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SoundStage’s review of Dutch&Dutch’s 8C

svart-hvitt

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Maybe @Floyd Toole could comment here?

Not on Dutch specifically but on how to measure and interpret anechoic speaker data below certain frequencies.

EDIT - - - FROM TOOLE’S BOOK - - - EDIT

«The low-frequency calibrations were referenced to both ground plane and tower measurements and are most accurate with closed-box woofer systems. Multiple-woofer tower systems, and reflex systems with ports on other than the front baffle, can show anomalies, especially when the woofers of horizontally positioned tower loudspeakers swing far from the rotational axis shown in Figure 5.1 . The problem is that the chamber standing waves being corrected for are energized differently by the different woofer configurations. Often the best estimate of bass response is the sound power calculation, embracing all 70 curves. Relocating the woofers of tall loudspeakers to be closer to the axis of rotation can yield more precise data at low frequencies, which then can be spliced to the mid-/high-frequency data. Doing low-frequency measurements outdoors is the only way to avoid such complications, but that has its own difficulties. In reality, listening rooms are the dominant factors in the bass region, so small errors at low frequencies are unlikely to be traceable to listening experiences in rooms, certainly if room equalization is involved».
 
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Kal Rubinson

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image
It looks like an AR1 or AR3 who is the guy?
 

Juhazi

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Floyd Toole

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^It is from here, no name though - in 1978
https://nrc-digital-repository.canada.ca/eng/view/object/?id=3e37fcdf-4a3a-49f8-bdcd-ce8714d21374

Looks like speaker position varies, but hey -they are just posing...
image


Here is a more modern peep at the chamber, with PSB's Paul Barton
http://www.theabsolutesound.com/art...ded-tour-of-canadas-nrc-acoustics-labspart-1/

These NRC archival photos are interesting, but I have never seen them before - but I was there at the claimed date . . . I suspect that the dates are wrong, as it looks as though they are testing the acoustical attenuation of ear defenders - the hard shell, liquid-filled cushion design was invented and patented by two of my colleagues before I got there in 1965. The speaker was almost certainly an AR-3, which was there when I arrived, and which I used in my first blind listening test in 1966.

One of the first things I did when I got full-time access to the chamber was to remove the acoustically hostile catwalk. The Barton photos show the new chamber wedges with the mic arrangement as it was when I left - along with the ancient, but obviously still functional, measurement apparatus. I left in 1991 - a long time ago.

For measurements below the approximately 80 Hz cutoff frequency, as quoted in post #125, calibration is necessary. The original calibration done in 1983 used measurements on a 10 meter tower as a reference. It was a significant effort, but deemed necessary. One can also use ground plane measurements. Incidentally the determining factor for low frequency cutoff is the length of the wedges - about 1/4 wavelength is the determining factor. To move the cutoff frequency down to 30 HZ would require impractically long wedges: about 10 ft! Chamber size is not critical, except that with long wedges more space is needed between them to be able to do the measurements.

The calibration woofer, as stated, was a closed box monopole. ANY bass radiator with different radiation characteristics, such as dipoles, long towers, bass reflex, cardioid, etc. will couple differently to the residual standing waves in the chamber and the calibration will be wrong, and will change with angular orientation within the standing wave pattern - exactly as happens in listening rooms. As I said, the most likely realistic response is the sound power metric, which soundstage does not purchase.
 

Martijn Mensink

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Hi everybody,


Definitely interesting to see the differences between NRC & the 8C's spec sheet. Perhaps @Martijn Mensink could explain a bit about how to measure this sort of speaker in a chamber.

I've been approached by several people to chime in. Great discussion! I’m also very happy the guys at Soundstage did these independent measurements in the anechoic chamber of the NRC. I think speakermeasurements.com is the best source of independent measurements on the web. Great stuff! The results of their measurements on the 8c mostly correspond with our own, although there are also a couple surprises.


Great FR measurements, except the ~9dB dip at approx 60Hz?


