Hiss in active speakers

[JJB70]

Silence can be just as uncomfortable as background noise under certain circumstances. In my youth I was an engineer at sea and there was always a constant background noise. HVAC, vibration from machinery and the propellers etc. You associated silence with blacking out which is a highly problematic condition. After several months of that I always found it was too quiet to sleep properly for the couple of nights off the boat.
In those days I used to take a Sony Discman away with me and a couple of wallets of CDs. Maybe two or three books because of the weight when flying out or flying home,meaning you relied on the ships library for reading material. I think nowadays we just take it for granted that you can carry around a lifetime of music in CD quality on a DAP or device and a library on an e-reader or device.
I have been thinking about what I would replace my system with lately. It owes me nothing and has given me not far short of 30 years of good service. I have no desire to change it (the tactile quality and build shame most modern gear) but nothing lasts forever. I am very interested in system speakers but two things put me off. One is a worry that if they go pop that they may not be supported particularly well (I am sure the KEFs I have are fix by replacement). That is a risk with anything but passive speakers have less to go wrong and good amplifiers and DACs don't cost much. The second thing is the hiss issue. I know this may sound irrational but even though it may be inaudible at normal volume and listening difference just knowing it was there would annoy me.

 

[Krunok]

I need to come closer than 15cm (6") from the tweeter to hear hiss from my Rotel amp and even then I would describe it as bearly hearable. I never noticed it before reading this topic and checking it and I don't consider it as a problem. According to amp specs S/N Ratio (IHF A) is 115dB.

 

[pkane]

I wondered: If the hiss is measured at 5 dB at 1 meter, when will the speaker’s self-generated noise be inaudible or masked by ambient noise depending on:

1) Ambient noise level
and
2) Distance from speaker?

I have JBL 306P in my office system. These do produce hiss when playing silence. The hiss is audible from about 0.5m and closer, but the speakers are about 2m away from me and the hiss is completely inaudible from where I sit. My iMac and NAS systems make about 5x as much noise in comparison, but they are also much closer to my ears than the speakers. When playing music, the hiss is undetectable even close up.

 

[svart-hvitt]

I have JBL 306P in my office system. These do produce hiss when playing silence. The hiss is audible from about 0.5m and closer, but the speakers are about 2m away from me and the hiss is completely inaudible from where I sit. My iMac and NAS systems make about 5x as much noise in comparison, but they are also much closer to my ears than the speakers. When playing music, the hiss is undetectable even close up.

Maybe @restorer-john has better ears?



I await eagerly hiss comments on audibility of say 5 dB inherent noise across distances in rooms of different background noise levels.

 

[pkane]

Maybe @restorer-john has better ears?

I wouldn’t be surprised

 

[Soniclife]

I think some people are more sensitive to 'hiss' that others. I'm one who can't stand hiss.

I'm sure that's right. I hate it, I'm the same with fan noise, and a whole host of other daily noises that most people don't seem to notice, even after I've pointed then out. It's not a hearing ability, unless my tinnitus has something to do with it, it's a brain thing.

Any hiss in my systems will not be tolerated, fortunately my Devialet passive system is as close to noise free as I could imagine a system being, and my DSP active Eve audio are also hiss free, as long as I don't have them at max volume and have my ear right next to the tweeter.

 

[restorer-john]

Maybe @restorer-john has better ears?

I highly doubt they are better than anyone else's here/hear. I have however spent decades listening for noise, faults and anomalies and being able to identify contributions from various circuit components and sections when restoring/repairing gear, particularly vintage gear where noisy transistors are common. I listen for noise first and foremost.

We also live in a very quiet area with little constant noise from human activities. It's only nature noises, and at night it's dead silent. (you know that quiet where the blood flowing in your ears is the noise floor). That's brutal on HiFi.

Back when I lived in a large city, there was that constant 'city noise' all the time. All my HiFi sounded different and I definitely listened at much higher levels for those several years. The noise floor was naturally (or un-naturally) elevated to mask the 'hiss'.

 

[watchnerd]

The only preamp/amplifier I've ever owned that produces imperceptible amounts of noise is the Devialet. All other preamp/amplifier combinations I've used make some noise when the volume control is fully opened up.

Me, too.

It makes me believe their 130+ dB SNR claims are not bogus.

 

[restorer-john]

It makes me believe their 130+ dB SNR claims are not bogus.

With respect to what output conditions and load? That's the big issue.

As an example (all things being equal):

35uV with respect to 580W@8ohms is ~126dB
35uV with respect to 200W@8 ohms is ~121dB
35uV with respect to 200W@4ohms is ~118dB
35uV with respect to 40W@8ohms is ~114dB

35uV with respect to 1W@8ohms is ~98dB

The noise levels are all the same, but the S/N varies massively. Same as the D/A converters with stupid high output levels so they can claim sky high S/N.

S/N should be specified at 1W/8ohms for amplifiers (as it used to be) and 1V or 2V for line level (domestic RCA), shorted input or infinity zero (no muting) for D/As etc.

 

[Soniclife]

With respect to what output conditions and load?

They will be specifying at full power I expect.
I've done tests using super quiet test files, as it mutes very quickly with digital silence there needs to be a real signal, and at full power on the better digital inputs the noise level at full volume is very very low, about 6 inches away I cannot here anything. The analogue inputs will be noisier because of the ADC.

 

[jonfitch]

I am an advocate of active speakers, but it is something I've noticed that many of them seem to suffer hiss to a degree, however minor. The KEF speakers I have suffer from it but I can't honestly say it is a distraction or noticeable when listening to music.

Yeah and that's why I've discovered studio monitors generally don't work well for ultra-nearfield listening because of the high noise floor.

Now newer active designs from big mass market companies like Sonos or Google with their active wireless speakers etc have devised a way to disconnect the amp when there is no output which is a nice for quality of life for mass market actives, but the actual problem here is the hiss is generally loud enough to hear that it is part of the output at low listening levels.

For example late night, if I were to listen to a Genelec 8341 (nearfield) and just playing some quiet piano tracks at 50db, I can certainly hear the active monitor hiss as part of the output, so I'm not getting the same qualitatively clean output at low levels as I would get from a passive speaker.

So while actives have advantages in terms of size, SPL, and flatter stock FR through active equalization, for some uses, like ultra-nearfield or low level playing, passive still has huge advantages.

 

[mhardy6647]

I wonder if snake oil might help reduce hiss in powered monitors?

 

[restorer-john]

I wonder if snake oil might help reduce hiss in powered monitors?

Surely snake oil would add to the hiss? It's made with bits of real snakes you know.

 

[Thunder22]

The only active speakers I own are Devialet Silver Phantoms. They are completely silent. The only way to tell if they are on is to touch the heat sink at the back which are slightly warmer than ambient when they are on.

Bottom line... Refrigeration makes noise, but also makes beer cold. However, if one were to insulate the compressor cabinet in addition to the compressor itself, one would acquire a quieter kitchen thus making Audyssey mesurements more exact.

You're on your own with quieting the fans.

 

[Thunder22]

Sorry wrong thread. Whoops.

 

[Andysu]

Snake Oil can I use it to reduce my hiss tinnitus?