- Written by John E. Johnson, Jr.
- Published on 15 November 2010
- Paradigm Reference Signature SUB 2 Subwoofer
- Page 2: Design of the Paradigm Reference Signature SUB 2 Subwoofer
- Page 3: The Paradigm Reference Signature SUB 2 Subwoofer In Use
- Page 4: The Paradigm Reference Signature SUB 2 On the Bench
- Page 5: Conclusions About the Paradigm Reference Signature SUB 2 Subwoofer
- All Pages
I think I improved my cardiovascular fitness just getting the SUB 2 out of the box. It is packed upside down, so what you have to do is first open the top of the box and fold the flaps out of the way, then turn the box upside down, keeping the flaps from getting underneath the box. Then you lift the box off the subwoofer.
Moving the sub into place is an experience in itself, but I managed. At that point, I took a break so I could get a cold drink and wipe the persperation off my face. Then, back to the lab.
Because the SUB 2 has drivers pointing in three directions, and so as not to color the test results with corner loading, I performed the bench tests with the sub sitting about 6 feet away from the nearest two walls. I put the test microphone 2 meters away from the subwoofer. Once I was done with the bench tests, I moved the sub into the left front corner (and then went back to the kitchen for a second cold drink).
Music-wise, I pulled out every pipe organ SACD I had. But, before I listened to the music, I ran Paradigm's Perfect Bass Kit (PBK) software program. The kit consists of a software disc that you install on your computer, and two USB cables. One connects your computer to the included microphone that has specific calibration files for that microphone embedded in the software. The second USB cable connects the subwoofer to your computer. The USB jack is at the bottom of the amplifier panel.
Running the program is very simple. On the rear panel of the subwoofer, set the volume control to the middle position (12 o'clock), the cut-off frequency to Bypass, and the phase dial to 00. Then, put the microphone on its included stand at listening level height, and point it at the ceiling. Boot the Perfect Bass Kit program and click "New Measurement". This procedure will step you through the measurements, and the minimum number of positions needed to perform the calculations is five, so you have to put the microphone in five different locations as it prompts you to do so. Once the five measurements are completed, the program calculates a room response curve (EQ) that will generally satisfy all five locations. You can save the EQ file, move the sub if you are not quite happy with the results, and do another run. If you like the first one better, move the sub back to its original location, run the software, and upload the first EQ file.
The resulting graph for my EQ with the sub in the front left corner is shown below (click on it to see the full size graph). The red graph line is a composite of the response in all five locations. There is an obvious 50 Hz suck-out, as well as a peak at about 35 Hz. The blue line is the "desired" target, i.e., the ideal EQ curve that the software wants to achieve. The green line (actually, the default color is different, but I set it to green so I could see it better) is the calculated EQ curve that the software was able to achieve. Note that this is not the response in each of the five locations. It is a curve that is "approached" in each location, but the actual response will vary slightly in each of those locations. You can see from the curve below that there is a roll-off below 30 Hz that the software placed in the EQ. The reason for this is that in some of the locations, the response actually rose below 30 Hz.
The second graph below shows the room response before EQ, with the sub in its original location six feet away from the nearest two walls, and the microphone set in four different spots. I set the volume in each microphone location so that 20 Hz was 100 dB. You can see that for three of the four locations, the response rose significantly below 30 Hz. All four curves cross the 20 Hz point at 100 dB, which is where I set the SPL for that frequency before I gathered the spectra. The Perfect Bass Kit compensates for this tendency by rolling off the bass as its generalized EQ compensation. After I performed the EQ of the sub in the corner, I was able to get a maximum output of 110 dB at 20 Hz, at a distance of 20 feet, using the 240 Volt outlet.
And now, on with the music. I tested the SUB 2 with an OPPO BDP-83SE/NuForce universal player, McIntosh MCD500 SACD player, Lamm LL1 preamplifier, Anthem D2v SSP, Classe CA-5200 power amplifier, Carver Mark IV ribbon speakers, and Final Sound electrostatic speakers. Cables were Legenburg, Emotiva, and Marc Audio. During the listening, I tweaked the crossover, volume level control, and phase such that the deep bass from the SUB 2 blended with the rest of the audio system. All music listening was done with the SUB 2 plugged into the 240 Volt outlet.
None of these albums could faze the SUB 2. After all, it responds down to 7 Hz, which is as low as any pedal tone on any pipe organ in the world. For the lowest notes, I could only feel the sound, not hear it, an indication of very low distortion.
I don't know what the low frequency limit is on the canon shots in The 1812 Overture, but I thought the air conditioner was going to fall out of the window.
With my standard CD test track, Copland's "Fanfare for the Common Man" (Telarc), I listened to the huge bass drum that pounds away throughout the composition, and my Carver Mark IV ribbon speakers have four 12" woofers in each speaker. They deliver excellent bass, but when I added the SUB 2, using a low-pass setting of 40 Hz, it was obvious that the lowest octave improved significantly. I could actually feel the bass in my chest each time the percussionist struck the bass drum. This is one powerful subwoofer.
And for movies . . .
This movie made Bruce Willis a star, and John McTiernan one of my favorite directors. It has all the action any fan could desire, and plenty of firepower to loosen the cobwebs in the corners of your home theater. Although the SUB 2 delivered stunning deep bass, I put my hand on the enclosure and could feel almost nothing. That is due to the clever placement of the drivers so that their motion cancels out enclosure vibration.
The attack scene in Pearl Harbor is one I always use to demonstrate my home theater to visitors, nothwithstanding the poor acting (I think Ben Affleck is trying to switch over to directing). And, with the amazing SUB 2, I had occasional sensations that my feet were coming off the floor. The SUB 2 is a hexagonal box of thunder. The punch and slam of 50 caliber machine guns, combined with the rumble of bomb explosions made me feel some sympathy for those Navy men and women caught in the melee of December 7, 1941.