I’m pretty sure this is the result of the anechoic chamber not being anechoic at low frequencies. You need very thick layers of fiberglass to damp long wavelengths effectively. At low frequencies even in anechoic chambers you have reflections and room-modes. The speakers don’t have the dip.


Looking at the on-axis response, I’d put the difference at 1.5-2 dB, not 3-4 dB:



jOEuHg0m_cGrtKiNif7XFC_j8QlmRa6X6jqyf8XrYRnCEp3W_Rtz7g3u3BShPD3FrkGzMG5OleR_oJNDlvS7rtgYg4DHUnh3ZCk5Q7EP0qbP_B1xB-Mbnmf8nJ_k-NJYd7HxETGm




I too suspect it’s a deliberate voicing decision, since of all measurement methods, true anechoic is least likely to exaggerate the bass response, ie if the designers used ground plane or near field measurements in the design process you’d expect any measurement error to push them the other way.



Interesting.


I’m not sure how to explain the excess in energy between about 100 and 400 hz. It’s not the result of a voicing decision. We believe in accuracy. Flat response and at the very least smooth directivity are the most important factors in that. We aim for a flat on-axis response and minimal variation within any likely listening window. In the NRC measurements the response in the low midrange also is a bit less smooth than our own. I don’t know why.


Perhaps the platform the 8c stands on can in part explain the rise at low frequencies? It’s probably not the whole story though.

1557147920374.png



I don’t fully understand the measurement of NRC (see frequency response of Dutch & Dutch 8C in NRC’s anechoic chamber below).



View attachment 25080



According to the specifications of Dutch & Dutch 8C, we should expect this:

View attachment 25081

Source: https://dutchdutch.com/wp-content/uploads/2018/11/8c-Spec-Sheet-2019.pdf



In plain numbers, Dutch & Dutch state this: FREQUENCY RESPONSE 30 HZ – 20 KHZ ± 1 DB (Source: https://dutchdutch.com/8c/).



So the question arises: How did Dutch & Dutch come up with the chart and the frequency response figures on their web site?



Have Dutch & Dutch invented a new way of stating specifications, where they use an estimated room response compensation, especially for the lower frequencies?



Have Dutch & Dutch made a speaker with a big dip in the low frequencies to take into account that the speaker will compensate for this in many rooms (i.e. many rooms, not all rooms, for example damped rooms)?



There has been some confusion among professionals in setting up the Dutch & Dutch speakers, confusion that may not have arisen if people knew about the NRC frequency response measurement, which is so different from Dutch & Dutch’s own version. The confusion arose among users with damped rooms (damped wall behind the speakers).



Again, I also noticed that the frequency response error, even over 100 Hz, is higher than the FR error of +/-1dB that the producer stated. Which begs the question if the specifications from some of the newer speaker producers come from computer calculations, not real measurements.


The measurements graphs in our spec sheet are based on measurements we did in the anechoic chamber of the Technical University of Delft for mid and high frequencies, spliced to a combination of near-field and ground-plane measurements for the bass. The anechoic chamber is a cube with internal dimensions of 10 meters. What I love about the anechoic chamber is that you can do a single measurement and get a clear picture of what happens across the entire audio bandwidth. It’s very convenient. However, even in this large anechoic chamber below about 200 hz you start seeing the effects of reflections.

1557148257786.png


I spent a lot of time in the anechoic chamber, but since about a year we have access to a large night club, with a concrete floor and a high ceiling. I can get a very clean window of approximately 70 ms, for a frequency resolution of about 14 hz. I actually get cleaner results than in the anechoic chamber, by combining ground-plane measurements for the lower frequencies and semi-anechoic measurements for higher frequencies, with the speaker on a high tower. Although extremely convenient, an anechoic chamber is never completely anechoic. Reflections are much reduced in level and number, but they are still there. In the bass you also see the effects of standing waves. Combining ground-plane measurements and semi-anechoic measurements is more work, but the results are ultimately better.


Basically, nearfield and groundplane measurements tend to result in the measurement being slightly boosted in the bass and/or low-midrange.



