Dutch & Dutch 8c Review

[Bjorn]

Is this in a normal domestic room?

It's a well treated room. No doubt that differences become more audible when you remove masking effects. How a "normal room" without treatment is in low frequencies will vary greatly. Some actually measure quite well with no treatment, but most don't.

But quite frankly I don't think you need a great acoustic room to hear differences in the lows when the modulation distortion is high vs low. It seems most hear this easily. Setting up a scientific blind test to verify this wouldn't be straight forward though.

 

[Soniclife]

It's a well treated room. No doubt that differences become more audible when you remove masking effects. How a "normal room" without treatment is in low frequencies will vary greatly. Some actually measure quite well with no treatment, but most don't.

But quite frankly I don't think you need a great acoustic room to hear differences in the lows when the modulation distortion is high vs low. It seems most hear this easily. Setting up a scientific blind test to verify this wouldn't be straight forward though.

Are your low distortion speakers constant or controlled directivity? And what are you comparing them to, the 8c?

 

[Bjorn]

Are your low distortion speakers constant or controlled directivity? And what are you comparing them to, the 8c?

Not sure how you define the difference between constant and controlled directivity as people seem to define these differently, but the speakers I use generally have a very uniform directivity over a broad range. Some with wide dispersion and some with narrow. But that's not really related to distortion in lower frequencies.

There are several ways to do comparisons here. One would be to compare a speaker with something like a 8" woofer to a speaker with a 15" woofer. Another would be to simply add subwoofers to the speaker with a 8" woofer, make two presets that you switch between and listen to the difference. I've done both.

There are challenges when comparing because adding separate subwoofer may also change the frequency response and one ends up listening to more than just lower distortion. But one of the reasons why I don't think this is only related to the response, is because I've several times added subwoofers where the low freq. response actually got worse compared to running a speaker full range. And I still experienced that adding three 15" subwoofers sounded considerably better in regards to less compression and more effortless low frequency sound.

 

[pma]

This is also interesting

from Stereophile

To me, by far the most interesting speaker posted at ASR.

 

[Soniclife]

Not sure how you define the difference between constant and controlled directivity as people seem to define these differently, but the speakers I use generally have a very uniform directivity over a broad range. Some with wide dispersion and some with narrow. But that's not really related to distortion in lower frequencies.

To me constant is something like the 8c above 100Hz, controlled would be something like a Revel where the directivity is only controlled much higher up. Your description of yours sound like constant, just with different beam widths. A true omni would be constant.
The reason I was asking is it sound like you are saying low distortion constant directivity is clearly better than high distortion constant directivity, but that does not seem to be quite what Erin (and others) are comparing, as very few have probably done the comparison, they seem to be comparing low distortion controlled directivity speakers vs constant directivity but high distortion speakers, and saying they much prefer the latter, based on the speakers of both types they have so far heard. So that when it comes to real speakers you can buy and put in a lounge they will happily trade off a lot of distortion for a lot of directivity control, and without reference to something else don't hear the compromise.

The easy way to blind test this would surely be with low distortion speakers fed a mix of clean test tones, and distortion added test tones, no change of dispersion to engineer around.

 

[Ericglo]

Love this John, it is amazing how technology has made accurate measurements so much easier in recent years.
I won't designing a "F1" boom, it would be too expensive and my expertise is not in acoustics, I bought my most recent microphone stands on Amazon but my daughter has borrowed them.

LOL, I will let you off the hook.

I will ask this. How thick would a carbon fibre rod need to be to remain rigid enough to hold a mic? I would guess that Klippel rod is around a meter to a meter and a half.


I think a quicker and easier solution for you Erin would be to buy a 1/16" Neoprene sheet. You could build up enough thickness to wedge the mic into the conduit without the copper. From there you could taper strips up to make it even with the outside of the conduit. Attack with electrical tape.

 

[ctrl]

What really surprises me is that in the reviews by @napilopez, @hardisj and stereophile so far, not one has done a near field measurement of the side slots.
This is the most distinctive feature of the speaker, that's what I would measure first, to see how much sound pressure level and frequency range the slots must contribute to achieve the cardioid radiation.

