|Sunfire True Subwoofer Super Junior Subwoofer|
|Home Theater Loudspeakers Subwoofers|
|Written by Richard Elen|
|Sunday, 01 September 2002|
The Sunfire True Subwoofer Super Junior priced at $995 is an astonishing achievement. The latest in Bob Carver’s stunning line of audio components – in particular a line of powerful subs – the Super Junior is a step up from the earlier Junior, previously reviewed extremely favorably in Audio Revolution. And a remarkable successor it is, too.
Weighing in at 29 pounds, and taking the form of a nine-inch cube, the Super Junior is incredibly small for what it aims to do, which is to move a great deal of air. It manages this with the use of two long-excursion drivers on opposite sides of a cube, one active and the other presumably passive, driven by an amplifier capable of an exceptional 1500 watts RMS (for short periods, thanks to Bob Carver’s Tracking Downconverter amplifer technology) into the driver’s 4.6 ohm impedance. The diaphragms (they are not really cones as such) are thus able to push a great deal more air than you would expect for something so small. You can tell it’s a hefty amplifier: when you switch it on, the uninterruptible power supply connected to the computer beeps, suggesting that the line voltage has dropped suddenly – something that my microwave does, but I wouldn’t expect a piece of audio equipment to manage, even out here in the sticks.
The unit is capable of generating peak levels in excess of 108 dB SPL from 25 to 90 Hz. Two differential-gain line level inputs are provided, left and right having slightly different gain structures and configured to retain both sum (left plus right) and difference (L-R) signals fed to the device. As a result, the diaphragm movements can be quite different and frighteningly large – apparently up to five times as much as normal drivers – so much so that the sub can “walk around” a bit at high levels if it’s not properly secured. There are also speaker-level inputs. The controls provided handle the usual level crossover frequency (30-100 Hz plus bypass, with a helpful “normal” mark at the 65 Hz setting), and phase (0-180 degrees, with “normal”, interestingly enough, marked at 90 degrees).
The reason for the “normal” phase position being marked at 90 degrees is due to the recommended method of installing the sub. It should be placed, ideally, across a corner, so that the two drivers are aimed at angled walls that reflect the sound to the front. Now I don’t know if you’ve ever tried setting up your entire system cater-corner, but it is a really useful solution if you have a box-like room with a lot of standing waves. Mounting your front speakers (and TV as appropriate) across a corner can solve a lot of those problems, and as a result, it’s exactly how I have my system configured. Popping the Super Junior into the corner with its drivers pointing left and right and the settings panel to the rear took only a moment, and this tiny cube can go anywhere. If you do have to orient it differently, so that a driver is pointing directly at the wall, you may get rattles from the wall in question, as the thing moves a lot of air, and will thus put a lot of pressure on the wall.
As with configuring any subwoofer, there is a temptation to get out the sound pressure level meter and start playing sweep tones and other stuff, but as always, this can deliver some rather intractable results. My personal view is that the best thing to do is to plug it in, start with reasonable settings, and then listen and twiddle for the best results. If you do some measurements afterwards and find they make sense, good for you.
While the Super Junior has left and right inputs, I only have one sub output on my main amplifier. Although I have the benefit of a two-channel subwoofer output on my Outlaw ICBM bass management system, that’s only active for my hi-resolution DVD-Audio and SACD inputs, and not for the system as a whole, so I used the single output from the amp and connected it to the left input of the sub. I was using the Marantz 7200R receiver for test purposes, and this has a 100 Hz crossover on the sub output, so there is little sense in setting the sub’s crossover frequency any higher. Instead, I set it to bypass, so that any additional filtering is out of the way.
Left and right sub inputs are often a bit meaningless, because they just get summed anyway – but not in this case. (There is plenty of point in having two subs, especially associated with large left and right front speakers, because whatever anyone says, there is some apparent directionality to bass frequencies that can be more effectively rendered by a pair of subs – and here a pair of Super Juniors would probably be killer.) The Super Junior is interesting, however, in that it does actually handle both sum and difference signals. What it does with them, however, I don't
Adjusting the phase setting while playing a piece of music with plenty of repetitive bass (my favorite Alan Parsons track again), I found that the best setting for me was nearer to zero than to the “normal” 90 degrees, perhaps because my sub is set back in the corner a couple of feet behind the front pair of speakers, which follow the line of the front of the TV. I quickly found, too, that the best place to put the sub was on the floor in the corner. Even so, it can go walkies sometimes under extremely loud operating conditions.
