This is a review and detailed measurements of the Definitive Technology Demand D11 bookshelf/stand-mount speaker. It is on kind loan from a member who I think bought it used. The normal cost on Amazon is US $1,000 including Prime shipping.
I must stay, the enclosure is very attractive and well built. But I don't care for the look of the drivers:
The offset tweeter is supposed to reduce effect of diffraction but it bugs me and I don't even have ADD! There is a passive radiator on top which you can't see but is covered in nice fabric.
Back panel terminals are too close as usual but otherwise feel fine:
Speaker is built in China.
Measurements that you are about to see were performed using the Klippel Near-field Scanner (NFS). This is a robotic measurement system that analyzes the speaker all around and is able (using advanced mathematics and dual scan) to subtract room reflections (so where I measure it doesn't matter). It also measures the speaker at close distance ("near-field") which sharply reduces the impact of room noise. Both of these factors enable testing in ordinary rooms yet results that can be more accurate than an anechoic chamber. In a nutshell, the measurements show the actual sound coming out of the speaker independent of the room.
I used over 800 measurement point which was enough to compute the sound field of the speaker within 1% error.
Temperature was 78 degrees. Measurement location is at sea level so you compute the pressure.
Measurements are compliant with latest speaker research into what can predict the speaker preference and is standardized in CEA/CTA-2034 ANSI specifications. Likewise listening tests are performed per research that shows mono listening is much more revealing of differences between speakers than stereo or multichannel.
Was not sure what to use for measurement axis given the offset tweeter. I decided to place it slightly to the left of the tweeter center.
Spinorama Audio Measurements
Acoustic measurements can be grouped in a way that can be perceptually analyzed to determine how good a speaker is and how it can be used in a room. This so called spinorama shows us just about everything we need to know about the speaker with respect to tonality and some flaws:
Gosh, this is close to being good had we not had the sharp jaggies around 600 Hz. The disturbance is narrow in nature so maybe not too audible.
Early window reflections show the same indicating it is not simple diffraction:
Predicted in-room response shows what we already know:
There is a slight rise in energy in lower treble region that would lead to a bit of brightness. And whatever that peak does around 600 Hz.
The peak appears in the woofer response but could be due to the passive radiator which I did not measure due to its location:
Impedance dips to 4 ohm which is typical of these small speakers:
Radiation in horizontal axis is not flat which is a bit of concern:
Here is the same in the form of a heatmap:
Notice how we have more energy on the right than on the left due to tweeter being offset. If we made that the upper range of woofer would be out of alignment.
Here it is vertically:
Speaker Distortion Measurements
Playing a sweep at both 86 and 96 dB SPL @ 1 meter shows that the woofer is not happy at either level:
There was a horrendous rattle/noise at very low frequencies as you see below:
So best not feed it ultra low bass.
Finally CSD/waterfall:
Speaker Subjective Listening Test
I listened to the D11 without seeing the measurements. First impression was positive. My reference tracks translated well and provided good "audiophile" enjoyment as they should. After a few minutes, I noticed a bit of brightness in female "s" sounds. And a bit of unhappiness in upper bass region in my brain.
I then looked at the measurements and attempted to fix these. Putting a notch at 618 Hz even with "high q" (narrow) filter caused bass to be lost which subjective is not a good trade off. I think the problem is that we have a dip right before this region with poor directivity to boot so EQ is not as simple as it seems.
I added very low Q (1) dip centered around 6 kHz and I thought that made a positive change in shaving the highs some. But it turned out to be more of a taste thing so I am not showing it.
At this point, I turned off the EQ and played music for a while and sound was enjoyable. With exception of tracks with deep bass which caused static in the woofer, the D11 could play quite loud without bottoming out. Its deep cabinet is helping in this regard.
Conclusions
The cabinet construction and finish is definitely a step above budget speakers. The look of the drivers is gimmicky but maybe you can put the grill on to hide it which may also lower the highs and make them acceptable. Subjectively the D11 sound was almost right.
So while not a perfect speaker, I generally liked the Definitive Demand D11 and am putting it on my recommended list. Note that I am not paying attention to price with this.
-----------
As always, questions, comments, recommendations, etc. are welcome.
