Dutch & Dutch 8c: boundary coupling, bass peaks/dips, and comparing to Kii

[PCmusic]

I have done serious research into 8c and Kii. I went to audition 8c in a showroom twice and Kii for once. In one (out of three auditions) I particularly asked the 8c dealer to position 8c in positions similar to that in my home. I am not an audio engineer / studio mastering guru, though I have tried to understand as much as possible many technical terms related to acoustics. Consider me a guy who love music very much and is eager to learn. The following are my concerns, based on my limited technical knowledge. I hope someone could address my questions below and help me decide which speakers to go (I'm now more in favour of 8c, perhaps due to my tastes and the performances delivered by different showrooms, which may not reflect the true capacities of those two different pairs of speakers)

 

Since for now I am more in favor of 8c (but with some worries), I shall first talk about my 8c experiences and then talk about Kii later.

 

8c: Boundary Coupling, Listening Position, and Bass Peaks and Dips (in my room in particular)

 

My room is around 3.9m (W) x 7.9m (D) x 2.8m (H), with speaker positioning shown below (see the attached picture of the 'front-wall' part of my room now). It's similar to the dealer's room (around 4.3m x 6.7m if I remember correctly). I want to see how 8c perform in positions similar to my home as I am really worried about the loss of advantages due to the lack of boundary coupling.

 

I read John Atkinson's review of 8c in Stereophile, and he said he needed to place the speaker more than 1.5m farther out from the front wall as shorter distance wasn't possible: 

"Ideally, these speakers should be positioned between 100mm (4") and 1.5m (59") from the wall behind them, which allows the output of the twin rear-firing subwoofers to be reinforced with the in-phase reflection from the wall. However, this wasn't possible in my room; I had placed the speakers farther out, sitting on 24" stands in the positions ... I connected the 8c's to my network and, using the control app at the Dutch & Dutch site lanspeaker.com, set each speaker to "free space" regarding both the rear wall and sidewalls" 

(https://www.stereophile.com/content/dutch-dutch-8c-active-loudspeaker-system-john-atkinson-april-2020)

 

In the rest of the article he said he found abnormality around 30Hz. He said just below 30Hz, and he needed to apply a 12dB cut through filters. 

 

But looking at "Fig.2 Dutch & Dutch 8c, spatially averaged, 1/6-octave response in JA's listening room with Martijn Mensink's REW correction filters (red) and without (green)", I also noted there was no serious dips of 12db. 

 

Yet (again) another measurement show unexpected notches (but some said it's an artifact):

https://www.soundstagenetwork.com/index.php?option=com_content&view=article&id=2073:nrc-measurements-dutch-dutch-8c-loudspeakers&catid=77:loudspeaker-measurements&Itemid=153

 

So I am rather confused. 

 

After reading John and in fact many others' reviews, I really wonder (and in fact my concern), under free-positioning, if 8c will produce:

 

(1) more and higher 'peaks' when using 'free position' as compared to using any 'close-to-the-wall' positions,

 

(2) but less serious bass 'dips' (+3 to 4db).

 

I asked the above questions with the following background info of my needs and constraints:

 

1. Place the speakers as seen on the attached drawing; I can't place the speakers since the front-wall has a wall-to-wall bookcase there. It definitely cannot use the advantages offered by Boundary Coupling. 

 

2. One of the key reasons why I want to change my speakers is: I want to have more evenly distributed bass in my room, without any serious peaks and dips, and without the need to add bass traps (that's impossible anyway). 

 

3. I am experiencing uneven bass ... my sitting position, being closed to the center of my room (as seen from the pic), experienced various bass dips.

