Closed Thread
Results 1 to 14 of 14

Reload Thread: Differences in subs concerning VAS

  1. #1
    Bass Addict's Avatar
    Bass Addict is offline customizer



    Join Date
    Dec 2008
    Location
    somewhere in the mountains
    Posts
    1,341
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    5 Post(s)

    Differences in subs concerning VAS

    if two speakers have the same wattage output and in the same vented box and one has a vas of say 12.6 and the other has a vas of 66.what would be expected of the sub that has the vas of 66 vs the 12.6 vas in a perfect invironment ? i know the one with the vas of 66 will have a looser suspension.so does that mean the sub can bottom out more easily than the 12.6 ? appreciate any input



    Ride;370z
    alpine 9887
    DD6




  2. #2
    kushy_dreams's Avatar
    kushy_dreams is offline The resident hippie



    Join Date
    Sep 2009
    Location
    twenty past four
    Posts
    4,091
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    1499 Post(s)

    Re: Differences in subs concerning VAS

    If im not mistaken the higher vas sub will be suited to a smaller box than the lower vas sub.



    13 Dodge Dart Rallye 1.4T


    http://mobileaudioforum.com/forum/forum.php<

    BOYCOTT SKAR AUDIO! SHADY BUSINESS PRACTICES SHOULD NEVER BE ENCOURAGED!

  3. Thanks Bass Addict thanked for this post
  4. #3
    Join Date
    Sep 2011
    Location
    Tennessee
    Age
    34
    Posts
    318
    Post Thanks / Like
    Images
    3
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    42 Post(s)

    Re: Differences in subs concerning VAS

    Quote Originally Posted by kushy_dreams View Post
    If im not mistaken the higher vas sub will be suited to a smaller box than the lower vas sub.
    I think it maight be the other way around; little box controls little Vas, and big box controls big Vas. I'm not 100% on that though...



    Simple SQ System:

    Head Unit: Alpine CDA-117
    Active Crossover: Cache' CEX
    Front Stage Amp: Boston Acoustics GTA-704
    Components: Polk Audio DB 6501
    Sub Amp: Boston Acoustics GTA-1000m
    Sub: JBL P1224, 2.5 ft^3 @ 25 hz enclosure
    Rear Fill: Sony Xplod 5.25s on HU power lolz

  5. #4
    Tupolev's Avatar
    Tupolev is offline Mountaintop Stainer



    Join Date
    Jul 2011
    Location
    Under the bridge, seriously.
    Posts
    402
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    43 Post(s)

    Re: Differences in subs concerning VAS

    Well, I would think that the looser suspension would need a smaller box so it doesn't unload.




  6. Thanks Bass Addict thanked for this post
  7. #5
    Bass Addict's Avatar
    Bass Addict is offline customizer

    Threadstarter


    Join Date
    Dec 2008
    Location
    somewhere in the mountains
    Posts
    1,341
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    5 Post(s)

    Re: Differences in subs concerning VAS

    Quote Originally Posted by kushy_dreams View Post
    If im not mistaken the higher vas sub will be suited to a smaller box than the lower vas sub.
    this makes sense as i have my d6 in a 2.3 cube box.it has a vas of 12.6 and it will not bottom out.when i had it in the spec'd sealed box,it had high excursion and bottoming out.



    Ride;370z
    alpine 9887
    DD6

  8. #6
    Bass Addict's Avatar
    Bass Addict is offline customizer

    Threadstarter


    Join Date
    Dec 2008
    Location
    somewhere in the mountains
    Posts
    1,341
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    5 Post(s)

    Re: Differences in subs concerning VAS

    Quote Originally Posted by Tupolev View Post
    Well, I would think that the looser suspension would need a smaller box so it doesn't unload.
    good points and basically thats what i needed to know.thanks everyone for the helpfull responses



    Ride;370z
    alpine 9887
    DD6

  9. #7
    mylows10's Avatar
    mylows10 is offline Dc,tantric,singer,phd rep mylows10 is a Supporting Member of the forum!

    mylows10 is a Supporting Vendor of the forum!

    Join Date
    Sep 2009
    Location
    monterey , ca
    Age
    51
    Posts
    19,579
    Post Thanks / Like
    Images
    9
    Mentioned
    9 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    5144 Post(s)

    Re: Differences in subs concerning VAS

    Quote Originally Posted by Tupolev View Post
    Well, I would think that the looser suspension would need a smaller box so it doesn't unload.
    he means so that the woofer loads properly




    pioneer avhx 5500 dvd, gzpa 1.4000 x 2
    ab vfl 350.4 ,7 pc 2150 and a 150 ah power ware agm ,275 amp singer alt , 2nd one coming soon
    cdt 6.5 es 6 mids,cdt es 010 tweets,es 03 Mids ,mx1000 3 way x overs , sky high and stinger hpm o gauge wires ,also 2 tantric hdd 15's in a 9.5. ^3 ported no wall box 11.5 octo port.
    NOR CAL DB DRAG JUDGE
    http://www.dcsoundlab.com

  10. #8
    kushy_dreams's Avatar
    kushy_dreams is offline The resident hippie



    Join Date
    Sep 2009
    Location
    twenty past four
    Posts
    4,091
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    1499 Post(s)

    Re: Differences in subs concerning VAS

    My Boston G5s have a fairly high vas and they are suited to small sealed boxes. My old Kicker Solo Classic (09 model) had an even higher vas and they were intended for only small sealed enclosures. Im fairly certain the higher vas indicates the ability to utilize a smaller box. We need audioholic in here



    13 Dodge Dart Rallye 1.4T


    http://mobileaudioforum.com/forum/forum.php<

    BOYCOTT SKAR AUDIO! SHADY BUSINESS PRACTICES SHOULD NEVER BE ENCOURAGED!

