- Written by John E. Johnson, Jr.
- Published on 07 November 2012
On the Bench
I used one subwoofer for all the tests, with the microphone two meters away. Although the DXD-12012 is designed specifically to be placed in a corner, I tested it about 3 feet into the room because I have bass traps permanently mounted in all the corners. For the measurement results shown below, when the Peak Amplitude is less than 100 dB, it represents the maximum volume I could obtain before the amplifiers clipped. Undoubtedly the lack of corner placement reduced the maximum volume obtainable, so you can add 3 - 6 dB to the Peak Amplitudes less than 100 dB that would be obtainable if the subwoofer were in the corner as it is designed to be.
At 15 Hz and 90 dB output, THD+N was 8%. This is really very good for 15 Hz, but wait until you see the other graphs.
At 20 Hz and 97 dB, whoa ! ! ! Less than 1% THD+N. I watched the screen and spectrum as I dialed up the volume, and I could not hear anything as I began raising the SPL. The only indication the subwoofer was doing anything was the peak on the spectrum as it rose while I increased the volume.
Try 0.7% THD+N at 25 Hz and 98 dB with most subwoofers, and you will see a similar number, but the decimal point will be moved one number to the right.
30 Hz, 101 dB, 0.6% distortion? No problem with the KREISEL. No wonder movie and music studios use this subwoofer.
At 35 Hz, still below 1% THD+N.
I was surprised to see the distortion up somewhat at 40 Hz, but the Audio Precision just tells it like it is.
And at 50 Hz, again, the distortion approached 2%. This is still very good, but it is apparent that the DXD-12012 is optimized for the lowest octave, which is just fine with me.
If you like distortion in deep bass, this is not the subwoofer for you.
The frequency response was flat enough that any modern receiver with auto room correction can easily take care of the peaks, and boost the output below 18 Hz. Just be sure to place the subwoofer in a corner as outlined in the DXD-12012 instruction manual.
I also tried the subs in a DUO setup, where one sub sits on top of the other, but upside down, with rubber spacers in each corner to minimize sound transfer between the two enclosures. Here is where you use the Pass-Through jack. It was no surprise to see the maximum SPL jump several dB. However, I do prefer to use two subs in stereo mode rather than connecting them together in dual mono.
Here is what a DUO setup looks like.