This is because:

  • Groundplane measurement effectively doubles the baffle width
  • Nearfield measurement tends to effectively increase the baffle dimensions to infinity
This means that if a speaker’s bass or lower midrange response is off due to a measurement error on the part of the designers’ use of these measurement techniques, it will tend to be too lean rather than too pronounced (assuming flat was their target ofc).



in other words, their groundplane/nearfield measurements will be telling them there is more bass than there really is, so to hit a flat target they will end up dialling in too little bass.



However, I don’t think that would be the case here, hence my suspicion that the slightly elevated bass is deliberate.



Does that make sense?



PS ofc I’m not talking about the apparent dip under 100Hz here - that is a result of the rear-firing woofers being more directional at the top of their passband and is merely an artefact of their orientation combined with the anechoic measurement method, and should therefore be ignored as others have pointed out.


The two woofers are still almost point sources up to their crossover point at 100 hz. They are simply much smaller than the 3.4 meter wavelength of a 100 hz tone and they have negligible horizontal directivity. In free-field conditions the woofers have a more or less spherical radiation pattern, when you put them in front of a wall that becomes a hemi-speherical radiation pattern, with a directivity index that is close to that of the cardioid midrange.


With a ground-plane measurement, you do indeed have to be careful in your interpretations. If you measure like this...

1557148332800.png




… it seems as if the baffle is twice as large as it really is. Because the ground works as an acoustic mirror, the microphone ‘sees’ two speakers on top of each other. As a result of the seemingly larger baffle, you’ll measure more output in the lower midrange than the speaker has when it’s on a stand. However, if you place the speaker like below and you tilt it so that it points straight at the microphone…

1557148618436.png



Source: https://www.stereophile.com/features/105kh/index.html


… you’ll get proper results. Ground-plane measurements then actually give you the exact same results as anechoic free-field measurements up to about 2 khz. Above that, the level gradually starts drooping because the microphone is not exactly flush with the ground-plane and you do actually get a bit of a reflection that gets more and more out of phase with the direct sound as frequency goes up.


Now on to distortion. The 8c is a relatively compact full-range loudspeaker that offers low distortion at normal and somewhat elevated listening levels. At high levels distortion can become audible on some program material. This is the price we choose to pay for a cardioid radiation pattern in a speaker this size. However, 96 dB at one meter at a single frequency from a single speaker is very loud. In practice, in rooms with some reflections a pair of 8c’s can be played quite loudly and they do actually sound clean at quite high levels. But if you’re into very loud music, they certainly have their limits.


Distortion in the bass is a bit higher than our own measurements. We use very low distortion Wavecor subwoofers in the 8c, so I'm not really sure why the distortion rises so quickly at around 50 hz. I also don’t know what causes the narrow peaks in the NRC’s distortion measurements at higher frequencies.


Hi Mitch

Thinking about it more, the 8C's may have that gentle house curve rise from 1 kHz down to 100 Hz to have the cardiod subjectively sound closer to the in room response of a standard 4pi to 2pi transitioning direct radiator which is usually used to produce recordings.



For sure an in-room steady-state response flat above the midrange would be unpleasantly bright. The 8Cs large waveguide will also reduce off axis treble energy, which I think you'd favour.


Actually, during the design of the 8c I also expected to have to tilt the midrange a bit because a flattish power response might sound too bright. However, the 8c is the first speaker I ever designed that didn’t require any voicing at all. It sounded very neutral straight from the lab. Its tuning is purely based on measurements.


Its the low pass of the subs (looks like 3rd order acoustic) followed by the cardiod acting less cardiod and bleeding through to the back before the mid gets directional. This would be easier to see with 45 degree horizontal (from the back) measurements.


