You have successfully designed and successfully manufactured (in quantity) the smallest, deepest going (frequency response) and loudest subwoofer. Cautionary note for some readers: That's not the same as the deepest going and loudest subwoofer! It's so successful sales-wise that a proliferation of imitations and copies inevitably and eventually follow. There's a difference between imitate and copy; the former is the American way and a compliment (the highest form) while the latter is a dubious practice. But never mind. The question now becomes, what do you do for an encore? Well, you could go smaller, deeper, and louder. But that smaller (than an 11" cube!) part imposes immense design and manufacturing difficulties. Furthermore, overcoming the design and manufacturing difficulties would result in a final cost that would be prohibitive for most audiophiles. Hey, why not slightly (only slightly, mind you) larger, deeper going, and louder, huh? Of course I am talking about the original Sunfire True Subwoofer and the new Sunfire True Subwoofer Signature. So there's no confusion: In this review the original Sunfire True Subwoofer will be referred to as the Sunfire True and the new subwoofer will be referred to as the Sunfire Signature.

My original review of the Sunfire True created quite a bit of commotion. Most comments were civil but others (a few) would make you think I was associated with Sunfire and the subwoofer had been named in my honor. Hey, I thought Astonishing Subwoofer was a better name than True Subwoofer but it's certainly not the JC subwoofer! Man, the things I was accused of ran the gamut from being a liar to being too enthusiastic! The former accusation is easy to do, especially from a computer terminal in another country! And what can I say about being too enthusiastic? I'm guilty. I don't want to go through an agonizing eight months of denying being "enthusiastic" and then be embarrassed to tears and face impeachment as I finally admit I am enthusiastic! And, quite frankly, I am at least as enthusiastic about the Sunfire Signature as I was for the Sunfire True.

The Sunfire Signature is the ultimate subwoofer for those who want lowest and loudest in unbelievably small. How low? 16 Hz. How loud? 116 dB sound pressure level (SPL) with room gain. How small? 13" X 13" X 13". It finishes what the Sunfire True started. A subwoofer that goes down flat to 16 Hz and shakes the house and surrounding counties! Not bad for a 10" driver encased in a 12" basket!

I covered the details of the design, construction, and operating controls of the Sunfire True in my original review. No need to rehash the details, but a summary follows for the Sunfire Signature.

The Sunfire Signature 10" driver is the same design as the Sunfire True 8" driver but heftier. The internal amplifier is unchanged; there's no need for more than 2,700 watts; equal wattages for the Sunfire True and Sunfire Signature result in a higher SPL for the larger driver. It's in a larger enclosure, resulting in more efficient operation. Note to this who seem to have a problem with the stated wattage: Don Keele measured peak wattages approaching 5,000 watts and stated that the continuous sine wave power of 2700 watts could be sustained for at least intervals of approximately two minutes!

The active low-pass crossover frequency network for the Sunfire Signature is adjustable from 30 Hz, to 100 Hz. The crossover point is user selected and results in the subwoofer complimenting the main speakers from the user selected point downward. In effect the main speakers run full range and the Sunfire Signature fills in the bottom end down to 16 Hz. Working in conjunction with the crossover is a volume control (labeled BASS LEVEL) and a phase control, adjustable from 0 to 180 degrees. These three controls (crossover point, bass level, and phase) are interrelated and are used to make for a smooth integration of the Sunfire Signature's output with the output of the primary speakers.

There's also a passive, high-pass, fixed crossover (70 Hz) that is recommended for use with smaller (bookshelf) speakers. Operating small speakers full-range (in conjunction with the adjustable crossover on the Sunfire Signature) could result in the demise of the small woofer driver as the listener turns-up the volume on the preamp to accommodate his or her desire for room shaking bass. Far better to eliminate the low bass from the small speaker's driver by using the high-pass, fixed crossover.