 

4. But I also want to avoid serious peaks.

 

5. I can't change my listening position ...

 

6. Attached is my Trinnov's measurement of my speaker in 2015 (after that I have no time to do serious measurement) - but I haven't removed any major furniture like the three seat sofa at the center of my living room (I don't know if it will have influence on the validity of my measurement). But it seems that the graph somehow represents what I have been experiencing as well - at the listening position, a relatively lack of deep bass and certain range of bass frequencies (notch from 250Hz to 400 Hz; -10db from 20 to 50Hz; also notch from 1kHz to 4kHz for the upper mid-range), and too much emphasis at 6k, which increase harshness of the overall sound.

 

Summing up, my biggest concern is, when I use 8c in free positioning mode, will I be just using it just like any conventional speakers (the only difference is the two subwoofers firing bass backward, but still in free positioning)? Will the bass (below 100Hz) peaks and dips be just as many as what any conventional speakers could produce? I could correct peaks, but can't do anything to dips.

 

So would the worst scenario be: will I go back to where I am starting ...?

 

My audition of 8c, however, with close proximity to my current speaker placement, offers a very good experience overall. The smoothness offered by 8c is impressive. 

 

But during listening I also at times wonder: is the bass a bit too much? Up to a point it masks the details of musical instruments / elements? Are there any possibilities the speaker, placed in 'free-positioning' mode, excites one or even more peaks? The audition was done within 45 mins;  I was so rushed so I forgot to turn down the bass just for experiment ...

 

So I really don't know what is happening when 8c is placed NOT close to the front wall.

 

Kii: extremely detailed, but smoothness and integration ...

 

I generally like 8c more than Kii, but Kii during my audition does not give any impression that the bass might gone too much (5m W x 8m L x 3m H), and at the same time Kii offered very sharp details of different instruments (up to a point it's too sharp).

 

My 'finding' of Kii, seems to confirm a lot of comments in forums. But I still can't decide if it's really true for:

 

1. Speaker placement: The showroom is 5mW x 8.2mL x 2.8mH. The dealer insisted on putting them 3.4m (around 11 ft 1 inch) apart! I was 'told' to be listening to Kii outside the equilateral tingle, 3.8m away from both speakers. When I asked if I could change the speaker positioning, the salesman said 'no' and said 'it's the best position'. I have never encountered such a audio salesman, and many things he said is unprofessional and contradictory - 'telling' me that Kii is nothing 8c could be on par with; Kii could produce louder volume with better SQ than 8c but when I wanted to crank up the volume beyond 85db@1m (measured by iphone app), he was very nervous and said Kii are only bookshelf speakers ... that's another story. The salesman probably have read very few professional reviews and measurements. This is also another worry - buying from a dealer with unprofessional service & knowledge.

 

Anyway, back to the original point. I doubt if 11 ft or 3.4m created my experiences: everything sounded very sharp (and thin) in the presentation. Yes, it's very detailed, but there's little integration between different elements presented in the music. Originally I wanted to ask the salesman to bring closer the speakers, but as he insisted he wouldn't move them, I was off.

 

I know Kii (and 8c) is designed to 'meet the challenges of most domestic rooms', but I still wonder if the overly-detailed characteristics in my audition is due to the dealer's positioning? But as many have also commented the 'dryer' side of Kii if it's listened out of the box, it seems distance between speakers won't 100% explain my experience. I am still very puzzled, especially considering the next point . 

 

2. Kii and 8c may sound very close?: Martijn Mensink has made a very intriguing statement in this forum: "I agree. I've had the Kii's and the 8c's side by side in my living room for a while. The Kii's too are remarkably good speakers. With just some subtle EQ the two could be made to sound very similar on most program material - to the extent that I might not be able to distinguish them in a proper blind test. I'm still amazed sometimes by the extent to which differences in sound can be explained by frequency response" (https://audiophilestyle.com/forums/topic/54065-article-dutch-dutch-8c-loudspeaker-review/page/5/#comments)

 

There're other experienced users saying this in different forums, but perhaps Martijn Mensink said this with a bit more authority.

 

But Martijn Mensink's comment seems to contradict many people's experiences. It may be that

 

1. Many people didn't listen to two pairs of speakers in the same room.

 

2. When they did, most don't have prolonged period of time to experiment, let alone making them looking similar in terms of frequency responses.