The additional measurement to capture the output of the woofers is done at 180 degrees, with the mid and tweeter on. What you see is the bass (LR4 lowpass), then the very good rearward rejection in the midrange up to about 550 hz and then the somewhat higher level (although still quite low relative to on-axis) between 550 hz and say 1 khz. In the latter range directivity is the result of baffle shading. These results correspond quite well with our own measurements: https://dutchdutch.com/wp-content/uploads/2018/11/8c-Spec-Sheet-2019.pdf


Please note that at precisely 180 degrees rearward rejection is a bit less good than just off the rear axis. That is because right behind the speaker the diffracted sound around the left and right baffle edge are in phase and thus louder than slightly off-axis. This is particularly easy to see in the horizontal directivity plot in our spec sheet.


I may look into having my 8Cs measured at the 3D3A Lab.


That’d be really great!


That's what I've been taking from this. It is interesting that even with a chamber things are hard to measure, and translating that to how they are expected to work in real rooms far from easy. I'm more interested in this than how these particular speakers measure.


I agree. Fact is that no anechoic chamber is completely anechoic. You still have to take into account its limitations. Doug Schneider of Soundstage on 8 April posted the following:


On the topic of measurements, we had a couple editors of publications chime in that they think that including measurements might confuse or put off readers. Is that true? Would readers, as well as manufacturers and distributors, etc., like to see measurements accompany reviews or not? Yes (for measurements) or No (for none) is sufficient, but if you'd like to explain your stance, go ahead.


An interesting discussion followed. Check it out! Personally I’m much in favor of measurements, plus interpretation by someone who knows what they’re talking about.

Please let me know if you guys have any more questions.

Cheers!
 

svart-hvitt

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Hi everybody,




I've been approached by several people to chime in. Great discussion! I’m also very happy the guys at Soundstage did these independent measurements in the anechoic chamber of the NRC. I think speakermeasurements.com is the best source of independent measurements on the web. Great stuff! The results of their measurements on the 8c mostly correspond with our own, although there are also a couple surprises.





I’m pretty sure this is the result of the anechoic chamber not being anechoic at low frequencies. You need very thick layers of fiberglass to damp long wavelengths effectively. At low frequencies even in anechoic chambers you have reflections and room-modes. The speakers don’t have the dip.





I’m not sure how to explain the excess in energy between about 100 and 400 hz. It’s not the result of a voicing decision. We believe in accuracy. Flat response and at the very least smooth directivity are the most important factors in that. We aim for a flat on-axis response and minimal variation within any likely listening window. In the NRC measurements the response in the low midrange also is a bit less smooth than our own. I don’t know why.


Perhaps the platform the 8c stands on can in part explain the rise at low frequencies? It’s probably not the whole story though.

View attachment 25789





The measurements graphs in our spec sheet are based on measurements we did in the anechoic chamber of the Technical University of Delft for mid and high frequencies, spliced to a combination of near-field and ground-plane measurements for the bass. The anechoic chamber is a cube with internal dimensions of 10 meters. What I love about the anechoic chamber is that you can do a single measurement and get a clear picture of what happens across the entire audio bandwidth. It’s very convenient. However, even in this large anechoic chamber below about 200 hz you start seeing the effects of reflections.

View attachment 25790

I spent a lot of time in the anechoic chamber, but since about a year we have access to a large night club, with a concrete floor and a high ceiling. I can get a very clean window of approximately 70 ms, for a frequency resolution of about 14 hz. I actually get cleaner results than in the anechoic chamber, by combining ground-plane measurements for the lower frequencies and semi-anechoic measurements for higher frequencies, with the speaker on a high tower. Although extremely convenient, an anechoic chamber is never completely anechoic. Reflections are much reduced in level and number, but they are still there. In the bass you also see the effects of standing waves. Combining ground-plane measurements and semi-anechoic measurements is more work, but the results are ultimately better.





The two woofers are still almost point sources up to their crossover point at 100 hz. They are simply much smaller than the 3.4 meter wavelength of a 100 hz tone and they have negligible horizontal directivity. In free-field conditions the woofers have a more or less spherical radiation pattern, when you put them in front of a wall that becomes a hemi-speherical radiation pattern, with a directivity index that is close to that of the cardioid midrange.


With a ground-plane measurement, you do indeed have to be careful in your interpretations. If you measure like this...

