AH FabricationsSky Insurance
Results 1 to 10 of 10
  1. #1
    Jay
    2nd Gear

    Status
    Offline
    Join Date
    Aug 2006
    Posts
    323

    Tuning a ported Sub enclosure.

    I have an Alipine 12" type R sub in a ported Alpine enclosure. I was wondering if it could be tuned to around 30hz? and how i would go about doing this?

  2. # ADS
    ADS
    Join Date
    Always
    Posts
    Many
     
  3. #2
    BMW Expert

    Status
    Offline
    Join Date
    Jan 2008
    Location
    127.0.0.1
    Posts
    29
    How do you mean tuned to? To cut off after 30hz?


  4. #3
    5th Gear

    Status
    Offline
    Join Date
    Dec 2006
    Location
    barnsley
    Posts
    1,020
    depends on what you mean ?
    do you mean so as the port itself is tuned so as its peak effiecency is at 30hz ? or do you mean you only wish to play music which is above or below this frequency ?
    to stop music below this frequency with a ported enclosure you will need to use a subsonic filter (most good amplifiers have them built in )
    i cant imagine why you would want to ... but if you mean you only wish to play music upto and including 30hz then youll need a low pass filter set to 30 hz
    the box the port and the speaker interact and work as a team it will really depend on what tuning frequency its tuned to now if its fairly high
    then the only way youll be able to achieve a tuning frequency of 30 hz will be by re-designing a new box and port
    2003 pearlescent black s4 avant tiptronic - milltek exhaust - pre cats removed - remapped ...
    koni adjustable suspension front and rear
    alpine f1 dvi9990 -pxah990 headunit and processor - alpine d511r
    4 x focal 5ws midbass drivers - focal audiom 6w midrange - focal tce tweeters - velodyne df 12 sc servo controlled subwoofer
    3 x phoenix gold zpa 0.5 amplifiers

  5. #4
    Jay
    2nd Gear

    Status
    Offline
    Join Date
    Aug 2006
    Posts
    323
    Quote Originally Posted by dualmono21 View Post
    depends on what you mean ?
    do you mean so as the port itself is tuned so as its peak effiecency is at 30hz ? or do you mean you only wish to play music which is above or below this frequency ?
    to stop music below this frequency with a ported enclosure you will need to use a subsonic filter (most good amplifiers have them built in )
    i cant imagine why you would want to ... but if you mean you only wish to play music upto and including 30hz then youll need a low pass filter set to 30 hz
    the box the port and the speaker interact and work as a team it will really depend on what tuning frequency its tuned to now if its fairly high
    then the only way youll be able to achieve a tuning frequency of 30 hz will be by re-designing a new box and port
    thanks, looks like it would be easier to buy a sealed box than to redesign a box and the port.

    Next question is would my Mono Alpine M605 amp be able to run 2 12" 1242 type R subs wired in parallel or would I need to buy a new amp?
    Last edited by Jay; 14th August 2008 at 20:05.

  6. #5
    4th Gear

    Status
    Offline
    Join Date
    Oct 2003
    Location
    up north...
    Posts
    767
    if its already in a ported alpine enclosure, why do you want to change things?

    if its the swr 1242d sub, then it should live in a sealed box of around 38L, or a tuned box between 45-85L for each sub - quite a big box.

    the 45L tuned box would have a f-3 i.e. -3db point at about 25hz, but its a very peaky boomy box and would only play bass at 1 note (my opinion only) according to the calculations
    TT-RS 410hp revo
    Fiat 500 1.3 tdi 120hp
    A3 8P 2.0tdi 240hp Autograph Cars
    RS4 B5 520hp MTM
    S3 8L 345hp MTM
    Volvo 850 T5 300hp BSR
    Fiat Punto GT 130hp
    Lancia Delta Turbo 185hp
    Lancia Beta Coupe 122hp
    Mini 74hp

  7. #6
    Jay
    2nd Gear

    Status
    Offline
    Join Date
    Aug 2006
    Posts
    323
    Quote Originally Posted by dunk View Post
    if its already in a ported alpine enclosure, why do you want to change things?

    if its the swr 1242d sub, then it should live in a sealed box of around 38L, or a tuned box between 45-85L for each sub - quite a big box.

    the 45L tuned box would have a f-3 i.e. -3db point at about 25hz, but its a very peaky boomy box and would only play bass at 1 note (my opinion only) according to the calculations
    Exactly...with the new HU I find that its drowing out the music from the fronts. I tested a 12" in a sealed box and it sounded so much better.

    Any ideas on my problem

    "would my Mono Alpine M605 amp be able to run 2 12" 1242 type R subs wired in parallel or would I need to buy a new amp?"

    cheers
    Last edited by Jay; 15th August 2008 at 09:49.

  8. #7
    Moderator

    Status
    Offline
    Join Date
    Jun 2003
    Location
    World of my own
    Posts
    9,813
    That amp should be fine as it kicks out 600wrms at 2 ohms. Your 2 subs in parallel will provide a 2 ohm load.
    "How to tear apart the ties that bind, perhaps fcuk off might be too kind"
    Alex Turner

  9. #8
    5th Gear

    Status
    Offline
    Join Date
    Dec 2006
    Location
    barnsley
    Posts
    1,020
    [quote=Jay;598828]Exactly...with the new HU I find that its drowing out the music from the fronts. I tested a 12" in a sealed box and it sounded so much better.

    Any ideas on my problem

    YES its a ported box
    if you prefer the sound of sealed then why not buy a sealed box instead ?
    ported boxes are great for effiency and great if you want something really loud BUT... if you want something thats musical and you can listen to all types of music then there is no substitute for a sealed enclosure
    2003 pearlescent black s4 avant tiptronic - milltek exhaust - pre cats removed - remapped ...
    koni adjustable suspension front and rear
    alpine f1 dvi9990 -pxah990 headunit and processor - alpine d511r
    4 x focal 5ws midbass drivers - focal audiom 6w midrange - focal tce tweeters - velodyne df 12 sc servo controlled subwoofer
    3 x phoenix gold zpa 0.5 amplifiers

  10. #9
    Jay
    2nd Gear

    Status
    Offline
    Join Date
    Aug 2006
    Posts
    323
    [QUOTE=dualmono21;598853]
    Quote Originally Posted by Jay View Post
    Exactly...with the new HU I find that its drowing out the music from the fronts. I tested a 12" in a sealed box and it sounded so much better.

    Any ideas on my problem

    YES its a ported box
    if you prefer the sound of sealed then why not buy a sealed box instead ?
    ported boxes are great for effiency and great if you want something really loud BUT... if you want something thats musical and you can listen to all types of music then there is no substitute for a sealed enclosure
    Sorry i was talking about the issue of a mono amp powering 2 subs which Andymacs answered.

    Am I better off getting a box custom made? or can i get any sealed double enclosure. I'm probably gonna get another Alpine 1242.
    Last edited by Jay; 15th August 2008 at 11:01.

  11. #10
    two
    Reverse Gear

    Status
    Offline
    Join Date
    Aug 2008
    Posts
    16
    custom box which is design to work with your speakers specs
    bass box pro is a great piece of software that does the maths for you
    (also winisd)
    bass box pro help file give a good commentary about different speaker box designs
    i'm about to pop out.. but could work out a box size at some point over the weekend

 

 

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Single Sign On provided by vBSSO

Garage Plus, Vendor Tools vBulletin Plugins by Drive Thru Online, Inc.

Content Relevant URLs by vBSEO