JBL One Series 104 Powered Monitor Review

[Francis Vaughan]

Why is this hiss so common with powered monitors, but not with passive speakers?

Hiss isn't generated in the speaker*, it is generated in the signal chain feeding the speaker. Powered speakers put some of this chain inside the speaker cabinet. These speakers are silly cheap. The hiss is a reflection of the quality of the amplifier they used. You could just as easily get a passive speaker that hissed if you fed it from a noisy amplifier and signal chain. Try pricing up even the cheapest passive speakers plus an amplifier. These various powered monitor speakers are astounding for their price. The 104's are probably pushing price as hard as you can reasonably go an still retain performance. Every single design element will have been balanced for price/performance. This is where having a big company with high end design and testing capability, and in-house manufacture of drivers wins. They have to make calls on the balance, and noise perfomance is going to be one of them. Class D amplifiers can be a noisy problem, but it may be a case of taking some noise, or not being able to make the price point. Eventually the market decides if you got it right.

*Ignoring thermal noise in the voice coil, which is so far below hearing threshold to be essentially non-existent.

 

[bobbooo]

Common with cheap monitors mostly... But think about it, the amp is open full gain. So unless it has a great SINAD, it will be hissy. And speakers like this Samsung 104, use the cheapest chip amps they can find.

If you have passive speakers, turn the volume all the way up, without anything playing, and see if you can hear the hiss.

I can hardly hear any hiss from my cheap AV receiver and budget passive speakers, and none at my maximum listening volume, so the amps in these powered monitors must be seriously awful. Even the JBL 305P had hiss, and they're not that cheap. Makes me wonder why AV receivers are reviewed so badly as stereo amps due to their low SINAD, yet many powered speakers with even higher noise floor are lauded.

 

[Thunderlips]

I can hardly hear any hiss from my cheap AV receiver and budget passive speakers, so the amps in these powered monitors must be seriously awful. Even the JBL 305P had hiss, and they're not that cheap. Makes me wonder why AV receivers are reviewed so badly as stereo amps due to their low SINAD yet many powered speakers with even higher noise floor are lauded.

These are all bottom of the barrel monitors. Everything about them is seriously awful. But get some Neumann or Genelec and it will be a different story.

 

[jhaider]

One thing - when dealing with coaxes or round waveguides it's probably more reasonable to point out dips as on axis cancelations than just "rough treble."

I can hardly hear any hiss from my cheap AV receiver and budget passive speakers, and none at my maximum listening volume, so the amps in these powered monitors must be seriously awful.

Passive crossovers usually include significant resistance on the tweeter. This resistance will attenuate amplifier noise. A biamped active speaker is the worst case scenario for hiss.

 

[gvl]

As well as some others I got these for $50 on a Black Friday deal. Mediocre measurements notwithstanding the 104 is probably the best speakers $50 can buy. I wasn't blown away by what I hear but I was pleased. The built in EQ explains the amount of bass they can produce. Given the size I expected them to sound tinny but they sound pretty big for their size. Keeping the volume knob notch to the left of 12 o'clock takes care of the hiss. As for the angling them in reco in the manual, if you set them on the desk as they also suggest your ears remain off axis and the cancelation will remain at the chest level, for most people anyway.

 

[Milt]

What do you expect for $129?
Me, not much

 

[Thunderlips]

What do you expect for $129?
Me, not much

A waste of time.

 

[jhaider]

While this data is interesting, I think this speaker is also the rare case where the full anechoic data does necessarily map to the intended usage.

The data that seems most relevant here is a spatial average of them placed as intended (i.e. on a desk) in a number of points - per Geddes and Blind 5 should do it - that describe an approximate head position of a listener seated at that desk. I would just buy a pair, but our basement is already full enough of my idle audio equipment. I'm leery of the ethics of buy-test-return. If anyone in or around Atlanta has a pair and is interested, feel free to message me.

 

[napilopez]

While this data is interesting, I think this speaker is also the rare case where the full anechoic data does necessarily map to the intended usage.

The data that seems most relevant here is a spatial average of them placed as intended (i.e. on a desk) in a number of points - per Geddes and Blind 5 should do it - that describe an approximate head position of a listener seated at that desk. I would just buy a pair, but our basement is already full enough of my idle audio equipment. I'm leery of the ethics of buy-test-return. If anyone in or around Atlanta has a pair and is interested, feel free to message me.

Yeah, not trying to get into another KH80 debate at all, but it would be interesting to see that. I still have the 104s so I can give that a go sometime. JBL says the speakers are specifically designed to be used right on a desk so that might tame the highs a bit. Doesn't seem to be anything to specifically account for a desk reflection in the frequency response but at least the coaxial design means it's less detrimental than it might otherwise be.

 

[bigjacko]

One thing - when dealing with coaxes or round waveguides it's probably more reasonable to point out dips as on axis cancelations than just "rough treble."



Passive crossovers usually include significant resistance on the tweeter. This resistance will attenuate amplifier noise. A biamped active speaker is the worst case scenario for hiss.

What is the cause of axis cancellation? Is it because of baffle diffraction? For passive crossover how does the resistance attenuate the hiss? Thought the high pass should leave the high frequency unchanged.

 

[hugodlc]

Bought 2 pairs for Atmos ceiling speakers, but after installing, the level needed made the hiss a dealbreaker, but then I tested the balanced connection, and the Hiss was gone even at full blast.
I think the 104's make great ceiling speakers as long as you don't mind carving mounting holes on wood boards.

 

[jhaider]

What is the cause of axis cancellation? Is it because of baffle diffraction?