 

3. One way of testing this claim is to having them to achieve the same targeted curves ('just some subtle EQ') - if I was allowed to translate Mensink's comment bluntly, Kii won't have less bass than 8c, as many said. Or alternatively, 8c could be 'adjusted' by EQ (shifting the tone and balance) to have the details of Kii (due to subtle shift of tonal balance?). Many Kii owners say it loud and clear that 'details' provision is a reason of choosing Kii.

 

4. But so far it seems no one has done it this way and publishes measurements and experience.

 

5. Yet I can't ignore what Mitchco said in his review of 8c: "But with the 8c’s larger drivers, more onboard room calibration controls, and the best directivity polar map I have seen ...", reminding us there's something beyond 'achieving similar targeted curve'. Would differences in other areas (such as directivity and hence overall tonal balance in the very same room) be so important that it is in fact impossible to bring 8c and Kii to sound much more similar?

 

What's next after confusion and uncertainty

 

Ideally, I would love to have the details of Kii I heard during audition, but keep all other things of 8c (bass, smoothness, emotion, musicality etc), with no irritating peaks and dips in my room.

 

As I am more in favour of 8c now (also a dealer issue), I wonder how/if I could come closer to this 'bass' goal with 8c, and 'lift up' the amount of details of 8c, within the constraints I have discussed (free positioning issue, peaks and dips).

 

As said, I am not well-versed in audio technical knowledge. I apologize if I have misused some terms. But I have tried my best to explain my audition experiences, worries and questions. To me, both Kii and 8c are remarkably designed speaker, but given my room and placement, I'd like to know more which may work better.

 

 

[fas42]

I would go for the 8c's ... the Kii's appear to have some of the engineering of the electronics not as well refined as the 8c - which you may find hard to 'solve' - bass issues are going to be easier to tame. Personally, for long term enjoyment I see it as a no contest situation ...

[firedog]

The Kii definitely gives you more possibilities for room placement, as it isn't designed to use coupling to the front wall to sound it's best. 

 

Many users of both speakers set them up to their optimal point, and then also use a DRC program of  some type to perfect the sound for the room and positioning. Recommended. In my case that eliminated a room node at 38hz and basically gives me flat response in room from 20hz-20000 hz. With the 8c you can use REW and integrate the correction into  the speaker. 
 

I  personally don't think the Kiis are lacking in "warmth", or "smoothness" (I'm not sure what that is) but I use EQ to adjust the Kii's for my personal taste and hearing issues. Either speaker will allow you to perform digital EQ internally to the speaker or via Roon or some other program. One of the advantages of such a speaker. The Kii's are a lot more useful/easy to deal with if you buy them with the Kii Control. 

 

I'd tend to agree with the idea that by using DSP egualization, you can adjust the sound of either speaker and make it sound how you'd like.

 

Do you have no possibility of trying a different Kii dealer? Maybe one who will give you a home audition?  Have you thought of contacting the importer/distributor where you live and discussing it? Will your 8c dealer also not allow an in home audition?  Many dealers of both speakers will set the speakers up in your home and also do DRC so you can hear exactly how well they can perform in your listening area. 

 

If you aren't happy with the Kii dealer and you think you prefer the sound of the 8C, I'd tend to go with that. Note that in the JA measurements he didn't find any lack of bass, so I don't think the "free" positioning is a  major issue with the 8c.  He also pretty much eliminated peaks with the use of REW. You might want to contact D&D directly and ask them about placement when not coupled to front wall. 

[firedog]

8 hours ago, fas42 said:

I would go for the 8c's ... the Kii's appear to have some of the engineering of the electronics not as well refined as the 8c - which you may find hard to 'solve' - bass issues are going to be easier to tame. Personally, for long term enjoyment I see it as a no contest situation ...

fas-42

total nonsense. 

