Stereo Integrity Magnum D2 (Sealed)
I am not a professional installer. I'm not a professional box designer, or box maker, or guru with amp settings. I'm not much more, if any more, than an average installer. So bear in mind, the notorious SI Mag D2 is not getting any royal treatment today. Just two sealed enclosures of different designs.
THE (RELEVANT) EQUIPMENT:
Alpine CDA 9807
SI Mag D2 15"
1992 Ford Taurus sedan
THE WOOFER (COSMETICS):
The Mag D2 is the pinnacle of two years of R&D by Stereo Integrity. Blah blah blah blah... It's big! Huge! The 15" version weighs in at nearly 40 pounds. I can feel it as I lift it by the basket and carry it around. I have to tuck it in my arm and carry it like a child to ferry it from place to place. It looks like it uses a standard overhung motor design, I can see the copper coil around the fomer through venting holes in the basket. It's a very solid look. The suspension feels very smooth and even when the cone is pushed down. My only quirk is the chrome. I was never a fan of chrome.
THE INSTALL (PART 1):
The first install comes from a design BASED ON BUT NOT TRUE TO the "Inverted Wedge" design by Decware: http://www.decware.com/newsite/invertedwedge.htm available for $10. In my design, I extended one half of the enclosure to 32" while preserving the angle of the wedge itself. I also raised the bottom plank to a start of 2" off the ground and ending 6" off the ground to allow for the xmax limits. The enclosure itself was roughly 3 cubic feet internally. The back wall nearest to the baffle (Green wall in diagram) was double thick. Bracing in the box was limited . (IMPORTANT DETAIL RIGHT THERE) See the attachment for the design I used. Read the next part to decide if you want to try it.
LISTENING (PART 1):
Listening to this enclosure I used a lot of random tracks from the rock and metal CDs I own. Included but not limited to are Lacuna Coil, Dimmu Borgir, In Flames, Immortal Souls, Dream Evil, Iced Earth, Old Mans Child, and Tristania.
The woofer is a low end monster! In fact, it played too low. I have never before heard a low end like this enclosure / woofer combo played. Music that shouldn't have dropped below the level of a normally tuned bass guiter suddenly rumbled on levels I can only call subsonic. The bass itself didn't have any impact at all. Upon further testing, I found the box was flexing... really, really, bad. The flexing had a serious effect on output, yet the low end played to extremes I'm glad to not have anymore. The only way I found of getting music to play in it was to set a variable Q subsonic filter over the woofer at 33hz to remove the loudest part of the bass it was playing. Even then it was somewhat less than I was expecting. Yes, it sounded very good, it just wasn't the mind blowing good I hoped for.
OUTPUT (PART 1):
Output was... disappointing. I reset my gains to where I liked them and listened again and something just wasn't right. I set out, opened my trunk, and once again the box flexed somethin' fierce. TOTAL OUTPUT KILLER RIGHT THERE. A better installer would find the time and material to brace the enclosure or simply double over the walls. I did not have such luxeries and abandoned the enclosure to the garage.
OVERALL (PART 1):
This enclosure and this woofer, for those with a taste for low end, will satisfy all your needs and more, but you have to make your own way with how you build and fortify the enclosure. Serious, SERIOUS, home theater potential with a very large enclosure.
THE INSTALL (PART 2):
The second install was to make for a reference against the first box. It follows the simple strategy of a plain sealed enclosure, heavily braced and calculated to right around 2 cubes after displacement and bracing, I could use it as a universal standard against some of my other more unique designs. Pictures of this box can be found here: http://www.epicrevival.net/projects/box/
LISTENING (PART 2):
The sealed box uses the same music, the same amplifier gain and LPF, and the same woofer. The difference is intense! The music is much louder, a gain of 4-6 dB if my ears and my 2dB / tick Head Unit are to be trusted. The music sounds like music again! Transients are transient, and kickbass kicks. Every bassline I throw at it is handled flawlessly. I don't know what to say besides after setting the gain by ear that the low end of music is just there, totally transparent against my Rainbow SLCs.
However, not all is well. The woofer has trouble with highs. I like to set my crossover a little high, in the 90hz range to help with low midbass duties. The Mag just isn't made to handle these highs and keeps a well managed dropoff that drops off just too quick for the guitars I want to play, regardless of crossover setting.
OUTPUT (PART 2):
The output is pretty flat from the high end of the woofer to the low end. I don't hear any peaks that I didn't already know i'd find (Thanks Ford Motor Company!) and the output is well above the previous enclosure. The woofer seems to like 2 cubes, dispite the high end that I miss so much that my IA LIs provided with ease.
OVERALL (PART 2):
This woofer will supply the musical needs of any form of music in the right sealed enclosure. It is just that, a musical woofer. If the music is meant to pound, you can expect it to pound. If the music calls for soft bass, you get soft bass. The woofer plays what it's given, no more, no less. It's something a music lover can be greatful for. It's only the lack of it's ability to play higher than normally necessary bass that I'm still not too thrilled about.
9/10. Excellent woofer to own if you like to go sealed. If it played about 25% higher, I'd give it a perfect score. Perhaps a better installed could get the high ends out of it, but I'm not that installer yet.