Symmetry, I believe. There are plenty of others on this thread who know a lot more than I do, so if one of them offers a different answer I am inclined to defer.

For passive crossover how does the resistance attenuate the hiss?

By lowering the overall level of the tweeter. Say the tweeter on its own is 90dB/2.83V/1m sensitive. In a passive system you're not going to get a 90dB/2.83V/1m woofer unless you accept zero bass. Often the value will be close to 82dB/2.83V/1m to 85dB/2.83V/1m. So for good spectral balance resistors in the tweeter crossover circuit will lower the tweeter level by 5-8dB. Hiss will therefore be lowered by approximately that amount.

By contrast, in an active speaker balancing the driver levels typically happens before the amps, i.e. either in the active crossover circuits or by varying the amp gain itself. There is nothing between the amp and tweeter to attenuate the hiss.

 

[jhaider]

Yeah, not trying to get into another KH80 debate at all, but it would be interesting to see that.

I was not suggesting anechoic data shouldn't be taken, nor is what I proposed a job for the Klippel equipment.

Hopefully that was clear, if implied. Still, for the sake of clarity I should state it rather than imply it.

 

[Thomas savage]

A waste of time.

Responding to multiple reported post authored by this individual

A little bit like your contributions, repeatedly rude and insulting remarks across several threads has earnt you a suspension.

 

[Jimster480]

I had never heard of these before; but they actually seem decent for $70. However with all the bluetooth speakers I've been testing for Amazon; I can tell you that there are a bunch of "decent" soundbar type bluetooth speakers for $12-35.

Maybe you can test some of them here?

 

[rajapruk]

For what frequency?

A frequency that looks really good
Maybe like 800Hz for woofer operation alone and 5KHz for tweeter operation alone.
And maybe the crossover area, was it 1800Hz?

 

[Juhazi]

What is the cause of axis cancellation? Is it because of baffle diffraction? For passive crossover how does the resistance attenuate the hiss? Thought the high pass should leave the high frequency unchanged.

A waveguide is a short and shallow horn, as well a coaxial unit's woofer makes a horn for the tweeter. This horn gives gain (increased spl) to certain range of frequencies by concentrating/narrowing radiation pattern. Below certain freq, this "loading" doesn't happen anymore (around 2kHz with IN-8). And at high frequencies loading doesn't happen any more, but soundwaves start to make interferences in the horn - this makes on-axis response and directivity ragged (around 8kHz with IN-8). When frequency goes even higher, tweeter's junction to the woofer/midrange makes interferences, typically above 10kHz.

Coaxial units can have very smooth directivity both horizontally and vertically, and thus very smooth listening window and power response, giving excellent imaging and wide sweet spot. But they are extremely difficult to make!

KEF has made tremendous work with coaxials, check their website for more info.
https://us.kef.com/blog/uni-q-far-more-than-a-co-axial-speaker
https://us.kef.com/innovation

In case of JBL 104, naturally the framework/body of the speaker makes more interferences, the driver unit should always be flush mounted on the surface of baffle, not in a cavity in a narrow baffle with sharp edges!

 

[bigjacko]

A waveguide is a short and shallow horn, as well a coaxial unit's woofer makes a horn for the tweeter. This horn gives gain (increased spl) to certain range of frequencies by concentrating/narrowing radiation pattern. Below certain freq, this "loading" doesn't happen anymore (around 2kHz with IN-8). And at high frequencies loading doesn't happen any more, but soundwaves start to make interferences in the horn - this makes on-axis response and directivity ragged (around 8kHz with IN-8). When frequency goes even higher, tweeter's junction to the woofer/midrange makes interferences, typically above 10kHz.

Coaxial units can have very smooth dierectivity both horizontally and vertically, and thus very smooth listenig window and power response, giving excellent imaging and wide sweet spot. But they are extremely difficult to make!

KEF has made tremendous work with coaxials, check their website for more info.
https://us.kef.com/blog/uni-q-far-more-than-a-co-axial-speaker
https://us.kef.com/innovation

In case of JBL 104, naturally the framework/body of the speaker makes more interferences, the driver unit should always be flush mounted on the surface of baffle, not in a cavity in a narrow baffle with sharp edges!

View attachment 47438

Thanks for explaining, just have a few questions. What is IN-8? Does all horn and coaxial create interference? A lot of people like horn and coaxial designs, does the interference affect the sound of them a lot?

 

[thewas]

In the end every edge/discontinuity creates interference, also on not-coaxial or non-horn drivers, the problem at coaxial drivers is that their edges are usually symmetrically (all at the same radius) so they add up, only very few manufacturers like KEF and Genelec (who uses a patent from KEF) have perfectionised them after several iterations to minimise those. On the other side coaxial drivers have less problems in the vertical radiation and you can't generalise, there exist great and not so great loudspeakers of both coaxial, classical, horn and other implementations and its very difficult to state out how much which problems contribute to what we hear as we hear total implementations. Almost everything in this world is a compromise and each one must find the one that suits better his own needs.

 

[Juhazi]

Thanks for explaining, just have a few questions. What is IN-8? Does all horn and coaxial create interference? A lot of people like horn and coaxial designs, does the interference affect the sound of them a lot?

Sorry, Kali Audio IN-8 has coaxial mid-tweeter, and was recently tested by Amir. JBL 104 is the second coaxial tested here so far. Please check IN-8 off-axis response to see a textbook example of how a round coaxial behaves!
https://www.audiosciencereview.com/.../kali-audio-in-8-studio-monitor-review.10897/