Another issue is where the crossover lies in the signal chain. In an active speaker noise created after the active crossover filters plays at all frequency bands through all drivers. For example, kilohertz range noise plays through both tweeter and woofer (and midrange if >2-way). Woofers and mids won:t play treble noise "flat", but they will still play it some and haphazardly, and in some bands quite peaky. Passive crossover keeps the noise seen at each driver confined to its band.
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WHY oh WHY do monitors have hiss?!?
- Thread starter Head_Unit
- Start date
And you have self noise from 2 or 3 amps or more playing full spectrum noise to each driver ?
Added to the above I find my audiosmile monitors quiet enough, my KEF LSX are also Quiet but have some noise if go straight up to the speakers ( as previously mentioned the LS60 are very quiet )
What I’ve heard this can be an issue for nearfield monitors at living room distances it’s has to be really bad to be noticeable at all .
I must say that every stereo I had in the 80’s and 90’s very noiser and they where normal passive speakers.
Added to the above I find my audiosmile monitors quiet enough, my KEF LSX are also Quiet but have some noise if go straight up to the speakers ( as previously mentioned the LS60 are very quiet )
What I’ve heard this can be an issue for nearfield monitors at living room distances it’s has to be really bad to be noticeable at all .
I must say that every stereo I had in the 80’s and 90’s very noiser and they where normal passive speakers.
MrBlueSky4470
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Not all studio monitors have hiss. Genelec 8331 for example are specified 0dB / 1m and are absolutely inaudible to me when idle.
solderdude
Grand Contributor
In active monitors it is caused by design choices (costs, power, speaker sensitivity).
Then there is profit margin and expected sales numbers as well as the target audience.
Nearfield usage or not also makes a difference as well as age from the listener.
Then there is the noise spectrum.
In a room there often is a high noise level but mostly is low frequency (brown noise alike). In the mids and treble there is usually less noise and below audible levels. If there is 'white noise' or 'blue noise' it is probably some needed airflow or a device causing it.
Electronics usually have white noise and darn it ... our hearing is most sensitive in the 1-5kHz area and it does not take much of it to hear it when it is wide band.
This all leads to compromises in the design.
When buying a sensitive speaker or (ear-/head-phone) the self noise plays an important role.
Especially when auditioning active speakers audit at home, at night in a quiet room and determine at which distance you can hear hiss and if that is audible in your use case and bothers you.
Clearly some active speakers/systems have more background hiss than others... this is always a design choice that was made.
Then there is profit margin and expected sales numbers as well as the target audience.
Nearfield usage or not also makes a difference as well as age from the listener.
Then there is the noise spectrum.
In a room there often is a high noise level but mostly is low frequency (brown noise alike). In the mids and treble there is usually less noise and below audible levels. If there is 'white noise' or 'blue noise' it is probably some needed airflow or a device causing it.
Electronics usually have white noise and darn it ... our hearing is most sensitive in the 1-5kHz area and it does not take much of it to hear it when it is wide band.
This all leads to compromises in the design.
When buying a sensitive speaker or (ear-/head-phone) the self noise plays an important role.
Especially when auditioning active speakers audit at home, at night in a quiet room and determine at which distance you can hear hiss and if that is audible in your use case and bothers you.
Clearly some active speakers/systems have more background hiss than others... this is always a design choice that was made.
Roland68
Master Contributor
My three setups are relatively identical: desks about 160cm wide and 75-80cm deep, with the monitors positioned at the very back.
It's possible that you never hear anything from your monitors, and that's good for you. I certainly haven't tested every monitor, but I have tested most of the well-known and recommended ones.
No, I don't have any USB or grounding issues in my setups. Aside from the fact that I have plenty of fully isolated devices and effective industrial USB isolators for such tests, the setup is the same, except for replacing, for example, the PA5 II with an active monitor.
Furthermore, background noise is clearly distinguishable from such problems.
Déjà vu, someone told me something similar over 20 years ago
.Roland68
Master Contributor
That might be the case in other setups, but expert opinions aside, I can't confirm that from experience.Passive speakers hiss as well just usually a lot lower in volume where it might not be noticed. The reason is the crossover in a passive circuit absorbs some of the energy so it reduces the his volume. In an active speaker the amplifier is connected directly to the driver making it very sensitive to noise, so much easier to hear especially in the near field. Newer active designs are much better in general. Here is a thread which discusses it. I would definitely look at Ilka Rissanen's responses from Genelec. He is definitely an expert in this field.
Hissing from Genelec G Two at short range — should I be worried?
Hi - I’ve just bought one Genelec G Two active monitor (one unit), but it has a slight hiss (white noise) even with all input cables disconnected. The noise appears to come from the amplifier (no transformer/coils whining) and is mainly coming from the HF driver - it’s barely audible from the...
In my third setup, I'm testing a DBR62 without the passive crossover, using two PA5s and Acourate as an active system. Previously, it was a passive system with a DBR62 and a PA5 II.
It's just as quiet as the other two passive systems. The system is even located in a soundproofed lab where such noises are even more noticeable.
Exactly. Designing a really low noise active speaker is possible but comes at a cost as the signal chain and headroom situation is quite a bit more complex. One of the bigger issues is that the user volume control is usually upstream and outside of the monitor rather than just right before the internal amps which is the equivalent of the situation with amp and passive speakers.
Ultrasonic
Major Contributor
RFI and EMI
Where Can EMI/RFI Come From - Premier Filters
The sources of EMI can be both natural and man-made. Almost any electrical source has the potential to disrupt the electrical components of a product in its neighborhood.......premieremc.com
This is not what causes the hiss being discussed.
theREALdotnet
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Which again begs the question, how relevant are the things that we measure and fuss about? Are there other things we should be measuring instead, or in addition?
