Studio monitor speakers without hiss?

[Krit]

One of the reasons why speakers hiss is 2 vs 3 pin AC Input.

For me 2 pin input usually does not hiss or make any bad noises and 3 pin almost always is bad in terms of hiss and other noises it's related for both speakers and subwoofers.

 

[Meyer]

I think some of you guys are exaggerating. So you can hear a faint hiss when no music is playing and everything else is dead quiet. Does it mean it is above the noise floor of your quietest recording? for most speakers it is a clear "no".

Some people have different hearing and needs. Hearing hiss when no audio is playing is grating to my ear.

I measured several different amps using a D2 compression driver and horn from a JBL M2. The measurements are at the mouth of the lens. Compared are PuriFi and Hypex Class D, and some various Class A/B including a very old but fine working vintage Aiwa micro amp. I measure with and without the passive network, which does make a difference. I compared the measured spectra to the noise floor of the room with the mic in the same position in the D2 lens as the active measurements.

Topping PA5 II Stereo Amplifier Review

Please report on your findings. Perhaps if you use the stock psu with a regulator this may help, with sufficient capacitance to prevent voltage sag at high volumes 1 - what makes you think there is voltage sag? 2 - The stock PSU is probably already regulated. 3 - Even if there were voltage sag...

www.audiosciencereview.com

The D2 plus the passive network with either the Hypex or PuriFi amps is really quiet, even at extreme close range, and both are inaudible to me at ~1 meter. The Aiwa is audible to me at 1 meter. The other A/B amps were really faint to my ears. None of my subjective impressions were in a heavily treated room, and are with my ears, so take it with a grain of salt.

Thanks for this. Ultimately, I'm ready to move to a passive setup.

 

[somebodyelse]

One of the reasons why speakers hiss is 2 vs 3 pin AC Input.

For me 2 pin input usually does not hiss or make any bad noises and 3 pin almost always is bad in terms of hiss and other noises it's related for both speakers and subwoofers.

I doubt the correlation let alone the causation. It's more likely to be implementation specific.

 

[AnalogSteph]

I am extremely sensitive to hiss due to a hearing disorder and have tested and owned some of the top tier actives. They all hiss when powered on and connect to a high quality source (e.g. my RME UFX II or my BabyFace Pro). Same story using this equipment in numerous locations.

Could you elaborate on "some of the top tier actives"? What is your listening distance?

The lowest self-noise values according to Sound&Recording have been (in dB(A) SPL @ 10 cm - subtract ~20 dB for 1 m anechoic):
Kii Three - 15.0
ADAM F7 - 15.0
Monkey Banana Gibbon 5 - 15.0
ATC SCM25 ASL Pro - 16.0
Neumann KH310 - 16.5
ADAM F5 - 17.1
PMC DB1S-A II - 18.0
Neumann KH420 - 18.3
ESI nEAR 05 - 18.8
Quested S8 - 18.8
Dynaudio Air 12 - 19.0
Nubert nuPro A-600 - 19.0
Neumann KH120 - 19.9
ADAM A7X - 20.0
Focal CMS 40 - 20.0
Focal Shape 65 - 20.0
Fostex NX-6A - 20.0
Neumann KH80 DSP - 20.0
Neusonik NE05 - 20.0
ADAM ARTist 5 - 20.7
Klein & Hummel O410 - 20.7
Genelec 8331A - 21.0

You will notice that a few of them are "cheating" by using no or minimal waveguides for their tweeters. Waveguides increase sensitivity, making it easier for hiss from the amplifier or preceding signal chain to become a problem. Passives have to match sensitivity to the least sensitive driver, generally the woofer, which noise wise tends to be a blessing.

Hiss levels may further be dependent on input gain / level settings as there may be enough gain to show up output noise or even their own input noise levels. (A lot of Genelecs top out at 106 dB SPL @ 1 m for 0 dBu in. It is not uncommon to see balanced receiver circuits with noise levels in the -98 to -105 dBu range. See the problem? It's particularly egregious on the little 8010A, which offers only two choices of 106 and 96 dB and is always hissy.) The "old" Babyface Pro does not appear to have the +4 dBu (lower output) mode yet which may prove an issue unless complemented with a passive monitor controller. The UFX II should be very flexible though, with the lowest output 0 dBFS level being +2 dBV (+4 dBu) at the -10 dBV reference level setting and further options of +13, +19 and even +24 dBu on out 1/2.

The only reason I can hear any hiss on my K+H O110s is my ridiculous listening or more importantly non-listening distance (30 cm is not uncommon). Actives without audible hiss even in the absolute nearfield do exist though... on my little EVE SC203s in the office I literally have to stick my ear to the tweeter in order to hear anything.

 

[Meyer]

Could you elaborate on "some of the top tier actives"? What is your listening distance?

