SoundStage’s review of Dutch&Dutch’s 8C

[DDF]

Interesting choice of voicing in those Dutch and Ducth 8c's with 3 dB extra level in the upper bass and lower mids even on axis.

I checked Soundtsage's measurements of other speakers and a surprising number show this as well (Revel (most models), some PSB (Persona B, 15B, X2T), Dynaudio, smaller KEFs).

Others speakers are notably flatter below 1 kHz (Golden ear, PSB T3, Monitor audio, Magico, larger KEFs, Warfdale, Joseph).

It looks like a number of these "objective" speakers are cheating in a bit of a house curve "loudness control" for better perceived balance at lower level listening while adding a bit of euphonic punch at high levels.

 

[mitchco]

I for one prefer D&D 8c's voicing and find the other speakers you mention sound too thin in-room - like the Dynaudios I measured here: https://audiophilestyle.com/ca/reviews/dynaudio-focus-600-xd-loudspeaker-review/ Here is my 8c review with some in-room measurements:
https://audiophilestyle.com/ca/reviews/dutch-dutch-8c-loudspeaker-review-r739/ I certainly prefer this response...

Same thoughts and measurements for the KEF LS50: https://audiophilestyle.com/ca/revi...ker-comparison-with-binaural-recordings-r768/

I wonder if the traditional "single on-axis flat response in the anechoic chamber" approach is flawed: https://audiophilestyle.com/ca/reviews/dutch-dutch-8c-loudspeaker-review-r739/#soapbox

 

[Juhazi]

I haven't heard the D&D or Kii3, but followed their reports and measurements. Cardioid response happens only in rather limited band, and their behaviour near front-wall is different from traditional 3-ways.

Typical anechoid and pseudo-anechoid measurements up to 45-60¤ off-axis hide what happens at sides and on the backside. Bass level and roll-off are also room-dependent and closed/direct/cardioid/dipole bass all have their specific traits in small rooms. This is why listening impressions are needed in tests and still one can't be sure if that is applicable to ones own room...

I am happy to read that the tester liked D&D's bass, I am a fan of dps-controlled closed box woofers too! Best result comes only with freely adjustable parameters, but I understand that this is too much asked for commercial products. The high distortion around 100-200Hz is obviously because the leaky midrange is getting stressed.

About hiss, the tester heard it only when putting his ear next to the tweeter, not at listening position. Nothing to be worried about.

By the way, here is a thread by "keyser", one of the developers of D&D - very much the proto of 8c. Cardioid studies way back in 2011!
https://www.diyaudio.com/forums/multi-way/192737-2-waveguide-cardioid.html

 

[restorer-john]

About hiss, the tester heard it only when putting his ear next to the tweeter, not at listening position. Nothing to be worried about.

Considering the description of the hiss by the reviewer, it was clearly greater than his other amplifier and speaker combination and deserved comment.

I am yet to hear a silent active speaker of any sort using a Class D amplifier/s. The comments keep coming from buyers, reviewers and people who use small powered speakers nearfield or on desks. They are too noisy. At the price they should be silent.

It seems some people are obsessing over THD levels they cannot hear and yet are happy to dismiss high residual noise. S/N is well and truly compromised by laziness in noise floors. I make no excuses for manufacturers who wont quote a residual noise figure in uV for amplifiers.

 

[HammerSandwich]

I am yet to hear a silent active speaker of any sort using a Class D amplifier/s. The comments keep coming from buyers, reviewers and people who use small powered speakers nearfield or on desks. They are too noisy. At the price they should be silent.

I absolutely agree with your last point but believe we need to maintain perspective here: this is 1 detail in a sizable system. We must prioritize our parameters as long as we're dealing with imperfect systems, and I don't anticipate perfection to arrive soon.

If the noise is inaudible at >1M, is it really a problem? And wouldn't you prefer a little hiss to wacky frequency response, poor directivity, 80dB/watt sensitivity or audible HVAC?

 

[oivavoi]

FWIW: I have the 8Cs, even though I'm not currently listening to them due to a technical issue that will get fixed as soon as my distributor comes home from vacation and brings the spare part with him. I can confirm that there is a hiss when listening very close. I can't hear it from my usual listening distance though, which is approx 1,5 - 2 m. With my other active speakers from AVI, which have an active analog crossover and AB-amps, there is no hiss at all, except when I turn the preamp very low and the gain on the speakers very high (which is the absolute worst way of doing gain if the goal is to reduce noise).

This doesn't bother me since I usually don't listen with my ear placed against the tweeter. But I do think that it's a less than optimal part of the design.

 

[DDF]

Class D makes sense to simultaneously achieve great headroom, cool operation and small form factor all very desirable in an active speaker, but are Class D amps really noisier? The Hypex's are dead quiet by spec and measurement. My speakers are dead dead dead quiet even with ear right at tweeter using the NC400 but my tweeters (standard direct radiator, no waveguide) are passive and resistively padded down to 85 dBSPL/1m.

I think instead the hiss points to trade offs with the sort of system design used in the 8Cs and like speakers:
- the tweeter waveguide narrows dispersion in the lower working range of the tweeter for more constant DI but it does this while raising sensitivity on axis in the same frequency range. This gets equalized in the DSP upstream but the waveguide gain still exists and it amplifies the noise output from the amplifier and D/A on axis.
- Direct coupling the amp to the speaker (active xover) means there is no resistive padding of the tweeter (passive xover) to reduce noise from the amp or D/A. In practice this can be easily 5 to 8 dB.

