I lost it. I was replying about what an active guard was when I hit a key and launched out of the thread somehow. A shielded cable has quite a bit of capacitance, often around 30pF/foot or so, and a long length of cable can capacitively load down a device under test or DUT (I worked as a test EE) if it's necessary to test a device long distance away at the end of a long cable like that. So to get around the capacitive loading problem, an actively driven guard (shield) is used. At the signal source (could be a preamp) end of such a cable, a unity gain buffer with high input impedance is connected to the preamp's output along with the signal carrying center wire in the cable. The buffer's output is connected to the shield of the long cable and drives the shield with the signal. The center conductor and its shield now are driven together, but isolated by the buffer from each other, effectively eliminating the capacitance of the cable from the DUT's output, since the center wire and the shield are always at the same instantaneous voltage. Since the shield buffer driver's output impedance is very low, it effectively acts like a shield to extraneous external disturbance signals. A separate ground wire connects the DUT ground to the source's ground. The driven shield is not grounded at the signal destination end. I have used this approach in both my test engineering and a couple of audio installations, and it worked well in both settings.
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How do you SUBJECTIVELY quantify improvements in sound
- Thread starter gks333
- Start date
Ahhh… So ^it^ is 5% worse?
Three colloquialisms that I know of - but never use - come to mind after reading the initial post and a few comments in this thread:
Balderdash
Bunkum
and
Bunkum
and
I don’t attempt to quantify it at all. I buy what I want and if it isn’t what I thought it would be, I move on. When I was poor and audio equipment was less developed sometimes a new something was a big leap in performance, usually better/more expensive speakers. Many times things are not so much better as different. I have an Ortofon moving coil cartridge and an Audio Technica moving magnet. They sound different but I couldn’t tell you which one was better. Some of the audio magazine mumbo jumbo I just don’t understand. Pinpoint images on a “black background” doesn’t describe anything I have ever heard, including in high end audio stores. Live music sure as hell doesn’t sound like that so I don’t even know why it would be a goal.
What a farce!
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JeremyFife
Addicted to Fun and Learning
Kicked off an interesting thread though
From my experience, subjective analysis is a learnable skill but only in some situations.
Works fine for one's own personal use but you can't expect anyone else to understand what you mean!
In a group (beer tasting here, or wine trade for me) you can spend time agreeing a common language and standards - for me this was backed up by well conducted blind tasting. After that, then that group can communicate subjective, qualified findings in a reasonable way. Doesn't work outside the group though.
Market research will do something similar, but with large sample sizes, well designed questions and statistical analysis on the results ... just too dull for music!
If you feel that a change to your system makes an X% improvement (or degradation) then that's true for you ... but it's meaningless outside of your head. No criticism.
Quantifying qualitative measures is just as tricky as it sounds ... not worth it!
Glad you enjoyed the upgrades
Quantifying subjectivity is something we should all be used to in audio. Most album reviews give an album a score. Allmusic has its famed 'user ratings' with often tens of thousands of music fans rating each and every album. If I give the Abbey Road album 5 stars and the Sgt Pepper album 4 stars, we all know what I mean by that, which is not specifically that Abbey Road is 25% better than Sgt Peppers. Same with Hi-Fi. If I change my cartridge I might move my rating of my system from 8 out of 10 to 9 out of 10. Everyone knows what that means. If someone else describes that same change as a 12% improvement in sound then mathematically it amounts to the same thing, but it just sounds slightly ridiculous.
My way to test for a possible speaker step up:
1. Remove the new speaker's grille
2. Place the speaker, drivers' side facing up
3. Place a well-used paving brick in the center of the larger driver's cone
4. Play Grateful Dead record, loudly
5. Listen for that V-curve, warm, detailed wide sound stage.
If the sound is improved, it's not a speaker improvement over what you presently have.
Corollary:
No brick? A one-litre bucket of size #57 gravel can be substituted but play Diana Krall instead.
1. Remove the new speaker's grille
2. Place the speaker, drivers' side facing up
3. Place a well-used paving brick in the center of the larger driver's cone
4. Play Grateful Dead record, loudly
5. Listen for that V-curve, warm, detailed wide sound stage.
If the sound is improved, it's not a speaker improvement over what you presently have.
Corollary:
No brick? A one-litre bucket of size #57 gravel can be substituted but play Diana Krall instead.
Robin L
Master Contributor
D
Deleted member 46664
Guest
"How do you SUBJECTIVELY quantify improvements in sound"
I usually just say "There, that's sounding better."
I usually just say "There, that's sounding better."
No different from how pple quantify other things... Its very common for pple to put a number when it comes to subjective judgement..
I am sure you have come across surveys that does 1-10 rating (1worst, 10 best).
Its also commonly used in the medical where doctors ask patient to rate themselves on a 1-10 scale, esp. for symptoms.
Even pple do it regularly... Eg. My knee is 80% back to normal or 1/2 as good..
Daughter was attending to a fellow with a broken hip from a quad bike crash.
Asked what the level of pain was between 0-10.
She got back 20 out of 10, and later 50 out of 10.
Haha, I think many of us should have seen such a scale on the table or somewhere when we visit the doctor, 0 for no pain, 10 for unbeareable pain.
So, this is to say that its quite normal for pple to try to quantify feels/symptoms etc.... We do use words frequently like slightly, alot, little, not much etc etc....
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Just use this after you measure something...
Whoa!
3dB is 200%
Db ↔ Percentage Calculator - Calculator Academy
Enter the total decibels (dB) into the calculator to determine the percentage.
calculator.academy
Whoa!
3dB is 200%
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I try to describe the specific difference I see or hear. Like:
1) the subwoofers automatically turn on now at lower volumes.
2) at the same volume and same movie scene the upstairs couch is now vibrating and my wife texted me she could feel the movie. Where she never texted me before.
3) the voices are no longer sounding muffled and I'm not constantly trying to adjust the volume due to lowering the front speakers so I'm within the 20' vertical listening window.
1) the subwoofers automatically turn on now at lower volumes.
2) at the same volume and same movie scene the upstairs couch is now vibrating and my wife texted me she could feel the movie. Where she never texted me before.
3) the voices are no longer sounding muffled and I'm not constantly trying to adjust the volume due to lowering the front speakers so I'm within the 20' vertical listening window.
Why not? You probably been doing it so often that you didn't even realise it..... we all have been doing it very often, literally on a daily basis without even realising it...
How often do you use words like excellent, good, bad, very bad etc etc?? Thats subjective quantify itself. Now, assign a number to those words and you have a scale.
I am sure all of us have been asked to fill up surveys, put some rating numbers 0-5 or 0-10...0 means very bad and 10 means excellent. Very common in service rating..
If you work in a company, you also have performance appraisal. That itself is a form of "subjective quantify". What your boss thinks of you and put it in a number (some may use letters but doesnt matter).
Even for time, work etc... I am sure you use words like almost done, halfway there, alittle more to go, just started. If we were to put this on a 0-100 scale. Almost done could be 90% or more. Halfway would be 50%, just started 10%.
Subjective quantify is part of everyday life. I do not know anyway in my life who doesnt do it.
So now to sound. You pretty much do the same thing which someone has posted in much earlier post .. simply put words like good, very good on a scale with numbers.