View attachment 25792



… it seems as if the baffle is twice as large as it really is. Because the ground works as an acoustic mirror, the microphone ‘sees’ two speakers on top of each other. As a result of the seemingly larger baffle, you’ll measure more output in the lower midrange than the speaker has when it’s on a stand. However, if you place the speaker like below and you tilt it so that it points straight at the microphone…

View attachment 25793


Source: https://www.stereophile.com/features/105kh/index.html


… you’ll get proper results. Ground-plane measurements then actually give you the exact same results as anechoic free-field measurements up to about 2 khz. Above that, the level gradually starts drooping because the microphone is not exactly flush with the ground-plane and you do actually get a bit of a reflection that gets more and more out of phase with the direct sound as frequency goes up.


Now on to distortion. The 8c is a relatively compact full-range loudspeaker that offers low distortion at normal and somewhat elevated listening levels. At high levels distortion can become audible on some program material. This is the price we choose to pay for a cardioid radiation pattern in a speaker this size. However, 96 dB at one meter at a single frequency from a single speaker is very loud. In practice, in rooms with some reflections a pair of 8c’s can be played quite loudly and they do actually sound clean at quite high levels. But if you’re into very loud music, they certainly have their limits.


Distortion in the bass is a bit higher than our own measurements. We use very low distortion Wavecor subwoofers in the 8c, so I'm not really sure why the distortion rises so quickly at around 50 hz. I also don’t know what causes the narrow peaks in the NRC’s distortion measurements at higher frequencies.





Actually, during the design of the 8c I also expected to have to tilt the midrange a bit because a flattish power response might sound too bright. However, the 8c is the first speaker I ever designed that didn’t require any voicing at all. It sounded very neutral straight from the lab. Its tuning is purely based on measurements.





The additional measurement to capture the output of the woofers is done at 180 degrees, with the mid and tweeter on. What you see is the bass (LR4 lowpass), then the very good rearward rejection in the midrange up to about 550 hz and then the somewhat higher level (although still quite low relative to on-axis) between 550 hz and say 1 khz. In the latter range directivity is the result of baffle shading. These results correspond quite well with our own measurements: https://dutchdutch.com/wp-content/uploads/2018/11/8c-Spec-Sheet-2019.pdf


Please note that at precisely 180 degrees rearward rejection is a bit less good than just off the rear axis. That is because right behind the speaker the diffracted sound around the left and right baffle edge are in phase and thus louder than slightly off-axis. This is particularly easy to see in the horizontal directivity plot in our spec sheet.





That’d be really great!





I agree. Fact is that no anechoic chamber is completely anechoic. You still have to take into account its limitations. Doug Schneider of Soundstage on 8 April posted the following:


On the topic of measurements, we had a couple editors of publications chime in that they think that including measurements might confuse or put off readers. Is that true? Would readers, as well as manufacturers and distributors, etc., like to see measurements accompany reviews or not? Yes (for measurements) or No (for none) is sufficient, but if you'd like to explain your stance, go ahead.


An interesting discussion followed. Check it out! Personally I’m much in favor of measurements, plus interpretation by someone who knows what they’re talking about.

Please let me know if you guys have any more questions.

Cheers!

Thanks for chiming in!

:)
 

SSK84

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Hi everybody,




I've been approached by several people to chime in. Great discussion! I’m also very happy the guys at Soundstage did these independent measurements in the anechoic chamber of the NRC. I think speakermeasurements.com is the best source of independent measurements on the web. Great stuff! The results of their measurements on the 8c mostly correspond with our own, although there are also a couple surprises.





I’m pretty sure this is the result of the anechoic chamber not being anechoic at low frequencies. You need very thick layers of fiberglass to damp long wavelengths effectively. At low frequencies even in anechoic chambers you have reflections and room-modes. The speakers don’t have the dip.





I’m not sure how to explain the excess in energy between about 100 and 400 hz. It’s not the result of a voicing decision. We believe in accuracy. Flat response and at the very least smooth directivity are the most important factors in that. We aim for a flat on-axis response and minimal variation within any likely listening window. In the NRC measurements the response in the low midrange also is a bit less smooth than our own. I don’t know why.