Miracles happen: the panthers have volunteered to help pick our incredible garden harvest. Alas, there is a whole set of regulations for panthers doing such field work requiring major investment in protective gear. They need googles to protect their eyes, speaker shoes to keep the dirt from getting stuck to their paws, etc. That is where you come in with donating money for this equipment using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
I must stay, the enclosure is very attractive and well built. But I don't care for the look of the drivers:
The offset tweeter is supposed to reduce effect of diffraction but it bugs me and I don't even have ADD! There is a passive radiator on top which you can't see but is covered in nice fabric.
Back panel terminals are too close as usual but otherwise feel fine:
Speaker is built in China.
Measurements that you are about to see were performed using the Klippel Near-field Scanner (NFS). This is a robotic measurement system that analyzes the speaker all around and is able (using advanced mathematics and dual scan) to subtract room reflections (so where I measure it doesn't matter). It also measures the speaker at close distance ("near-field") which sharply reduces the impact of room noise. Both of these factors enable testing in ordinary rooms yet results that can be more accurate than an anechoic chamber. In a nutshell, the measurements show the actual sound coming out of the speaker independent of the room.
I used over 800 measurement point which was enough to compute the sound field of the speaker within 1% error.
Temperature was 78 degrees. Measurement location is at sea level so you compute the pressure.
Measurements are compliant with latest speaker research into what can predict the speaker preference and is standardized in CEA/CTA-2034 ANSI specifications. Likewise listening tests are performed per research that shows mono listening is much more revealing of differences between speakers than stereo or multichannel.
Was not sure what to use for measurement axis given the offset tweeter. I decided to place it slightly to the left of the tweeter center.
Spinorama Audio Measurements
Acoustic measurements can be grouped in a way that can be perceptually analyzed to determine how good a speaker is and how it can be used in a room. This so called spinorama shows us just about everything we need to know about the speaker with respect to tonality and some flaws:
Gosh, this is close to being good had we not had the sharp jaggies around 600 Hz. The disturbance is narrow in nature so maybe not too audible.
Early window reflections show the same indicating it is not simple diffraction:
Predicted in-room response shows what we already know:
There is a slight rise in energy in lower treble region that would lead to a bit of brightness. And whatever that peak does around 600 Hz.
The peak appears in the woofer response but could be due to the passive radiator which I did not measure due to its location:
Impedance dips to 4 ohm which is typical of these small speakers:
Radiation in horizontal axis is not flat which is a bit of concern:
Here is the same in the form of a heatmap:
Notice how we have more energy on the right than on the left due to tweeter being offset. If we made that the upper range of woofer would be out of alignment.
Here it is vertically:
Speaker Distortion Measurements
Playing a sweep at both 86 and 96 dB SPL @ 1 meter shows that the woofer is not happy at either level:
There was a horrendous rattle/noise at very low frequencies as you see below:
So best not feed it ultra low bass.
Finally CSD/waterfall:
Speaker Subjective Listening Test
I listened to the D11 without seeing the measurements. First impression was positive. My reference tracks translated well and provided good "audiophile" enjoyment as they should. After a few minutes, I noticed a bit of brightness in female "s" sounds. And a bit of unhappiness in upper bass region in my brain.
I then looked at the measurements and attempted to fix these. Putting a notch at 618 Hz even with "high q" (narrow) filter caused bass to be lost which subjective is not a good trade off. I think the problem is that we have a dip right before this region with poor directivity to boot so EQ is not as simple as it seems.
I added very low Q (1) dip centered around 6 kHz and I thought that made a positive change in shaving the highs some. But it turned out to be more of a taste thing so I am not showing it.
At this point, I turned off the EQ and played music for a while and sound was enjoyable. With exception of tracks with deep bass which caused static in the woofer, the D11 could play quite loud without bottoming out. Its deep cabinet is helping in this regard.
Conclusions
The cabinet construction and finish is definitely a step above budget speakers. The look of the drivers is gimmicky but maybe you can put the grill on to hide it which may also lower the highs and make them acceptable. Subjectively the D11 sound was almost right.
So while not a perfect speaker, I generally liked the Definitive Demand D11 and am putting it on my recommended list. Note that I am not paying attention to price with this.
-----------
As always, questions, comments, recommendations, etc. are welcome.
Miracles happen: the panthers have volunteered to help pick our incredible garden harvest. Alas, there is a whole set of regulations for panthers doing such field work requiring major investment in protective gear. They need googles to protect their eyes, speaker shoes to keep the dirt from getting stuck to their paws, etc. That is where you come in with donating money for this equipment using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/