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where to put port in crx

Discussion in 'Car Audio / Security / Electronic Accessories' started by raceinspiredrex, Dec 26, 2008.

  1. raceinspiredrex

    raceinspiredrex New Member

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    i have a small box with a jl 10" w6ae and was told it would sound a little better if i let it breathe by installing a port. so i have two 2" plastic round ports that are about 4" long that i can install. if you open the hatch and look into the hatch area, the sub box would be to the bottom right. i was told that the best way would be to point it away from the driver, but then again, it's all the way up again the back so i wouldn't think it would be the best. anyways, let me know what you guys think. i have two but don't have to use them both. whatever you guys think is best. thanks
     
    Last edited: Dec 29, 2008
  2. OGMatt

    OGMatt Not a real OG lol

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    in a crx you should point the port back. It does not really matter if the box is almost touching the back if any thing you will get more bass. I have a 2x12 inch port and it sounds stupid loud in my crx.
     
  3. TommyTheCat

    TommyTheCat Gonzo Scientist

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    You will need to take some time and figure out what effects will come of adding reactive vents to the enclosure. You wont so much be aiding to help the speaker breathe as forcing the speaker to blow across a coke bottle - the port will resonate, so hopefully it does it where you want it to.

    You need to know two attributes that define the resonant system - the spring and mass components. For a speaker enclosure this comes down to the springiness of the internal air of the box and the mass of the air in the port(s). You should be able to find some online calculators or downloadable box modeling programs (WinISD, etc.) that require the dimensions of the box and ports. Altering the box volume and port volumes will effect the frequency of resonance. Too high and it'll fart like hell and bottom the speaker on low notes (think about how you put a hole in the box and at low frequencies no longer have the box air to support the driver), too low and you'll get little benefit. Calculators tell you what you'll tune it too - but box modelers will show what benefits/risks are incurred by the choice to vent the box.
     
  4. Taco15

    Taco15 I wear stretchy pants VIP

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    normally i always face the subs and ports up in any hatch. I had friend with 2 12's facing back with the ports also facing back in a crx. it was ALL the way back agaings the hatch and still sounded loud. I does matter but it depends on how picky you are.

    I say face the port up along with the speaker.
     
  5. bjoebright14

    bjoebright14 New Member

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    you have to measure them perfect. if you dont know what your doing you might need to get someone to do it cause i have seen a bunch of peoples whitsle lol.i did mine i have 2 12 inch and 4000 watt amp i made my ports facing hatch
     
  6. bjoebright14

    bjoebright14 New Member

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    oppsite of hatch sorry
     
  7. raceinspiredrex

    raceinspiredrex New Member

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    meaning you faced the ports towards the interior of the car?
     
  8. raceinspiredrex

    raceinspiredrex New Member

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    i've researched a little bit, but it doesn't tell me the best place to put the port(s). and it doesn't say if i should use 1 or two or not, it gives me a choice. with the size of what i have though, it looks like 1 port would work best. it doesn't answer my question about where the port should be located. thanks again guys
     
  9. Taco15

    Taco15 I wear stretchy pants VIP

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    the amount of ports does not matter too much on a small setup.It the size that counts. Look at the subwoofer specs and it should tell you the amount of air it should have internally and what the port flow should be also. Once you have those nubers you can decide to do either 1 big port,2 small ports or a slot port. As long as they have the same volume it will be fine.

    on pvc ports make sure you sand the inside edges to make sure you dont get the wistle.
     
  10. TommyTheCat

    TommyTheCat Gonzo Scientist

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    Roughing the insides of port walls has not been shown to reduce any negative characteristics such as compression - the air mass will simply not reach velocities where turbulant effects take place.

    And I'd go subs up, port back. This is one of the most consistantly loud setups out there for rex's.

    And dont just stick a damn hole in the box, did you read my post above?
     
  11. raceinspiredrex

    raceinspiredrex New Member

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    i have my sub box all the way in the back, the bottom right corner if looking into the hatch. it's a small box, about .75 square feet. on jl's website, it says for a sealed box, it should be .65square feet and if it's slotted it should be 1square foot. since i'm just putting a port in it, i think that's a good size.

    anyways, i had to put the port in the side of the box because of how the setup sits. if you're looking at the box through the hatch, the sub faces the interior and the port is on the left side of the box towards the bottom of the box. we'll see how this setup works. just so everybody knows, i have a really nice slotted jl box that i was using but it took up half the hatch and was really heavy, this is why i went with a lot smaller box. the jl sub box sounded excellent, but wasn't ideal for speed and hatch space. i'm not trying to win a competition with this box, but i want it to sound as best as it can for what it is. let me know what you guys think. thanks a bunch
     
  12. raceinspiredrex

    raceinspiredrex New Member

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    thought i'd give an update. i know it's been a while, but i was going through my subscribed threads and checking them out. anyways, i didn't put tons of thought into where i was putting my port, i put it basically in the only spot it would fit lol. i bought a "scoshe build your own box" from walmart and put it together. it fits really nice into the very back right indent in the crx hatch, i have the sub facing forward, and the back of the sub box has the perfect angle to fit snugly against the very back. it fits right under the fold up tray or whatever it is, and fits with plenty of room under the hatch cover. i have the amp on the right side of the box which sits deeper into that back right indent of the hatch. i have a capacitor that is bolted to the left side of the box, and since the capacitor doesn't take up too much space, i put the port on the left side of the box as well, but toward the bottom right corner. the port is a 2" circle that's about 2" deep. i rtv'd all of the joints on the inside of the box, as well as rtv'ing the port in place and around the joint of the port where it meets the inside of the box. i also rtv'd the joint around where the plastic wire connector things sits inside the box, idk what it's called, but it's what you attach the speaker wire to. so all in all, it was a fun little project, and believe it or not, i think my sub sounds better and hits a lot better. before it was kind of a rattly bass, not it's really punchy and hits really clean. maybe this kind of box was a lot better for the sub? idk since i'm not into sound systems as deep as some people are. i wanted to give everybody an update because i know there's others out there who are looking for more space in their hatch and a lighter setup but don't want to sacrifice sub quality. and this is a great way to handle that situation. thanks a lot for all of your guys' input and knowledge, i appreciate the help
     
    Last edited: Feb 2, 2009
  13. c-rex-beat

    c-rex-beat yeah, it's a vtec.

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    I had 2 10'2 and 2 2400's. small individual box and the right port length for desired frequency. 158 dB with sub forward and port back. Crx is picky about what it will do. A jdm crx is best for SPL.
     
  14. OGMatt

    OGMatt Not a real OG lol

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    and why is a jdm one better?
     
  15. Taco15

    Taco15 I wear stretchy pants VIP

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    crx is a person now? And no the jdm is not better than the usdm when it comes to sound. they are the same exact layout. :mellow:
     
  16. OGMatt

    OGMatt Not a real OG lol

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    thats what I thought but once you think about it that rear seat will boost your db level another 100db's
    lol
     
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