Hiss List (S&R)

[pozz]

Lots of discussion about hiss lately, how perceptible or annoying it is, and if it matters.

I've created a sheet with Sound & Recording measurements of hiss in active loudspeakers: https://docs.google.com/spreadsheets/d/1n62hGAdKptSSKC74_fIT_R7DxFJ60YR2_O9C8x-vYQI/edit?usp=sharing Viewers can comment if something's off or missing.

S&R measures hiss in dB SPL (A-weighted) at 10cm in a calibrated anechoic chamber. Using the basic rule of 6dB decline for every doubling of distance (or the inverse square law), the chart below shows how far away you have to be for hiss to reach 0dBa. It's a simplified model since it doesn't take into account critical distance, reinforcement through reverberation, room noise, spectrum or masking.



A-Weighting was originally developed to assess speech intelligibility, but has since become a standard metric for environmental noise because it broadly centers around the most sensitive area of our hearing. @sweetchaos also measured the hiss of his JBL 305P Mk2 here and here, with the result centering around 2kHz, for example.

Room noise tends to rapidly decline from the bass region onwards, and falls close to 0dB SPL once you get into the kHz range. There is of course a lot of variation in ambient conditions and you can expect some hiss to be masked, most prominently by the music itself when it's playing.

Some other stats of the set:

 

[Deleted member 65]

My recently acquired Adam Artist 5 seems to fair quite well.

 

[pozz]

My recently acquired Adam Artist 5 seems to fair quite well.

The old ADAM A7 and ADAM S2V I used had prominent hiss, though I got used to ignoring it. Neither were measured, but the A77X and S3V had 29.5dBA and 22dBA.

Edit: I found an A7 measurement in an old S&R article: 25dBA.

 

[Juhazi]

Pozz, do you know more info about these hiss measurements, Is is with Level at max, no signal in?

 

[tmtomh]

@pozz , thanks for this - this is excellent, in fact IMHO essential, for considering powered monitors. We all have different preferences, but personally I can't stand significant hiss/self-noise.

 

[pozz]

Pozz, do you know more info about these hiss measurements, Is is with Level at max, no signal in?

I can't read German, so I miss all of the commentary by Prof. Goertz. Maybe another member can help here.

 

[pma]

It might be interestIng to include the hiss into the SINAD war charts. Because if you try to come to conclusion that the hiss in active speakers does not matter, then SINAD of dacs and amps does not matter twice .

 

[pozz]

@pozz , thanks for this - this is excellence, in fact IMHO essential, for considering powered monitors. We all have different preferences, but personally I can't stand significant hiss/self-noise.

I was surprised how many companions the KH 80 DSP had, and how many beat it. It's by far the quietest active speaker I've heard. Nothing at 1m at home.

 

[waynel]

This is great, thanks for compiling. I wonder how they chose the settings for the hiss measurement. My KH120s don't have audible hiss at the gain settings that I use but can if you crank the gain knob and sensitivity switch up,

 

[pozz]

It might be interestIng to include the hiss into the SINAD war charts. Because if you try to come to conclusion that the hiss in active speakers does not matter, then SINAD of dacs and amps does not matter twice .

You can't help spreading your ire around, can you? You miss the point.

Hiss matters and impacts the experience for a lot of listeners. Actively ignoring it is tiring, and electronics can mess things up further if you don't know what you're buying or how to set it up. For the millionth time, the charts do not replace review commentary and the other presented data, or doing personal research.

It would be far more helpful if you would explain to members who have the wrong idea how to contextualize measured data instead of posting snide comments.

 

[waynel]

There is something very satisfying about a hiss-free setup even at closer than listening distances. I make it a requirement for all my systems and active speakers have the greatest challenge.

 

[Juhazi]

https://www.soundandrecording.de/equipment/studio-monitor-messdaten-verstehen/ (Google translate works quite well)

but I didn't find info about hiss measurement. But for sure that has been standardized, I believe.

Noise/hiss is in summary, and you can't see that or even other measurements if you stay too long on pages for free...

 

[pozz]

This is great, thanks for compiling. I wonder how they chose the settings for the hiss measurement. My KH120s don't have audible hiss at the gain settings that I use but can if you crank the gain knob and sensitivity switch up,

Same with the KH80s. If you use anything other than the 100dB sensitivity/output level setting the hiss goes up significantly.

 

[KSTR]

Nice to see that the ADAM F5 and F7 fare so well. I was the lucky one who was chosen to design the electronics and the "minimalist signal path" (for low cost, mind you) also paid off in the noise department.

 

[Berwhale]

Crikey, this must be one of the only lists on ASR where the Genelec don't do so well. 29 dBA from the £3k Genelec 8351A? That's worse than the JBL305p MKII's I sent back.

 

[maverickronin]

Surprised that the 305s are aren't further down in the bottom of the barrel.

 

[richard12511]

Crikey, this must be one of the only lists on ASR where the Genelec don't do so well. 29 dBA from the £3k Genelec 8351A? That's worse than the JBL305p MKII's I sent back.

In terms of audibility, there must be more to it, or I have weird samples, or the measurements are flawed, or the 8351b is a lot better than the a version.

I just used a laser to measure the distance I can no longer hear the hiss.

308p on the lowest input sensitivity was detectable to to 5'6" in my office with my macbook fan going.

8351b on the highest input sensitivity(to try and match the JTRs) was detectible to 2'2" in my living room that's much quieter(23 acoustic panels, 2 double layered sound absorption curtains, wool rug with absorption mat underneath).

Not running the A/C atm since it's cold outside.

 

[pozz]

8351b

The 8361A is from the same era as the 8351B, and does 5 dB better in hiss than the 8351A. That's definitely acoustically significant.

 

[richard12511]

The 8361A is from the same era as the 8351B, and does 5 dB better in hiss than the 8351A. That's definitely acoustically significant.

Perhaps that could mostly explain it. Also, I see the 308p(which I'm comparing) is ~2dB worse than the 305p, so maybe a 7-8dB overall swing(assuming the 8351b is as good as the 8361A).

 

[MarsianC#]

Let me know if you need something translated from german. I also have a copy of S&R's study monitor guide.

PS: I see, all of them are already included. Nice List!