CS_Ultra calibration question

Discussion in 'Archived Threads 2001-2004' started by Shaun Thompson, Aug 15, 2002.

  1. Shaun Thompson

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    Finally bought a new house and got my whole HT system setup. Was wondering if anyone had any suggestions on the current setup of my sub. Right now it just feels a little anemic in some parts. Maybe I’m just too picky or maybe I need to get a Buttkicker and another CS_Ultra. I wouldn’t mind the last part but my wife would.
    Here’s the layout of my room.
    [​IMG]
    The sub is using a Samson 1000 amp and has been calibrated using Avia to about 95db. It’s chained from the pioneer elite vsx-26tx – black box – bfd – Samson amp. Crossover has been set at 80 hz.
    Here’s a graph of the sub before and after using the BFD with the following filters.
    [​IMG]
    Filter 1
    47 freq
    10/60 BW
    -8db
    Filter 2
    63 Freq
    6/60 BW
    +5db
    Any thoughts on what I can improve?
    Thanks for any input!
     
  2. Shaun Thompson

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    anyone... anyone... bueller...
     
  3. Tom Vodhanel

    Tom Vodhanel Cinematographer

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    Hi Shaun,


    A couple things come to mind,

    1)you do have the bottomend boosting 12-13dbs(20hz compared to 80hz)...is this by design?

    2)at 95dB, you have the Ultra about 13dB *hot*(the RS SPL meter rolls off about 3dB with the typical subwoofer calibration tone). This is OK with low to moderate levels....but if you pop in a DVD like LOTR and push the volume within 12-18dBs of *reference* level you'll really be pushing the operating limits of the single Ultra. So be CAREFUL when calibrated this hot!

    3)it appears as if you are measuring >110dB under 25hz during your sweep tests? Again, be CAREFUL. Believe me, if you fry a voice coil doing these sorts of tests...you don't even want to know what a replacement driver costs. FR sweeps are typically done at 85-90dB levels max.

    Could you give me some examples of the source material that seems a little weak to you? Thanks.

    TV
     
  4. Shaun Thompson

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    1. Actually I was a little surprised at that reading myself. I calibrated my speakers using the Avia cd at reference level - 85 db - and then set the sub to about 95+-. For the sweep test I used the Stryke zone cd.

    2. I've been extremely careful with this sub and actually I've pushed the amp knob back a few clicks just to be sure afterwards. Just doesn't seem to be hitting me like it should.

    Here are a few scenes that I've played that just don't seem to live up to my expectations

    1. Matrix - helicopter explosion - just doesn't to have any impact like others have described. The wooshing of the blades beforehand seems to have more of an impact.

    2. LOTR - I've listened to this DVD at a friends house on a high end model Klipsh sub and it seemed to have more impact on his sub. I know several factors may be involved along with the Klipsh being a little boomy but still it had my body shaking and I haven't felt that effect yet with the Ultra.

    Dumb question and one I hope I don't experience but what will I experience before I fry a voice coil. Any warning signs?
     
  5. Steve Zimmerman

    Steve Zimmerman Second Unit

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  6. Shaun Thompson

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    The sub has been calibrated to be 10 db higher than the rest of my main speakers at refence level using Avia so at 1hz the main speakers are at 85db. I know that running the sub hot is taking a risk but like I said if I have it running at 85db with the rest of my main speakers the sub is polite and does not hit me like it should.

    So I guess my question is put out there again. I've calibrated and eq'd and I still don't feel like I'm getting what I should out of this sub. Do I get another cs_utlra, a buttkicker, or am I just setting expectations for this sub that aren't there or at least can't fullfil for the size of my room.

    Thanks
     
  7. Dustin B

    Dustin B Producer

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    Your room is enclosed? No openings to other rooms?
    A 2300ft^3 enclosed room isn't all that big (and you are less than 10ft from the sub). An Ultra 10dB above the other speakers should overwhelm them (keep in mind 10dB means the sub will roughly be percieved as twice as loud as your other speakers by you). Either something is wrong with your sub/setup or you are more of a bass head than Bob Sorel or Mike Strassburg combined :p)
    My Tempest sonosub should be pretty close in performance to a single Ultra. And not including everything my room is open to, I have 2500ft^3 (there is still a kitchen, hallway and entranceway that are open to this room). With my speakers at 75dB on Avia and my sub at 73-78 (meter swings this much during the tone) on Avia it shakes the whole house. I wouldn't want to even try 85dB speakers (amp couldn't handle this) and 95dB sub (don't think my sub could do this on most action movies).
    I think you'll have to get an email conversation going with Tom to make sure there are no problems with the sub/setup. Then if you want to play that loud I'd suggest 3 more Ultras and a couple bass shakers [​IMG]
     
  8. Shaun Thompson

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    Thanks for the info Dustin. I'll talk to Tom and see what we can figure out. Ever since I bought the Ultra it's been giving me this performance and with reading everyone's reviews I seem to be missing out. Not something I want to have with a fairly expensive purchase.
     
  9. Tom Vodhanel

    Tom Vodhanel Cinematographer

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    Hi Shaun,
    I don't have any hands-on with the BFD but I believe it has a few *memory* settings you can store to quickly compare one curve to another. So I would recommend storing the current curve,and then setting at least 2 other curves for comparison. I would try for a *flat* curve, and then a curve that is tilted so the upper bass is slightly higher than the 20-30hz area.
    Also be sure your receiver doesn't have any peak limiters/dynamic compression modes engaged.
    As Dustin said...a single Ultra will provide quite a bit of clean output in this size room...so I'm not sure if the problem is one of subwoofer potential yet.It might jsut be an issue of finding the EQ curve that suits your personal listening preferences the best.
    The Matrix xhopper stuff was mostly >30hz if memory serves.The *rsw* Klipsch subwoofers are monsters >30-35hz, but roll off
     
  10. Shaun Thompson

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    Hey just wanted to give an update on my svs ultra. After a little bit of calibration and equalizing on my subwoofer I really respect SVS – still have more to go on the calibration part. It’s nice and tight and not over flabby like some subwoofers are. A BFD does help to get to where you would like. Th only thing that I warn people is not to take the reviews that the subwoofer will tear your house apart but more that your sub will integrate with your existing speakers like it should – shake your chest and your couch when it needs it and shut up when it doesn’t. If you want a good example of a fast efficient sub you should watch the movie “ When we Were Soldiers”. Great flick for a most depresssing content.
     

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