Dutch & Dutch 8c Review

[changer]

I say Amir should change his plots.

fair enough!
anyway, thanks for your service mentality, appreciated. maybe over the the time, some deliberate ASR standardization concept will emerge from discussion, that would be great. I think standards should never only follow path dependency.

 

[dc655321]

OT but is dB(Z) same as dB SPL?

AFAIU, yes, same thing.

 

[napilopez]

Erin, thank you -- I've been waiting for this one! But I also curse you, for there is now a set of D&D 8C measurements better than mine.

On a separate note, I sometimes fear Audio Science Review is becoming a bit more like Audio Distortion Review of late, like people got bored with directivity and FR.

If that level of distortion is what was needed to get this kind of performance in a bookshelf format (even if a large one), so be it! If I can't hear it, I don't care. Yes, you can get less distortion with other speakers, but no way does that make up for the bass extension here. You don't need subs with the 8C. You do with most other speakers that have less distortion. So that becomes another price detail to factor in.

Also, yes, the Studio version (black mdf) costs $9,750.

 

[changer]

I am hoping so. But I don’t know how it will work out long-term. This is kind of a shotgun effort to reduce those costs. Especially if I want to provide high resolution graphics which I think are helpful.

I wouldn't bother compressing the shit out of them, if we are speaking about graphs here. Should be good enough.

 

[dc655321]

Agreed, I also thought it is somewhat high compared to all superlatives of the speaker.

It is high relative to what you've shown - DD8C is 3% at 200Hz, 10% at 100Hz.
-60dB == 0.1%
-40dB == 1.0%
-20dB == 10.0%

But, I'm beginning to think that THD is not that important, or golden-eared reviewers (all of us) just don't notice it's effects at lower frequencies.
Or both.

 

[Biblob]

I know that distortion isn't that important at a reasonable distance and room size, but we're talking about $10k speakers (studio version?). The 1% H3 at the crossover point shows the woofer crying, I still wonder why they didn't went with a 4-way system and maybe less exotic drivers; especially to fight the sadly not measured IMD.
Anyway, thanks a lot Erin, this is a very nice review with what really interests us and without the fluff. Another question that probably has meaning seeing the very horn-like waveguide: any hiss?

Also, I wondered before this review if the cardioid pattern extended to the vertical plane too, as the slots aren't here, but surprisingly, it does!

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.

 

[changer]

Everything, save the distortion figure, looks superlative as expected.

What is happening with distortion? Is this an effect of heavy DSPing? I want to know!

 

[dc655321]

What is happening with distortion? Is this an effect of heavy DSPing? I want to know!

Yes, DSP (boosting output) is responsible. There is a conversation on this site about this, as "excessive" THD was measured previously.
Basically, some gain is required on the woofer to achieve the cardioid behavior and maintain target frequency response.

i.e. no free lunch.

EDIT: previous discussion on 8c distortion here. Good stuff in that thread...

 

[hardisj]

Alright, here's the distortion data vs fundamental. Don't nitpick colors/size/etc. I just don't have the patience to keep up with changing scales and whatnot.


86dB @ 1m.

96dB @ 1m.

 

[changer]

big up!

 

[hardisj]

EDIT: previous discussion on 8c distortion here. Good stuff in that thread...

I was just about to link that.

 

[Dj7675]

Totally fine with Erin doing his distortion graphs how he likes. I would just like to understand Erin’s ab it more. Amir’s make sense to me and I am used to them. Anyone care to give a “Distortion for Dummies” rundown of how to read/interpret them? Below are one of Amir’s for the F208 and Erin‘s 8C. Appreciate it.

 

[dfuller]

Alright, here's the distortion data vs fundamental. Don't nitpick colors/size/etc. I just don't have the patience to keep up with changing scales and whatnot.


86dB @ 1m. View attachment 116452



96dB @ 1m.
View attachment 116453

Thank ya much, Erin. Much easier to read this way.

 

[Matias]

But, I'm beginning to think that THD is not that important, or golden-eared reviewers (all of us) just don't notice it's effects at lower frequencies.
Or both.

Indeed. A future research topic for Harman group would be a formula for preference rating of tonal balance versus distortion levels, and see how casual listeners, audiophiles and pro audio people rate speakers trading off both variables.

 

[thewas]

Thank you for another superb review Erin, as you can see the highest effort you put into them gets also highly appreciated here.

Also nice to see again confirmed that the CTA-2034 predicted in room response matches responses in real rooms very well above modal region, here yours PIR vs the MMM response of a pair D&D 8c I had measured some time ago at a friends house:

Interestingly I had thought that the 400 Hz bump was just a room issue but reading your review I think now it could be partially also related to a resonance as you suspect. Shame he doesn't own them anymore as I would do some measurements to look into it.

 

[changer]

Anyone care to give a “Distortion for Dummies” rundown of how to read/interpret them?

That would be lovely! Still, easy comparability of measurements from a consumer standpoint is something different than just being fine with a certain way of displaying them. We may call this a problem of user interfaces. If only measurments where the case, we could (or: could not! as in the case of many informed enthusiasts with limited knowledge) just talk raw data. Yet here, we are essentially gathered as a community around measurement representations to compare objective performance for a wide variety of speakers in an easy way! This is the only reason I was thinking about comparable graphs. It might still well be the less reasonable representation to show distortion in percentage rather than absolute data and I wish an open discussion on the appropriate formats can and will happen here. We have some experienced audio engineers in our rows, maybe they can provide persuasive arguments on 'What is to Be Done' (Lenin).

 

[q3cpma]

Totally fine with Erin doing his distortion graphs how he likes. I would just like to understand Erin’s ab it more. Amir’s make sense to me and I am used to them. Anyone care to give a “Distortion for Dummies” rundown of how to read/interpret them? Below are one of Amir’s for the F208 and Erin‘s 8C. Appreciate it.
View attachment 116454View attachment 116455

Now that I look at it better, H5 reaching 1.5% at 100 Hz definitely isn't nice; inaudibility threshold at 100 Hz and 100 dB is 1% for H5.

 

[Dj7675]

Thank you for another superb review Erin, as you can see the highest effort you put into them gets also highly appreciated here.

Also nice to see again confirmed that the CTA-2034 predicted in room response matches responses in real rooms very well above modal region, here yours PIR vs the MMM response of a pair D&D 8c I had measured some time ago at a friends house:

View attachment 116457

Interestingly I had thought that the 400 Hz bump was just a room issue but reading your review I think now it could be partially also related to a resonance as you suspect. Shame he doesn't own them anymore as I would do some measurements to look into it.

Thanks for posting. Nice to see an estimated and an actual room for fun.

 

[dc655321]

inaudibility threshold at 100 Hz and 100 dB is 1% for H5.

Is that figure for tones? Source?

 

[hardisj]

Thank you for another superb review Erin, as you can see the highest effort you put into them gets also highly appreciated here.

Also nice to see again confirmed that the CTA-2034 predicted in room response matches responses in real rooms very well above modal region, here yours PIR vs the MMM response of a pair D&D 8c I had measured some time ago at a friends house:

View attachment 116457

Interestingly I had thought that the 400 Hz bump was just a room issue but reading your review I think now it could be partially also related to a resonance as you suspect. Shame he doesn't own them anymore as I would do some measurements to look into it.

Thanks for sharing. My MMM results just plain didn't make sense so I did some more testing with a set I had measured previously. Totally different results again, from what was measured before. I hated not being able to provide the results. So thank you for sharing yours.