Passive speakers, separate boxes...help me understand the appeal

[Ilkless]

I wouldn't argue with anything you've written above, but to what does the phrase...

refer?

It's clear that any speaker design which prioritizes one particular holy grail over everything else is unlikely to succeed overall. Above all, speaker designers must not fall victim to failure to see the wood for the trees.

Green Mountain Audio is the name of a (now-defunct) cottage industry speaker manufacturer that retains a cult following on Audiogon and several other audio fora for its single-minded focus on the first-order passive with time alignment paradigm (akin to Thiel and Vandersteen).

 

[Biblob]

I also found Dynaudio prefers first order crossovers. They tried to explain why in their "ask a expert" series. But I found they did not gave convincing arguments.
Are there cases where first order crossovers are preferred? Especially at the low-budget speaker (<€500 per speaker)?
And does DSP help free speaker manufacturers of the limitations, accompying the low-order crossovers?

 

[Ilkless]

I also found Dynaudio prefers first order crossovers. They tried to explain why in their "ask a expert" series. But I found they did not gave convincing arguments.
Are there cases where first order crossovers are preferred? Especially at the low-budget speaker (<€500 per speaker)?
And does DSP help free speaker manufacturers of the limitations, accompying the low-order crossovers?

First-order acoustical slopes (6dB/octave) do not have any phase rotation. Acoustical slopes are to be distinguished from first-order electrical slopes, because a first-order electrical crossover can add on to a driver's natural acoustic roll off to yield a nominally second-order or steeper acoustic roll-off, depending on the corner and crossover frequency of the high-pass or low-pass. Accordingly designs that maintain a 6dB/octave roll off or close to it for a very broad crossover band are very demanding on drivers in how they require very extended and linear performance. A slanted/stepped baffle can be calculated to provide time-alignment on top of linear-phase.

DSP allows any arbitrary time delay to be set over any given range of audio frequencies; FIR all-pass filtering also allows linear phase regardless of crossover slope. Time and phase performance, with DSP (to some extent, even active analog electronics), is largely decoupled from FR and directivity, compared to the constraints of passive crossovers and physical time-alignment. DSP also allows far more granular control, and can of course be reprogrammed as needed without necessitating parts changes in the crossover.

This article is a good summary, though I think it a bit too equivocal when talking about the degree of compromise, mental gymnastics and workarounds to pull up such a retrograde design method.

 

[soundwave76]

I read this thread with interest. I have been using active DSP speakers from Genelec for a few years now. There was one comment that pro active DSP speakers are always VERY expensive. Not at all, for example a pair of Genelec 8330 + GLM software and measurement microphone bundle costs 1690€ and that is a truly great entry level set. I personally have 8340s in the living room and 8331+7350 sub in the desktop setup. Feel free to ask me questions about these.

P.S. Somewhat entertaining Z_Review of the 8341, have a look

 

[Blumlein 88]

Yeah, the 1st order crossover in a passive usually causes severe off axis lobing with a very uneven response. Which makes the speakers very picky about positioning and treatment to the sides and often makes them sound brighter than they should. They are only phase and time coherent in one plane.

My comment about Jim Thiel, he went to great lengths to control the impedance and response so his speakers had genuine 1st order acoustical slopes. This made his crossovers very complex. It would have been simpler to use 4th order and with his drivers it would have been a better, less expensive speaker. Here is one of his 1st order crossovers. Simple isn't it. And all the evidence points to our ears not much caring about phase above 1500 hz. With active speakers and DSP crossovers you could have time and phase alignment at 4th order if you cared to do so.

 

[RayDunzl]

That's more crossover than I've ever seen.

Assuming it comes from a Thiel CS5 (per Google)

Measurements: https://www.stereophile.com/content/thiel-cs5-loudspeaker-measurements-0

 

[svart-hvitt]

I read this thread with interest. I have been using active DSP speakers from Genelec for a few years now. There was one comment that pro active DSP speakers are always VERY expensive. Not at all, for example a pair of Genelec 8330 + GLM software and measurement microphone bundle costs 1690€ and that is a truly great entry level set. I personally have 8340s in the living room and 8331+7350 sub in the desktop setup. Feel free to ask me questions about these.

P.S. Somewhat entertaining Z_Review of the 8341, have a look

What a review

And what a guy... He seems to be honest, and an experienced listener, though, and he doesn’t seem to have any financial interest, this being speakers on loan from a patreon?