  11. #9
    hispls's Avatar
    hispls is offline CarAudio.com Veteran



    Join Date
    Sep 2009
    Location
    Cape Cod, Massachusetts
    Posts
    6,454
    Post Thanks / Like
    Images
    15
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    2019 Post(s)

    Re: Differences in subs concerning VAS

    It will have more to do with how good it sounds in a particular size box. Heavily damped woofers require less air preasure to prevent them from ringing (sounding "boomy")

    Looking at Vas without considering Qts and what you're actually trying to accomplish doesn't really tell you much.




  12. #10
    kushy_dreams's Avatar
    kushy_dreams is offline The resident hippie



    Join Date
    Sep 2009
    Location
    twenty past four
    Posts
    4,091
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    1499 Post(s)

    Re: Differences in subs concerning VAS

    So the high vas would go well with a low qts to sound good in a small sealed enclosure? The previous examples I mentioned both have fairly low qts, .47 on the G5 and .464 on the solo classic.



    13 Dodge Dart Rallye 1.4T


    http://mobileaudioforum.com/forum/forum.php<

    BOYCOTT SKAR AUDIO! SHADY BUSINESS PRACTICES SHOULD NEVER BE ENCOURAGED!

  13. #11
    Join Date
    Sep 2011
    Location
    Tennessee
    Age
    34
    Posts
    318
    Post Thanks / Like
    Images
    3
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    42 Post(s)

    Re: Differences in subs concerning VAS

    Man I'm confused. I wonder which it is. I once was told my RE SE/x 15 needed a large sealed box because of its high Vas. But, all the above comments make sense, so... I dunno.



    Simple SQ System:

    Head Unit: Alpine CDA-117
    Active Crossover: Cache' CEX
    Front Stage Amp: Boston Acoustics GTA-704
    Components: Polk Audio DB 6501
    Sub Amp: Boston Acoustics GTA-1000m
    Sub: JBL P1224, 2.5 ft^3 @ 25 hz enclosure
    Rear Fill: Sony Xplod 5.25s on HU power lolz

  14. #12
    Ryan shaw's Avatar
    Ryan shaw is offline CarAudio.com Elite



    Join Date
    Nov 2010
    Location
    Boulder, CO
    Posts
    718
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    3 Post(s)

    Re: Differences in subs concerning VAS

    "Vas Volume of air equal to the driver compliance.

    This can be thought of as how stiff the movement of the cone is. The value is given in litres or cu inches. There are a lot of variables that determine the Vas, so you can’t really say that high values of Vas mean a certain thing or are better. A single or double suspension spider will affect Vas, so does the size of the cone. The temperature of the air and also the humidity will affect Vas and so it is one of the hardest parameters to evaluate."



    --2004 Lincoln Aviator
    In-dash - Pioneer AVH4300 double din
    Front stage - Memphis coax's
    front amp - Kicker zx100.2
    Sub Amp - Soundigital 8000.1
    Subs - 4 TC Sounds 5200 18"
    Electrical - 300 amp alt from excessive amperage with big 3 and 4/0 cable

  15. #13
    hispls's Avatar
    hispls is offline CarAudio.com Veteran



    Join Date
    Sep 2009
    Location
    Cape Cod, Massachusetts
    Posts
    6,454
    Post Thanks / Like
    Images
    15
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    2019 Post(s)

    Re: Differences in subs concerning VAS

    Quote Originally Posted by kushy_dreams View Post
    So the high vas would go well with a low qts to sound good in a small sealed enclosure? The previous examples I mentioned both have fairly low qts, .47 on the G5 and .464 on the solo classic.
    .4 and .45 is pretty much middle of the road Q.

    Anyway, this is a decent quick read that correlates those parameters. Take this with a grain of salt, not sure if it is trying to get optimum ouptut, optimum "flat" response, or maximum low extension.

    QTS parameters How to Pick the Right speaker for your Speaker Cabinets




  16. Thanks Bass Addict, kushy_dreams thanked for this post
  17. #14
    audioholic's Avatar
    audioholic is offline Moderator



    Join Date
    Aug 2003
    Location
    Parts Unknown
    Posts
    23,586
    Post Thanks / Like
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quoted
    320 Post(s)

    Re: Differences in subs concerning VAS

    "Vas
    Measured in litres (L) or cubic metres, is a measure of the 'stiffness' of the suspension with the driver mounted in free air. It represents the volume of air that has the same stiffness as the driver's suspension when acted on by a piston of the same area (Sd) as the cone. Larger values mean lower stiffness, and generally require larger enclosures. Vas varies with the square of the diameter. A typical factory tolerance for Vas spec is 20–30%" - Thiele/Small - Wikipedia, the free encyclopedia

    So a larger Vas means a looser suspension, and a looser suspension means (usually) a larger box. But as said by someone above, just looking at Vas in a vacuum (not considering other specs) will only serve to give false conclusions.



    No speaker, in the history of speakers, has ever been blown by too little power. Ever. I don't care what your friend told you, he's a dirty liar.


  18. Thanks kmanian, kushy_dreams thanked for this post
Closed Thread

User Tag List

Posting Permissions

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