Dual Review as I haven't listened to either component individually.
Two Stereo Integrity BM mkIV 12 inch shallow subwoofers wired to two Zed Audio Minotaur III mono amplifiers.
Each sub is DVC 4 ohm, wired to 8 ohms on each Minotaur. There is no 8 ohm rating for the amplifier, but I spoke with Steve and he said it would be somewhere around 425.
Each is in its own fiberglass custom built box (by me) at about .45 cubic feet. After installation I found that there is actually a massive air leak in each box which I have to repair. I will also post my findings after I've repaired this leak but I had to get out my initial impressions as I'm literally shaking from the experience.
**EDIT** Sealed up the air leaks, and everything just ends up sounding even better. Time to tackle the rattles throughout the car!
Zed Audio Minotaur III -
Fantastically built. Aluminum chassis and acrylic cover that shows the fun parts and some interior LEDs that you can use to monitor the status of the amplifiers. The amplifier feels beefy but isn't overly heavy due to aluminum construction. Aluminum also sheds and draws heat away faster than iron and is much lighter so I can see why this would be a better choice. It is brushed and cosmetically quite beautiful.
The power connections are very solid and I wrenched on them pretty hard and they didn't appear to show any signs of wear or danger of stripping that I'm used to seeing on other amplifiers after first use. They are angled however making it a PITA for installation on a flat surface.
RCA connections are ROCK SOLID.
Dials for crossovers, phase, input gain, etc all were still the cheap plastic dials I am used to that get marred up even after first use. However they are still buttery smooth and you can tell they are connected securely. One downside is, while adjusting the gains, they weren't spot on. I had them both set pointing right at the 1.9v label and one was putting out about 3db more than the other so some inconsistency may be expected.
The Minotaurs come with a bass knob that will control both amps simultaneously but I didn't have it hooked up yet (will comment on it's use later). The bass knob is heavy and feels solid. The knob itself has great feedback as you swivel it.
BM mkIV -
Inverted, so pretty! Regularly mounted, kinda blah. Yes it is a super cool flat diaphragm, but the flat black on flat black on flat black isn't that great to look at. If you are going for UNDERSTATED, these are the subs for you! Flip them around however and its a whole other story. Glossy black finish with chrome stainless steel mesh vents and cast aluminum? looking bumped pole. Much easier on the eyes.
Speaker connections, I expected more. Steel connectors with springs to hold the wire in place. Seemed solid and not likely to fail but not a ton of class.
Overall, the subwoofer takes up its entire 12" footprint and is basically a 5 inch deep cylinder with a lip for installation. When I put the subwoofer down on a steel cabinet I expected the neo magnets to hold it firmly down to the table, but this did not happen and in fact it didn't hold quite nearly as hard as even a smaller ferrite magnet on a regular subwoofer. However, I cannot see the Neo magnets in the structure so I'm not sure how close they are to the basket.
**EDIT** I've had a few days to listen to the subwoofer and I have to say, I'm still being impressed. This sounds like it would be perfect if you are going for OEM feel. You certainly aren't going to win any SPL competitions but overall, two of these is PLENTY. They still hit harder and louder than systems were a decade ago so I believe these are a great value.
I originally bought two of these with the hopes of it being far louder than it is. Now I know my expectations for SPL were too high. But that is no problem in my book. There is no compromise for sound quality with the BM, and I personally would rather have that, then a woofer that does neither perfectly. So if you want SPL and SQL, just buy a bunch of these I guess.
Once my installation is complete, ie. front stage and Audison BitOne installed, I'll be able to tell if these are enough for my setup. If not, I may add 4 more of them to the trunk. The Zeds wired up to 8 ohm give about 425w, and at 2.7ohm might be giving about 325w to 3 woofers. So I would be expecting about 9db gain.
I have to say, after I got the system decently tuned in, I was almost brought to tears over the sound and output of these subwoofers and amplifiers. Despite where it currently is in setup, the sound is rich. I hear all of the bass smoothly blending in where it belongs. The sub region surrounds you and you cannot tell where it is coming from.
I listed to a mix of genres, including alt. rock, hip hop, dubstep, old school "gangsta" rap, and classic rock. I honestly couldn't tell that there were subwoofers in the car on the songs that didn't over emphasize the subwoofer frequencies. It sounded like I had just simply "opened" up the lower frequencies to my current system. It responded quickly to everything I played and sounded similar to a real instrument. I however got a couple of artifacts in the midbass region, which I corrected by adjusting the HPF on the Minotaur from 150Hz to about 100-115Hz. One downside I noticed on the BM's was when playing notes around 10-15Hz it sounded like a flapping flag in the wind and was not nice at all. I expect this is a result of the air leak in the box and will report my findings on this once the leak has been repaired. In the meantime I adjusted the subsonic filter on the Minotaur to 20Hz and solved the problem. The rolloff on the Minotaur is very impressive and made me feel like there was no "rolloff" but a "cliff off" (i think its an incredibly steep 48db per octave). Overall I was deeply impressed, and even with my incomplete installation is the best I've ever heard.
I will come to this after I've completed the install and worked out the quirks.