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Passive vs active DSP speakers KEF and Genelec

HooStat

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#1
I have read that active speakers with DSP are, all other things equal, better performing speakers than passive. The "all things equal" part is nearly impossible for most speakers, of course. But looking at the KEF R3 and the Genelec 8341A, it is interesting how little difference there is in the spinorama measurements. Both are coaxial 3-way speakers that have been recently measured, and both companies provide similar measurements to those provided by Harman, so I thought it was instructive to think about these two options.

There are certainly other benefits of active dsp speakers -- room correction becomes much easier as does sub integration. But in a real-world listening room with proper setup, I wonder if there would be much difference? Particularly on the cost side -- the do-it-yourself approach with KEF leaves plenty of budget for the amp, DAC and subs of your choice.

Is there more to the active + DSP approach that I am missing, or that is there, but more subtle in the measurements?
 

andreasmaaan

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#2
There are a few benefits of DSP-based active speakers that are probably worth mentioning.

Firstly, there is finer control over frequency response and crossover filters. This means that smoother and more accurate overall response can be achieved, as well as more linear phase response (although the former can be sufficiently realised with well-designed passive crossovers, and the latter is of questionable audible benefit).

Secondly, there are fewer limits than with passive crossovers, as differences in drivers' physical locations (for example between a midrange and a tweeter) that might otherwise be problematic or unworkable can be partially mitigated by (for example) digital delay, steep(er) crossover filters, etc. This might allow, for example, for the use of a particular driver combination with otherwise desirable properties that could not be made to work passively. Essentially, active DSP gives the designer far more options.

Thirdly, the woofer(s) can be high-pass filtered and limited to optimise extension and output while minimising stress, although this is of relevance only if the speaker is intended to be run full-range (and it can actually be applied to the woofer of a passive speaker with DSP, too).

Finally, power is dissipated in the passive crossover, so active speakers will be, all else equal, more efficient.

OTOH, because the midrange and tweeter are more or less acoustically aligned in a coaxial driver, passive crossovers are likely to work very well (there is unlikely to be much need for delay or steeper crossover filters), i.e. coaxial speakers are probably the very best candidate for passive design.

Having said that, as good a speaker as the R3 is, it could be improved if the passive crossover were replaced with an active one.
 
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#3
Active speakers are better performing than passive. Better performing doesn't mean that performance advantage is operating on an audible level at the frequency response domain, which is what makes up either all or the majority of audible perception. A discrete amplifier is "better performing" than a chip amp, but it doesn't really mean anything if you are putting into a bathroom clock radio to listen to Howard Stern while you are taking a shower. It really depends on the parameters here.

Also active + DSP tends to be more expensive than just a passive design, so you should also factor a third candidate in passive + DSP (like Dirac Live).
 

Sancus

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#4
The Kef R3 is 40% larger than the 8341a, yet the 8341a still has better bass extension. A lot of the nearfield studio monitors are designed around packing as much performance as possible into a small space. The real comparison for the R3 would be the 8351B, which hasn't been reviewed, but which has a -6db point that is roughly 10hz lower than the R3, and incrementally better measurements in all other aspects.

Genelec 83xx are definitely not cost effective though, no question about that, but they're not really designed to be. The Ones are their halo product targeted at buyers who don't care much about price. I wouldn't say that there's many cases where an active speaker is a better BARGAIN. They do have a higher theoretical performance capability, that's all. But typically a premium is charged for the performance level.

In general, your price/performance ratio gets worse the higher the performance level you seek. One could easily make the argument that the Kef R3 are very overpriced compared to the Elac DBR62, but that's just not how the market works.
 
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HooStat

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Thread Starter #5
Also active + DSP tends to be more expensive than just a passive design, so you should also factor a third candidate in passive + DSP (like Dirac Live).
OK. I had not really looked at that option. So, add miniDSP to the R3. Is that going to get you to the Genelec level? Or are some important things not possible unless you are "inside the speaker"? I don't know anything about Dirac or miniDSP, so apologies if this is obvious.
 

andreasmaaan

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OK. I had not really looked at that option. So, add miniDSP to the R3. Is that going to get you to the Genelec level? Or are some important things not possible unless you are "inside the speaker"? I don't know anything about Dirac or miniDSP, so apologies if this is obvious.
It would get you quite close IMO.

The 8341 would still have slightly smoother off-axis response, but both speakers are already well ahead of most others in this regard anyway. It would also have wider dispersion than the R3.

