Help putting together a system

Discussion in 'General Car Audio Discussions' started by Zelgaddis, Mar 12, 2007.

  1. TheViking

    TheViking Well-Known Member

    I see a nice big ported box in the back of that thing!!!!!!!!!!!!
     
  2. aznboi3644

    aznboi3644 Full Member

    Thats what I see too!!! lol
     
  3. pedro quiroga

    pedro quiroga Well-Known Member

    man a 15 in that small car will ROCK.do it,and do it soon.
    welcome by the way
     
  4. TheViking

    TheViking Well-Known Member

    well guys, help this nice guy out!!!!!


    He needs a box that is optimized for his amp power!!! I would fire the vents to the rear of the car and have the sub pointing upwards.....tuned at about 40Hz.....
     
  5. aznboi3644

    aznboi3644 Full Member

    I said the exact same thing Viking!!!! you bastard
     
  6. Zelgaddis

    Zelgaddis Full Member

    OH! Now I understand everything you guys are saying, I misinterpreted the CRX box to be much more complex than it really is. So I've made a few adjustments to the box dimensions now to accomdate the sub port and sub's cubic displacement. The boxes new dimensions are:

    28 In. Wide
    16.5 In. Height
    18 In. Depth
    .75 In. Thick MDF Fiberboard
    28x16.5x18 = 3.79557 cubic feet.

    Now with displacement that sounds a little better, and I'm going out to buy the MDF Fiberboard tomorrow and fab it this weekend, I'll be sure to post pics, and the subs, amp, and wiring kit get here around the 19th so i'll throw up pics of the final install when I get it all done!

    So, I should tune this in at 38-40Hz.....

    Last question before everything gets here then is, how long should the ports be if they are 4in in diameter, and what should I line the inside of my box with as far as padding?
     
  7. aznboi3644

    aznboi3644 Full Member

    Well for the ports you can use thick cardboard tube or PVC pipe like what most people use...I have about 10 feet of thick cardboard paper tubing I'm gonna use for a box this week.

    But with about 3.79 cu ft you can use three 4 inch diameter ports approx 14 inches long...will give you a net volume of approx 3.5 cu ft and tuned at 41Hz....tuning between 40Hz and 41Hz will make no difference...should be loud as hell
     
  8. Zelgaddis

    Zelgaddis Full Member

    Ok, when I enter the numbers for my box and the tuning frequency that you're giving me and port diameter the calc that I'm using is saying that the 4in diameter holes should only go back 2.65052 in.

    14in long ports compared to 2.65 is just huge.

    I'm not trying to say either is right or wrong because I don't know much about this stuff, I just noticed that its a vast difference, and I'd just like to know the reasoning behind it?

    And just to clarify you do mean cutting a 4in diameter hole in the back of the box then gluing a 4in diameter PVC or Cardboard into the back of the box that extends 14inches into the box, correct?

    [EDIT]Calc Link

    http://www.the12volt.com/caraudio/boxcalcs.asp
     
    Last edited: Mar 14, 2007
  9. aznboi3644

    aznboi3644 Full Member

    This calculator is for ONE port...I was talking about THREE 4 inch diameter ports....What I do is place the port tube on the place where I want it and trace around the tube....then cut the hole out...place the port in and caulk it in place....and maybe a couple screws from the inside of the tube into the baffle.
     
  10. Zelgaddis

    Zelgaddis Full Member

    Ok, sorry about that. Still nub haha, but now I've got a crystal clear idea of how the install is going to work, how its going to be wired, and just about everything else. I'd just like to say thanks so much, you were patient and explained everything really well, and I just cant say thanks enough.

    On another note, looks like my amp is getting here the 19th, and everything else late tomorrow. Meaning, I'll have the box fabed with a sub sitting in it with pictures by the weekend. Thanks again so much.

    [EDIT] Since I'll be running 850Watts RMS, is there anything that I should do to avoid frying my speaker? I know this will hit hard, but is there a way to tell when the system is being pushed to hard? I just don't want to do any damage here. Because I want to push the speaker to its limits, or will it only draw as much as it needs?
     
    Last edited: Mar 14, 2007
  11. ibanezFreak87

    ibanezFreak87 Full Member

    YES!!!! Finaly a damn kenwood.

    that is a FINE @ss headunit.

    nicely done
     
  12. pedro quiroga

    pedro quiroga Well-Known Member

    wouldnt pointing the ports to the rear really make the rear panels rattle really bad.?

    when i pionted my port to the rear it was louder but,it made a horrible rattleing
     
  13. aznboi3644

    aznboi3644 Full Member


    Just because the amp is RATED at 850 watts doesn't mean it will put out 850 watts constantly all the time.

