SVS Subsonic Filter On Powered Models

Discussion in 'Archived Threads 2001-2004' started by James Edward, Aug 8, 2001.

  1. James Edward

    James Edward Supporting Actor

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    Does the subsonic filter on the powered models make it less likely that the driver would bottom out on very low frequency material?
     
  2. Tom Vodhanel

    Tom Vodhanel Cinematographer

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    Yes,less likely...but if you try to bottom it(Like Toy Story 2 at full reference in a 9000 cu-ft room)...you probably will.
    The CS series can always be combined with subsonic filters in the $60(basic filter only unit)-$350(rane pe17/sysmetrix 551)if there's going to be a lot of extremely low bass tossed it's way.
    TV
     
  3. Jack Gilvey

    Jack Gilvey Producer

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    One of the virtues of the SVS models is that they do not employ limiters. While these do prevent bottoming, they severely degrade performance. This is one reason why SVS, and DIY stuff, so handily outperforms just about anything out there. And, while a subsonic filter certainly helps with this, by getting rid of stuff which you aren't going to hear anyway,there's still a point where the driver will reach it's limits.
    Tom, what's the corner frequency of the bass boost/subsonic filter in the PC series? Is the filter disengaged when the boost is set to "0"? It's a very flexible arrangement.
    [Edited last by Jack Gilvey on August 08, 2001 at 10:13 AM]
     
  4. James Edward

    James Edward Supporting Actor

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    This all sounds encouraging. The reason for my question is this: I'll be visiting a friend in N.C., and I'm trying to have him replace his Velo CT-100 with the 20-39PC or 25-31PC.
    His room is about 18x20 with a vaulted ceiling. He loves his Home Theater that I set up, but tends to get very 'exuberant' at times, and I'm afraid that after I leave, he'll destroy the driver. Since the Ct-100 is limited(pretty sure on this), I figure he can't destroy it as easily. I have to do the setup, calibration, and listening tests in three days, and try and get a feel for whether or not he'll fry things.
    I do feel that the 20-39PC is quite a step up from the CT-100, and maybe I'm concerned over nothing.
     
  5. Steve_D

    Steve_D Second Unit

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    And if you are using an ART 351 on a 16-46, or a 20-39 for that matter, where do you set it (the low filter)? 15 HZ? 10 HZ? 20 HZ?
    -----------------
    http://www.sdiver.org
    [Edited last by Steve_D on August 08, 2001 at 11:06 AM]
     
  6. James Edward

    James Edward Supporting Actor

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    He hasn't really stated one. He relies on me for advice- so if I make the case for the 20-39PC, he'll probably go for the 779.00. If that price is over the top, I may give him an early birthday gift and make up the difference. His wife does not care (within reason) what he spends, and actively encourages him to do so. Yes, she has two sisters.
    The 'other one' I mentioned in the previous thread has a backlog of at least two weeks, and I'll be there by the 20th, so it's SVS or nothing for now. I guarantee he won't buy without me there. He just does not trust himself to set everything up correctly, though I'm sure he can do it. it's just the way he is...
     
  7. Kevin Peak

    Kevin Peak Agent

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    So do subsonic filters roll off towards higher frequencies?
    If so, then is 20hz a pretty much sweet spot number for the 20-39pc since it is tuned to ~19-20hz?
    ------------------
    Thanks,
    kevp
     
  8. Andrew Beacom

    Andrew Beacom Supporting Actor

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    So do the PC series have actual sub-sonic filters? If so can they be bypassed? I'm a bit confused that people say SVS's are not limited like most commercial subs but now we are saying the PC series has a filter?
     
  9. Jack Gilvey

    Jack Gilvey Producer

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    quote: So do the PC series have actual sub-sonic filters? If so can they be bypassed?[/quote]
    If you look at the website, it lists a subsonic filter for the amp. Usually, the bass-boost and subsonic filter are the same circuit, typically a second-order high pass of a certain corner frequency and "Q", ideally "tuned" to the Fb of the sub. If this is the case, it can apparently be switched out.
    quote: I'm a bit confused that people say SVS's are not limited like most commercial subs but now we are saying the PC series has a filter?[/quote]
    I've seen this confused a bit lately. A limiter is something completely different. A limiter limits output when sensing the onset of distortion, or at a certain preset level, and some clamp down pretty hard. A subsonic filter merely removes some of the really low garbage well below the tuning of the sub which wouldn't be heard, but could tend to cause overexcursion and bottoming. In this sense, a filter actually increases output in the woofer's passband.
    http://www.hometheaterforum.com/uub/...ML/041906.html
    [Edited last by Jack Gilvey on August 08, 2001 at 12:36 PM]
     

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