The R3 would play slightly louder, with overall lower distortion.

On most other metrics I reckon the two would be fairly close.
 

q3cpma

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#7
OK. I had not really looked at that option. So, add miniDSP to the R3. Is that going to get you to the Genelec level? Or are some important things not possible unless you are "inside the speaker"? I don't know anything about Dirac or miniDSP, so apologies if this is obvious.
The ability to do the crossover in digital can bring some nice advantages. I guess the speaker can be calibrated at the factory using this.
But since the R3 is bi-amplifiable, anything is possible (would be nice for KEF to give some ideal crossover settings, though).
I wouldn't say that there's many cases where an active speaker is a better BARGAIN.
If you add the amp to the equation, most budget actives are real "bargains"; especially when you consider the corner cutting going into passive crossovers. Even something like the 8030C or KH120A, with their examplary performances, would probably be much more expensive on the passive side of the river.

Really, you must consider the competition, because KEF's R3 (made in China) isn't something I'd compare to the 8341A/8351B in general quality. The Reference 1, made in Britain and costing $8000 , is a better match for a flagship.
 
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#8
OK. I had not really looked at that option. So, add miniDSP to the R3. Is that going to get you to the Genelec level? Or are some important things not possible unless you are "inside the speaker"? I don't know anything about Dirac or miniDSP, so apologies if this is obvious.
With DSP, whether you are using active or passive, you are reducing some dynamic range in order to flatten the response of the driver. The Genelecs probably have significant DSP to flatten the response, especially in the bass range. But the trade-off here is the drivers start to compress at a much lower overall SPL, which is a common complaint of the Genelecs, but that's fine since they are designed for and are mostly used for nearfield.

With DSP you won't get both speakers to sound exactly the same because their dispersion curves are a little different. Both have uniform 3d dispersion but I believe the KEFs are a bit narrower and less uniform but the difference is quite slim and won't be audible unless you are actually outside of the listening axis with both speakers and we are talking about small degrees of difference here. With this case I don't think this has anything to do with active or DSP, the Genelec probably just has better designed waveguide geometry.

The active speaker has much steeper crossover curves possible than with a passive crossover. Mainly the advantage here is better rejection of ringing (if it exists) in the woofer above where it's crossed over but since KEF is using aluminum which doesn't really have major ringing issues it shouldn't be an obvious advantage. Back in the mid 2000s all the rage was DEQX with 10,000db/octave active crossover slopes which you could use to tame woofer ringing issues with exotic driver materials, but that's sort of died down these days.

An active speaker that has discrete amps in theory is more efficient since each amp can be paired specifically to a driver but it's not known if the are any actual audible benefits from this.
 
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napilopez

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#9
I have read that active speakers with DSP are, all other things equal, better performing speakers than passive. The "all things equal" part is nearly impossible for most speakers, of course. But looking at the KEF R3 and the Genelec 8341A, it is interesting how little difference there is in the spinorama measurements. Both are coaxial 3-way speakers that have been recently measured, and both companies provide similar measurements to those provided by Harman, so I thought it was instructive to think about these two options.

There are certainly other benefits of active dsp speakers -- room correction becomes much easier as does sub integration. But in a real-world listening room with proper setup, I wonder if there would be much difference? Particularly on the cost side -- the do-it-yourself approach with KEF leaves plenty of budget for the amp, DAC and subs of your choice.

Is there more to the active + DSP approach that I am missing, or that is there, but more subtle in the measurements?
I'm a big fan of active DSP speakers, but there's nothing magical about them, they just give designers more flexibility to work with. I think the evaluations here have shown that even if its very difficult for passive speaker to get that last bit of flatness and pretty graphs, they can come pretty darn close.

Imo the biggest practical disadvantage of passive speakers is bass extension. Passive speakers just can't get the same bass extension as active ones for a given size.

Of course, that bass extension comes with limitations in SPL or distortion, but depending on your listening habits those may not be an issue. If the speaker is decently designed in the first place, chances are the engineers considered your likely use case (i.e., that you're not using a tiny studio monitor in a massive living room). Still, a well-designed active speaker can be pushed pretty far: the speaker with the best (or at least, most) bass out of the box I've heard in my home is the Devialet Phantom Reactor, and the thing is smaller than an american football. Though it has SPL limitations, I never listened loud enough to reach them.