Perhaps the platform the 8c stands on can in part explain the rise at low frequencies? It’s probably not the whole story though.

View attachment 25789





The measurements graphs in our spec sheet are based on measurements we did in the anechoic chamber of the Technical University of Delft for mid and high frequencies, spliced to a combination of near-field and ground-plane measurements for the bass. The anechoic chamber is a cube with internal dimensions of 10 meters. What I love about the anechoic chamber is that you can do a single measurement and get a clear picture of what happens across the entire audio bandwidth. It’s very convenient. However, even in this large anechoic chamber below about 200 hz you start seeing the effects of reflections.

View attachment 25790

I spent a lot of time in the anechoic chamber, but since about a year we have access to a large night club, with a concrete floor and a high ceiling. I can get a very clean window of approximately 70 ms, for a frequency resolution of about 14 hz. I actually get cleaner results than in the anechoic chamber, by combining ground-plane measurements for the lower frequencies and semi-anechoic measurements for higher frequencies, with the speaker on a high tower. Although extremely convenient, an anechoic chamber is never completely anechoic. Reflections are much reduced in level and number, but they are still there. In the bass you also see the effects of standing waves. Combining ground-plane measurements and semi-anechoic measurements is more work, but the results are ultimately better.





The two woofers are still almost point sources up to their crossover point at 100 hz. They are simply much smaller than the 3.4 meter wavelength of a 100 hz tone and they have negligible horizontal directivity. In free-field conditions the woofers have a more or less spherical radiation pattern, when you put them in front of a wall that becomes a hemi-speherical radiation pattern, with a directivity index that is close to that of the cardioid midrange.


With a ground-plane measurement, you do indeed have to be careful in your interpretations. If you measure like this...

View attachment 25792



… it seems as if the baffle is twice as large as it really is. Because the ground works as an acoustic mirror, the microphone ‘sees’ two speakers on top of each other. As a result of the seemingly larger baffle, you’ll measure more output in the lower midrange than the speaker has when it’s on a stand. However, if you place the speaker like below and you tilt it so that it points straight at the microphone…

View attachment 25793


Source: https://www.stereophile.com/features/105kh/index.html


… you’ll get proper results. Ground-plane measurements then actually give you the exact same results as anechoic free-field measurements up to about 2 khz. Above that, the level gradually starts drooping because the microphone is not exactly flush with the ground-plane and you do actually get a bit of a reflection that gets more and more out of phase with the direct sound as frequency goes up.


Now on to distortion. The 8c is a relatively compact full-range loudspeaker that offers low distortion at normal and somewhat elevated listening levels. At high levels distortion can become audible on some program material. This is the price we choose to pay for a cardioid radiation pattern in a speaker this size. However, 96 dB at one meter at a single frequency from a single speaker is very loud. In practice, in rooms with some reflections a pair of 8c’s can be played quite loudly and they do actually sound clean at quite high levels. But if you’re into very loud music, they certainly have their limits.


Distortion in the bass is a bit higher than our own measurements. We use very low distortion Wavecor subwoofers in the 8c, so I'm not really sure why the distortion rises so quickly at around 50 hz. I also don’t know what causes the narrow peaks in the NRC’s distortion measurements at higher frequencies.





Actually, during the design of the 8c I also expected to have to tilt the midrange a bit because a flattish power response might sound too bright. However, the 8c is the first speaker I ever designed that didn’t require any voicing at all. It sounded very neutral straight from the lab. Its tuning is purely based on measurements.





The additional measurement to capture the output of the woofers is done at 180 degrees, with the mid and tweeter on. What you see is the bass (LR4 lowpass), then the very good rearward rejection in the midrange up to about 550 hz and then the somewhat higher level (although still quite low relative to on-axis) between 550 hz and say 1 khz. In the latter range directivity is the result of baffle shading. These results correspond quite well with our own measurements: https://dutchdutch.com/wp-content/uploads/2018/11/8c-Spec-Sheet-2019.pdf


Please note that at precisely 180 degrees rearward rejection is a bit less good than just off the rear axis. That is because right behind the speaker the diffracted sound around the left and right baffle edge are in phase and thus louder than slightly off-axis. This is particularly easy to see in the horizontal directivity plot in our spec sheet.





