Wilson Audio Duette 2 vs Sophia

[Pogre]

You should contact Salk (Jim, I think?) and see if they've sold to anyone in your area. I know of a couple guys who got lucky and were able to demo before buying.

 

[murl]

I finally found a pair of speakers that seem to suit my taste. Dutch and Dutch 8c. At first I was thinking no way these could sound amazing. Wow they are incredible, given them a listen if you are ever in an area with a dealer.

 

[shadyJ]

The 8C speakers are amazingly accurate. Very nice choice! I would love to hear a pair myself.

 

[murl]

The 8C speakers are amazingly accurate. Very nice choice! I would love to hear a pair myself.

If you are ever in the panhandle area you are more than welcome to drop by. My wife likes them because there are less boxes. Also will be room ready soon which makes like easier.

 

[KEW]

Was curious what these looked like (never heard of them).
Figure I'm not the only one, so here:

Review:

Dutch & Dutch 8c active loudspeaker system

www.stereophile.com

 

[shadyJ]

Was curious what these looked like (never heard of them).
Figure I'm not the only one, so here:

Review:

Dutch & Dutch 8c active loudspeaker system

www.stereophile.com

Also Soundstage reviewed a pair: their measurements.

 

[snakeeyes]

Possibly check out all the threads from @ematthews He went thru several high quality towers the past couple years in the $4k budget.

 

[murl]

I honestly kind of brushed them off at first. I listened to several high end speakers over the past two months and these were my favorites. I was honestly kind of torn between these and salon 2s. It was emotionally difficult to give up all of my separate components but they really do fit into our condo quite well.

 

[Verdinut]

I understand the fact that those 8Cs have an excellent performance. But how are the enclosed amplifiers kept cool?

 

[KEW]

I understand the fact that those 8Cs have an excellent performance. But how are the enclosed amplifiers kept cool?

From the Stereophile review:

On the 8c's underside are a small vent and a variable-speed fan that kicks in when needed to ventilate the amplifiers. I never heard it.

 

[murl]

From the Stereophile review:

Yeah you can’t hear it at all.

 

[Matthew J Poes]

The 8C speakers are a very cool design, very technologically advanced, and have among (if not THE) best measured performance I've ever seen. If they are in your price range, they would be by far the best speakers discussed so far. I haven't heard them either, but since the day they were introduced I've been sending links and articles about them to James. It's on my short list of speakers to try out.

I was talking to Gene yesterday about some of the silly things that speaker designers do when building speakers. One of the problems we see a lot is that they prioritize the wrong things. One company may focus on the best possible on-axis frequency response, but the phase coherence and off-axis response may be bad. The distortion may be high. They may be too dynamically limited.

In my opinion, the characteristics of a good speaker, in order of importance are:

1. Listening Window Response
2. Early Reflection Response
3. Bandwidth
4. Smooth upward tilted DI (but flat frontal hemisphere DI)
5. Dynamic Limit
6. Phase Coherence/Time Alignment
7. Distortion within linear range
8. Looks

I might even switch 7 and 8 around simply because most speakers are so sorted in the distortion arena that it just isn't a major concern right now.

In any case, the cool things about the D&D 8C is that it is nearly perfect at 1, 2, 4, 6, 7, and 8. While its bandwidth may not extend as far as we would like, it isn't a problem really, and if you add some subwoofers, problem solved. As for the dynamic limit, well, for 99% of users its fine. It certainly plays louder than most speakers. For me, I'm sure I'd be happy enough, but it would be a bit limited for my usage. I suspect it would really struggle to reach reference levels in my theater.

As for the technology to achieve that near perfect performance, my favorite is the side vents that allow for cardiod bass radiation. Basically, through the use of a clever passive design principle, the speaker cancels some of the response to the sides of the woofer driver. By matching the waveguide/tweeter directivity to the now narrower directivity achieved with this woofer/enclosure setup, we get a speaker whose DI can remain raised and flat over a far larger range than would otherwise be possible. This speakers DI is flat to a point that would normally require a speaker about twice as big as this one is.

 

[davidscott]

But those Magnepans sound sooo sweet.

 

[NINaudio]

The 8C speakers are a very cool design, very technologically advanced, and have among (if not THE) best measured performance I've ever seen. If they are in your price range, they would be by far the best speakers discussed so far. I haven't heard them either, but since the day they were introduced I've been sending links and articles about them to James. It's on my short list of speakers to try out.

I was talking to Gene yesterday about some of the silly things that speaker designers do when building speakers. One of the problems we see a lot is that they prioritize the wrong things. One company may focus on the best possible on-axis frequency response, but the phase coherence and off-axis response may be bad. The distortion may be high. They may be too dynamically limited.

In my opinion, the characteristics of a good speaker, in order of importance are:

1. Listening Window Response
2. Early Reflection Response
3. Bandwidth
4. Smooth upward tilted DI (but flat frontal hemisphere DI)
5. Dynamic Limit
6. Phase Coherence/Time Alignment
7. Distortion within linear range
8. Looks

I might even switch 7 and 8 around simply because most speakers are so sorted in the distortion arena that it just isn't a major concern right now.

