Closed Thread
Results 1 to 11 of 11

Reload Thread: tuning question...

  1. #1
    outspoken's Avatar
    outspoken is offline CarAudio.com Elite



    Join Date
    Oct 2007
    Location
    Between The Golden Gate And The Bay Bridge
    Age
    37
    Posts
    1,530
    Post Thanks / Like
    Mentioned
    0 Post(s)

    tuning question...

    so i know this may get me flamed, but, in an l shaped ported box, longer port = lower tuning, shorter port = higher tuning? i would like to modify my box until i can get a new one built. flame me if you must, i probably deserve it anyway



    Refs: vitveet(x2)-audiobahnuser18(x2)-fargof-mazzasec-loudcartunez-jeeper07-NE14MX-pitbull12887-datboiroy-littleviet-XxSuperAdamxX(x2)-uS3-craigzter-LazyRider-juckstapose



    Quote Originally Posted by endofdays89 View Post
    yeah, put in some white girl or three 6 mafia and sit in your car and let us see how much the rear view mirrors move. It usually is the best indicator that the low lows are hitting well or not. Cuz it should vibrate quite a bit.



    Quote Originally Posted by matrxx dude View Post
    my girl ask me once to choose between her and my car audio,i told that ***** i had made harder decisions at the coke machine.




  2. #2
    P.rick's Avatar
    P.rick is offline P.rick



    Join Date
    Nov 2008
    Location
    atlanta
    Age
    27
    Posts
    80
    Post Thanks / Like
    Images
    3
    Mentioned
    0 Post(s)

    Re: tuning question...

    "longer port = lower tuning, shorter port = higher tuning?"

    yes sir



    P.rick

  3. #3
    outspoken's Avatar
    outspoken is offline CarAudio.com Elite

    Threadstarter


    Join Date
    Oct 2007
    Location
    Between The Golden Gate And The Bay Bridge
    Age
    37
    Posts
    1,530
    Post Thanks / Like
    Mentioned
    0 Post(s)

    Re: tuning question...

    o.k., that's what i thought,now how do i figure out how much i need to reduce the port to get it to the freq. i want? it's at 32 now need it to be at more like 38...



    Refs: vitveet(x2)-audiobahnuser18(x2)-fargof-mazzasec-loudcartunez-jeeper07-NE14MX-pitbull12887-datboiroy-littleviet-XxSuperAdamxX(x2)-uS3-craigzter-LazyRider-juckstapose



    Quote Originally Posted by endofdays89 View Post
    yeah, put in some white girl or three 6 mafia and sit in your car and let us see how much the rear view mirrors move. It usually is the best indicator that the low lows are hitting well or not. Cuz it should vibrate quite a bit.



    Quote Originally Posted by matrxx dude View Post
    my girl ask me once to choose between her and my car audio,i told that ***** i had made harder decisions at the coke machine.

  4. #4
    simpsonbuck's Avatar
    simpsonbuck is offline Decibles for breakfast



    Join Date
    Mar 2008
    Location
    Dallas, TX
    Posts
    1,721
    Post Thanks / Like
    Mentioned
    0 Post(s)

    Re: tuning question...





  5. #5
    mlstrass's Avatar
    mlstrass is offline Shaggy DOA



    Join Date
    Jul 2006
    Location
    Illinois
    Posts
    10,488
    Post Thanks / Like
    Mentioned
    28 Post(s)

    Re: tuning question...

    also realize that changing the port length will change the box volume...




  6. #6
    9seconlives's Avatar
    9seconlives is offline Senior VIP Member



    Join Date
    Jun 2008
    Location
    Houston,TX
    Posts
    328
    Post Thanks / Like
    Mentioned
    0 Post(s)

    Re: tuning question...

    Is it true that every 1/2" in port length (shorter or longer) eitherway is the equivelant to 1hz increments of tuning?



    There is NEVER a stupid question but there ARE always dumb answers.........usually given by a matching individual.





    REFS:
    Traded W/- mrmakinmoves-

  7. #7
    dragnix's Avatar
    dragnix is offline LXIX



    Join Date
    Dec 2006
    Location
    Socal cuz i'm So cool
    Posts
    19,635
    Post Thanks / Like
    Mentioned
    21 Post(s)

    Re: tuning question...

    Quote Originally Posted by 9seconlives View Post
    Is it true that every 1/2" in port length (shorter or longer) eitherway is the equivelant to 1hz increments of tuning?
    never heard of this and i don't think it would be right anyway. Tuning also has to do with box size and port area.




  8. #8
    Rashaddd's Avatar
    Rashaddd is offline Terrrrrist



    Join Date
    May 2008
    Location
    Sacramento
    Posts
    5,095
    Post Thanks / Like
    Mentioned
    0 Post(s)

    Re: tuning question...

    Quote Originally Posted by 9seconlives View Post
    Is it true that every 1/2" in port length (shorter or longer) eitherway is the equivelant to 1hz increments of tuning?
    Absolutely not.




    Refs: themommyvan, CharlieAnderson, bassknocker23, bigbirney420, wu501, _JaY_, lrc131, R/T Pimp, NeverEnuffBass, d-REW, slapmaster, headbussaboi, edzy, adio, 1ndatrunk, jfink, k_schutte, bigredhybrid, ARSkemp, s-saudio, pimpdaddyq, AudioFreak, scarolinablazin, ssackett, kylebechtold, craigzter, etc..................

  9. #9
    9seconlives's Avatar
    9seconlives is offline Senior VIP Member



    Join Date
    Jun 2008
    Location
    Houston,TX
    Posts
    328
    Post Thanks / Like
    Mentioned
    0 Post(s)

    Re: tuning question...