That’d be really great!





I agree. Fact is that no anechoic chamber is completely anechoic. You still have to take into account its limitations. Doug Schneider of Soundstage on 8 April posted the following:


On the topic of measurements, we had a couple editors of publications chime in that they think that including measurements might confuse or put off readers. Is that true? Would readers, as well as manufacturers and distributors, etc., like to see measurements accompany reviews or not? Yes (for measurements) or No (for none) is sufficient, but if you'd like to explain your stance, go ahead.


An interesting discussion followed. Check it out! Personally I’m much in favor of measurements, plus interpretation by someone who knows what they’re talking about.

Please let me know if you guys have any more questions.

Cheers!

Thanks for the comprehensive comment. Sometimes it’s a pain to set the record straight afterwards. Your honest thoughts and explanations shows deep knowledge and passion! Makes me confident!
 

Martijn Mensink

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I had an online chat with Doug Schneider of Soundstage. We discussed the measurements of the 8c. He had some comments I think you guys will appreciate (partly direct quotes, partly paraphrased):

  • The steeply rising distortion in the deep bass and the dip around 60 hz are artefacts of measuring in the chamber.
  • The narrow distortion spikes are real. They measured a few times just to check. He thinks it could be the smallest thing like a wire rattling, or something came loose during shipping, possibly a narrow band resonance being excited.
  • One thing to note is the deviation from linearity measurement. That’s actually a torture test on the thermal characteristics of the drivers. The 8c’s did exceptionally well.
 

pozz

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I'd say the Klipschorn and the Bose 901 are in the 8C's lineage. Both take account of room boundaries as extensions of the acoustic design. Would anyone agree?

The next stage, for hifi at least, seems to be inclusion of custom laser measure + mic systems (either built into the speakers or as attachments) to handle all the issues of placement pretty much automatically. SBIR could be optimized fairly easily in a dedicated listening room that way. And the in-built calculation system would probably help people learn something about acoustics.

I wouldn't buy the D&Ds or the Kiis, though. A good portion of the cost could easily go to room treatment.
 

mi-fu

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I hope D&D would improve their web app's interface. Now, it is functional, but rudimentary at best.

@Martijn Mensink is it possible to at least add a master on/off switch for all the Parametric EQ control? That would be much easier to conduct A/B comparison.
 

Martijn Mensink

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I hope D&D would improve their web app's interface. Now, it is functional, but rudimentary at best.

@Martijn Mensink is it possible to at least add a master on/off switch for all the Parametric EQ control? That would be much easier to conduct A/B comparison.


We're working on a completely new app, incorporating all the comments and requests we've received over the past year or so. It's going be a big improvement!
 

mi-fu

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We're working on a completely new app, incorporating all the comments and requests we've received over the past year or so. It's going be a big improvement!

It is very exciting news! Looking forward to it!! :D
 

q3cpma

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Hello,

I have some questions that maybe you can answer:
* Why is the midrange 8" when the usual ones are between 3 and 5"?
* I see you respect the GPL nicely, which is a big plus for some, but is the network protocol open enough for tech savy users to write their own remote? In case I'm using a minimalist OS without a modern web browser, for example.
* Any reason the warranty is only 2 years on such a pricy product?
 

Soniclife

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Why is the midrange 8" when the usual ones are between 3 and 5"?
I'm sure the designer has explained this properly here before, but mainly because they are using a very low mid to tweeter crossover, 1200hz from memory, so the 8" driver is still very happy at that frequency, and they use steep slopes so out of band isn't a problem. The bigger driver helps go lower to where the subs take over, this is probably the only week area of the design, there isn't enough cone area at 100hz to keep distortion very low at higher volumes.
 
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