The Sunfire Signature has two types of input hardware, RCA line-level input jacks and speaker/amplifier level, five way standard speaker jacks. Output of the Sunfire Signature is accomplished via an active driver and a passive radiator. A Flat-Video contour two way switch allows the user to operate the Sunfire Signature with a flat frequency response (switch in the Flat position) or a rolled off frequency response (switch in the Video contour position), starting at 30 Hz, which is more appropriate for the Home theater scene. I kept the switch in the "Flat" position at all times.

A hefty power cord and external AC fuse complete the tour of the controls and sundry electronic things that are part of the metal control panel. The subwoofer enclosure has a very clean fit and finish that is indicative of quality workmanship and the care taken in the assembly of the product. Enough of the details, let's get into listening.

16 Hz is the lowest generated acoustical note (low C) emanating from the King of Instruments, the Organ. This 16 Hz note has been a reference point that speaker designers have been trying to reach since the postwar (WW II). So what better way to test for the low end of the Sunfire Signature then with a 16 Hz organ note and what better CD to use for listening to the Organ than a John Eargle engineered DELOS CD.

There are some really excellent Recording Engineers out there, but John Eargle is the proverbial, "in a class by himself." His recordings consistently (that's the important word) seem to have just a little more of whatever it is that approximates the sound of a live performance. And a case-in-point is the CD, "A Listener's Guide To The King OF Instruments/The Art and Science of recording the Organ"- D/CD 3503. Information is provided (in the CD booklet) that describes the characteristics of the different Organs used and the different recording venues. Included in the details are the places where the 16 Hz notes appear. Even without the liner notes I wouldn't have any problem identifying the 16 Hz notes! Impressive as heck listening to those 16 Hz notes as they rattle the house and create miniature tidal waves in the neighbor's pool.

Another Organ CD for demonstrating low frequency response is Dorian CD DOR-90117, Jean Guillou playing the Great Organ of the Tonhalle in Zurich, Switzerland. A combination of a huge instrument in a huge hall, played by the enfant terrible of the Organ world, makes for as enjoyable an experience as one can have in listening to an Organ. Jean Guillou plays his transcription of Mussorgsky's, "Pictures at an Exhibition." This recording is loud and low! Tracks 14 and 15 ("Baba Yaga, The Hut on Fowl's Legs" and "The Great Gate at Kiev") contain 16 Hz notes that are felt as well as heard,. The Sunfire Signature recreates sound levels and frequencies in the listening room that were at one time never heard outside of churches and cathedrals!

These two Organ recordings are absolutely knockout demonstration sound, but solo Organ performances aren't something most people listen to, at least not for long. If the truth be known, I can only listen to so many solo Organ recordings, no matter how well recorded and how low the notes and how brilliant the interpretation, before I go bonkers. So what else is there to test the mettle of the Signature at the subterranean portion of the audio spectrum? What used to be (for me, at least) the ultimate test CD comes quickly to mind. It's the sounds of the space shuttle Atlantis lifting off from Cape Canaveral, recorded 25,000 feet from the launch pad. (BAINBRIDGE/SONIC BOOMS 2/BCD 6285) No, it's not music, but this is a demanding CD; if there's a weak spot in the low frequency reproducing portion of your system this recording will bring it to your attention very quickly. The notes supplied with this CD mention, "...contains an abundance of extreme low frequency information, flat to ¼ Hz...." ¼ Hz! That's a wavelength of approximately 4,500 feet. No, the Signature can't go that low but it reproduces everything from 16 Hz up. The result is ultra-low, bone-shaking sound. But you ain't heard nothing yet!

I noticed in the liner notes that BAINBRIDGE was planing to record another Space Shuttle launch. And this time the microphones would be only 4,000 feet from the launch pad! I called BAINBRIDGE and ordered SONIC BOOMS 3/BCD 6289. There are some nifty sound effects on this CD, but I will confine my description of the sounds to tracks 6, 7, and 8. Track 6 is the launching of the Space Shuttle Discovery, carrying the Hubble space Telescope into orbit. The microphones are located at the press site, 16,000+ feet from the launch pad. Track 7 is recorded several months later (Discovery sans the Space Shuttle); the microphones are located only 4,000 feet away from the launch site! Since, "No humans are allowed this close....", the recording system was installed the day before and activated by automatic timers. Track 8 is the combining of tracks 7 and 8 for an aural tour de force of earth shaking proportions. As a side note the low end frequency on these recordings dips to 1/8 Hz And the SPLs, imposed upon the microphones located 4,000 feet from the launch pad, averaged 144 dB!