 

[Ron Texas]

Z is always entertaining. He says these speakers make good recordings sound great and bad recordings sound awful while with most other speakers the bad recordings can sound good. The Genelecs strip all the layers away and give you the raw music. I suppose this is transparency. He said someone warned him the 8341's might be too analytic. This might explain an occasional bad review of a speaker with excellent measured performance and the many good reviews of passive speakers.

Transparency in a recording studio is one thing, but do you want it in your house? It turns your listening experience into a game where only "audiophile" recordings are good enough.

 

[Blumlein 88]

That's more crossover than I've ever seen.

Assuming it comes from a Thiel CS5 (per Google)

Measurements: https://www.stereophile.com/content/thiel-cs5-loudspeaker-measurements-0

View attachment 21379

Yes, the CS5, but even his simpler speakers have rather lots of parts. I've worked on a few replacing tweeters and midranges. Another danger of shallow crossovers. Here is the crossover for the CS 3.6

 

[Bjorn]

What do you guys think. Is the market ready for speakers that utilizes an external crossover unit and external amps? Both of choice and bought separately from the speakers. Different presets would be given to upload to certain units or the crossover/EQ settings would be given to enter manually.

 

[sergeauckland]

What do you guys think. Is the market ready for speakers that utilizes an external crossover unit and external amps? Both of choice and bought separately from the speakers. Different presets would be given to upload to certain units or the crossover/EQ settings would be given to enter manually.

Active 'speakers are already a niche in the market, so 'speakers with external amps and crossovers would be a niche within a niche. Hardly a sensible marketing proposition except perhaps for a really boutique manufacturer or dealer.

Alternatively, that's pretty much what us DIYers have done, converted otherwise good passive 'speakers to active, or indeed, even built from scratch including the woodwork and chosen suitable drive units.

S.

 

[svart-hvitt]

Z is always entertaining. He says these speakers make good recordings sound great and bad recordings sound awful while with most other speakers the bad recordings can sound good. The Genelecs strip all the layers away and give you the raw music. I suppose this is transparency. He said someone warned him the 8341's might be too analytic. This might explain an occasional bad review of a speaker with excellent measured performance and the many good reviews of passive speakers.

Transparency in a recording studio is one thing, but do you want it in your house? It turns your listening experience into a game where only "audiophile" recordings are good enough.

What surprised me was his placing the speakers far away from walls. That’s the way I always heard them in the importer’s room, though, and I think they always sound very good in this room. In my place, I follow the Genelec instructions to place the speakers just 5-10 cm from wall.

 

[Ron Texas]

What surprised me was his placing the speakers far away from walls. That’s the way I always heard them in the importer’s room, though, and I think they always sound very good in this room. In my place, I follow the Genelec instructions to place the speakers just 5-10 cm from wall.

Z does most of his tests near-field. I wonder how the 8341's (or other small active studio monitors) sound mid-field. Some fairly good speakers designed for mid and far field don't sound right near-field.

 

[svart-hvitt]

Z does most of his tests near-field. I wonder how the 8341's (or other small active studio monitors) sound mid-field. Some fairly good speakers designed for mid and far field don't sound right near-field.

FWIW, I was surprised how good the 8351s were in a mid-field (350-400 cm from speakers) set-up at my importer’s place. The 8341 and 8331 were not as convincing from same distance.

(Just one experience in one situation!)

 

[Bjorn]

Active 'speakers are already a niche in the market, so 'speakers with external amps and crossovers would be a niche within a niche. Hardly a sensible marketing proposition except perhaps for a really boutique manufacturer or dealer.

Alternatively, that's pretty much what us DIYers have done, converted otherwise good passive 'speakers to active, or indeed, even built from scratch including the woodwork and chosen suitable drive units.

S.

Speakers with built in crossover and amps seems to be taking gradually over. If you take into account the small active speaker systems bought at a typical electronic store, I wouldn't be surprised that active speakers sell in larger quantity than passive speakers. However, when it comes to more expensive and larger speakers I agree with you about it being a niche market. And you're probably right about using external amps and crossovers making an even more niche. Unless if you could make a new fad out of it somehow.

FIY: I'm working on high-end speaker designs where external crossover and amps will be used. We'll see how it goes.

 

[Ilkless]

FWIW, I was surprised how good the 8351s were in a mid-field (350-400 cm from speakers) set-up at my importer’s place. The 8341 and 8331 were not as convincing from same distance.

