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SPL & SQ / Fabrication

Calculations, Concepts, Designs, Theories. All General SPL Or SQ Questions Can Be Discussed Here.

  1. Started by cx-7heaven,

    I have loved my 18's since I got them, but due to a baby being on the way, I have to get rid of the 150 pound 12 cu.ft monster in the back of my little XUV. I'm replacing them with......(drum roll please)...... A pair of Critical Mass UL 12's! I hope to god that they fit the bill for me output and soundwise.

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  2. Started by jemorgan85,

    ghs_wrestler 189 and I went to a local comp yesterday and they were using an old K & M mic that had been calibrated by Audiocontrol, according to the JL rep there. Somehow we went from 143 dB on a new Termlab with 5.1 cubes @ 36hz to 131 on this mic with 5 cubes @ 46 hz. Everyone was hitting kind of low, but there were people there that I guarantee would not have done better than us, but did. Any suggestions?

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    • 2 replies
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  3. Started by pimpedout97x,

    to seal this gap inside my box....if i glass it, whats the absolute BEST way to approach this, so the glass doesnt ever pop off from the bass over time?

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    • 5 replies
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  4. Started by XxRobxX,

    Im looking to make a box for 2 12inch kicker l7s. I want the subs to have individual chambers and to face up. I want to use aero ports and have the ports facing back. I want to use 3/4 inch birtch plywood. I am having trouble to come up with a design. I want to tune it to 32hz. I am looking for help with this design and I am looking for opinions on what I want for this box. I want it to be loud with little distortion. the width of the over all box cannot exceed 40inchs and the depth of the box cannot exceed 24inchs.

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    • 8 replies
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  5. Started by oxsign,

    I need to find out what the correct airspace is with this box. The depth is 20" with the sub facing up. The 36" is the bottom of the box. It's shaped like a "T" to fit over the wheel wells. I know it's kinda crazy, but I need to maximize the room I have for an 18" sub I have coming in shortly. Thx for your help, Vic.

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    • 3 replies
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  6. Started by on1wheel06,

    im building a box for a Pioneer TS-W1207D4: 1.65 cu ft 3"x5.5'' port displacement: 0.076 the box ive built is about 1.9ft^3 without any displacements. i'm assuming the 3"x5.5" is the port area and i just need to calculate the length? if so, how long do i need the port for ~35-38hz?

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  7. Started by joshtazz,

    i cut out the factory speaker grill guard and i cut the hole to big and i was wondering what you guys recommend to patch it up. thanks alot.

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    • 7 replies
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  8. Started by dbrown23,

    I build ported boxes on a pretty regular basis using the re enclosure calculator and they are always slot ports but i want to build a different box that uses a square port that isnt a slot port but I dont know the formulat to calulate the port area or convert the round port to a square port can anyone please give me some insite on how to do this please thanks alot .

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  9. Started by djjdnap,

    The Effects of Cabin Gain in Car Audio Have you ever wondered why car audio systems can have so much bass as compared to a home stereo system? The reason has to do with space. Your home has a lot of it and your car audio system doesn't. Because there is so little space in a car the bass notes (which are long waves) build up inside the passenger area. To calculate the length of a sound wave you divide the speed of sound (in feet per second) by the frequency. At sea level, the speed of sound is approximately 1,127 ft/sec. For example, a 40 Hz note has a wavelength of approximately 28 ft (at sea level). (speed of sound)/(frequency) = wavelength OR (1,127 ft/sec)/(40Hz) = 28.…

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  10. Started by caintrain,

    When Calculating port length, How can you enter the box volume after port displacement, without knowing what the port length will be. Or do you put in what you want your box to be after the displacements and then design a box that takes this into account. For example, if you want a box to be 4.5 cuft. after displacements you would use this to calculate the port length. Then after you have that you would calculate the port displacement lets say is .5 , SO you would do .5 + 4.5 to get 5 cuft., then design a box that is five cuft before port displacement and use the port length that was calculated to get the desired tuning? If someone needs further explanation please ask. …

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  11. Started by Mr_Jones,

    Hello all, I have discovered I am going to have to build a new enclosure for my subwoofer to fit in the current vehicle I drive to work. The car is an early 80's sedan with a large but shallow(height) trunk and I do not really care if I have much space left over. I am pretty good at building things and have no problems making a pretty elaborate box, so my question is: In the trunk of a car like this what is the best enclosure to build without walling off the backseat? Any suggestions would be greatly appreciated! Thanks in advance, Mr_Jones

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    • 3 replies
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  12. Started by dbrown23,

    Which enclosure do you prefer and give your reasons for sayin so. Just trying to see who likes what type of enclosure the best. Me i am kinda in between you can get a good all around sound with sealed, given enough power to run push it. I used to use a lot of sealed boxes because I really didnt have the room for ported boxes given the subs i was usin. Now I have switched to ported since subs now work in ported enclosures the size of what the old sealed subs used to work in. Also which one do you think handles ungodly amounts of power better.

