On the hunt for a Polk sub

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Comments

  • Airplay355Airplay355 Posts: 4,019
    Are you creating a weird null from having 4 subs attached to two sources? 33hz is pretty high for a dramatic roll off and certainly others have gotten good output below that. At least down to 25hz http://forum.polkaudio.com/discussion/19484/psw505-frequency-response

    So if others are getting below 25 I'd bet it's probably not an enclosure issue and could be settings/setup.
  • FestYboyFestYboy Posts: 726
    I should clarify (I thought I stated earlier) that only the corner loaded sub was tested. No other subs were active at the time. I used a frequency generator that is capable of auto sweeping and has a resolution of .001Hz. manually sweeping below 33 hz caused a severe audible drop in dB. As mentioned earlier, I need to get my hands on a dB meter for actual numbers. At that point I'll plot it at several points in the room but I doubt this is a room node issue, as the area is 15x30 and half of that 30 opens into another area. It's more than large enough for a 1/4 wave at 20Hz.
  • Airplay355Airplay355 Posts: 4,019
    30x15 with a big opening to another room sounds like too much space for a single 505. I think that's what you're seeing more than anything else.
  • rooftop59rooftop59 Posts: 3,668
    Ed Mullen's room was pretty big as well. Look at his pre and post EQ measurements. There is a reason why almost ALL of the best subs (including HSU now, which used to avoid it) employ some kind of EQ or DSP built into the amp.

    As for how the SVS can get so much lower and louder with a 10-inch woofer (as opposed to the PSW's 12), besides DSP its pretty simple: WAY bigger enclosure, far superior woofer with a much bigger magnet and stouter spider, and a larger, lower-tuned port...it isn't rocket science. Take a really stout driver and put it in a massive box (that fits the driver's parameters of course) and then you don't even need that much power to move a lot of air and hit the really low notes...
    HT Rig:
    Yamaha RX-A1010; Parasound HCA-1000a; Arcam rDac; Mains: PSB Imagine Mini + MartinLogan Dynamo (original) sub; Center - Def Tech Procenter 1000; Heights, Center Surround - Klipsch KHC - 6 In-Ceiling; Surrounds - Monoprice in-ceiling; Sub - SVS PB10-ISD; Sony BDP-S390, FireTV gen 2

    Master Bedroom
    Marantz SR-5007; Audiosource Amp Two, Dynaudio Emit 10, NHT Super One CI, ACI Titan subwoofer, FireTV, Arcam rDac; Bryson BPD-1
  • FestYboyFestYboy Posts: 726
    ^ that's what I'm getting at... The box is all wrong. It may be ok for the 303, but then shoving a 12 in the same volume makes things go south quickly.

    Ok, so I'm gonna start a new thread documenting the baseline and mods done with results. Might take me a while to get to the meaty bits, but we'll all know for sure when I'm done weather or not they're worth keeping. Mind you, I'll be keeping the purchase price in mind, along with cost of mods to make the final determination.
  • rooftop59rooftop59 Posts: 3,668
    I agree with u that compromises on size were probably made to please the typical big box consumer, and that does limit performance, but the DRIVER is probably low quality with a small magnet and weak construction. Ur just only going to get so much out of it, cost was also a factor with those subs. I always remember John Atkinson of stereophile's measurements of the NHT super zero stating that the tweeter probably cost about one dollar considering the typical profit margin...

    But all that aside, if us have the time and energy and really need to save a few bucks over buying a new driver, good luck and I will be interested to see if you prove me wrong!
    HT Rig:
    Yamaha RX-A1010; Parasound HCA-1000a; Arcam rDac; Mains: PSB Imagine Mini + MartinLogan Dynamo (original) sub; Center - Def Tech Procenter 1000; Heights, Center Surround - Klipsch KHC - 6 In-Ceiling; Surrounds - Monoprice in-ceiling; Sub - SVS PB10-ISD; Sony BDP-S390, FireTV gen 2

    Master Bedroom
    Marantz SR-5007; Audiosource Amp Two, Dynaudio Emit 10, NHT Super One CI, ACI Titan subwoofer, FireTV, Arcam rDac; Bryson BPD-1
  • FestYboyFestYboy Posts: 726
    Challenge accepted :D
  • Airplay355Airplay355 Posts: 4,019
    :) :) Take lots of pics!
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