On the other hand, there are some practical disadvantages to active speakers too, mainly worrying about the electronics. You also usually end up with more cables, as you need both power cords and something for the sound.
 

q3cpma

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#10
But the trade-off here is the drivers start to compress at a much lower overall SPL, which is a common complaint of the Genelecs
It was a measured problem with the 8351A, but not really with the 8341A or 8351B. And obviously not with the 83x0. It's more about the "racetrack" drivers being highly experimental and not providing enough surface to get the full grunt; a subwoofer, that you'd be using anyway, solves the problem.

8331-MAX-1024x767.png

Genelec-8351A-Studiomonitor-Messungen3.png

Genelec-8350A5.png

I'd really like for Amir to make curves like this, since it's the real missing bit.
 

Sancus

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#11
If you add the amp to the equation, most budget actives are real "bargains"; especially when you consider the corner cutting going into passive crossovers. Even something like the 8030C or KH120A, with their examplary performances, would probably be much more expensive on the passive side of the river.
That's true, there certainly ARE budget actives, like the JBL 305ps and Kali's stuff. But it seems like high-performing actives in the midrange of prices($~1K/speaker) are rare for whatever reason. The JBL 705/708p seem somewhat disappointing. I'm not really convinced the 8030C/8040B would do better either. The KH120 is certainly good, but it also doesn't seem quite up to standard here. It is a 10-year-old design. There are persistent rumors that Neumann is working on a KH120 DSP, if they ever get that finished, it should be very interesting to say the least.

I'm not sure if we just haven't reviewed an amazing active speaker in this price region yet, or if they really are that uncommon. I'd been hoping the Kali IN-8 would break into Genelec performance levels, but it came up short, even with the fixed woofer. But it has a very low price point. If the LS50W is anything to judge by, Kef themselves seem perfectly aware that you can improve any of their passive designs by making them active, so, maybe they'll do that with the R-series one day.
 
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HooStat

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Thread Starter #12
even if its very difficult for passive speaker to get that last bit of flatness and pretty graphs, they can come pretty darn close
This is what I am coming to more fully appreciate. And, I assume that something like miniDSP can help with the flatness to some degree. It seems that the main issue is working through a passive crossover. I read in another thread that some people take them out and use miniDSP to re-create and improve the cross-over. That is beyond my interest level, but very interesting.
 

q3cpma

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#13
That's true, there certainly ARE budget actives, like the JBL 305ps and Kali's stuff. But it seems like high-performing actives in the midrange of prices($~1K/speaker) are rare for whatever reason. The JBL 705/708p seem somewhat disappointing. I'm not really convinced the 8030C/8040B would do better either. The KH120 is certainly good, but it also doesn't seem quite up to standard here. It is a 10-year-old design. There are persistent rumors that Neumann is working on a KH120 DSP, if they ever get that finished, it should be very interesting to say the least.

I'm not sure if we just haven't reviewed an amazing active speaker in this price region yet, or if they really are that uncommon. I'd been hoping the Kali IN-8 would break into Genelec performance levels, but it came up short, even with the fixed woofer. But it has a very low price point. If the LS50W is anything to judge by, Kef themselves seem perfectly aware that you can improve any of their passive designs by making them active, so, maybe they'll do that with the R-series one day.
I'd surmiss that the 2k/pair being a little barren is due to the 2-way -> 3-way jump. You have the 8340, maybe.
 

napilopez

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#14
That's true, there certainly ARE budget actives, like the JBL 305ps and Kali's stuff. But it seems like high-performing actives in the midrange of prices($~1K/speaker) are rare for whatever reason. The JBL 705/708p seem somewhat disappointing. I'm not really convinced the 8030C/8040B would do better either. The KH120 is certainly good, but it also doesn't seem quite up to standard here. It is a 10-year-old design. There are persistent rumors that Neumann is working on a KH120 DSP, if they ever get that finished, it should be very interesting to say the least.

I'm not sure if we just haven't reviewed an amazing active speaker in this price region yet, or if they really are that uncommon. I'd been hoping the Kali IN-8 would break into Genelec performance levels, but it came up short, even with the fixed woofer. But it has a very low price point. If the LS50W is anything to judge by, Kef themselves seem perfectly aware that you can improve any of their passive designs by making them active, so, maybe they'll do that with the R-series one day.
Not sure the KH120 is invalidated for being an old design though! For all intents and purposes it's as flat as the KH80. And the KH80 itself is a bit underrepresented here (high end squiggles, mic calibration, reference axis). But yeah, it'd be nice to have more in the price range. I wish devialet made a barebones monitor version of the Phantom Reactor...
 

