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What can cause variations in system performance?

Del monaco said:
If I’m happy with the sound I don’t really want to delve into measurements, placement, support, foo as I feel it begins to sow doubt when doubt should not really be there.
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Neither am I very interested in measurements, etc. However, this thread is about why does a system sound different from day to day. That is almost entirely for psychological reasons.
 
simon g said:
Neither am I very interested in measurements, etc. However, this thread is about why does a system sound different from day to day. That is almost entirely for psychological reasons.
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I think doubt can be part of this variation. That’s why I mentioned it.
 
Mike Hanson said:
I suspect most of us have experienced those days when our systems sound amazing, then the next day it sounds like utter crap. Psychological explanations are plausible, but it's typically the incoming electricity that gets the blame. Solutions for this include power conditioners, DC blockers, etc.

My buddy has extremely variable power (measured dips in voltage, etc.) In hopes of dealing with his issues, he purchased a PS Audio Power Plant P5. He contends that it's definitely improved things, but he still encounters days where his system sounds relatively poor.

I know that many don't believe in PS Audio's power regeneration marketing materials. I'm skeptical as well, and I actually had a P5 here myself for a few months. I didn't notice a benefit, but my power is notably more consistent than his.

Just for the sake of discussion, let's treat it as a given that power regeneration works as claimed. Other than that, what other things downstream might explain these variations in system performance?
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Does your friend ever enjoy the sound of his system?

Maybe there’s something not pleasing in the tonal balance or some nasty distortion (that is always present but aggravated by dirty electricity).
Some speakers impress at first listen but soon show their ugly teeth…
 
Del monaco said:
If I’m happy with the sound I don’t really want to delve into measurements, placement, support, foo as I feel it begins to sow doubt when doubt should not really be there.
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Without a more objective systematic approach we’ll just be making stuff up. Measurements are a must if one wishes to track down potential issues.
 
tuga said:
Without a more objective systematic approach we’ll just be making stuff up. Measurements are a must if one wishes to track down potential issues.
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I’ve bought stuff where measurements were great but the equipment was just not involving so I can’t really buy into this. It can be an absolute rabbit hole.
 
Del monaco said:
I’ve bought stuff where measurements were great but the equipment was just not involving so I can’t really buy into this. It can be an absolute rabbit hole.
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You must correlate your listening preference with measurements if they are to be useful for shortlisting.
If you prefer less accurate equipment look for other equipment which measures similarity.
Just because an equipment measures/performs well doesn’t mean you (or I) will like how it sounds (though generally I do).

But if we are discussing problems (not preference) measurements excel at diagnosing/highlighting problems, whether nastiness in electronics, resonances in speakers and rooms or issues with the mains.
 
darrenyeats said:
About the first two in my list:

https://www.doctorproaudio.com/content.php?2273-calculators-proaudio-sound-dmx#calc_humid
(Link 'Air absorption')

E.g. 5m distance, 16kHz attenuation
21C, 30% humidity - 2.3dB
21C, 80% humidity - 1.2dB
26C, 80% humidity - 1.0dB
Delta ( max diff ) - 1.3 dB (line item added by LPSpinner)
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Hi all,
Interesting link, thanks for posting.
I wonder how many of us here above the age of 40 could accurately hear 16kHz, sad, but a true reality. I have my hearing tested regularly as part of my employment health monitoring, at 57 years old My hearing curtails quite steeply above 12kHz; this is considered normal for someone above 50 years old. Also most of us listen a little closer than 5 meters, 3 meters between speaker and listening chair would probably cover more regular sized rooms unless you live in America where they build everything supersised.

If we run the numbers again and we get
---- 3m distance, 12kHz attenuation
21C, 30% humidity - 0.9dB
21C, 80% humidity - 0.4dB
26C, 80% humidity - 0.4dB (rounding to 2 significant figures)
Delta ( max diff ) - 0.5 dB

Looking at the original case scenario, the Delta for 16kHz @ 5m was -1.3dB between the highest and lowest case scenarios. Even if you can still hear 16kHz you would be very unlikely to hear a 1.3dB difference at that frequency. At 16kHz Many speakers would not even be matched within 1.3dB. Also a 1.3dB level change would not be perceptible over the time it took for the atmospheric conditions to move between these two case scenarios.

In this case I would argue that differences are well below the threshold of audibility and not worth considering as a factor.
I would still argue that the problem is with the listener, not the equipment.

LPSpinner.
 
I'm forever swapping boxes, not on too regular basis, but I always enjoy the music in the process.

