thinking of new project using AL1804 driver

Discussion in 'Home Theater Projects' started by Chris Brock, Apr 14, 2004.

  1. Chris Brock

    Chris Brock Second Unit

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    I am getting the itch to experiment again. so i am selling my tempest driver and am really considering going with one of the AL1804 drivers from audioliquidators.com. The alignment that i have been considering is an enclosure with 15 cubic feet of internal space and tuned to 16hz. I have a Nady XA900 amp (900wrms x 1 @ 4ohms) and a BFD. From what i can tell, after I do some eq'ing to get rid of the rise in response caused by the high inductance of the drivers VC, I would end up with a MONSTER sub. based on what i am seeing and on my past experiances i would guestimate that it should be able to produce a flat repsonse down to the mid teens and with the full power of my amp it should be in the neighborhood of producuing 120+ db in room clear down to 15 - 16hz. And the nice thing is because of the drivers large xmax and xmech i would almost never have to worry abotu bottoming the driver out. do you guys feel I am at least in the ballpark with these estimations? any input or comments would be appriciated!

    chris brock
     
  2. Wayne Ernst

    Wayne Ernst Cinematographer

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    Chris,

    Well, if you have the "itch" then you need to scratch it. The AL1804s seem like the way to go. [​IMG]

    You might also want to check with Kyle of Acoustic Visions to see when he'll start stocking the 18" driver based on the "Blueprint" design.

    Finally, is there any reason why you are not considering an infinite baffle sub? I mean, if you want to "do it right" you should take a few minutes and think of the "I.B." possibilities. Or, maybe, you want to save that option for the next upgrade. [​IMG]

    [edit]: Chris, you might want to check this thread out regarding Audio Liquidators:

    http://www.hometheaterforum.com/htfo...hreadid=193609
     
  3. Kyle Richardson

    Kyle Richardson Screenwriter

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    I'll have at least one 1804 in stock by the end of the week. Better hurry or I might find a use for it myself [​IMG]
     
  4. Chris Brock

    Chris Brock Second Unit

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    thanks for th info kyle! i might just hit you up on that one. i swear man sometimes this hobby gets frusturating. the second i think i have "the final setup" i get the itch to try new things and upgrade, it never fails. i think it is really just the fact that i enjoy the work of building new things. so when i get somthing built it isnt more then a month before i am craving that excitment you feel when you fire somthing up for the first time.
     
  5. Brian-K-Owens

    Brian-K-Owens Stunt Coordinator

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    I had te 1803 in 13ft tuned to 17 Hz. EQ'd flat to 15 Hz (actually a 4 dB hump at 17 Hz in the output) and would make 135+ dB with 1000 watts RMS input. VERY loud. It was in a small 11' x 12' room w/ 8' ceilings corner loaded, and would move the room walls about 1/4" with a 17 Hz test tone playing at full volume!!!

    Brian

    I should add: Some friends came to listen to it one day after work, and from that point on it was nick named "the earthquake machine"!!!
     
  6. Andrew Pratt

    Andrew Pratt Producer

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    Boy does that sound familar[​IMG]
     
  7. Chris Brock

    Chris Brock Second Unit

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    thanks brain for that little bit of info. that is really the type of output that i am looking for. i tend to like things loud when i watch action movies and i like to be able to reproduce liflike levels of sound. if a bomb goes of in the movie i want it to sound, well , like a bomb went off haha
     
  8. Seth_L

    Seth_L Screenwriter

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    Why stop at one of them Chris? [​IMG]

    I am thinking of running 4 AL1804 drivers in two sealed sonotube enclosures with a few KW on them. [​IMG]
     
  9. Chris Brock

    Chris Brock Second Unit

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    please dont temp me like that. [​IMG] [​IMG]

    but i actually think i will need all the ouput that this will give me. my HT room in my new house will be 19 x 21 x 8 and it is in the basement so all the wall and the floor are concrete.
     
  10. Chris Brock

    Chris Brock Second Unit

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    ok well it is done! i placed the order for one 1804 earlier this morning. Maby with some like it might get here next week. Now I have to start planning the enclosure.

    I am probebly going to do about a 14 - 15 cube box with 3 4" aero ports tuned to about 16 - 17hz. heavly braced of course[​IMG]
     
  11. Bryan Michael

    Bryan Michael Supporting Actor

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    do upi think 3 4 in ports would be enough?
     
  12. ThomasW

    ThomasW Cinematographer

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    You really need MUCH BIGGER ports for a 18" high excursion driver. Otherwise it's going to be chuffing like mad as the SPLs go up. I'd suggest using a 8" or better yet a 10" port.

    Might consider 3-18" PRs, that way the box could be smaller
     
  13. Brian-K-Owens

    Brian-K-Owens Stunt Coordinator

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    I used (1) 8" port with mine. You can go to home depot or lowes and they have sonotube in 8" diameters. Worked GREAT for me!!!

    That is also what I used in my car enclosure:

    [​IMG]

    Brian
     
  14. Chris Brock

    Chris Brock Second Unit

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    ok if i went with a 10" diameter port it would need to be 47" long to maintain my 16hz tune. the box i am planning is going to he 36" deep. do they even make a 90 degree elbow for 10" tubing? actually what about doing a slot port? I have done alot of those for car audio application but how would that work for HT?
     
  15. Brian-K-Owens

    Brian-K-Owens Stunt Coordinator

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    Edit:

    I would go with the slot port:
    Here is my favorite calculator:

    http://www.loudspeakers101.com/VentCal1.htm

    You might try the calculation for 8" port. Like I said, I was running 1000 watts rms to mine, and no port noise unless I was playing around with a sine save at 17 Hz. For normal HT at full volume, no noise.

    The XXX is capable of 5.1L of displacement, and I run 1600 watts to it. . .no port noise.

    Brian
     
  16. Chris Brock

    Chris Brock Second Unit

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    ok how would this be for a design? 8" x 8" and 38" deep. this would give me a tune of 16hz and a total of 64 sq in of port area.

    [​IMG]

    see any issues with that one?
     
  17. Brian-K-Owens

    Brian-K-Owens Stunt Coordinator

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    If it was mine. . .I would go all the way across the bottom and whatever height you need to get the port opening sized correctly.

    What are all the dimensions of the box, and what thickness material are you going to build from?

    Brian
     
  18. Chris Brock

    Chris Brock Second Unit

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    that is how i have my tempest enclosure built, here it is [​IMG]

    if i went that route i could go with a vent that was 3 x 22.5. it would give me right at the same amount of port area that the 8 x 8 would have. this would also make the port easier to construct.
     
  19. Brian-K-Owens

    Brian-K-Owens Stunt Coordinator

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    That is what I would do, and that is what I will do if I decide to port my Tumults. I actually already have the plans drawn. . .just can't decide if I want to.

    Brian
     
  20. Bryan Michael

    Bryan Michael Supporting Actor

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    i would like to upgrave my dual av 15 i can mod the box to fit 18 in it and i can add ports i have 4 4i dual flairs if i wint to 6 or 7 would this be or? i dont think i could add slot ports to the box.
     

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