(Just one experience in one situation!)

Genelec coaxs are too rich for my blood (I think very reasonable pricing for the amount of genuine innovation on offer though). The huge waveguide affords exceptional directivity control for its size, which is probably why it gave that effect in midfield, barring SPL limitations. Though I do wonder why the need for slotloading, and not using side-mounted woofers and leaving the waveguide baffle continuous with the rest of the enclosure. Someone once claimed to me on DIYAudio that the slot-loading lowered the directivity control frequency compared to using direct radiating woofers (basically in a way similar to the DD 8Cs passive cardiod), though I can't figure out why for the life of me. Not even Genelec's own excellent white paper mentions the role of the woofers in directivity control - they only mention the huge waveguide. FWIW there is some compression and intermodulation in the lower midrange that appears to be the result of the slot-loading, lowering measured max SPL to a surprisingly low level given the amount of woofer surface area. The max SPL in the bass is also low as well. The paradox of this speaker is in how exceptional directivity control has the greatest effect at relatively large listening distances where the direct sound doesn't dominate as much, but the max SPL might not be high enough for listening at that distance.

FWIW, I'm looking at active coaxials for my next setup, but budget options are thin. It is frustrating that the best direct-radiating coax drivers outside of the Genelec are all passive - TAD, KEF (except LS50W which doesn't suit my needs), ELAC and Technics. There's this sealed box coaxial that I'm slightly curious about, because of how they've managed to cram in FIR DSP, active crossovers, manufacturing in Germany and using a custom SEAS Prestige coax for LS50 passive money (also I want to try something without a port for a change). But their own curve:

looks nothing like what an independent lab measured unsmoothed in the review, even discounting the scale differences:

I don't think the factory graph looks excessively-smoothed either. So I shot them an e-mail with both graphs traced in VituixCAD, overlaid and smoothed 1/12-octave hoping to clarify. If it turns out there was a revision after the review that reduced some of the waviness in the FR and it is indeed +/- 1dB except in the bass (easy to EQ for anyway) as their own graph suggests, I might jump on it as the polars look nice enough.

 

[MattHooper]

Sorry – don't get that. Cultural divide....

If you tried googling their speakers I suspect you'd understand my reply.

You implied there are first order design speakers that, not being cuboid, people would find unpalatable. I still have no idea what you would find, or think other people would find, to be unpalatable. So I gave a guess. Take a look at Green Mountain Speakers. Otherwise I don't know what brands you have in mind.

It's ok. We are big boys. We can take it. ;-)

 

[vitalii427]

Though I do wonder why the need for slotloading, and not using side-mounted woofers and leaving the waveguide baffle continuous with the rest of the enclosure.

I think one reason is that all near field Genelec monitors designed to be able to put on a side and many use them that way. So it is impossible to use side-mounted woofers.

 

[levimax]

That's more crossover than I've ever seen.

Assuming it comes from a Thiel CS5 (per Google)

Measurements: https://www.stereophile.com/content/thiel-cs5-loudspeaker-measurements-0

The review is fascinating.... these speakers reproduce a square wave and impulse better than anything I have seen. The fact that is was done all passively is amazing. This all leads back to the question of are first order crossovers "better"? Clearly they measure better than any other crossover configuration if square wave's and impulse response in one spot is what you are measuring. If you are measuring off access or any number of other things including complexity and expense they are poor. Ideally a SOTA speaker would be able to reproduce a square wave/ impulse response/ not ring and have good off access response and frequency response and be practical to build and sell and would work in any room... obviously we are not there yet.

 

[Ron Texas]

The review is fascinating.... these speakers reproduce a square wave and impulse better than anything I have seen. The fact that is was done all passively is amazing. This all leads back to the question of are first order crossovers "better"? Clearly they measure better than any other crossover configuration if square wave's and impulse response in one spot is what you are measuring. If you are measuring off access or any number of other things including complexity and expense they are poor. Ideally a SOTA speaker would be able to reproduce a square wave/ impulse response/ not ring and have good off access response and frequency response and be practical to build and sell and would work in any room... obviously we are not there yet.

It's all in the implementation. I would love to get a pair of sub $500 (for two) active studio monitors in my house and see how they do compared to my evil, buggy whip inspired, drug induced, hyperventilating, agoraphobic, wordy, overly confident, prejudiced, and passive LS50's.