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Q about SVS PB2+ and setup

Discussion in 'Speakers & Subwoofers' started by Joe Szott, Mar 4, 2005.

  1. Joe Szott

    Joe Szott Screenwriter

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    I recently picked up an SVS PB2+ locally for a great price and hooked it up last night. I previously had a 20-39 PC+ setup in the corner, now the PB2+ is in the same place.

    This new PB2+ definitely has plenty of power and is LOUD, but so far I haven't really felt the "wall" of LFE that I've heard discribed elsewhere. Like where you feel the impact of the bass on your chest/body more than hear it in your ears. So I'm wondering if I might have this setup in an incorrect fashion. Here's how it's set up:

    One port blocked and the dial set to 20 Hz on back. Properly calibrated with Avia and crossover handled by the pre/pro. It's in a corner, probably has 3-4" of space behind it to the wall (for the ports). Also, I do run it a little hot but the volumes I listen to movies at isn't usually close to reference.

    Should I stick it flush against the wall, or give the ports more/less space? I will unblock the port and set it to 25 Hz, will that make a big difference? And lastly, maybe I just don't crank the volume up enough to get the full effect (do I need to approach ref level to get that kind of impact on deep LFE?)

    Thanks...
     
  2. Eric Ha

    Eric Ha Stunt Coordinator

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  3. Joe Szott

    Joe Szott Screenwriter

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    Pardon my ignorance, what's a peq? Is it a Phase Equalizer?

    I should mention, I only have access to the settings included on the back of the PB2+ and available in my Outlaw 950.
     
  4. MikeLi

    MikeLi Supporting Actor

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    The PB2+ or now its called the PB12+ is very location oriented and you need to move it to several locations and play some good action movies at reference or close to it and see what works best in your room. Mine wound up in the front left corner with the ports facing the wall about 1 1/2 feet out and one port plugged. Some have had better responses in the back of the room and even behind their couches or seating areas. If you have problems still call Ron or one of the guys at SVS. Even if your not the orig. owner they will help you get it to where it should be... Good luck
    Mike
     
  5. Eric Ha

    Eric Ha Stunt Coordinator

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    Parametric equalizer. You're familiar with a graphic eq, say 15 band with the sliders? Well with a PEQ you can adjust how far apart the bands are. With a sound pressure lever meter available at Radio Shack, some test tones and a PEQ, you can make all sub 100hz frequencies the same decibel level (flat resoponse).

    Go to SVS website and look under amps/eq's. The Rane PE-17 goes for $400 retail, but there's one on Ebay right now starting at $175 with no bids. Many others like the Behringer Feedback Destroyer. (Do a search for BFD)
     
  6. SethH

    SethH Cinematographer

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    Well, before you purchase a parametric EQ, you should try to graph your frequency response. I'd say it's pretty likely that you've got some nulls and peaks in there causing your problems, but you should graph to see how many there are and how bad they are. You may be able to get a sufficiently smooth curve by simply moving the sub to a different location (this is often done by first placing the sub at your seating location, then crawling around the room to see where it sounds best, then placing the sub there). If placement will not solve all your problems, then you should consider a parametric EQ such as the BFD.

    Also, how far below reference do you usually listen? If it's really far below, then you may be correct that you simply need to turn up the main volume to get the bass you're looking for.
     
  7. Joe Szott

    Joe Szott Screenwriter

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    I don't think I'm interested in picking up more equipment right now.

    What can I do with Avia DVD, an SPL meter, the PB2+ settings, and the Oultlaw 950 settings? Or rather, what order should I do the tests in and what do I look for? I ran the basic setup for all 5 speakers and then co-ordinated the sub SPL level using their tests, but I haven't done anything with the phase or changed the x-over settings from what they were with the 20-39 PC+. I would think those would likely be the same (my front LRC speakers haven't changed at all.)
     
  8. Joe Szott

    Joe Szott Screenwriter

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    Looks like from Eric's other post that the 'chest thumper' effect is in the 40 Hz range and not the deeper < 25Hz that I thought it was. Maybe I have a null in that range where I am sitting to listen.

    Good ideas Seth. I looked around a bit online and found some info that could be useful. Calculating for the size of my listening room (length = 22.5'), it seems the Room Mode Frequency would be just about dead on 25 Hz. So I would need to move the sub 11.3' from the corner to nullify that peak/null naturally. Unfortunately, I would then need to sit on top of the sub to watch TV, so I can't do that [​IMG] It also says I can move the couch (listening area) to try to address some of the nulls, to around 13.5' or 9' from the front wall. That might be doable, I think the couch is around there now.

    Otherwise, I guess I can run some Avia tests to fiddle with the phase a bit and see where that takes me. After all, I've only had this sub one day - and tweaking goes on forever. So other than the phase test, are there other one on Avia that I should run? Most of them are still greek to me.

    Thanks for all the help guys, appreciate it.
     
  9. steve nn

    steve nn Cinematographer

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    How do you feal the 20-39PC+ did for you in the same location Joe? Can you also give us a idea on your seating location, size room and openings. It would be nice if you had a Hz disk so we could see what your up against, but understandably not all have one.

    Edit> I see we posted at the same time.
     
  10. Eric Ha

    Eric Ha Stunt Coordinator

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    You might want to buy a test tone generator. You can enter any hz number from 1hz to 20000hz. Save 'em and burn 'em to cd. You can then do a test from 10hz to 80hz (in 1hz increments if desired) to plot your room response.
     
  11. Joe Szott

    Joe Szott Screenwriter

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    OK, I actually ran the sub a little less hot the other night and turned up the volume a bit. Put in the infamous Finding Nemo "Aquariaum Tap" scene, and cranked it to close to reference levels. I'm surprised my basement didn't suffer structural damage. I can't remember if I felt it in my chest or not, I was too freaked out by the noises in the walls and ceiling to notice.

    I'm going to run Eric's Hz test for fun, but I think this sub is fine now. Just needed to make some minor adjustments to bring down the mid level while retaining the lows.

    Thanks all...
     
  12. MikeLi

    MikeLi Supporting Actor

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    Now thats the HT feeling I am talking about!!!!
     

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