Be forewarned: To play these tracks at levels which begin to approximate the actual sound intensity and (low) frequencies demands the best in a playback chain, from preamp to amplifier to main speakers to subwoofer. Without going into the details and naming names I tried this CD using another subwoofer (two to be exact) and the result was a few seconds shy of disastrous. An associate at work tried this CD on a very nice Stereo/Home Theater system; it brought the system to its knees. Just for kicks and fun I disconnected my main speakers, turned the crossover frequency (100 Hz) and the Bass Level control to max, set the preamp volume control to ¾ of full rotation, and let it rip. If I hadn't been wearing ear protection the resulting sound would have ripped out my eardrums! One time was enough. I have no desire to do it again, but this subwoofer will make a killer low frequency vibrator (!) as part of a Home Theater system!

Eventually, if you're a music lover, the novelty of reproducing the various "special effect" sounds wears thin. I mean, how often can you listen to the Space Shuttle lifting off, or the sound of thunder, or the cannon in the 1812 Overture? These sounds are great demo material but as a regular concertgoer I want to know what the Sunfire Signature is going to do for music. And the news is all good!

Contrary to the what the small speaker advocates say about nothing below 40 Hz, that just isn't true. Sure, there are recordings where 40 Hz is the lower limit. But the double bass and the bass drum routinely dip below the 40 Hz point. And-if I'm not mistaken-a Concert Grande piano goes as low as 27.5 Hz. When the Sunfire Signature is dialed-in correctly there's a "punch" to large scale orchestral works that is lacking in small speakers and very minimal in even the best of integrated speaker systems. Again, the addition of a subwoofer approximates just a little more closely the actual sound of a real orchestra in a real hall. I did a little experiment to minimize the possibility that this "punchiness" was just my imagination.

Using a long extension cable and an multi-outlet power strip (with an on/off switch) I switched the Sunfire Signature in and out of the playback chain. There was not any problem in determining when the Sunfire Signature was in or out of the playback chain. I again want to emphasize that this was done with the Sunfire Signature's controls set at optimum. Obviously, if I had an excess of bass there would not be a problem in determining when the subwoofer was in or out of the playback chain! If I had enough time I would have done a double-blind test to ensure my knowing when the subwoofer was in or out of the playback chain was not based on knowing when the power to the subwoofer was on or off! Perhaps at a later time. I also played some musical selections where there truly wasn't anything below 40 Hz and there was no audible difference with the subwoofer in or out, further confirming an optimum setting of the controls.

Dialing in the Sunfire Signature is simply a matter of following the instructions included with the speaker. It isn't done in five minutes. It takes time and patience. However....the absolutely best directions for dialing in the Sunfire Signature- with a minimum of fuss-are included in a sidebar article by David A. Rich which is a part of a review for the Sunfire True by Peter Aczel of The Audio Critic (Issue number 24). All you need is the Stereophile test CD and a Radio Shack SPL meter. Just follow David Rich's instructions and the Sunfire Signature will be properly setup for CD's containing music. I would suggest to Sunfire Corporation that these instructions be included in the Sunfire Signature owner's manual....with an appropriate ok from Peter Aczel, of course. If you're into Home Theater these instructions do not apply! From what I've heard from most Home Theater systems it's the louder the better and to hell with balancing anything. But it's just a matter of time before everything comes together and we have multi-channel sound for music (only) that will put the two channel format to shame. We're not there yet, but in time....

