Studio monitor speakers without hiss?

[AnalogSteph]

Audible tweeter hiss is a problem that could be solved quite easily by including a resistive dropper or L-pad from the factory - much like what you find in the tweeter section of a passive speaker's crossover. Usually max SPL will be limited by the driver rather than amplifier output anyway, so you can bring up gain before that as needed. (Higher load impedance also reduces amplifier crossover distortion, in case that's a factor.)
Plan B would be using external compensation components to bring amplifier closed-loop gain even below specified minimums if needed. An extra series RC in the feedback network's ground leg for an ultrasonic gain increase to the level required for stability is one possible approach. Shouldn't matter much if you have to EQ / filter anyway.

The fundamental problem is that a bare tweeter in a waveguide can be a lot more sensitive than a finished speaker - sensitivities of around 92 dB / W / m are not untypical for a 1" even outside a waveguide, and inside one of the larger kind, sensitivity can reach 100 dB / W / m levels towards the lower end.

For 0 dB SPL of noise from a 90 dB / 2.83 V / m speaker, amplifier noise needs to be at 90 µV max. At 96 dB this limit decreases to 45 µV, at 100 dB to 28 µV.

The TDA2052 mentioned earlier exhibits 3 µV of input noise over a 20 kHz bandwidth and has a minimum stable gain of 30 dB. Implemented as suggested by the datasheet (Gv = 32.1 dB), output noise becomes 120 µV. Note how this value exceeds all the numbers given above. (BTW: It would still be considered very good for an integrated amplifier. These generally have substantially less sensitive speakers to contend with, of course - 85-90 dB / 2.83 V / m would be a typical range.)

LM3886 input noise is given as 2.0 µV, A-wtd (to which you can add about 2.2 dB for a 20 kHz flat equivalent, so maybe 2.5-2.6 µV flat). Minimum stable gain for this IC is 20 dB, though it can get rather finicky down there and is mostly used at 26 dB, sometimes more. So let's use the suggested standard values of 20k and 1k (Gv = 26.4 dB), which gives ~55 µV flat (44 µV A-wtd). That's more like it. Could be a tad lower still, but should yield acceptable results.

And that's purely power amplifier noise, assuming everything before is sufficiently low in noise that it doesn't matter (definitely not always true as proper gain staging must be observed, and the limits of converters in inexpensive DSP constructions are not making things any easier).

 

[Ilkless]

Audible tweeter hiss is a problem that could be solved quite easily by including a resistive dropper or L-pad from the factory - much like what you find in the tweeter section of a passive speaker's crossover. Usually max SPL will be limited by the driver rather than amplifier output anyway, so you can bring up gain before that as needed. (Higher load impedance also reduces amplifier crossover distortion, in case that's a factor.)
Plan B would be using external compensation components to bring amplifier closed-loop gain even below specified minimums if needed. An extra series RC in the feedback network's ground leg for an ultrasonic gain increase to the level required for stability is one possible approach. Shouldn't matter much if you have to EQ / filter anyway.

The fundamental problem is that a bare tweeter in a waveguide can be a lot more sensitive than a finished speaker - sensitivities of around 92 dB / W / m are not untypical for a 1" even outside a waveguide, and inside one of the larger kind, sensitivity can reach 100 dB / W / m levels towards the lower end.

For 0 dB SPL of noise from a 90 dB / 2.83 V / m speaker, amplifier noise needs to be at 90 µV max. At 96 dB this limit decreases to 45 µV, at 100 dB to 28 µV.

The TDA2052 mentioned earlier exhibits 3 µV of input noise over a 20 kHz bandwidth and has a minimum stable gain of 30 dB. Implemented as suggested by the datasheet (Gv = 32.1 dB), output noise becomes 120 µV. Note how this value exceeds all the numbers given above. (BTW: It would still be considered very good for an integrated amplifier. These generally have substantially less sensitive speakers to contend with, of course - 85-90 dB / 2.83 V / m would be a typical range.)

LM3886 input noise is given as 2.0 µV, A-wtd (to which you can add about 2.2 dB for a 20 kHz flat equivalent, so maybe 2.5-2.6 µV flat). Minimum stable gain for this IC is 20 dB, though it can get rather finicky down there and is mostly used at 26 dB, sometimes more. So let's use the suggested standard values of 20k and 1k (Gv = 26.4 dB), which gives ~55 µV flat (44 µV A-wtd). That's more like it. Could be a tad lower still, but should yield acceptable results.

