SVS B4 ~Alignment~ ???

Discussion in 'Home Theater Projects' started by Geoff L, May 3, 2003.

  1. Geoff L

    Geoff L Screenwriter

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    Question for the Sub Gurus:

    Out of just curiousity what type of alignment or combo alignment would this sub be considered?

    Being Multi Ported with 2 drivers mounted as usual (baskets inside) and 2 more with the baskets exposed & back to back "apperig to fire to the inside", what might this thing be considered?????

    A Ported Iso~,scratches his head.[​IMG]

    This aside, from being a Bass machine reading the few testers, & owner reviews

    Just an interesting design and always wondered just how it may be wired and put together inside.
    This aside from what you can obviously see in the outside pic's.

    Thanks for the education
    Geoff
     
  2. It is a ported push-pull. Not iso.
     
  3. Geoff L

    Geoff L Screenwriter

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    Anthony

    The 2 cones showing in phase, 2 drivers outside baskets showing out of phase right?

    All sharing the same internal space, aside from inside bracing, dampeing, fill, and ports, right?

    Geoff
     
  4. yup. that is how I understand it to be (iirc, this was discussed some time ago in an SVS thread)
     
  5. Geoff L

    Geoff L Screenwriter

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    Sorry about that, did not know they spoke of the "B4 alignment"...:b

    Seems as though the outside divers are acting similar to IB's.

    Anyway got it and thanks again...

    Geoff
     
  6. Michael R Price

    Michael R Price Screenwriter

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    Geoff,

    They don't act like IB's. They all work together just like 4 drivers in a ported box wired in phase, except the symmetry helps to cancel even order distortion. The middle drivers are wired out of phase electrically because their physical orientation is switched (they're on the outside of the box firing in).
     
  7. Chris Tsutsui

    Chris Tsutsui Screenwriter

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    The inner box design is like that of an infinite baffle, only the difference is that there is a box around the IB thus making it "bass reflex" or "Vented".

    Then they slap on two more drivers on the side of the box and make sure they push air out of the box when the two inner box drivers push air out. (Joke Edited)
     
  8. Chris.....I flush mounting the amp is null and void if you do not use ROUNDED CORNERS!!!!!!
     
  9. Geoff L

    Geoff L Screenwriter

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    Find away inside and it's an IB, stay outside and it's a ported push pull.
    Sit inside and watch your movie threw the tunnel port eye pieces while staying cool with the fully speed adjustable air-conditioning. [​IMG]

    Ok, just a little over the TOP...[​IMG]

    =============>

    Thanks Anthony, Michael, & Chris...

    Seriously though:
    Is there a site or pages (non-pdf) that gose into some depth on designing this type of sub encloser???

    I basicly understand how it works, but can't find anything with Internet & Forum searchs that deal with what type driver (TS-params) might be best suited for this and (how one goes about designing one)..

    Along with any software that may aid in this???

    Operating out of phase using just (2 drivers), dose this require one to possibly 1/2 the box volume similar to a compound face to face (clamshell) Iso-load?

    Or more likely are you looking to still keeping the box volume of a--->(typical single driver ported design be it 4th order, EBS, etc)..
    And the extra driver mounted outside firing "out of phase into it" is just to help with even order distortion?

    Sorry if I'm way off here with my novice thought process....:b

    Very interested in reading about this type design approach,,,, and any place you guys can point me to read about this would be very appreciated....

    Thanx
    Geoff
     
  10. Chris Tsutsui

    Chris Tsutsui Screenwriter

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    Edited for "flushmount" comment
     
  11. Tom Vodhanel

    Tom Vodhanel Cinematographer

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    Hi Geoff, everyone,

    If there are any sincere questions about the B4+ design it might be best just to email me at [email protected] with them.

    I really don't have time to wade thru the same grade school trollings from the same 1-2 guys in every thread dealing with SVS/ B4+ anymore.

    Tom V.
    SVS
     
  12. Geoff L

    Geoff L Screenwriter

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    Tom:

    Thank you for replying..
    You have mail in route...