In any case, the cool things about the D&D 8C is that it is nearly perfect at 1, 2, 4, 6, 7, and 8. While its bandwidth may not extend as far as we would like, it isn't a problem really, and if you add some subwoofers, problem solved. As for the dynamic limit, well, for 99% of users its fine. It certainly plays louder than most speakers. For me, I'm sure I'd be happy enough, but it would be a bit limited for my usage. I suspect it would really struggle to reach reference levels in my theater.

As for the technology to achieve that near perfect performance, my favorite is the side vents that allow for cardiod bass radiation. Basically, through the use of a clever passive design principle, the speaker cancels some of the response to the sides of the woofer driver. By matching the waveguide/tweeter directivity to the now narrower directivity achieved with this woofer/enclosure setup, we get a speaker whose DI can remain raised and flat over a far larger range than would otherwise be possible. This speakers DI is flat to a point that would normally require a speaker about twice as big as this one is.

Maybe I missed it, but what is DI?

 

[shadyJ]

Maybe I missed it, but what is DI?

Directivity Index. This article explains how it is determined.

 

[NINaudio]

Directivity Index. This article explains how it is determined.

Thanks, knowing what DI stood for here is what I needed for it all to make sense!

 

[D Murphy]

1. Phase Coherence/Time Alignment
2. Distortion within linear range
3. Looks

By matching the waveguide/tweeter directivity to the now narrower directivity achieved with this woofer/enclosure setup, we get a speaker whose DI can remain raised and flat over a far larger range than would otherwise be possible. This speakers DI is flat to a point that would normally require a speaker about twice as big as this one is.

The 8c's are definitely on my must hear list. One technical point--what exactly to you mean by phase coherence and time alignment? Are you requiring that the speaker be able to pass a square wave precisely, which would require the drivers not only to be in phase with each other at the crossover point(s), but be at the same cycle. For a conventional speaker using a 4th order Linkwitz-Riley acoustic crossover, the drivers will be in phase in the sense that they'll be going in and out together,, but they'll be a full cycle apart. That doesn't qualify as phase coherence, and they won't be time aligned either. Almost no speakers with passive crossovers can achieve true phase coherence, and even then it will only hold for one listening position and will probably require trade-offs on other performance dimensions. DSP can provide a phase coherent response at one listening position, but there's no evidence that you can hear it. Floyd Toole says that you just can't hear phase period. I'm not sure I agree with him there (or on a number of other points), and I always try to get drivers as closely in phase as possible, but mainly it's because that usually produces the smoothest response.

And one word of caution. Wave guides can produce impressive Spinorama measurements, but-- for me at least--that doesn't always, or even usually, make for a satisfying listening experience. it's very easy for the guides to produce coloration in the form of a closed-in and foggy upper midrange, lower treble. That was the problem with the lowly Pioneer BS22 and a much-vaunted higher end speaker that I'm auditioning now, as well as some speakers in between. All of which makes me even more interested to hear the 8c.

 

[Matthew J Poes]

The 8c's are definitely on my must hear list. One technical point--what exactly to you mean by phase coherence and time alignment? Are you requiring that the speaker be able to pass a square wave precisely, which would require the drivers not only to be in phase with each other at the crossover point(s), but be at the same cycle. For a conventional speaker using a 4th order Linkwitz-Riley acoustic crossover, the drivers will be in phase in the sense that they'll be going in and out together,, but they'll be a full cycle apart. That doesn't qualify as phase coherence, and they won't be time aligned either. Almost no speakers with passive crossovers can achieve true phase coherence, and even then it will only hold for one listening position and will probably require trade-offs on other performance dimensions. DSP can provide a phase coherent response at one listening position, but there's no evidence that you can hear it. Floyd Toole says that you just can't hear phase period. I'm not sure I agree with him there (or on a number of other points), and I always try to get drivers as closely in phase as possible, but mainly it's because that usually produces the smoothest response.

And one word of caution. Wave guides can produce impressive Spinorama measurements, but-- for me at least--that doesn't always, or even usually, make for a satisfying listening experience. it's very easy for the guides to produce coloration in the form of a closed-in and foggy upper midrange, lower treble. That was the problem with the lowly Pioneer BS22 and a much-vaunted higher end speaker that I'm auditioning now, as well as some speakers in between. All of which makes me even more interested to hear the 8c.

I've always heard the term phase coherent to mean the phase is "correct", meaning in phase at the crossover point. Not to be at the same cycle. I've heard that described always as time coincident (or some even say phase coincident).

I don't believe the term Phase coherence is all that well defined in speakers, so there are probably many definitions.

As for waveguides, probably won't convince me of that view. I'm quite the opposite in my view. I believe waveguides are needed to produce the best sounding speakers. I've heard lots of bad speakers with waveguides, but just as many, if not more, without. My reference speakers are the Gedlee Abbey C's and I've still never heard a speaker I think is clearly better. Different at best, most are worse. It is precisely the OS waveguide that gives them their magic.