Yes, same here. I'm glad to have found a Purify amp that is dead silent during pauses in music.
Waxx
Major Contributor
My personal diy setup is active, and has no noise at all. I use Audiophonics Hypex based amps and a minidsp, that are all low noise by themselves. When i use my tube amp (that is not low noise) without passive crossover, I also got hiss, with a passive crossover not. Recently i changed the top end with a CD in horn to test the cd in horn, and even it's 110dB sensitive, i still hear no noise.
I think a big part is that many studio monitors use fairly cheap standard amplifiers that are not that great, and without passive filtering the noise get's into the sensitive tweeters. The cheapest to solve that would be add a few passive components to tame the tweeter volume, so the noise goes down. Or use better amplfiers (what will drive the cost up). But for very cheap speakers, that is certainly not an option. I'm not an electronics guy who know the ins and outs of how to solve this problem in amps, but there are active speakers (like Genelec or Neumann) with little to no hearable self noise at all, so it's not impossible. It's more a budget thing than a technical flaw.
I think a big part is that many studio monitors use fairly cheap standard amplifiers that are not that great, and without passive filtering the noise get's into the sensitive tweeters. The cheapest to solve that would be add a few passive components to tame the tweeter volume, so the noise goes down. Or use better amplfiers (what will drive the cost up). But for very cheap speakers, that is certainly not an option. I'm not an electronics guy who know the ins and outs of how to solve this problem in amps, but there are active speakers (like Genelec or Neumann) with little to no hearable self noise at all, so it's not impossible. It's more a budget thing than a technical flaw.
Sokel
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That's the specs (SNR as well) of the amp used at the Genelec 8020B monitor, taken from this thread:
Looks decent to me even if we add the analog and digital sins a DSP monitor caries.
Looks decent to me even if we add the analog and digital sins a DSP monitor caries.
popej
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I see some hypothesis, which doesn't seem right. To summarize:
Passive crossover do not suppress noise. It has very little influence in pass band and outside speakers usually aren't efficient enough to make a difference.
Amplifier chips work the same in active and passive design. There is no reason to assume, that they generate more noise in active speaker.
Active crossover works similar as tone control in setup with passive speakers.
DSP is common in AVRs, which do not exhibit excessive noise.
IMO the main difference is position of volume control in the whole chain of electronics. With passive design volume control is usually after DSP and tone control, effectively supressing any noise at low volume.
With active speakers, volume control comes before active crossover (analog or digital) and generated noise is the same, regardless of volume or input signal level.
Usually active speakers have its own volume trimmer. It is worth checking if this control suppress noise.
Passive crossover do not suppress noise. It has very little influence in pass band and outside speakers usually aren't efficient enough to make a difference.
Amplifier chips work the same in active and passive design. There is no reason to assume, that they generate more noise in active speaker.
Active crossover works similar as tone control in setup with passive speakers.
DSP is common in AVRs, which do not exhibit excessive noise.
IMO the main difference is position of volume control in the whole chain of electronics. With passive design volume control is usually after DSP and tone control, effectively supressing any noise at low volume.
With active speakers, volume control comes before active crossover (analog or digital) and generated noise is the same, regardless of volume or input signal level.
Usually active speakers have its own volume trimmer. It is worth checking if this control suppress noise.
because they have input level adjustments that can be set to high
ZolaIII
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Fun fact the low SPL white static noise helps focus people experiencing difficulties caused by tinnitus. It doesn't always have to be a bad thing. You put PA regarding sensitivity tweeter because there are so many of such and they are cheap and then you pair it with amp that doesn't do that part of the spectrum solid to start with and there you have it.
Yes there are some very quiet amps today , maybe active speakers should use such technology ?
We can get an inkling on the absolute noise levels from amirs 5w measurement , but sure an absolute number in uV would be interesting
RobL
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Is there not hiss simply because self powered monitors must operate with their amps “wide open” to be able to give full output as attenuation is located upstream? You can replicate this if you have separate power amps on your passive speakers by turning the gain knobs wide open. You’ll get hiss.
RexrothPigeon
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lol any amp that is noisy during pauses in the music is borked
Waxx
Major Contributor
My Hypex based Audiophonics MPA-S125NC amps don't have that, and the volume knob is upstream in the minidsp flex. The Hypex amps i have have no volume kob.
I did use this with drivers between 89 and 110dB sensivity (2.83v/1m) without passive components between driver and amp, and could not hear nothing of hiss or other noise. With other lesser class D and tube amps i have hiss without passive attenuation or filtering.
I’ve been using cheap ‘studio monitors’ (Yamaha HS5) for years. I always tolerated the noise because I thought it was from the computer or ground loop. Turns out, yeah, they were just shite.
Recently I got a topping mini 300 amp and Dali Sonik 3 speakers. Dead silent.
There’s a lot of good reasons listed previously as to why this might be the case with studio monitors. But I also think that people buying cheap ish monitors aren’t into hifi (like I was) and just tolerate the noise. You can still make a decent mix with them, and they’re likely to be an upgrade from whatever was previously being used. Therefore there isn’t much incentive to put half decent amps in them.
Recently I got a topping mini 300 amp and Dali Sonik 3 speakers. Dead silent.
There’s a lot of good reasons listed previously as to why this might be the case with studio monitors. But I also think that people buying cheap ish monitors aren’t into hifi (like I was) and just tolerate the noise. You can still make a decent mix with them, and they’re likely to be an upgrade from whatever was previously being used. Therefore there isn’t much incentive to put half decent amps in them.