    Geoff
     
  13. hmmm..what is worse..the trolling, or the fact that the trolling is just revisiting SVS's own words...but we don't need to really answer this and start another flame war [​IMG]
     
  14. Geoff L

    Geoff L Screenwriter

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    I'm just trying to understand this type (sub design) and find some reading material on it. Push pull alignment.

    I don't know why the thread has appeared to go slightly into something else, what exactly thats is I don't know and don't care...

    No disrespect ment to anyone!

    Can we deal with the subject, which is information dealing with this type of sub design and not SVS.
    The B4+ was used simply for (it's type of design) and thats all.

    Regards
    Geoff
     
  15. Tom Vodhanel

    Tom Vodhanel Cinematographer

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    Anthony,

    >>>hmmm..what is worse..the trolling, or the fact that the trolling is just revisiting SVS's own words
     
  16. Tom, that was just in reference to the everst vs b4+ flame war. The rounded corners issue seemed to be layed on really really thick. I am not saying that they do not add to the visual appeal they do. I can dig through all those messages to find where it was said, but it would be a waste of time for both of us. I will drop it as asked [​IMG]

    ...but the flush mount on the amp comment on your site..... [​IMG]

    on a serious note, is there already, or will there soon be a B4+ anywhere in the southern california area? I would be interested in hearing it once I get the tumult sub up and running (if the owner would allow an audition)

    Note for the record: I am not anti-SVS. If I didn't build my own subs, there is a strong likelyhood that I would have a pair of ultras right now, or atleast at one time (actually, I'd want a pair of SS's over the ultras, but they are a bit too rich for my blood). I just think some of the advertising lines are a bit "odd" to say the least. SVS,..atleast how I remeber them a while ago, was a very straight shooter with no advertising BS.....now these days, I am seeing more of the typical commercial self inflating BS advetising. THAT specifically is what I don't like with SVS...the product I do like.
     
  17. to get back on topic...

    BESL is one of the companies that also uses the push-pull setup. http://www.bamberglab.com/ta_bassmodule.htm

    I could have sworn they had a tech paper on the alignment, but I can't find it.

    To illustrate what Michael was talking about:
    driver suspensions are not perfectly linear. the restoring force in one direction is different than the force in the other because the net forces are not perfectly symmetric. Suppose that the restoring force on the return is greater than on the way out by a factor of X. Two drivers moving in would have 2X more returning force than moving out. This asymmetry is distortion. Now, if you have a push pull arrangement like on the SVS B4+, the in and out returning forces sorta get smoothed out a bit so that they act symmetrically as a whole.

    Hope this helps
    (this is at least how I understand it to work. please correct me if I am wrong).
     
  18. Geoff L

    Geoff L Screenwriter

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    Thanks For the link Anthony.

    Was over looking at the M&K push/pull subs today too.

    I emailed Tom and he was kind enough to offer some information to help me understand futher the workings of this type alignment.

    I appreciate all who posted with information/workings dealing with this type design/alignment. I find in very interesting and will continue to research it.

    Thanx
    Geoff
     
  19. Michael R Price

    Michael R Price Screenwriter

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    Yeah, sorry for not explaining the push-pull arrangement enough... Anthony knows what he's talking about. To add to his remarks, the push-pull design cancels out most of the even order (asymmetrical) distortions inherent in the drivers but not the odd order (symmetrical) ones. As far as I can tell, in terms of the volume, driver parameters, and tuning, the B4 works like any other vented enclosure.
     
  20. Chris Tsutsui

    Chris Tsutsui Screenwriter

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    It appears even the best of people can have their buttons pushed. I sincerely appologize to Tom V and SVS if I offended them in any way.

    I will keep my tasteless sarcasm and humor to myself from now on in any type of SVS related threads. I forgot how much SVS cares about their customers and how they frequently visit the forums where they offer free support.

    "We will always respect opinions of other members, even if we do not share a particular opinion ourselves. We will not verbally attack other members in a personal way, but instead try to contribute to the common knowledge about, and understanding of all applicable topics discussed."
     

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