I believe the problem with the Pioneer bS22 is actually the crossover design relative to the capability of the tweeter, unrelated to the waveguide. It was crossed over too low and the tweeter distorted. When I measured it and the tower version, I was shocked to find really high distortion around the crossover region. I had thought the speaker was broken until multiple samples I tested from the line all had the problem.

Here is an example:


I wouldn't judge a waveguide by speakers like that. Listen to a JBL M22, anything from Geddes, even the Revel M126be and tell me if you still think waveguides cause coloration.

There are some older horns and waveguides that color the sound for sure. Def. don't judge the concept by those. Until folks like Geddes jumped in and really began to research and innovate waveguides, the understanding of what caused horn honk or other kinds of horn related distortions were not well understood. Often the solutions simply introduced new and different problems.

 

[Matthew J Poes]

Thanks, knowing what DI stood for here is what I needed for it all to make sense!

There are often two kinds of DI's created for a given speaker. One is based on the total sound power of the speaker. That is, all the sound radiated from the speaker around it's full 360 degrees. The other is known as the frontal hemisphere DI, and that is for the hemisphere of sound power generated around the front 180 degrees. These are sometimes further divided up into horizontal and vertical versions.

So what I was getting at is that I believe a "perfect" speaker would have a flat DI in the frontal hemisphere. What that means in practice is that the sound of the speaker does not change at all in tonal balance as you move out across the speakers 180 degree frontal hemisphere. Instead, it simply get's quieter as you move toward the side. However, I don't want my speakers radiating a lot of sound toward the back, so my "perfect" speaker also has a full DI that is upward tilted, meaning that the speaker becomes increasingly directional at high frequencies when considering its full radiation pattern. A speaker that primarily radiates its sound in one direction, in this case, toward the front, will show this kind of DI.

The reason I want this is that, while I want reflections in my room to enhance my listening experience, I like a high direct to reflected energy ratio (more direct than reflected). I want consistent sound and consistent sounding reflections. The best way to achieve that is through the speakers radiation pattern.

Which isn't to say I haven't heard speakers that don't measure exactly this way that sound good. I think my preference is as much cerebral as it is practical. But the 8C, none the less, is probably one of the most technically perfect speakers I've ever seen.

 

[Matthew J Poes]

Almost no speakers with passive crossovers can achieve true phase coherence, and even then it will only hold for one listening position and will probably require trade-offs on other performance dimensions. DSP can provide a phase coherent response at one listening position, but there's no evidence that you can hear it.

Vandersteen Quatro Wood CT loudspeaker & M5-HPA monoblock power amplifier Loudspeaker Measurements

Sidebar 3: Loudspeaker Measurements I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone to measure the Vandersteen Quatro Wood CT's frequency response in the farfield and an Earthworks QTC-40 mike for the nearfield responses. I left the loudspeaker's grille in place for the...

www.stereophile.com

This is a passive speaker that is time coincident and achieves it through passive crossovers.

Why do you say that it would only be time coincident at only one listening position? Across the horizontal plane I don't see any reason that this speaker would become not coincident? The relative distance between drivers and listener would not change? Even changes in height would not change the relative difference in distance. I would think it would show a time coincident response at all listening positions.

The cost of this speaker is just gross, but putting that aside, I'm not sure I would say there are many obvious trade-off's in it's measured performance. I'm actually pretty impressed by its performance.

I think saying that phase distortion is not audible is maybe a little extreme. I think the literature is a lot more vague, with lots of research evidence in support of its audibility. It just isn't all that audible (certainly not more audible or more important than amplitude response).

E-library page - AES

AES E-Library ← Back to search

www.aes.org

https://www.researchgate.net/profile/Malcolm_Hawksford/publication/269101420_THE_AUDIBILITY_OF_LOUDSPEAKER_PHASE_DISTORTION/links/58a19cb0aca272046aaea399/THE-AUDIBILITY-OF-LOUDSPEAKER-PHASE-DISTORTION.pdf

havent read this paper yet, but looks interesting.

Audibility of Loudspeaker Group-Delay Characteristics | Request PDF

Request PDF | Audibility of Loudspeaker Group-Delay Characteristics | Loudspeaker impulse responses were studied using a paired-comparison listening test to learn about the audibility of the loudspeaker group-delay... | Find, read and cite all the research you need on ResearchGate

www.researchgate.net

https://core.ac.uk/download/pdf/60365369.pdf

point being, lots of papers show we can hear phase errors, they just also point to the effect being subtle. It seems like it was also common to take a pragmatic approach. That is, the effect is audible in isolation, but these errors are all over the place, including encoded in the music, so whats the value in correcting the speaker.
While I think, in a perfect world, a speaker will be time coincident, I wasn't suggesting earlier that it must be. It must be phase coherent (per the definition I was using, which is the same as what you seemed to suggest was acceptable).