Thinking of a HSU VTF-15H Subwoofer

Discussion in 'Speakers' started by xxl2, Jun 17, 2014.

  1. FoxyMulder

    FoxyMulder 映画ファン

    Joined:
    Sep 14, 2009
    Messages:
    5,236
    Likes Received:
    1,613
    Location:
    Scotland
    Real Name:
    Malcolm
    That's good then, certainly from the specs it seems a very nice subwoofer.
     
  2. arjundeepakshriram

    arjundeepakshriram Stunt Coordinator

    Joined:
    Jun 11, 2013
    Messages:
    105
    Likes Received:
    1
    Does it have a motion feedback circuit like the D7 to limit distortion (accuracy is more important to me than quantity)?
     
  3. Tom Vodhanel

    Tom Vodhanel Cinematographer

    Joined:
    Sep 4, 1998
    Messages:
    2,215
    Likes Received:
    8
    Hsu doesn't use active feedback. But that is just one means to and end. I would bet the hsu would be preferred over a single D7 in most scenarios.

    Check post 106 here

    http://www.avsforum.com/forum/113-subwoofers-bass-transducers/1321789-anyone-heard-jamo-d6-d7-sub-thx-ultra-2-specs-how-would-compare-id-4.html

    Tom V.
    Power Sound Audio
     
  4. arjundeepakshriram

    arjundeepakshriram Stunt Coordinator

    Joined:
    Jun 11, 2013
    Messages:
    105
    Likes Received:
    1
  5. Sam Posten

    Sam Posten Moderator
    Moderator

    Joined:
    Oct 30, 1997
    Messages:
    20,839
    Likes Received:
    1,868
    Location:
    Aberdeen, MD & Navesink, NJ
    Real Name:
    Sam Posten
    /boggle
     
  6. arjundeepakshriram

    arjundeepakshriram Stunt Coordinator

    Joined:
    Jun 11, 2013
    Messages:
    105
    Likes Received:
    1
    what does that mean ??
     
  7. Tom Vodhanel

    Tom Vodhanel Cinematographer

    Joined:
    Sep 4, 1998
    Messages:
    2,215
    Likes Received:
    8
    First, it is important to remember that human hearing becomes increasingly insensitive to harmonic distortion as frequencies decrease.

    http://www.xlrtechs.com/dbkeele.com/PDF/Keele%20(2001-09%20AES%20%20Preprint)%20-%20Dev.%20Test%20Signals%20EIA-426-B.PDF



    1)servo = reduction in 2nd order harmonics. Other harmonics are not minimized.

    2)Harmonics manifest themselves in *even order* and *odd order*. 2nd, 4th, 6th, 8th(etc) are even order. 3rd, 5th, 7th, 9th(etc) are odd order.

    3)the higher (order) the harmonic the more audible it will be. So all things being equal 5% of a 9th harmonic will be more audible than 5% of a 2nd harmonic.

    4)Odd order harmonics tend to sound "wrong" to listeners. Even order harmonics----especially 2nd order then to sound like a natural extension of the fundamental.

    So what you have is the servo lowering the least offensive harmonic out of all of them. Nothing wrong with that, but to claim it "practically eliminates distortion" is just common marketing-speak.

    If you want to learn more visit http://www.data-bass.com/home and study the measurements for the various servo and non servo designs. You'll see patterns development eventually..:)

    None of this is to say the D7 isn't a good subwoofer of course. You are just comparing it to a *really* good subwoofer.


    Tom V.Power Sound Audio
     
    FoxyMulder likes this.
  8. arjundeepakshriram

    arjundeepakshriram Stunt Coordinator

    Joined:
    Jun 11, 2013
    Messages:
    105
    Likes Received:
    1
    Thanks Tom. I dont own a Hsu so I cant make any further objective judgements on the two..
     
  9. Sam Posten

    Sam Posten Moderator
    Moderator

    Joined:
    Oct 30, 1997
    Messages:
    20,839
    Likes Received:
    1,868
    Location:
    Aberdeen, MD & Navesink, NJ
    Real Name:
    Sam Posten
    That's what the /boggle meant. You were making magical assumptions based on marketing and not, ya know, actually hearing either sub.
     