You are writing from a position of ignorance and making baseless conclusions. Please tell us about your expert knowledge of the electronics of the Kiis. Have you even heard either speaker? 

 

It's such a "no contest" that there are plenty of people who prefer the Kii's to the 8c's. Some people think the 8c's have more warmth and more powerful bass. Others think the Kiis have a better high end and superior clarity, without lacking bass. That's a matter of taste-and what type of sound an individual prefers.  Both are excellent speakers with hundreds or thousands of happy owners. You probably can't go wrong with either. 

[baconbrain]

Fully agree with Firedog's suggestion regarding a home audition of both speakers if possible. That really affords the best opportunity to determine how well each integrate with your system and listening environment.

 

Out of curiosity, which speakers were you using when you measured them with the Trinnov back in 2015?

[PCmusic]

baconbrain: that ... was a pair of vintage speakers, ProAc EBS ... its measurement is too nasty to you? 

 

firedog: thanks for your suggestion. There is only one Kii dealer at where I live sadly. I also have one friend who doesn't buy Kii since he dislike that dealer ... he bought PSI instead but I guess he already has some good acoustics treatment. I think dealer may play a factor in the purchase decision as we're not talking about 500 USD but almost 10000 USD here.

 

fas42's love for 8c could be understandable. But personally I'd like to have two pairs at home for two months to address the questions I raised (which seems rather impractical unless I buy both haha).

 

BTW, what John Atkinson's measurement intrigued me is that normally we tend to have both peaks and dips together. But his room doesn't show any problems of deep notches, just a big peak. Perhaps his room has been specifically tuned though ...

 

I have asked D&D about the free positioning issue. Perhaps many bought 8c for studio uses, and I never see any users with pics of 8c pulling out from the front walls as 'domestic uses'.

 

Please share if anyone is using that way. I'd be grateful.

[Kal Rubinson]

2 minutes ago, PCmusic said:

I have asked D&D about the free positioning issue. Perhaps many bought 8c for studio uses, and I never see any users with pics of 8c pulling out from the front walls as 'domestic uses'.

I did that but the bass output was not as good as with proper rear wall coupling.

[PCmusic]

Thanks Kal, it's your first review of 8c that impressed me first ... 

 

Do you mind sharing more specifically how 'not as good as' means regarding possibilities of bass peaks and dips? 

[Kal Rubinson]

I must admit that I did no measurements but, audibly, the bass was greatly reduced and much less distinct.  Moving them back closer to the rear wall and setting that distance into the DSP was transforming.

[PCmusic]

Thanks Kal. For all D&D users who put them close to the wall, it's indeed a good news! 

[PCmusic]

8c (and Kii) put into domestic use, I like the promise from from 6 Moon: 

 

"The 8c sounds natural and neutral anywhere in the room. Sit close and listen into the recording - you are there. Sit farther away and hear more indirect sound with perfect timbre because of even dispersion and flat power response for a 'they are here' experience."

http://6moons.com/audioreviews2/dutchdutch/2.html

 

It does not seem to be very possible with traditional speakers due to wide fluctuation of off-axis frequencies ... during my audition, I noted 6 Moon's observation is correct and what I have experienced.

[baconbrain]

2 hours ago, PCmusic said:

baconbrain: that ... was a pair of vintage speakers, ProAc EBS ... its measurement is too nasty to you? 

 

 

No, but having used a Trinnov with 3 different bookshelf speakers & similar placement in my listening room, each had distinct differences when comparing the measurement results.

 

If you find the sound of the 8c to be more engaging, then they are probably the right choice for you. (trust your ears) Deficits in bass response can always be compensated through a good subwoofer integration. (which with a Trinnov is quite easy to do)

[Kal Rubinson]

3 hours ago, PCmusic said:

The 8c sounds natural and neutral anywhere in the room.

but not the same.

[fas42]

Don't know whether you've seen this video, but one of the designers explains some of the concepts in the design,