Dutch & Dutch 8c Review

[dc655321]

@hardisj, what does the background noise spectrum look like in your garage lab?
Does the NFS do any background subtraction of noise from measurements?
Not questioning measurement validity, just curious...

 

[q3cpma]

Is that figure for tones? Source?

This pure sine table everyone uses (source unknown). Since electronic music exists, it doesn't seem far fetched to use it as worst-but-still-realistic case.

 

[pozz]

This pure sine table everyone uses (source unknown). Since electronic music exists, it doesn't seem far fetched to use it as worst-but-still-realistic case.

Just FYI: https://secure.aes.org/forum/pubs/journal/?elib=5147

 

[napilopez]

For what it's worth -- and just to really drill down the idea that speakers should, in fact, measure very similarly across different measurement rigs -- here's how my spin of the 8C overlaps with Erin's:

Of course, I couldn't measure directivity reliably below 200Hz, and I have far less resolution in the low mids, but we see excellent agreement. So don't let anyone tell you you shouldn't expect consistency! (Remembering a certain youtube video...)

 

[q3cpma]

For what it's worth -- and just to really drill down the idea that speakers should, in fact, measure very similarly across different measurement rigs -- here's how my spin of the 8C overlaps with Erin's:

View attachment 116467

Of course, I couldn't measure directivity reliably below 200Hz, and I have far less resolution in the low mids, but we see excellent agreement. So don't let anyone tell you you shouldn't expect consistency! (Remembering a certain youtube video...)

Nice to see your not-Klippel-money rig kinf of validated (again).

 

[hardisj]

I updated the OP/review with the globes.

Horizontal Polar (Globe) Plot: This represents the sound field at 2 meters - above 200Hz - per the legend in the upper left.

Vertical Polar (Globe) Plot: This represents the sound field at 2 meters - above 200Hz - per the legend in the upper left.

This clearly illustrates the cardioid nature of the 8c. Especially when you look a more "standard" speaker like the Kef R3 (sneak peak!!!!):

 

[napilopez]

Nice to see your not-Klippel-money rig kinf of validated (again).

Definitely gives me some peace of mind!

 

[hardisj]

@hardisj, what does the background noise spectrum look like in your garage lab?
Does the NFS do any background subtraction of noise from measurements?
Not questioning measurement validity, just curious...

 

[MZKM]

I do not. I frankly don't put much stock in it. But I have provided the data in my OP so hopefully the guys who normally do all the "extra" stuff will be able to provide that. I tried to match Amir's outputs so they could just drop my data in their scripts and go.

I’m trying to download it (on my phone), and no matter what I try it only downloads the Horizontal SPL, and in .7z format. Figured it out, but it doesn't save as a folder, so I have to manually copy the horizontal/vertical data files.

Oh, and just to double check even though I asked a while ago, did you compute the Spinorama or did you manually calculate it? Because to my knowledge the Klippel software still does the incorrect calculation of the Early Reflections & PIR.

 

[Vini darko]

Awesome review of a very well engineered speaker. Thankyou for all the work on this
On a personal note those polar plots make no sense to me fortunately the normal ones make perfect sense.

 

[spacevector]

Are all the responses shown at 2m for this speaker? This is kind of related to my earlier question of driver integration integration. Is this Klippel software able to generate response at arbitrary distances also?

 

[Colonel7]

But your measurements here seem to suggest that, finally, we have a loudspeaker which can be placed close against a wall with the attendant LF gain without introducing a whole range of problems further up the frequency spectrum. They're not cheap but would certainly be on my shortlist if I were in the market for such a thing . Being small, unobtrusive &, placed against the wall, they're conducive to domestic harmony, too

Yes! Unlike some other interesting designs where the speakers "disappear" in the room only after following the direction to pull them 4 feet off all walls into the room

 

[MZKM]

The score should actually be higher, but my LFX code wasn’t working because it looks for -6dB point, and at 20Hz it is only down 3.5dB!!! As such, the “score w/ sub” is not accurate, but I added it for consistency.

Also, as expected, the flat in-room response from 1500Hz-15000Hz lowers the rating.

Preference Rating
SCORE: 7.2
SCORE w/ sub: 7.9

Frequency response: +/-1.7dB 25Hz-18kHz

Due to the super deep bass, my graphs that usually only go down to 30Hz needs to be extended to 20Hz, that’ll be uploaded ata later date as I want the standard scaling to be achieved.

 

[Pritaudio]

Jeez I need more coffee.
Great write up.

How do you think they differ from your setup of rme, nc502 and choice of speakers.
because you can apply eq after calibrating a mic with software. Do you think the combined sinad with eq option would be preferable to this speaker.
perhaps on value alone.

 

[Matias]

How do you think they differ from your setup of rme, nc502 and choice of speakers.
because you can apply eq after calibrating a mic with software. Do you think the combined sinad with eq option would be preferable to this speaker.
perhaps on value alone.

Good question which I have no answer for, other than speculation. But you can get an RME ADI-2 DAC fs + Hypex NCore NC502MP based amp for around 2k usd and that leaves some 8k usd for speakers, which is a lot of speakers to buy, until it reaches the price of the D&D 8c.

 

[617]

For what it's worth -- and just to really drill down the idea that speakers should, in fact, measure very similarly across different measurement rigs -- here's how my spin of the 8C overlaps with Erin's:

View attachment 116467

Of course, I couldn't measure directivity reliably below 200Hz, and I have far less resolution in the low mids, but we see excellent agreement. So don't let anyone tell you you shouldn't expect consistency! (Remembering a certain youtube video...)

Hey NL that is pretty impressive that you got such good measurements without an NFS. Great work.

 

[MZKM]

This is for sure an…intimidating speaker.
Erin, you didn’t hop on the ol‘ photo copier did you?

 

[hardisj]

As such, the “score w/ sub” is not accurate, but I added it for consistency.

If I understand you correctly, IMHO it should not be provided then. No reason to “penalize” the speaker due to the equations not taking a high-performer in to account.

 

[hardisj]

This is for sure an…intimidating speaker.
Erin, you didn’t hop on the ol‘ photo copier did you?
View attachment 116491

I did! Front side first. Unfortunately, that image is to scale.

 

[617]

I did! Front side first. Unfortunately, that image is to scale.

No shame in using a logarithmic scale