Dutch & Dutch 8c Review

[q3cpma]

Or, indeed, any speakers that are measurably perfect at any price.

Genelec 8351B + W371A (+ GLM, of course).

 

[Frank Dernie]

Bravo Erin, super work and on a speaker which is of use for something other than a desktop setup!

It appears that distortion is somewhat higher than might be desired or expected in upper bass and even throughout most of the midrange. At 96 dB it doesn't go completely through the roof like it does with a lot of speakers, but it teeters around 1% from 300 Hz up through 1 kHz, and reaches 10% at 100 Hz. I will speculate that this is a consequence of the cardioid design philosophy. The cardioid pattern is achieved via phase cancellation between the wave exiting the side opening and the wave directly from the woofer in front. This cancellation effect increases as the wavelength grows longer, and apparently ceases where the passive radiators take control. If this were done with a purely passive speaker, we would see a steady decline in response as frequency goes lower, with diminished bass. To compensate, they have no doubt used equalization to flatten the response. This lunch isn't free: there is surely a very significant increase in driver excursion. It should be apparent, just from watching the driver, that at frequency in the neighborhood of 200 Hz and at moderately high volume, the woofer excursion is greater than what would normally be expected at that combination of frequency and volume. Without question, the moderately high distortion is the price that was paid in order to achieve the cardioid pattern. Whether the cardioid pattern is of significant benefit likely depends on the room placement. It isn't a question that can be answered without spending a lot of time listening to the speaker, ideally experimenting with different room placements and even different rooms. And as long as you don't turn it up really loud, you likely won't hear the distortion.

You really should read a bit more about the speaker before wildly speculating, there has been plenty of information about it on the web for month, maybe years.
The driver on the front is a mid driver, not a "woofer" as you describe it.
There are no, and never have been, any passive radiators in this design, just 2 woofers benefiting from a clever use of the front wall and the physics of how sound radiates.
On a science based forum such ill informed speculation is not the sort of thing I hope to see.

As I've learned, the distortion is so high because the woofer is playing very hard, because the cardioid radiation requires a lot of power. And I think they chose this woofer because it has a high Qes.

There are 2 woofers and the cardioid pattern actually starts at 100Hz.

 

[simple6]

Now we need Kii Three and Genelec 8361A measures too and we're done

And Genelec 8351b pretty please!!

 

[Aerith Gainsborough]

FWIW, I pegged about 105dB with music without noticing any distortion or mechanical issues. That's at 4m listening distance.

View attachment 116432

First of all, congrats on the killer review!

121.4dB (Z) transient peaks at 4m listening distance? Oo
Was that the speaker or did you make a sound very close to the mic?

Distortion looks a bit "meh" at that kind of price point.
No problem with your graph, easy to read. Thanks.

 

[McFly]

It is not THD that makes a speaker sound shit. It is IMD. *frag out*
And no front page?

 

[fredoamigo]

And Genelec 8351b pretty please!!

For the 8361 in the same price range, size, amplification etc. etc.
the measurements are really not too bad either https://www.soundandrecording.de/eq...-mit-voll-koaxialer-treiberanordnung-im-test/

 

[Purité Audio]

A propos nothing in particular, when I measured ( just REW listening position) the Kii/BXT with the BXT on and then off, you can turn the BXt off instantly from the Kii ‘control’ distortions levels are much lower with the BXTs but you have to listen uncomfortably loudly, ( 5x7m room) before you can actually hear any difference and playing that loudly made room mode additions far more obvious even having corrected using the Kii internal PEQ filters.
Obviously this is something you should investigate in your own listening space.
Keith

 

[tktran303]

GedLee and Toole and others have stated that THD has no correlation with sound quality, or lack thereof.

MarkK and John Krutke have observed that it is higher order distortions that are more objectionable that lower order eg. Eg. of H6, H7, H8 more objectionable than to H2/H3.
H3 sounds different to H2. Better or worse- well that depends.

But so far these studies are in “pure form” in that they are observations/measurements of in individual driver units. Eg. woofers, and midranges, tweeters, not completed multi-way speakers where drivers blend with each and thus masking effects may other.

Distortion isn sub-bass is more difficult to hear than midrange frequencies. CEA 2010 standard takes this into account.

And none of this takes into account psychoacoustic phenomena like when you’re in a nightclub listen at 100+ dB and other stuff is vibrating and shaking... can you even hear anything -40dB down when you can’t even hear your friend talking at normal conversation volume (60dB)?

So It’s time we dispense of blunt instruments like THD in electromechanical devices.

I’m a bit disappointed that they aren’t using copper shorting rings for the midwoofer.
Hint: H3 higher then H2...

 

[q3cpma]

GedLee and Toole and others have stated that THD has no correlation with sound quality, or lack thereof.

MarkK and John Krevskovsky have observed that it is higher order distortions that are more objectionable that lower order eg. Eg. of H6, H7, H8 more objectionable than to H2/H3.
But those tests are in “pure” in that they are observations/measurements of in individual driver units. Eg. woofers, and midranges, tweeters, not complete speakers where drivers blend and thus can mask each other.

Distortion is sub-bass is more difficult to hear than midrange frequencies. CEA 2010 standard takes this into account.

And none of this takes into account psychoacoustic phenomena like when you’re in a nightclub listen at 100+ dB and other stuff is vibrating and shaking... can you even hear anything -40dB down when you can’t even hear your friend talking at normal conversation volume (60dB)?