Setting up a sub is always a pain because you have to reach around the back of the unit, change a setting, go and sit down, listen, get up, reach around to change a setting, etc. But in this case, the set-up went very well and, in a comparatively short space of time, I was able to sit back and listen, simply trying tiny setting adjustments on my ICBM from time to time to insure I had the best results, and after a while I didn’t even have to do that.
The challenge in setting up a sub is to get a smooth transition from higher frequencies down to those being handled by the sub. This is not so much a problem if your standard fare is movies, but if you listen to a lot of music as I do, you will spend a lot of time and effort getting that integration just right, and here a good bass management system – either in your receiver or, better still, an external unit – is a major boon.
The first thing I thought I would do was find some action/adventure movie material with a good bass end. The Bond movie “Tomorrow Never Dies” has some excellent examples, notably the destruction of the terrorist arms camp in Chapters 3 and 4, and the scene with the helicopter in Chapter 20. In the latter case, the helicopter engine has a good rhythmic rumble at the bass end, and of course there are numerous satisfying explosions. I then went on to the excellent – and in my view underrated – Dennis Quaid movie “Frequency,” in which the main title sequence includes some deep rumbles from the solar flares (ahem) and a lot of good bass end from the gas explosion. Similarly, the warehouse fire in Chapter 8, in which the past and present worlds are so beautifully intercut, comes across very well. In all cases, the bass has a remarkably low extension, which out-performs my normal reference system particularly in the very low frequencies. The 22 Hz bass capability in the specs was definitely borne out by experience.
Getting an impressive bass end on home theater material is not that difficult, of course. More challenging is the smoothness and bass integration required when replaying high-resolution music. I tried the new “SuperBass 2” surround SACD from Telarc, featuring the impressive talents of string bass trio Ray Brown, John Clayton and Christian McBride, recorded live at the Blue Note in New York. In this much more demanding test, the Super Junior passed with flying colors. Once again, I noticed how astonishingly far down the bass actually went, but also noted how careful adjustment of the ICBM delivered a beautifully smooth crossover from my mains to the sub, notably on “SuperBass Theme,” “Papa Was A Rolling Stone” and “Summertime” from this album. I had to check out Telarc’s cannons on their seminal “1812 Overture” recording, of course, and the results were as spectacular as expected, enough to rattle the windows (luckily my neighbors have moved away…) while still evincing smooth integration across the frequency range. Nice.
I also deliberately tried to overload the unit, by throwing high-level LF tones at it from a test disc. You can hear limiting come in at very high levels, and the soft clipping capability means that even if you are being really stupid, you will not get appreciable distortion out of this little box, although it will move about a bit at high levels.
If there is a downside to the Super Junior, it’s not a serious one. The only thing I can think of is that with its tendency to move around at very high levels, some users would benefit from being able to install spikes. There are some heavier-duty self-adhesive feet provided for optional application in cases where the built-in ones are insufficient, but I would have like to tie it down more.
The bass extension on this device outperformed all the other subs I have had on my system to date, including some quite large, powerful ones. I would like to try a pair of them, left and right, which I think might be even more impressive. I have regrettably never heard the larger units in the Sunfire line, but if they’re better than this, I must hear one, and soon. In addition to the LF extension, which is truly astonishing for a unit this size, I was impressed by the smoothness of the Super Junior when correctly set up – though this is always a bit of a pain, it’s always worth doing. The Super Junior is beautifully compact and would go with smaller speakers as well as it does with my rather larger ones. In addition, I can also imagine that it would make a stunning addition to a computer-based multimedia system. For me, the Super Junior is a very impressive achievement and, at $995 MSRP, it is not at all unreasonably priced. If you need to have a smaller sub – and even if you don’t – this is the one for you.