The lowest self-noise values according to Sound&Recording have been (in dB(A) SPL @ 10 cm - subtract ~20 dB for 1 m anechoic):
Kii Three - 15.0
ADAM F7 - 15.0
Monkey Banana Gibbon 5 - 15.0
ATC SCM25 ASL Pro - 16.0
Neumann KH310 - 16.5
ADAM F5 - 17.1
PMC DB1S-A II - 18.0
Neumann KH420 - 18.3
ESI nEAR 05 - 18.8
Quested S8 - 18.8
Dynaudio Air 12 - 19.0
Nubert nuPro A-600 - 19.0
Neumann KH120 - 19.9
ADAM A7X - 20.0
Focal CMS 40 - 20.0
Focal Shape 65 - 20.0
Fostex NX-6A - 20.0
Neumann KH80 DSP - 20.0
Neusonik NE05 - 20.0
ADAM ARTist 5 - 20.7
Klein & Hummel O410 - 20.7
Genelec 8331A - 21.0

You will notice that a few of them are "cheating" by using no or minimal waveguides for their tweeters. Waveguides increase sensitivity, making it easier for hiss from the amplifier or preceding signal chain to become a problem. Passives have to match sensitivity to the least sensitive driver, generally the woofer, which noise wise tends to be a blessing.

Hiss levels may further be dependent on input gain / level settings as there may be enough gain to show up output noise or even their own input noise levels. (A lot of Genelecs top out at 106 dB SPL @ 1 m for 0 dBu in. It is not uncommon to see balanced receiver circuits with noise levels in the -98 to -105 dBu range. See the problem? It's particularly egregious on the little 8010A, which offers only two choices of 106 and 96 dB and is always hissy.) The "old" Babyface Pro does not appear to have the +4 dBu (lower output) mode yet which may prove an issue unless complemented with a passive monitor controller. The UFX II should be very flexible though, with the lowest output 0 dBFS level being +2 dBV (+4 dBu) at the -10 dBV reference level setting and further options of +13, +19 and even +24 dBu on out 1/2.

The only reason I can hear any hiss on my K+H O110s is my ridiculous listening or more importantly non-listening distance (30 cm is not uncommon). Actives without audible hiss even in the absolute nearfield do exist though... on my little EVE SC203s in the office I literally have to stick my ear to the tweeter in order to hear anything.

In order of least to most hiss: ATC SCM20, KH120, SCM45, Dutch and Dutch 8C.

Prior to tinnitus/hyperacusis, this wouldn’t bother me but now it’s a struggle. I think hiss is generally a lot clearer in a spectrogram than generic dB spl, since these tend go be high pitched and tonal they tend to “punch above their weight” in annoyance factor.

Appreciate points about input level, I have tested it extensively and typically found the best result with the +4dBU standard.

I have never noticed it on passive setups so I have happily decided on a passive monitoring setup.

 

[unpluggged]

The lowest self-noise values according to Sound&Recording

Neumann KH 150: 19.8 dB (A)
Neumann KH 120 II: 15 dB (A)

 

[hashhar]

I doubt the correlation let alone the causation. It's more likely to be implementation specific.

Not really. Having a ground pin can cause problems IF you have a ground loop.

 

[somebodyelse]

Not really. Having a ground pin can cause problems IF you have a ground loop.

And leakage currents can cause a similar problem even without the ground pin. In both cases you need a properly engineered system to ensure ground-related noise is kept out of the signal.

 

[Krit]

I doubt the correlation let alone the causation.

Highly disagree with you i have a lots of studio monitors in past and around six different subwoofers in total. Only subwoofer that makes noises comes with 3pin ac input and the same aplies to studio monitros they all hiss with Class D amplification and 3pin ac input. Only Class AB is somewhat decent in hiss area when using 3pin ac input.

These manufacturers who are using 3pin ac input and Class D amplification for speakers or SUB are making a big mistake because two pin ac input is correct way to go.

 

[somebodyelse]

Highly disagree with you i have a lots of studio monitors in past and around six different subwoofers in total. Only subwoofer that makes noises comes with 3pin ac input and the same aplies to studio monitros they all hiss with Class D amplification and 3pin ac input. Only Class AB is somewhat decent in hiss area when using 3pin ac input.

These manufacturers who are using 3pin ac input and Class D amplification for speakers or SUB are making a big mistake because two pin ac input is correct way to go.

Back to post #364 - joint top of the list (least measured hiss) is the Kii Three which has class D amps and 3 pin ac input. Meanwhile the KRK Rokit 6 that featured in EEVBlog #1118 - Why are studio monitors noisy? uses class AB amps. Do the engineering right and you can make a quiet monitor, irrespective of amp class or whether the AC input includes safety ground.

 

[AnalogSteph]

Yeah. I can see major correlation with interoperability issues like ground loops or Pin 1 Problem (which may manifest as increased hiss when combined with switch-mode power supplies and layout issues *cough* JBL 305 *cough*), but not inherent noise floor that's always present even with the input shorted.