So It’s time we dispense of blunt instruments like THD in electromechanical devices.

(I assume you mean that THD is useless, not HD)
Ask AP to compute GedLee's metric, then. Everything you said is true, but it's not really conclusive; personally, I just ignore H2 and am way more interested in multitone distortion (and not just two tone IMD measurements) like S&R does.

 

[tktran303]

(I assume you mean that THD is useless, not HD)
Ask AP to compute GedLee's metric, then. Everything you said is true, but it's not really conclusive; personally, I just ignore H2 and am way more interested in multitone distortion (and not just two tone IMD measurements) like S&R does.

Well look Dutch & Dutch could do an 10c or 12c or 15c.

With dual 10/12/15” bass drivers.

I bet it plays “cleaner” and by that you tend to play music at a louder level, without it sounding LOUD or uncomfortable.

That’s what low non-linear distortion sounds like.

 

[Dialectic]

It's not appropriate to compare what Streaky does to what Erin does. I'm not sure Streaky deserves more views.

 

[Pearljam5000]

It's not appropriate to compare what Streaky does to what Erin does. I'm not sure Streaky deserves more views.

I'm not comparing at all

 

[TimVG]

Well look Dutch & Dutch could do an 10c or 12c or 15c.

With dual 10/12/15” bass drivers.

I bet it plays “cleaner” and by that you tend to play music at a louder level, without it sounding LOUD or uncomfortable.

That’s what low non-linear distortion sounds like.

Actually in their early days they made a cardioid speaker with a 15" driver and a horn, along with a seperate cardioid sub

 

[Absolute]

In my experience a loud sweep will far easier determine if something is audible than any given number on distortion. You will clearly hear when the sweep goes from clean to distorted. So perhaps reviewers should think about including a little comment about sweep at 95 dB sounds fine, 100 dB sounds fine but 105 sounds distorted.

IMD distortion is what we should be looking at, imo.

 

[Puddingbuks]

Great review and results!

Last week I got a pair of Dutch & Dutch 8m, a simpler version of the 8c made for a short period. Bass reflex, no woofers in the back, non cardioid.

Love them, sound, finish and dsp are fantastic.

 

[Puddingbuks]

Is there a version of this speaker without the integrated subwoofers? I'd say it's rare that optimal subwoofer placement coincides with optimal speaker placement in a room.

They had the 8m, which is no longer in production. It was a nice addition at a lower price point, 6000 euro/pair.

https://ultimate-stream.co.uk/images/brands/dutch-dutch/studio-series/8m-manual-english.pdf

 

[deni]

Congrats on the NFS and this great review Erin! The 8C measures as expected - a phenomenal speaker.

In my experience a loud sweep will far easier determine if something is audible than any given number on distortion. You will clearly hear when the sweep goes from clean to distorted. So perhaps reviewers should think about including a little comment about sweep at 95 dB sounds fine, 100 dB sounds fine but 105 sounds distorted.

IMD distortion is what we should be looking at, imo.

I would be careful with going past 95 dB with single tone sweeps. You can easily damage drivers in small bookshelf speakers doing this at 105 dB which is absurdly loud in single tones. I like the idea of listening to the sweeps though. I also find it interesting to watch the clip/protect lights on active speakers when conducting a sweep to see where the limiters are kicking in.

I'll also mention that for anyone conducting distortion sweeps of their own, make sure that your equipment is properly calibrated. The last thing you'd want to do is potentially damage your hearing or your speakers from a mistake in calibration. I've seen the sensitivity of lower cost electret measurement mics do some interesting things over time. Make sure you have a quality mic calibrator.

 

[Absolute]

I would be careful with going past 95 dB with single tone sweeps. You can easily damage drivers in small bookshelf speakers doing this at 105 dB which is absurdly loud in single tones. I like the idea of listening to the sweeps though. I also find it interesting to watch the clip/protect lights on active speakers when conducting a sweep to see where the limiters are kicking in.

Just arbitrary figures in the example, of course. As I'm no engineer, speaker builder or reviewer the best practice should really not be up to me.

I only know that it was far easier to listen through a loudish sweep that something was off in my drivers than looking at distortion plots. Distortion was too low on normal listening levels to see that something was wrong, but it was clearly audible.

Sweeping made it painfully obvious, but on distortion plots it didn't show until very loud sweeps of around 100 dB @1m.

In some cases the ears are the better judge, and when it comes to the distortion side of things there's no question that numbers by itself means little. At least the THD side of it.

 

[Dialectic]

I'm not comparing at all

My apologies, I didn't mean to allege that you were.

We should be grateful to Erin, who has just provided the most useful, careful and thorough analysis of these speakers' performance that I have seen.

I do tend to discount the subjective impressions of reviewers, although Streaky's impressions are probably more useful than those of most audiophile reviewers. And it is interesting that, excluding the Soundstage review, subjective impressions have been consistent with the measurements.

 

[Dialectic]

Actually in their early days they made a cardioid speaker with a 15" driver and a horn, along with a seperate cardioid sub


View attachment 116572

I would love to see a "bass bin" to accompany the 8Cs--similar to the Kii BXTs but perhaps less expensive.

Would such bass modules audibly benefit my system? Probably not, although I'm sure they would improve the distortion measurement. In my listening room, I can listen to organ music at levels that make the house shake, and whatever distortion is there (and I'm sure it's easily measurable) is not audible to me.