    Quote Originally Posted by dragnix View Post
    never heard of this and i don't think it would be right anyway. Tuning also has to do with box size and port area.
    Understood BUT why then by making the port shorter or longer does it change the frequency to which the box is tuned? just curious and not trying to pick a fight with a senior member but it "almost" made sense to me when i heard it the first time. i understand that the size of the box and port are a major factor but i'm use to building by DD's specs most of the time and if i have a 2"-3"x16"port tuned at 40htz then how come if i make it an inch or 2 longer ir will drop it down to like 36 or so? cause you're tuning the box not the sub....maybe it's too late and my meds are kicking my a$$ but than you guys for clearing that up for me.
    here's what i mean though...doesn't matter if you have a 1510 or a 3512 the area of the port is different but the length and tuning frequency is the same..i also understand that thes #'s are not set in stone..
    http://www.ddaudio.com/dd/caraudio/e...Size_hiEff.asp
    SORRY TO JUMP OFF TOPIC!!



    There is NEVER a stupid question but there ARE always dumb answers.........usually given by a matching individual.





    REFS:
    Traded W/- mrmakinmoves-

  10. #10
    mcsoul's Avatar
    mcsoul is offline such is life



    Join Date
    Mar 2008
    Location
    dfw
    Posts
    4,427
    Post Thanks / Like
    Mentioned
    0 Post(s)

    Re: tuning question...

    Quote Originally Posted by P.rick View Post
    "longer port = lower tuning, shorter port = higher tuning?"

    yes sir
    Quote Originally Posted by Juha Hartikainen
    Designing your Box, help file from winISD
    If your mach rating is too high, the only way to lower it is to either increase the number of or the diameter of the ports. Of course, here comes that dreaded "trade-off" word again! If you make your port(s) bigger in diameter, they will be able to pass more air with less effort. However, in doing this, you have lowered the "loading" of the speaker(s) in the box. This, of course, changes the -3dB point of the box. The only way to get back to your desired -3dB point is to "load" the speaker(s) again. How? Well, you gotta make the new, larger port(s) longer! This forces the speaker(s) in the box to work harder to move the air into and out of the box, and brings your -3dB back to where it should be. THE END OF YOUR PORT(S) MUST BE AT LEAST 3 INCHES AWAY FROM ANY INTERIOR WALL OF YOUR ENCLOSURE.
    OP, keep in mind the a the depth of the port gets longer for the same tuning when
    the port area (port length x width) are increased. The depth needed will also increase for every port when you add additional ports.



    ________________________
    Car: 2004 Nissan Altima 3.5 manual
    Head unit: Alpine CDA-9815 (running active)
    Midbass: Morel HU-621 Hybrid Uniflow 8 ohms
    Mid Amp: Audison lrx 4.300 bridged 2x140w @ 8 ohms
    Doors: 24ft Damplifier Pro, Second Skin D-flex pads, eggcrate foam, sealed up.
    Tweeter: SEAS 27TFFNC
    High Amp: Audison Lrx-2.150
    Subs: Two RE SE 12 d4's
    Box: 4 cubes net at 30hz
    Sub Amp: Sound Stream Van Gough 1600.2
    Electrical: Knu Flex 1/0, Batcap 2000 in back
    Rear Deck: No 6x9's just holes and grills

  11. #11
    Rashaddd's Avatar
    Rashaddd is offline Terrrrrist



    Join Date
    May 2008
    Location
    Sacramento
    Posts
    5,095
    Post Thanks / Like
    Mentioned
    0 Post(s)

    Re: tuning question...

    Quote Originally Posted by 9seconlives View Post
    Understood BUT why then by making the port shorter or longer does it change the frequency to which the box is tuned? just curious and not trying to pick a fight with a senior member but it "almost" made sense to me when i heard it the first time. i understand that the size of the box and port are a major factor but i'm use to building by DD's specs most of the time and if i have a 2"-3"x16"port tuned at 40htz then how come if i make it an inch or 2 longer ir will drop it down to like 36 or so? cause you're tuning the box not the sub....maybe it's too late and my meds are kicking my a$$ but than you guys for clearing that up for me.
    here's what i mean though...doesn't matter if you have a 1510 or a 3512 the area of the port is different but the length and tuning frequency is the same..i also understand that thes #'s are not set in stone..
    http://www.ddaudio.com/dd/caraudio/e...Size_hiEff.asp
    SORRY TO JUMP OFF TOPIC!!
    This only works if you have the exact same proportion of box size to port area regardless of the particular box. For example...if you always use exactly 12sq in of port area per cube, then yes, you will always have the exact same change by lengthening or decreasing port length by a specific amount. DD recommends what I believe 16sq in per cube and that's what all their recommended boxes are calculated at, so all of their boxes have the same ratio of port area to air space, which means all of their boxes will be affected by a 1" decrease or increase in port length in the exact same way.

    Certainly not a good idea to use this as a rule of thumb, and it will never be 1" = 1hz for any number times you do it, because the rate of change in frequency will also change over the range of port lengths due to the fact that the port is inside the box and by changing it's length you also change the boxes air space and therefore tuning is affected twice. The 'L's in a slot ported box will also make variations in the rate of change of tuning frequency based on change in port length because of the extra wood that is being used and the wood length to actual port length being inconsistent.




    Refs: themommyvan, CharlieAnderson, bassknocker23, bigbirney420, wu501, _JaY_, lrc131, R/T Pimp, NeverEnuffBass, d-REW, slapmaster, headbussaboi, edzy, adio, 1ndatrunk, jfink, k_schutte, bigredhybrid, ARSkemp, s-saudio, pimpdaddyq, AudioFreak, scarolinablazin, ssackett, kylebechtold, craigzter, etc..................

Closed Thread

Posting Permissions

  • You may not post new threads
  • You may post replies
  • You may post attachments
  • You may edit your posts
1e2 Forum