    Lets look at it like this....you have a 500HP V8 engine...it does not always put out 500HP right??? only when you run it hard and floor it.

    Same concept goes for an amp...it will not always put out 850 watts...you can set it for 300-850 watts easily...depends on the input voltage and gain setting...so I would set it up for around 600 watts
     
  14. Zelgaddis

    Zelgaddis Full Member

    Double post, sorry.
     
    Last edited: Mar 15, 2007
  15. Zelgaddis

    Zelgaddis Full Member

    Ah I see, and the instructions on how to do that will be in the amp owners manual? Going to try and find one online now

    I was just reading the owners manual for the amp and found nothing on gain levels. Also the min LPF-Hz setting on this amp is 50Hz. If thats even related to to tuning it in at around 40Hz that you guys were suggesting.
    So my question is, what should I do to adjust the RMS Wattage of the AMP? Set the bass boost to 0 and watch my volume?

    My head unit is a KDC-MP628 PDF Below
    http://akamaipix.crutchfield.com/Manuals/613/613MP628.PDF

    The manual mentions LPF-Hz, ISF, Input Sensitivity, Phase, and Bass Boost Settings that I can toy with.

    Here is the link to the amps owners manual as a PDF.
    http://akamaipix.crutchfield.com/Manuals/113/113KAC9102.PDF

    [EDIT]

    So this is pretty sweet, I just went out to my car to mess around with some settings just to see what my head could do before I even installed the speakers, it fried. Thankfully its still under warranty, so I have to go up to best buy tomorrow and tell them to give me a damn new unit. When I turn the volume over 20 on FM or put in a CD the unit just turns on, then off. Never stops, just keeps going, it looks like it gets half way through the boot up screen and just shuts down again. This makes me doubt Kenwood right before my install, but maybe it was just BestBuy who screwed up the original install.
     
    Last edited: Mar 15, 2007
  16. aznboi3644

    aznboi3644 Full Member

    May be a ground problem....make a new 12 gauge ground for the head unit.

    Low pass filter has NOTHING to do with box tuning...it is just a low pass filter

    phase I would keep at 0 degrees, bass boost at zero, and infrasonic filter turn on to prevent the sub from unloading below tuning.

    Here is a guide on how to set your gain

    http://forum.realmofexcursion.com/showthread.php?t=1990
     
  17. Zelgaddis

    Zelgaddis Full Member

    The head unit is fixed and working in perfect condition now, both the sub and wiring kit arrived today and the sub is.....gigantic and heavy. I can't imagine how hard this thing will hit. The amp is due to get here Monday which is perfect because I can fab the box over this weekend and run the wires and have everything waiting for the amp.

    I just had a look-see in my car, and the firewall looks to be impermeable! I'm about to head back out there but it looks like running this to the back of the car is going to be a guised nightmare. There is a single sheath of shielded black cable that manages to punch through the firewall on the passenger side, more details when I have them later and pictures of the fabbed box soon as well!

    If anyone knows where you can find a wiring guide for a 1998 Mitsubishi Eclipse GS, link please =), if not i'll manage. You guys have been great, you really have.

    [EDIT]

    I was just toying around and it looks like if I remove the passenger side wheel and plastic I should have "moderately" easy access to the firewall hole. So the install starts tomorrow and I'll be sure to take lots of pics!

    I was thinking about a previous post though, in an eclipse will the trunk rattle to hell? I just had a look back there its ALL plastic that seems to overlap. I hope I'm wrong there, but if rattle occurs whats the cheapest way to deal with it? Dynamat?
     
    Last edited: Mar 16, 2007
  18. Zelgaddis

    Zelgaddis Full Member

    I just spoke with a Kenwood rep, and it turns out I can bridge the terminals!!!

    Resulting @ 500Watts RMS


    The secondary voice coil negative and positive would be connected on one side.
    Then the positive primary voice coil would be attached to one of the positive terminals while the negative side would follow the same suit, but to the other terminal's negative.

    Because there are 2 terminals, each with a pos and neg hookup.

    Jesus thats the best news I've heard all day, I've just had this worry in the back of my mind that somehow I would mess up the gains or turn it up to loud one time and blow up a bunch of money.
     
    Last edited: Mar 16, 2007
  19. aznboi3644

    aznboi3644 Full Member

    Sorry...but the rep is WRONG!!!!!

    There are only two sets of positive and negative terminals for ease of wiring multiple subs.

    This amp is a MONO amp...mono meaning ONE. The rep is a F U C K ING RETARD...DO NOT LISTEN TO THE KENWOOD REPS
     
  20. Zelgaddis

    Zelgaddis Full Member

    Oh, well thats nice to know. Out of curiosity what would have happened had I hooked that up?