Was so looking forward to it, I'll never talk to you guys again

 

[hardisj]

What really surprises me is that in the reviews by @napilopez, @hardisj and stereophile so far, not one has done a near field measurement of the side slots.
This is the most distinctive feature of the speaker, that's what I would measure first, to see how much sound pressure level and frequency range the slots must contribute to achieve the cardioid radiation.

90/100 degrees off axis tells you that. Unless you specifically need nearfield of the vents.

 

[Bjorn]

To me constant is something like the 8c above 100Hz, controlled would be something like a Revel where the directivity is only controlled much higher up. Your description of yours sound like constant, just with different beam widths. A true omni would be constant.
The reason I was asking is it sound like you are saying low distortion constant directivity is clearly better than high distortion constant directivity, but that does not seem to be quite what Erin (and others) are comparing, as very few have probably done the comparison, they seem to be comparing low distortion controlled directivity speakers vs constant directivity but high distortion speakers, and saying they much prefer the latter, based on the speakers of both types they have so far heard. So that when it comes to real speakers you can buy and put in a lounge they will happily trade off a lot of distortion for a lot of directivity control, and without reference to something else don't hear the compromise.

The easy way to blind test this would surely be with low distortion speakers fed a mix of clean test tones, and distortion added test tones, no change of dispersion to engineer around.

You are mixing directivity with low frequency distortion. Two very different topics and I've talked about low frequency distortion alone. Your definition of controlled and constant directivity is something not used in the literature. So the argument here becomes difficult since we seem to be talking about different things.

That being said, the Dutch & Dutch 8C certainly has a much more constant or uniform directivity than most speakers and is a well designed speaker. But it still changes quite a bit (for example from 100° to 140° within a quite sensible area) and there are speakers that a have a more uniform dispersion than this.

 

[Pearljam5000]

So... was the perfect speaker found and now we can close ASR? lol

 

[pma]

So... was the perfect speaker found and now we can close ASR? lol

Nothing is perfect, as you know. It is still a small speaker that would not play low distortion high level bass. No chance to break physics. Church organ is church organ.

 

[diddley]

 

[VintageFlanker]

Nothing is perfect, as you know. It is still a small speaker that would not play low distortion high level bass. No chance to break physics. Church organ is church organ.

Yep. From an objective POV, these are not perfect relative to their distorsion.

I would expect my (much smaller) Buchardt A500s to perform even worse in that area. Yet, they sound amazing at loud level.

 

[Frank Dernie]

I will ask this. How thick would a carbon fibre rod need to be to remain rigid enough to hold a mic? I would guess that Klippel rod is around a meter to a meter and a half.

It isn't simple. Depends on fibre choice, fabric type, fibre orientation and thickness.
Rigid enough would need defining too.

 

[MZKM]

So... was the perfect speaker found and now we can close ASR? lol

Nah, that tiny crossover dip in the off-axis is unacceptable, they need to now make an even crazier tower version to make up for it. Do I hear a 4-driver front baffle with dual midrange drivers and 4 8” subs on the rear (8 total, equivalent to a single ~23” sub)?

 

[Lorenzo74]

Great review and great speaker engineering. As an occasional DIY speaker builder I don't understand how they can cross a rather standard tweeter at 1250 Hz and have it play 106 dB and not have issues. Part of the great directivity is that a 1" dome tweeter is playing from 1250 up. Thanks for any help understand how this can work.

simple... LR 24dB octave.
it is the same as 2500Hz LR 12 dB octave as in seas specs.
On top of that you might have 2-3 dB from waveguide and maybe a dynamic XO frequency like the one implemented in kii three...(an algorithm look ahead and change freq if peak occurs)
Best
Lorenzo

 

[Lorenzo74]

So... was the perfect speaker found and now we can close ASR? lol

pls wait Kii three + BXT.
then we’ll see.
my 2 cent
Best

 

[Dialectic]

pls wait Kii three + BXT.
then we’ll see.
my 2 cent
Best

Which is 3X the cost and has over 90ms of latency...

 

[Scholl]

Which is 3X the cost and has over 90ms of latency...

The 90ms latency is only if you want to correct the crossover induced group delay down to the lowest frequencies (which is hardly audible in the first place). They also have a low latency mode, which is mandatory for multiple professional uses.

 

[Sancus]

Which is 3X the cost and has over 90ms of latency...

It's also more than double the cost of Genelec 8351B + W371A, for another competitor.... pretty crazy price.