  10. arjundeepakshriram

    arjundeepakshriram Stunt Coordinator

    Joined:
    Jun 11, 2013
    Messages:
    105
    Likes Received:
    1
    I own a D7. Not a Hsu..
     
  11. Tom Vodhanel

    Tom Vodhanel Cinematographer

    Joined:
    Sep 4, 1998
    Messages:
    2,215
    Likes Received:
    8
    Yeah, no worries. The D7 is Ultra THX certified. Even though you need two of them to meet the standard that is still fairly impressive. I'm sure it performs really well..:)Tom V.
    Power Sound Audio
     
  12. Sam Posten

    Sam Posten Moderator
    Moderator

    Joined:
    Oct 30, 1997
    Messages:
    20,839
    Likes Received:
    1,868
    Location:
    Aberdeen, MD & Navesink, NJ
    Real Name:
    Sam Posten
    OK so you own one of the two and want to pass judgement based on a very weak spec. It just boggles me that's all but happens all the time.
     
  13. arjundeepakshriram

    arjundeepakshriram Stunt Coordinator

    Joined:
    Jun 11, 2013
    Messages:
    105
    Likes Received:
    1
    One is enough in my very small room..
     
  14. arjundeepakshriram

    arjundeepakshriram Stunt Coordinator

    Joined:
    Jun 11, 2013
    Messages:
    105
    Likes Received:
    1
    Weak spec? I think not..
     
  15. arjundeepakshriram

    arjundeepakshriram Stunt Coordinator

    Joined:
    Jun 11, 2013
    Messages:
    105
    Likes Received:
    1
    400W RMS 20 HZ 109 DB SPL 700W PEAK
     
  16. schan1269

    schan1269 HTF Expert
    HW Reviewer

    Joined:
    Jul 4, 2012
    Messages:
    17,112
    Likes Received:
    898
    Location:
    Chicago-ish/NW Indiana
    Real Name:
    Sam
    Wait, I thought the D7(never seen one) was some Von Schweikert class subwoofer capable of cracking a concrete slab.For a good laugh...the spec page at Jamo(and clearly...the Audiovox penchant for truth looms large) says...20-200Hz +/- 3db
     
  17. Sam Posten

    Sam Posten Moderator
    Moderator

    Joined:
    Oct 30, 1997
    Messages:
    20,839
    Likes Received:
    1,868
    Location:
    Aberdeen, MD & Navesink, NJ
    Real Name:
    Sam Posten
    Sorry I stated that poorly. Not that specs of the box itself are weak but that "it virtually eliminates distortion". i.e. I'm assuming you are talking about it's THD which really isn't perceptibly different by humans tho I'm sure you can measure the differences with a scope.i.e. if you are picking subs by THD rating alone.... well, again attributing to magic and brand fandom rather than what your ears and wallet tell you =)
     
  18. Tom Vodhanel

    Tom Vodhanel Cinematographer

    Joined:
    Sep 4, 1998
    Messages:
    2,215
    Likes Received:
    8
    That's pretty much spot-on actually.

    http://www.soundandvision.com/content/jamo-d-7pex-speaker-system-ht-labs-measures


    Tom V. Power Sound Audio
     
  19. Tom Vodhanel

    Tom Vodhanel Cinematographer

    Joined:
    Sep 4, 1998
    Messages:
    2,215
    Likes Received:
    8
    I'm sure, it looks like a very powerful subwoofer. Just take THX Ultra specs and subtract 6 and you get worst case performance for the D7...which is still *really* good..:) Many AVS members were picking these up for $500 each I think(?). Incredible value.Tom V.
    Power Sound Audio
     
  20. Dave Upton

    Dave Upton Owner
    Owner

    Joined:
    May 16, 2012
    Messages:
    2,504
    Likes Received:
    276
    Location:
    Houston, TX
    Real Name:
    Dave Upton
    Tom is being humble in here, but his own products are a definite contender in this space. I've been to many subwoofer shoot outs, and at the last one I attended, the XV15 astonished everyone.
     

Share This Page