And that's purely power amplifier noise, assuming everything before is sufficiently low in noise that it doesn't matter (definitely not always true as proper gain staging must be observed, and the limits of converters in inexpensive DSP constructions are not making things any easier).

Someone needs to license and integrate THX AAA into active speaker amp modules. Think a scaled-back AHB2.

 

[Alchemist_]

by the way, Presonus (R65) support assures me that I will not hear a hiss from a distance of 50-70 cm. or the usual distance for monitoring.

 

[restorer-john]

by the way, Presonus (R65) support assures me that I will not hear a hiss from a distance of 50-70 cm. or the usual distance for monitoring.

First review I came across:

 

[Alchemist_]

First review I came across:

View attachment 53535

I carefully read all the reviews that I found, reviews on this subject are really contradictory. I found a review when the user said that he did not hear the noise. I hope that some of the feedback is caused by grounding problems. and the hiss of the amplifier itself is not as strong...

 

[AnalogSteph]

One review I found says "subtly audible in quiet passages @ 1 m, barely detectable in silence @ 1.5 m". That doesn't scream "inaudible" to me. (The input was also noted to be quite hot, so you wouldn't even dare cranking 'em all the way up.) My current K+H O110s roughly halve these distances. Actually my old Tascam VL-X5s emanated even less hiss (to the point where you would basically have to put your ear next to the tweeter to hear any if the input wasn't turned up a great deal), but those also had a 3/4" tweeter with only a hint of waveguide (besides one tweeter emitted a rather nasty mains buzz).

Mackie MR series monitors have a pretty decent reputation for noise - but they seem to have what I guess is some transformer buzz in return. That's what you get with cheap toroidals mounted to a speaker cabinet. So... maybe Yamaha then?

Funnily enough, one of my O110s will also start to emit a bit of transformer buzz once in a while, until it suddenly stops again. I suspect it's something creating a DC component on the mains. (I might test whether a hairdryer at partial power would do it, but the things have a habit of making quite the racket.) Heaven knows why just one, maybe a loose winding? Only happens during daytime, too. I suspect the culprit is something rather industrial.

 

[Alchemist_]

One review I found says "subtly audible in quiet passages @ 1 m, barely detectable in silence @ 1.5 m". That doesn't scream "inaudible" to me. (The input was also noted to be quite hot, so you wouldn't even dare cranking 'em all the way up.) My current K+H O110s roughly halve these distances. Actually my old Tascam VL-X5s emanated even less hiss (to the point where you would basically have to put your ear next to the tweeter to hear any if the input wasn't turned up a great deal), but those also had a 3/4" tweeter with only a hint of waveguide (besides one tweeter emitted a rather nasty mains buzz).

Mackie MR series monitors have a pretty decent reputation for noise - but they seem to have what I guess is some transformer buzz in return. That's what you get with cheap toroidals mounted to a speaker cabinet. So... maybe Yamaha then?

Funnily enough, one of my O110s will also start to emit a bit of transformer buzz once in a while, until it suddenly stops again. I suspect it's something creating a DC component on the mains. (I might test whether a hairdryer at partial power would do it, but the things have a habit of making quite the racket.) Heaven knows why just one, maybe a loose winding? Only happens during daytime, too. I suspect the culprit is something rather industrial.

maybe Yamaha ... at least she doesn't hiss. I just wanted something more serious and with a flat frequency response.

 

[Alchemist_]

The first clue should have been the pitiful published noise spec of a mere 75 dB A-weighted. By comparison, Audio Engine rates the A5+ at 95 dB A-weighted.

Thus you might have to up your budget if you want quiet active speakers.

I can’t find a noise spec for my old Swans M200, but they are dead silent.

Regards,
Wayne A. Pflughaupt

please tell me - the lower this indicator (75 db A-weighted), the quieter the hiss at the time of downtime?

 

[sam]

Is there really a active speakers without the hiss at near distance? Most of the active speakers that I used for testing had hiss, but maybe it's because the speakers were in the low price range $100~$500.

 

[hyperplanar]

Is there really a active speakers without the hiss at near distance? Most of the active speakers that I used for testing had hiss, but maybe it's because the speakers were in the low price range $100~$500.

Yes, but it seems like you have to spend more to get a monitor without hiss.

 

[Erik]

by the way, Presonus (R65) support assures me that I will not hear a hiss from a distance of 50-70 cm. or the usual distance for monitoring.

THXstandard.com measured the self-generated noise levels of Presonus R65 and JBL LSR305 monitors. Unfortunately they decided to close the website, but IIRC the noise level of the R65 was not lower than the JBL's.