It may be my imagination but the Sunfire Signature seemed to go deeper once it was broken in (approximately 40 hours). I didn't do any serious listening until the 40 hour point; although not usually stated in my reviews I almost always allow at least 40 hours to break in a speaker before doing any serious listening. There seems to be some debate over this "breaking in" but I'll believe the majority of speaker designers who state this as fact and use measurements to confirm it. More importantly, my ears also are telling me the same thing.

Any shortcomings for the Sunfire Signature? This is just me but I prefer an on/off switch, not an electronic switch, as on the Sunfire Signature, that is always in a standby state. The switch immediately turns on when the subwoofer receives an input signal, and goes back to standby after a signal is absent for approximately five minutes. Most subwoofers work this way so this is not a shortcoming, just my own personal feeling that an electronic piece of equipment should be completely off when not being used.

The "stick-on" rubber feet included with the subwoofer are not appropriate for a quality product like this subwoofer. I certainly am not advocating spiked feet but why not permanently and securely attached metal feet that are contoured to make it easy to slide this mini-behemoth around on a carpeted surface. Moving the subwoofer with the present undernourished and undersized rubber feet results in the immediate removal of the rubber feet from the base! And once removed they tend not to stick! Yes, the enclosure can be moved-without taking off the rubber feet-by sliding it along one of its edges, but its easier said than done. Balancing a 53 lb. weight on its edge and moving it across the floor at the same time isn't the way a $1,895 speaker should be moved!

Oh, one other point worth mentioning. The early models of the True Subwoofer had a very slight hum, and I do mean slight. The hum could be reduced with by turning around, in the AC receptacles, the various power plugs (subwoofer, preamp, amplifier, CD player, etc.). This slight hum was eliminated (reduced to insignificance) with the later True Subwoofer production units and True Subwoofer Mark II models. The Sunfire Signature is also devoid of hum. Well, if you want to place your ear against the driver to prove me wrong, be my guest. I for one don't want to have my ear against the driver and some passing CB cowboy causes the CD player to go into play. With my luck it would be at the point that off a bass drum whack....or the Space Shuttle at maximum SPL!

I found myself hesitating with a feeling of trepidation regarding the expressing of my enthusiasm for what I consider a product that has no peers in the subwoofer world. The easy thing to do would be to write a lukewarm endorsement of the Sunfire Signature and avoid confrontation with those who have a vested interest in attacking the product, and those who are just plain nuts. But there's an old Polish saying which is the ultimate insult about an individual: He's lukewarm water. Well, I may be many things but I'm definitely not lukewarm water.

This latest version of Bob Carver's subwoofer is a tour de force in the design and manufacturing areas. And as I stated in my original review of the True Subwoofer, there's not a speaker going that is more home or spouse friendly. 16 Hz at well (and I do mean well) over 100 dB is something that I didn't think I would hear in my lifetime. To hear it from a 13 inch cube sitting unobtrusively in a corner is astonishing to most and envied by a small minority. The Sunfire Signature gives you maximum SPL and maximum low frequency extension in the smallest box available to the public. And keep in mind that smallest is measured in cubic feet (1.3 for the Sunfire Signature), not just footprint area!

Here is another Bob Carver product that doesn't defy the laws of physics but it sure as hell makes one aware that this dude knows more about the laws of physics-and how they relate to speaker design-than most conventional speaker designers. Hey, don't listen to me but do give the Sunfire Signature a listen. Let your ears make the final determination as to what I have enthusiastically reported. And no lukewarm water from this reviewer. It's the lowest going, loudest, and smallest (remember, cubic feet, not just footprint area) subwoofer for under $2,000, or $18995 to be exact. The bottom line is I give the Sunfire Signature a highly recommended rating without any reservations.

Addendum: Just as I finished this review the November issue of Stereo Review came bouncing in. Well, what do you know! The reviewer (Ken Pohlmann, one of the objective reviewing clan) rants and raves so enthusiastically about the Sunfire True Subwoofer Signature that you'd think the subwoofer was named after him! I rest my case about enthusiastic!