27-Aug-2016, 14:32
I have been doing some experiments with room correction with the D400 and B&W 800D speakers in my basement room. The D400 has a special SAM mode for the B&W 800 Diamond, a closely related variant of the 800D.
In this measurement, I set the bass control to -6, without which the speakers were clearly overloading the room with too much bass energy in the 10-40 Hz range. With the bass shelved down by 6dB, the bass region is fairly accurate down to below 20 Hz (Devialet specifies the -3dB point to be 16 Hz, which the measurements verify). There is a classic set of room modes, one at 50 Hz (big dip), the next at 100 Hz (rise), and another at 200 Hz.
In the treble range, shelving down by 6 dB produces a reasonably flat treble to 20 Khz and beyond. The 800Ds use a diamond tweeter capable of flat response to 50 Khz, but this is completely beyond the scope of my inexpensive microphone and Tact measurement system.
The green curve with red dots is the corrected Tact curve, slightly elevated by design (by +1 dB) in the lower bass down to 20 Hz and smoothly rolling off the treble above 10 Khz. Listening to this corrected response, the speakers sound absolutely neutral with no bass exaggeration or treble splashiness.
Finally, I'm seeing a lot of email on fancy power cords and USB cables for the Dxx. All of this is sounds like a bit fishy to me. Before you spend your hard earned money on dubious improvements like fancy power cords, spend the money on a decent microphone and a room measurement/correction system. The speaker that cannot benefit from some degree of room correction has not been invented yet. Particularly, if you have a full range moving coil, you will typically have huge problems in excess bass and room modes. Measurements will provide some education and you can intelligently use the bass/treble controls on the Dxx to tame these problems. Once your ears get used to the sound of a fully corrected speaker system, there is no turning back. You will instantly hear the effect of room modes, bass bloat, treble irregularities etc. on an uncorrected system.
Let me try to give an analogy here. Let's say you spend a lot of money on a fancy TV, which out of the box has the picture settings all of out whack because the colors are all wrong and the gray scale tracking is completely off. Investing thousands of dollars on an HDMI cable or a fancy TV stand will do nothing to produce a better picture. Investing a few hundred dollars in getting someone to professionally calibrate your picture will do wonders in showing you what a fundamentally correct color and grayscale reproduction looks like. You have to educate yourself because no one understands these things until they have been shown for themselves. Once educated, there is no going back to an uncorrected uncalibrated TV. I can't stand watching hotel TVs because the picture is so badly out of whack to my eyes!
In this measurement, I set the bass control to -6, without which the speakers were clearly overloading the room with too much bass energy in the 10-40 Hz range. With the bass shelved down by 6dB, the bass region is fairly accurate down to below 20 Hz (Devialet specifies the -3dB point to be 16 Hz, which the measurements verify). There is a classic set of room modes, one at 50 Hz (big dip), the next at 100 Hz (rise), and another at 200 Hz.
In the treble range, shelving down by 6 dB produces a reasonably flat treble to 20 Khz and beyond. The 800Ds use a diamond tweeter capable of flat response to 50 Khz, but this is completely beyond the scope of my inexpensive microphone and Tact measurement system.
The green curve with red dots is the corrected Tact curve, slightly elevated by design (by +1 dB) in the lower bass down to 20 Hz and smoothly rolling off the treble above 10 Khz. Listening to this corrected response, the speakers sound absolutely neutral with no bass exaggeration or treble splashiness.
Finally, I'm seeing a lot of email on fancy power cords and USB cables for the Dxx. All of this is sounds like a bit fishy to me. Before you spend your hard earned money on dubious improvements like fancy power cords, spend the money on a decent microphone and a room measurement/correction system. The speaker that cannot benefit from some degree of room correction has not been invented yet. Particularly, if you have a full range moving coil, you will typically have huge problems in excess bass and room modes. Measurements will provide some education and you can intelligently use the bass/treble controls on the Dxx to tame these problems. Once your ears get used to the sound of a fully corrected speaker system, there is no turning back. You will instantly hear the effect of room modes, bass bloat, treble irregularities etc. on an uncorrected system.
Let me try to give an analogy here. Let's say you spend a lot of money on a fancy TV, which out of the box has the picture settings all of out whack because the colors are all wrong and the gray scale tracking is completely off. Investing thousands of dollars on an HDMI cable or a fancy TV stand will do nothing to produce a better picture. Investing a few hundred dollars in getting someone to professionally calibrate your picture will do wonders in showing you what a fundamentally correct color and grayscale reproduction looks like. You have to educate yourself because no one understands these things until they have been shown for themselves. Once educated, there is no going back to an uncorrected uncalibrated TV. I can't stand watching hotel TVs because the picture is so badly out of whack to my eyes!
