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how much Dynamic Range audible in your environment? I was shocked...

mdsimon2

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you're saying you can hear tweeter hiss while music is playing when you have anything under 110db sinad? (for myself, as a general rule I would work to eliminate any tweeter hiss anyway)

When talking about tweeter hiss it is more important to discuss absolute noise level at the amplifier output rather than a relative measure like SINAD or dynamic range. I am saying that I can hear tweeter hiss with a DAC with 2 x 10^(-100/20) = 20 uV residual noise when paired with a low noise (45 uV residual noise) amplifier of modest gain (25.6 dB). End result at the amplifier output is sqrt[(20 x 10^(25.6/20))^2 + 45^2] = 384 uV.

I don't know exactly where the line is between 100 dB and 110 dB at 2 V but I can say 110 dB is silent and 100 dB is not. Listening tests and measurements of various DACs discussed here in more detail -> https://www.audiosciencereview.com/...m-china-with-topping-performance.24768/page-2.

EDIT: Should add this is only during silent parts of tracks but it is annoying and definitely detracts from the experience.

Michael
 

AnalogSteph

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When talking about tweeter hiss it is more important to discuss absolute noise level at the amplifier output rather than a relative measure like SINAD or dynamic range. I am saying that I can hear tweeter hiss with a DAC with 2 x 10^(-100/20) = 20 uV residual noise when paired with a low noise (45 uV residual noise) amplifier of modest gain (25.6 dB). End result at the amplifier output is sqrt[(20 x 10^(25.6/20))^2 + 45^2] = 384 uV.
The threshold of audibility for white noise is about 4 dB SPL. So with a 87 dB / 2.83 V / 1 m speaker, you want no more than 2.83 V - 83 dB ~= 200 µV worth of noise. Minus 26 dB for the power amp that's about 10 µV out of the DAC, or a dynamic range of 106 dB ref. 2 Vrms. Correspondingly more if speaker sensitivity or amplifier gain are higher, and with some variation depending on listening distance.
 

tvih

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Replace the fans with some of the Noctua brand fans. They are the quietest I'm aware of and not too expensive. Be Quiet Silent Wing fans are considered almost as good, but I've not heard any of them.
They're all Noctuas. Well, except the power supply one, but that one doesn't even spin unless under heavy load.

The most likely culprits:
1. Dust buildup. Smoking environments are particularly nasty. Pay particular attention to the areas between fans and heatsinks as well as dust filters.
2. Bad fan bearings. Sleeve bearing fans just do not hold up when operated in a horizontal position.
3. Thermal paste that has dried out and gone hard as a rock.
4. Rogue software that is putting load on the system.

Some of the most useful Windows tools for diagnosing such issues are HWMonitor and the trusty Task Manager (once you have exited the factory default Dumb User Mode).
It's nothing "physical", but despite fan control settings it just seems everything is spinning too fast - just normal fan whoosh noise, nothing indicating faulty bearings or such. I do have fan control software installed in Windows as well, and it claims they're spinning rather slowly, but it's very clearly not the case. Mind you, the "entirely silent" state was the case just three months ago after - and also before - I replaced the motherboard, CPU and RAM. I reckon I need to go to BIOS and try adjusting from there again to see how silent it gets that way now. Just haven't gotten around to it. If that doesn't work, well, time to start installing low noise adapter wires I guess...
 

dasdoing

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my PA speakers hiss AF, but I don't hear it when playing music. it seams to be all masked. but I still have to AB it with my other speakers that don't hiss at all. I plan to mix in a white noise and toggle it on and off. then I will be sure.
 

AnalogSteph

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I do have fan control software installed in Windows as well, and it claims they're spinning rather slowly, but it's very clearly not the case.
Depends on what you consider slow, I guess. (In idle, my home system has one 140 mm CPU fan at ~230 rpm and one 140 mm case fan at ~520 rpm, the other one is turned off.) Plus that's only the ones being monitored. Some cases also have fun stuff such as fan hubs / fan controllers, and the power supply fan can rarely be monitored. Definitely some screwup potential there.
Mind you, the "entirely silent" state was the case just three months ago after - and also before - I replaced the motherboard, CPU and RAM. I reckon I need to go to BIOS and try adjusting from there again to see how silent it gets that way now.
I don't know what sort of board you have, but e.g. with Asus boards you need to run the fan calibration routine first in order to unlock the full speed adjustment range. In general, expect fan control on modern boards to be fairly powerful, so there should be little need for crude measures like external low-noise adapters. Oh, and software fan control is generally going to override what the BIOS sets, so BIOS settings only need to be in the ballpark.

If I had to hazard a guess, your software fan control settings may have gotten nuked or something.
 
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