Ron Texas

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#15
Many studio monitors have a way of running out of gas so to speak. This was reported by our host in the test of the Adam SV2 noted as a rare exception. The 8341 may test better than anything else out there, but it was observed to have a limited maximum output. Fine for your desktop, but not for typical midfield listening. Comparing it to the R3, which can reach SPL's usually associated with mid size floor standing speakers, and also has excellent measurements does not make sense to me.
 

Sancus

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Not sure the KH120 is invalidated for being an old design though! For all intents and purposes it's as flat as the KH80. And the KH80 itself is a bit underrepresented here (high end squiggles, mic calibration, reference axis). But yeah, it'd be nice to have more in the price range. I wish devialet made a barebones monitor version of the Phantom Reactor...
True, I think a review of the KH120 would definitely be interesting and perhaps it is more competitive than I give it credit for.

Many studio monitors have a way of running out of gas so to speak. This was reported by our host in the test of the Adam SV2 noted as a rare exception. The 8341 may test better than anything else out there, but it was observed to have a limited maximum output. Fine for your desktop, but not for typical midfield listening. Comparing it to the R3, which can reach SPL's usually associated with mid size floor standing speakers, and also has excellent measurements does not make sense to me.
I'm not sure this actually matters if you're using them with subs as the OP indicates a desire to do. Genelec Ones, when properly evaluated for SPL(which, as much as I like ASR, Amir simply doesn't do at all) show roughly 10db less output capability below 100hz, and 10db is a huge amount. It's not clear to me that the R3s would be able to get any louder than the 8341a in the midrange and up. But of course, it's pretty hard to say since we don't have apples-to-apples evaluations at high SPL for either.
 

napilopez

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#18
Many studio monitors have a way of running out of gas so to speak. This was reported by our host in the test of the Adam SV2 noted as a rare exception. The 8341 may test better than anything else out there, but it was observed to have a limited maximum output. Fine for your desktop, but not for typical midfield listening. Comparing it to the R3, which can reach SPL's usually associated with mid size floor standing speakers, and also has excellent measurements does not make sense to me.
Whille everything you say is true, I also imagine most people buy the model with the output they need. It's also been noted that Amir usually listens louder than the average person, in a larger space than the average person. Plus crossing with a sub makes smaller monitors way more competitive with passive bookshelves.


True, I think a review of the KH120 would definitely be interesting and perhaps it is more competitive than I give it credit for.
I also think that the samples here have been tested here are heavily skewed towards speakers I'd already expect to perform well. Lots of JBLs, Revels, KEFs, Infinitys, Pioneers, ELACs, but comparatively few from less 'toole school' companies, perhaps because most of the readership cares about measurements. So I don't think the differene between the 8s and 7s is as much as it might appear. The average ignore LFX score so far is a 6.6 which I'd be willing to bet is well above the mean of the enthusiast audio market.
 

q3cpma

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#19
Many studio monitors have a way of running out of gas so to speak. This was reported by our host in the test of the Adam SV2 noted as a rare exception. The 8341 may test better than anything else out there, but it was observed to have a limited maximum output. Fine for your desktop, but not for typical midfield listening. Comparing it to the R3, which can reach SPL's usually associated with mid size floor standing speakers, and also has excellent measurements does not make sense to me.
That's not what hard data says and the 8341A is only one model. As long as the reviews don't include any SPL measurements, I don't see the point of this.

Everything being equal, active speakers should probably be able to play a bit louder due to steeper crossovers slopes. Not that's it's an important difference; but the efficiency gains of direct amplifier-to-driver connection means that you'll need to buy a fat amplifier to get the same dynamic capabilities.
 

Koeitje

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#20
The Kef R3 is 40% larger than the 8341a, yet the 8341a still has better bass extension. A lot of the nearfield studio monitors are designed around packing as much performance as possible into a small space. The real comparison for the R3 would be the 8351B, which hasn't been reviewed, but which has a -6db point that is roughly 10hz lower than the R3, and incrementally better measurements in all other aspects.
All this is just the DSP pushing the low end, so you trade peak SPL for more bass extension. You can do the same with the KEF with a DSP in front of it.
 
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