Presonus R65 measurements I saved from that website (frequency response and power response)



JBL LSR305

 

[Old Listener]

After all the post about hiss and hum from active speakers, I checked the Dynaudio LYD48 monitoras in my main system. I can hear a faint hiss with my ear 3" from the tweeter. At 12", I could perhaps convince myself that I could barely hear hiss. I am quite sure that I can't hear hiss at 18".

In months of use, I've never hear any his or hum from these monitors at my 8 to 9 foot listening position.

I think that the JBL 305 and 308 (and some competitors now appearing) represent great value and a real engineering achievement. I don't expect them to be perfect at their very low prices. I think some of the criticisms are overblown.

 

[anmpr1]

by the way, Presonus (R65) support assures me that I will not hear a hiss from a distance of 50-70 cm. or the usual distance for monitoring.

For PC use (I think I've mentioned this before) I use Presonus Eris 4.5 powered speakers. Not the Bluetooth model, but running digits from a Cambridge DacMag Plus. I don't hear any hiss. Some review comments on-line talk about hiss. So there are a couple of three takeaways: A) they have hiss but I can't hear it; B) my speakers don't have hiss but some examples do, so it's a variable thing C) at normal levels hiss is inaudible, but if you crank it up it could be. Again, I don't hear it in silent passages with mine, even if I put my ear next to the tweeter and turn it up.

With any of these small monitor speakers it's so easy to simply order them from your favorite guitar store, audition them in your setup, and find out for yourself whether it is a problem. Then return free of charge if you don't like them.

PS: one thing I have noticed, the left speaker appears to have lost some volume over the two years I've owned them--down probably a few dB. I use the balance control on MusicBee to level the channels out. This could be placement related (the louder speaker is in a corner). But given the overall price point of these speakers, I don't expect them to last forever. Who knows?

 

[Alchemist_]

THXstandard.com measured the self-generated noise levels of Presonus R65 and JBL LSR305 monitors. Unfortunately they decided to close the website, but IIRC the noise level of the R65 was not lower than the JBL's.

Presonus R65 measurements I saved from that website (frequency response and power response)

View attachment 53921View attachment 53922

JBL LSR305

View attachment 53923View attachment 53924

is it the noise level or is it the frequency response ?
if the frequency response is at Presonus it is much smoother, there is an frequency response on the official website and there is a detailed test for Prosound.ixbit that confirms this.

 

[Alchemist_]

Is there really a active speakers without the hiss at near distance? Most of the active speakers that I used for testing had hiss, but maybe it's because the speakers were in the low price range $100~$500.

I heard personally that it doesn 't hiss Yamaha HS.

I listened to Dynaudio Bm5 mk3 personally, I did not notice the hiss.. but I didn't pay attention to it then and when they turned on KRK RP5 G4 I heard a hiss. since then I 've been checking it everywhere)

they say that Tannoy Gold does not sizzle.

 

[Alchemist_]

Studying the topic of class D and hissing, I came to the conclusion that if manufacturers made the volume of the output sinal from the monitors and not only the volume of the incoming signal to the monitors.

then the noise level would decrease along with the level of music.
and the noise level would be the same with the music.

 

[gvl]

I recently picked a pair of Adam A3X monitors second hand. They hiss some. One speaker is worse than the other, I suspect there is some sort of issue as the hiss also comes through the woofer on that speaker, the other is much quieter and hisses through the tweeter only. Overall not very audible when the music is playing except low-level nighttime sessions. What I find surprising they distort if I feed them directly from a single-ended DAC into the RCA inputs, and speaker volume control doesn't help. Haven't tried the balanced inputs, going from RCA to XLR with an adapter will likely help.

 

[Alchemist_]

does anyone have any experience :
Mackie MR524/MR824(these don't seem to hiss. At least I didn't find any reviews about noise)
do they sizzle and how much (can there be an experience of comparison)?

 

[jonfitch]

I have some decent Genelecs (8040) and previously had the Focal beryllium monitors. Even expensive powered speakers will have more hiss than a typical passive speaker hooked up to a receiver, for the reason of post #2. Also even with passive speakers you can have some noise floor issues if you have a ton of separates hooked up one after the other as noise gets amplified with more and more analog devices hooked up. Generally you really only get near absolute silence if it's a passive speaker hooked up to an all-in-unit like a high end a/v receiver.

 

[usern]

Registered just to say that Presonus R65 is horrible in terms of hissing noise. If I listened something at low volume, then sometimes I could not tell if audio I'm playing back uses white noise or if it is the speaker self noise. Hihats can get drown in the noise. Horrible.