tight" bass are descriptions that reflect multidimensional evaluation results.
Furthermore the same or similar perception might be triggered by differenct physical events.
It is not an easy task to find correlations (and hopefully cause and effect relations) between perceptions and measurements.
Not an exactly new insight, but i thought it could help.
I cannot believe we still want to see a response curve from a speaker with the different cables... it will be 1. discredited. 2. irrelevant.
Cables sure have an impact, how important is the question, especially how much % of budget of an audio system is it worth?
That's what we would like to precisely quantify and know, as diy enthusiasts.
Cables sure have an impact, how important is the question, especially how much % of budget of an audio system is it worth?
That's what we would like to precisely quantify and know, as diy enthusiasts.
It is noted that here there is too much interest in being protagonists but little interest in being fair and respectful with the other parties. Ignoring others is a symptom of a superiority complex, pride, xenophobia, racism, or whatever you want to call it.
I have invested many hours documenting my construction of Troels cabinets and uploaded the whole process here, related with comments and photographs, and I do not get a single answer ..... ???? Well, I have to admit that it is quite disappointing
There are many foristas that adapt more to a competition of "who has it bigger" and not as it should be, to a place where to share knowledge -----
And do not tell me that English is bad, because I only asked for opinions about a link., It is obvious that it was understood ...
About the rapidity or slowness of the bass, is one of the many ways to give a name to the sound. Others speak of bass round, treble sharp, etc.
I've got excellent bass until the second octave, and how can I prove it ? With words ?? The seem to give a lot of authority to the affirmations, but the final thing is listening! What are the calculations about how to change the calbe to the DF if the listening environment can alter the room of the And measurementsI can not invite them to my living room ....
Troels has said this many times, you can not describe the sound only with words or measurements.
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