Ultimate IB


  • Keymaster
    john@aespeakers.com on #249

    after i saw that John had gotten this new forum up and running i decided to join Chrisbee and post information on my Infinite Baffle subwoofer.

    I thought i used to know what bass was, i ran a Diamond D6 subwoofer in a custom slot ported box with a 4400 watt Brutus amplifier in my truck, in last year’s USAC competition i ran a 143.2dB on the dash and 165.1 at the port at 32hz. I loved the sound of the Diamond paired with a slot ported box, it was tight, quick and absolutely loud.

    So i set out on a quest to add the same smooth and loud bass to my home theater, only i knew i wanted lower… much lower. I am a fan of Pipe organ music and special effects in movies that shake you to your very core.

    The first project was a 3rd order bandpass using a dayton 15… well it was low, but only if the music was playing one note 🙁

    the second was a 4cu foot ported box tuned to 31hz with a f3 of 28hz using a 18″ Kilomax driver, which lasted me for about 3 years. It wasn’t as loud, deep or quick as i hoped for but it looked awsome and did pretty good for nice thumpy bass explosions in movies and the driving beat of pop or rap.

    After deciding it was time for a new sub i began to dig into box designs and plans… finally i know what i wanted. A horn, a big one… i wanted it to be able to put out my organ music with power, very low and also, LOUD. Several weeks of researching horns, shapes, types and sizes, I soon realized that to make a horn do what i wanted i was going to need a horn over 50 feet long… so then i looked into making the bass tuba folded horn, wow… so complicated 😯 🙁

    so for several months i do nothing but look around considering 6th order bandpass box, a huge ported box, large sealed… i couldn’t seem to find anything… until i happened across a webside of some person in Australia who used 8 huge JBL drivers open to the outside air under a beautifull looked wood housing to keep the elements out. But the interesting part was that the box coupled through the wall to the home theater room, turned the whole room into the inside of a sealed box… and with 8 18’s combined essentially became one huge speaker. I was intreaged. 😯

    Several weeks went by and as i delved deeper, i came across a website, talking about a magazine article called, “the subwoofer that shook the world.” Needless to say i clicked on the link and began reading over this strange contraption… using the basement to put a huge ported box, covered in speakers, firing up into his living room to cause such results as to physically move his couch with him on it during bass scenes. The auther raved about how powerfull and how low this sub went… but he also said, “accurate.” And on that website was a link… to the Cult of the Infinitly Baffled…

    When i clicked the link, my life, without knowing, took a change for the best. As i spent several weeks pouring over the data and facts and raves by the members there i began to wonder if maybe, just maybe it was posible to have what all these people were raving about… insane low end, down even into single digit frequencies 😯 wow i’m hooked… easy to make, really?! now i’m really interested… uses huge drivers with massive displacement for record shaking volume, i’m starting to drool… but what really startled me was how everyone, i mean everyone said “they sound better than anything else.”

    What?? That can’t be right… i mean everyone knows that 10 inch drivers sound the best, the cleanest and the fastest bass response…right??? I mean you can’t have ultra low bass, ultra loud bass, and perfect sounding bass all in one sub with huge drivers can you??! Everyone i’ve always heard has said how you can’t have fast bass from a huge, slow 15″ or 18″ driver… they are just too big and slow to make beautifull, lifelike and musical bass.

    So around November i learn that John, yes our very own John of Acoustic Elegance, has just put finishing the touches on a new driver, exclusively for infinite baffle use… but best of all… they were VERY affordable… up to that point i was only looking at being able to afford two 18″s maybe four if I really skimmped and squeezed every penny that i could. But now, i could afford eight 15″s…. EIGHT!!! Mind made up, hoping i wasn’t a victim of some feindish plot to make me waste my money i called John… and ordered eight AEIB15 subwoofers and groaned as my wallet began to feel lighter.

    I ordered them on a Friday and John assured me that they would probably be in Wendsday or Thursday at the earliest. As i was finishing up some work and getting ready to leave for lunch Tuesday morning, our shipped manager came to me and informed me that i had some packages that i needed to pick up from his office. Subwoofers being the farthest thing from my mind, i opened the door to the dock and my jaw sagged. There on the dock were eight huge, white and green boxes with the logo AE printed on their sides. To say i was impressed would be at least, an understatement. Needless to say i promptly grabbed a utility knife and slashed the sides and top of the tape.

    After pulling the thick double walled cardboard flaps back and removing the foam braces that held the speakers in place i began to utter words in an un-known language of gibberish as i pulled the plastic bag off of the speaker and began to drool at the construction of this new toy. A thick heavy pressed paper cone with weather treatment over the front surface offered a delicious thump when i tapped the cone softly with my finger… the spider was soft, already broke in it seemed, just waiting to be played. The basket felt as though you could almost suport your car on them and looked fantastic with the black powder coating and shiny machined surfaces gleaming up at you. Sighing, I carefully repacked the speaker and taped the box shut… dreading the remainder of the day until i could leave and take these beauties home with me.



    After serveral weeks of poor weather, rain, snow, a bad flue… shortly after christmas i finished cuts and routing on the manifold or box that the subs would be mounted into and then that box would be assembled and clamped together in the attic instead of on the ground, simply because i didn’t want to wrestle this huge 4′ x 18″ box up the stairs and around in the attic.
    The manifold is made from 4 sheets of 13ply baltic birch laminated together with polyurathane construction adhesive and weighs 105lbs without the drivers.


    After several hours of getting rather happy with a sawsall and a maul and crowbar the old section of the ceiling was removed and some structural beams were relocated to allow for the massive box which was then swarmed with a variable assortment of clamps and screws and glue.

    First pictures are when i just had it mocked up in place for measurements and seeing what all needed to be moved.




    after a long and sleepless night, wishing that it was working i got up and managed to shuffle my way to work where i moaned and groaned that no one was fair, forcing me and my beloved project apart… But after the hell day was over and i made it home i record time i began removing the clamps and hunting down the ladders and tnuts and bolts to mount all the drivers. I used 1/4″ machine allenwrench head screws which required me to carefully take a drill press to each mounting hole on the speakers to allow them to fit easily through the holes.




    I then proceeded to spend the rest of the hour trying to mount them inside the manifold… which is anything but easy, but finally was done.


    i will finish writing this when i get home… it is snowing rather heavily and i am going to head home before it gets too bad


    Member
    Robsan on #3288

    What is wrong with you? 😀 I am jealous, I need to order 8 too…..


    Keymaster
    john@aespeakers.com on #3289

    i’ll finish the above post with full descriptions and feelings when i can, this week has been extremely busy and i’ve had very little time to do anything i’ve wanted to do… but i did figure i would put up a Spectrum response chart for everyone interested or that think that infinite baffle subs can’t keep up with sealed or ported.

    this test was performed at listening position WITHOUT any eq’ing… when i get time i will intergrate the DSP1124 to smooth out the peaks and dips in the 20hz area with 1/60 octave smoothing, the 53hz dip is a room null that i will have to hunt down but i have a pretty good idea where it is.

    without further adue, the Carvernut Terror Subwoofer


    Member
    ballasnt on #3290

    Looks awesome so far! Keep us updated with pictures and graphs!


    Member
    dgilme on #3291

    Mmm now that is some nice speaker porn to make it through the day with.

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