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    • 7 replies
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  13. Started by mklett33,

    Without a good understanding of the proper way to wrap a subwoofer enclosure, applying carpet can be a daunting task. Allow me to solve your problems as I teach you how to rap... er I mean WRAP a sub box! If you enjoy be sure to check out my plethora of other videos! (Click the image for video)

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    • 5 replies
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  14. Started by hiloracerboy84,

    im planning on building a spl box for my 12" BL and would like some input from people with experience on a basic design to work around. for an spl box, i know people sometimes use a smaller box with more port area. my daily box is at 1.8ft^3 tuned to 33 with 26.5in of port area. approx how much port area would be ideal for this sub in say, a 1.5 cu ft box? im powering it with a hifonics bx1606d @ 1ohm and its in a 97 4runner, so anyone have ideas on tuning freq also?

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  15. Started by Bobby32,

    Alright so my box is 5.38 cubes internally after the displacements besides the port. Im using a tube port thats 8'' diameter and I want to tune to 32Hz. My box only has about 20 inches of height to work with inside, so some of the port will be sticking out the top. I want at least 4 inches between the port and the bottom of the box. If anyone can help me calculate it out that'd be appreciated.

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    • 5 replies
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  16. Started by Lord Baccus,

    What is a 4th order & 6th order Banpass ? anyone have a diagram ?

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  17. Started by kilcrease92,

    hey im workin on my third box build and i want this one to be perfict i need help on the port i wanted it tuned too like 33 htz and i dont know how to caculate that can anybody help me if i give you box demention and mdf thickness ???

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    • 3 replies
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  18. Started by spencers,

    I need some advice on whether to go with 2 btl 15s or 2 btl 18s. I have about 16 cubic ft of space to put a box in my car. I will post pics of the car asap. I am just looking a system that hits hard hopefully around 148 to 150 dbs.

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    • 3 replies
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  19. Started by justin smith,

    i was looking at the 6x6 in aero ports at parts express but the only boxes ive ever built have been slot ports so i dont know anything about it, how much air do they displace?, or how do i get a turning freq. with them, and just the basics i quess? idk thanks for any help guys

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    • 6 replies
    • 841 views
  20. I'm posting this up again....... THIS time heavily revised, it now has slot port calculations, and CUT SHEETS! This EXCEL based box calculator will take your enclosure size, woofer displacement, the wood thickness you plan on using and the frequency you wish to tune it to and gives you the GROSS enclosure size, dimensions (Including CUSTOM dimensions in which you input two of the OUTSIDE measurements and it gives you the last one.) PLUS gives you the cutout sizes for each panel of the enclosure you just asked for....... I'm putting it out for real world testing to be sure the math is good and the cuts are helpful......... Let me know ASAP what you think and what proble…

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    • 3 replies
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  21. Started by BigPerm,

    If you're building a downfire enclosure, how do you calculate the distance from the floor? I've searched and haven't found a definitive answer. All i've found is calculations for woofer sag and "just do 3"-4" from the floor." Half the radius, or plus 5% of Xmax... What? Help please! Thank you.

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  22. Started by Davo2378,

    Ok i need some more help trying to figger out how big to make my port, it is for two sa-15's on the saz-1500d .v2 in a 97 Blazer. The box will be 19H, 38W, and 26D, subs up and port back. But i wanna put the port on the bottom centered and i was going to make the port. 6H, 20W, and 19L, but that didnt give me enuff port area and i want it somewhere between 32 to 38 or so Hz. So if someone could please help me out it would be much appreciative thanks.

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  23. Started by sinistervr6,

    car- lexus gs300 music- hip hop and rap sub- audioque sdc2.5 12 amp- jl audio 500/1 max height- 14.25 port tuning- figured 38 max depth- 14.125 max length- 31.125 using .75 thick mdf i get roughly 2.75 cubix feet.. so i figured with sub displacment and port i would be at about 2.5 which is what audioque is the biggest i should run the box.. now with the port i put in 2 inches wide by 8 inches tall and i would need a port length of 7.51 inches.. now my question is does all that sound about right? should i have the port longer? when i did the port at 14.25 tall and 2 inches wide it said i needed a port length of 14.71.. basically just looking for some advice on what to do…

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    • 3 replies
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  24. Started by mason_herold,

    im going to have two FI BL 15s and i want a good enclosure. my max dimensions are 50 inches in width, 28 inches in height, and 25 inches in depth, and i kinda wanted a design plan such as the port dimensions and should i go double or single baffle?

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    • 4 replies
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  25. Started by explosivesound,

    Ive made my own ported boxes in the past but nothing more than a rectangular ported box with f-glass. I dont want to pay a shop to make my box, I want to build it myself. Its a 2000 grand am. Back seat obviouslly removed. I dont really understand how to do the edges and different angles. to take up ALL the space. Or do I forget angles and just do what I can. I was going to do it all in fiberglass but that is probably a stupid idea and a stupid amount of work. The only other problem is how to calculate volume with so many different angles and how to exactly calculate how to measure the bracing and port volume. If anyone has a site to direct me to that deals with Wall setu…

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    • 6 replies
    • 838 views

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