You can't have your cake and eat it too: either the gain is early in the chain (passive speakers) with more wasted power or its later in the chain (active speakers) but noise is higher.

 

[Soniclife]

Is the hiss lower with a digital input than the analogue input? Probably not if the ADC is good as it probably is.
I assume it's fixed level and does not change with volume setting?
Do they have a mute switch that makes any difference?

 

[LightninBoy]

I gotta say ... the measurements are disappointing overall. Particularly the distortion graph.

 

[Dialectic]

My wife absolutely hates them. But they are quiet.

What color did they send you?

 

[Dialectic]

FWIW: I have the 8Cs, even though I'm not currently listening to them due to a technical issue that will get fixed as soon as my distributor comes home from vacation and brings the spare part with him. I can confirm that there is a hiss when listening very close. I can't hear it from my usual listening distance though, which is approx 1,5 - 2 m. With my other active speakers from AVI, which have an active analog crossover and AB-amps, there is no hiss at all, except when I turn the preamp very low and the gain on the speakers very high (which is the absolute worst way of doing gain if the goal is to reduce noise).

This doesn't bother me since I usually don't listen with my ear placed against the tweeter. But I do think that it's a less than optimal part of the design.

Uh oh, what is the technical issue?

 

[oivavoi]

Uh oh, what is the technical issue?

Technical failure in the DSP board in one of the speakers probably, which needs to be replaced.

 

[Dialectic]

Technical failure in the DSP board in one of the speakers probably, which needs to be replaced.

Oh man, I hope it's repaired soon.

@Purité Audio @Martijn Mensink Is the warranty two years or five? I've read conflicting statements in different forums.

 

[oivavoi]

Oh man, I hope it's repaired soon.

@Purité Audio @Martijn Mensink Is the warranty two years or five? I've read conflicting statements in different forums.

Should be mentioned that this was a production failure I noticed immediately upon receiving it - xlr input worked, but not the AES input. So it's not something which broke down over time. It's only that we (the distributor and me) didn't get around to fixing it before now.

 

[Kal Rubinson]

What color did they send you?

What my wife chose: Black/Black. She hoped they would be minimally noticeable.

 

[DDF]

I for one prefer D&D 8c's voicing and find the other speakers you mention sound too thin in-room - like the Dynaudios I measured here: https://audiophilestyle.com/ca/reviews/dynaudio-focus-600-xd-loudspeaker-review/ Here is my 8c review with some in-room measurements:
https://audiophilestyle.com/ca/reviews/dutch-dutch-8c-loudspeaker-review-r739/ I certainly prefer this response...

Same thoughts and measurements for the KEF LS50: https://audiophilestyle.com/ca/revi...ker-comparison-with-binaural-recordings-r768/

I wonder if the traditional "single on-axis flat response in the anechoic chamber" approach is flawed: https://audiophilestyle.com/ca/reviews/dutch-dutch-8c-loudspeaker-review-r739/#soapbox

Hi Mitchco,
I think your conflating more aspects than I was.

"On axis flat" as the only goal is of course wrong. Local diffraction and reflection (eg tweeter reflecting off a large woofer surround) effects vary with point of observation, and equalizing for them at one location means error everywhere else. Tonal balance will be damaged. By measuring off axis and looking at multiple observation points, one can discriminate driver irregularities*, resonances or 4pi to 2pi artifacts common over most of the listening window and then equalize for them over an average window (which includes some consideration for first reflection radiation directions). The system design must then make sure off axis is smooth and gently smoothly sloping down, to sound neutral.

I'm pointing out something different. According to Soundstage's measurements, the 8C's and many "accurate" speakers have this 3 to 4 dB rise in lower mid and upper bass at all observation points. I can only conclude 1 of 2 things is happening:
- the designers are providing some loudness control for 80% of listening and tolerate inaccurate punch at high levels, or
- the circle of confusion dictates that if most production speakers had this error, build it into the playback speakers for an "on average" more accurate experience. I read your links and it seems that this is your perception because you find this boost natural.

I don't come from a recording environment, but from a product design one, so don't know what the recording side hears on average. After making designs with and without this boost (in a passive design, its easily dictated by the main low pass inductor size), I've always found not having this boost is more natural. I attend ~ 20 -30 classical concerts a year and try and use that as my guide. However, I also realize that what I've listened to over my lifetime probably dictates what is is "right" to me more strongly than my live listening experiences (which have acoustics varying wildly over venue and seat).

However, we would never tolerate this boost in an amplifier. Interesting inconsistencies in standards.

I'm assuming the NRC chamber isn't knackered. I know they had calibration issues at one time but they calibrated those out many moons ago.

* many "hard" (metal cone for example) driver breakup resonances actually change spectral shape and center frequency significantly over different observation points.

 

[HammerSandwich]

My wife saw the black units at Purite Audio. She said they looked like lumps of coal.

Seeing that you already have 8Cs, could you convince her to get me a pair if I'm very, very naughty until Christmas? I promise not to complain about the color!

 

[Aaron Garrett]

What's not to like?

 

[Kal Rubinson]

My wife saw the black units at Purite Audio. She said they looked like lumps of coal.

The issue is not the color as we have matte black speakers in CT and piano black speakers in NYC. It is the shape and their perch on the stand.

 

[Kal Rubinson]

What's not to like?View attachment 25037

It is obvious but a matter of personal preference.