Ray Garrison Posted October 1, 2001 Share Posted October 1, 2001 again with the disclaimer that this is only a layperson's perspective and I am by no means an engineer... Plugging the port on a powered subwoofer will typically (a) reduce the sensitivity of the system, which will both reduce the maximum output level (particularly at and below the port resonant frequency, probably in the 45-60 cycle area with the KSW-12) and produce less output at the same volume setting compared to not plugging the port, ( somewhat extend the lowest bass response by reducing the rolloff rate below that port resonant frequency, © reduce the system "Q" which means the frequency response peak that used to occur at the system's maximum output frequency (around 60 or so with this sub, I think???) will be lower and broader. These affects will be very audible, and may or may not be an improvement depending upon how the sub works with your other speakers and how it interacts with your room. I wound up plugging the ports on my CF4 because they sounded better in my room in my system that way. To plug the port, I found the things that worked best were: a tightly rolled up pair of socks; a cylindrical slug cut out of the closed cell foam that's used in packing electronics in the shipping box; or a tightly compressed wad of fiberglass insulation material (the pink Owens Corning type stuff). If you use the latter, be sure you where gloves when you roll it up and stick it in the port, or your hands will itch for a week. ------------------ Music is art Audio is engineering Quote Link to comment Share on other sites More sharing options...
Marvel Posted October 1, 2001 Share Posted October 1, 2001 A 30 ounce magnet for the sub. It is funny how things change. My old JBL 4311 Studio Monitors have a 25 ounce magnet on the tweeter. The woofer has a 6.5 pound magnet. How is the amp cooled? Some subs have amp compnents inside the cabinet, and actually use air flow through the port to help cool the amp. Marvel Quote Link to comment Share on other sites More sharing options...
toussi1 Posted October 1, 2001 Author Share Posted October 1, 2001 Yea no kidding. The amp has no cooling method other than it being open inside to the box. What would you guys think of replacing the subwoofer in there with an another subwoofer with huge Xmax: such as the Infinity Perfect or a kicker or Rockford fosgate? But, might as well just build a subwoofer and keep this sub too. later on of course. ------------------ http://www.autodirectsave.com Quote Link to comment Share on other sites More sharing options...
TheEAR Posted October 1, 2001 Share Posted October 1, 2001 Well Marvel my tiny Sunfire Junior sub has a magnet of over 5 lbs!And its a 9" cube(minus the drivers and sourrounds sticking out). The Sunfire Mark II and Signature have 14 lbs magnets and over 30 lbs of magnetic structure!10" and 12" woofers mind you! The Revel B15 has a 7.5 lbs magnet!And the Velodyne HGS series has 15 lbs magnets(magnetic structure about the double)! LOL Oh and the hated(because of price)Krell Master Reference has a Titanic magnetic structures of over 80lbs! Over 80 lbs this is MONSTER REFERENCE like Colin said! Remember the KSW12 even with its 30 oz magnet sounds good.The magnet is part of the sub,the magnet does not make a sub. And like Ray said,adding a 50lbs magnet may not give you much more quality.If money is no object then go for it,if not then compromises have to be done.Cut well and you diminish performance a bit and save alot. TheEAR(s) Now theears Quote Link to comment Share on other sites More sharing options...
t-man Posted October 2, 2001 Share Posted October 2, 2001 Thanks for the info. It's been interesting reading all this. As for the amp cooling, with that pound of new stuffing inside, how does the amp now breathe? If you cover the port, won't this make things even worse in this area? I hope your stuffing is flame retardant. T-man ------------------ KG 5.5 (mains) KG 2.2v (center) KLF-C7 (center in storage) KG 1 (rears) KSW-12 (sub) Denon AVR 681/1601 Toshiba SD-3109 DVD Kenwood LVD700 LD Sony CD changer Sony 27" Trinitron Sony PLX I Quote Link to comment Share on other sites More sharing options...
TheEAR Posted October 3, 2001 Share Posted October 3, 2001 T-man he should install sprinklers in the sub! LOL This would extinguish any minor fire in the Klipsch! TheEAR(s) Now theears Quote Link to comment Share on other sites More sharing options...
Marvel Posted October 4, 2001 Share Posted October 4, 2001 Maybe just have some of Handel's 'Water Music' on hand! I know there are a lot of variables in any speaker, and magnet size is just one. My son worked at a movie theater that had those JBL compression drivers that weighs in around 30lbs. They will empty your wallet quicker than anything. Marvel Quote Link to comment Share on other sites More sharing options...
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