All components will sound different and have different presentations and they are designed to please in their own way.
Current system is Arcam CD8se, Arcam A85 and KEF Cantor II.
Gets a bit glary at high levels, but with expressional jazz (is that a thing?) at low to medium levels, this system gets what I like to hear in the music.

So to the OP, a lot of it is about what you listen to, how you listen and gearing the system to it.
 
Which brings us nicely to ambient noise level and volume level used.

https://www.engineeringtoolbox.com/outdoor-noise-d_62.html (outdoors)
"It is common that Day-Night sound levels - Ldn - in different areas may vary a range of 50 dB. "

Let's take a 20dB difference. You can compensate by changing the volume level of the hi-fi, let's say you change the volume level by even just 10dB, this could have a very significant effect on the distortion levels of playback (also on feeling low frequencies). Plausibly audible/perceivable IMO.

Again, most of us say mood is a factor, it must be. Not the only thing though.
 
darrenyeats said:
0.5dB roll off at 12kHz is to many unacceptable in a DAC for example. Humidity reaches 100% in the UK.

This stuff is well within established audible levels.
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I would argue otherwise,

From the "Enginnering tool" box web site.
These are industry recognised and empirically derived values with many other web sites confirming these numbers as well.
I take most technical information from specialist "audiophile" sites with a very generous serving of salt.

Sound Awareness | Change in Sound Pressure in dB
Insignificant | 1
Just perceptible | 3
Clearly noticeable | 5
Twice or half as loud | 10
Significant | 15
Much louder or quieter, | 20
four times as loud

Also remember above numbers are based around the midrange frequencies, understand that as we go beyond 8 kHz our hearing sensitivity progressively diminishes as we move into the higher in frequencies.
As mentioned earlier, at higher frequencies there is generally a greater mismatch between speakers. Above 10Khz a 3dB mismatch in output is considered quite good. Speakers are still the weakest link in the audio reproduction chain. Allot of the time we audiophiles; In our enthusiasm for audio excellence, often loose site of the bigger picture, At the end of the day we need to maintain a sense of perspective. I would still argue that over a period of a day (and probably a night's sleep), we cannot perceive a difference of 1.3dB at 16kHz, even 3 dB at 10kHz would be a stretch.

LPSpinner.
 
LPSpinner said:
I would argue otherwise,

From the "Enginnering tool" box web site.
These are industry recognised and empirically derived values with many other web sites confirming these numbers as well.
I take most technical information from specialist "audiophile" sites with a very generous serving of salt.

Sound Awareness | Change in Sound Pressure in dB
Insignificant | 1
Just perceptible | 3
Clearly noticeable | 5
Twice or half as loud | 10
Significant | 15
Much louder or quieter, | 20
four times as loud

Also remember above numbers are based around the midrange frequencies, understand that as we go beyond 8 kHz our hearing sensitivity progressively diminishes as we move into the higher in frequencies.
As mentioned earlier, at higher frequencies above there is generally a greater mismatch between speakers. Above 10Khz a 3dB mismatch in output is considered quite good. Speakers are still the weakest link in the audio reproduction chain. Allot of the time we audiophiles; In our enthusiasm for audio excellence, often loose site of the bigger picture, At the end of the day we need to maintain a sense of perspective. I would still argue that over a period of a day (and probably a night's sleep), we cannot perceive a difference of 1.3dB at 16kHz, even 3 dB at 10kHz would be a stretch.

LPSpinner.
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Trained listeners (not necessarily audiophiles) are far more able to discriminate differences than the general public.
This makes me weary of your typical audibility threshold levels.
 
A difference of less than 1dB over a period of one day to the next ???
Even less than one dB difference under controlled conditions is a stretch.

LPSpinner.
 
The only thing that I've heard to cause a real difference in system performance is different qualities of the production and mastering on different LPs and CDs.

Lots of people claim that mains quality makes a difference too, manufacturers, salespeople and audio enthusiasts alike.
 
LPSpinner said:
A difference of less than 1dB over a period of one day to the next ???
Even less than one dB difference under controlled conditions is a stretch.

LPSpinner.
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I haven't written, you'll notice the roll-off as a roll-off, or notice the volume knob being changed by 1dB between one day and the other.

You may perceive "some difference" in the sound (e.g. I'm enjoying it more today) and it be caused by a change in sound that's audible. In this particular case, roll-off of 0.5dB at 12kHz and 1dB at 16kHz. You might not make a conscious connection.
 
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