vl3rd Posted January 12, 2005 Share Posted January 12, 2005 What is the difference between a sealed subwoofer and a ported one? Ported subwoofers have better extension right? What exactly is extension? Quote Link to comment Share on other sites More sharing options...
prodj101 Posted January 12, 2005 Share Posted January 12, 2005 Sealed and ported woofers have different extension types, not so much better or worse. Sealed woofers typically have a more gradual roll off, so if it's rated to 30 hz, it will gradually become softer from then on. Ported subwoofers typically have a sharp roll off, so from after 30 hz you'd get very little performance. Sealed subwoofers will also typically be more clean sounding, but it is very posssible to have a ported subwoofer that will perform comporably, you'll just have to spend a little more. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted January 12, 2005 Share Posted January 12, 2005 Extension is how low (Hz) a sub will go. The smaller the # (30, 28Hz, etc) the lower the sub will play. Basically how far down the spectrum it will "extend". Output on the other hand is how loud (dB) it will go. Carl Quote Link to comment Share on other sites More sharing options...
gcoker Posted January 12, 2005 Share Posted January 12, 2005 I cannot completly say on eis better then the other because it's hard to compare between manufactures. However, sealed subs a cleaner then ported subs. Quote Link to comment Share on other sites More sharing options...
DrWho Posted January 12, 2005 Share Posted January 12, 2005 It's interesting how people claim sealed subs are "cleaner" yet ported systems exhibit far less cone movement than sealed systems... Quote Link to comment Share on other sites More sharing options...
Olorin Posted January 12, 2005 Share Posted January 12, 2005 . . . implying that cone movement might not be the indicator of "cleanliness" that you seem to think it is . . . Quote Link to comment Share on other sites More sharing options...
meuge Posted January 12, 2005 Share Posted January 12, 2005 Every sealed sub I've heard has been cleaner than any ported sub I heard. However, I've seen ported subs from $200 to $800, but sealed subs from $900 to $1500 Quote Link to comment Share on other sites More sharing options...
TBrennan Posted January 12, 2005 Share Posted January 12, 2005 There can be no doubt that for a given cone size and f3 that vented designs have less excursion and therefore have lower distortion. People that are sensitive to spurious tones may well like vented better than sealed and say vented is cleaner. However for a given cone size and f3 a sealed box, with it's slower rolloff, will often exhibit better damping--putting on the brakes so to speak. People sensitive to this may well like sealed better and say sealed is cleaner. So what it boils down to is preference. Nobody can say which is better, the most one can reasonably say is which one prefers. Note too that both sealed and vented can be designed with various degrees of damping. An optimally damped vented design will have better damping than a sealed design with a high system "Q". Indeed, it's easy enough to design a flabby, boomy sealed design. Think of the BBC LS3-5A. Quote Link to comment Share on other sites More sharing options...
TheEAR Posted January 12, 2005 Share Posted January 12, 2005 ---------------- On 1/12/2005 6:14:28 PM meuge wrote: Every sealed sub I've heard has been cleaner than any ported sub I heard. However, I've seen ported subs from $200 to $800, but sealed subs from $900 to $1500 ---------------- Ported are not any less clean if you compare two competent well executed designs. Ported more often will reach deeper with power(port tuning)and fall very fast below.Sealed will be capable of deeper extension but the rolloff starts early and slowly continues with freq. going down. Small sealed subs can reach very deep,small vented do not(porting would be unpractical,save for mass loaded PR's).Sunfire,Paradigm's Seismic subs(and a few others)are examples,Sunfire being the best example of a PR in a tiny package well done. Its more practical and easy to design a sealed sub than a well optimised unit using a PR(or multiples). Quote Link to comment Share on other sites More sharing options...
DrWho Posted January 12, 2005 Share Posted January 12, 2005 ---------------- On 1/12/2005 6:07:14 PM Olorin wrote: . . . implying that cone movement might not be the indicator of "cleanliness" that you seem to think it is . . . ---------------- Well I wasn't trying to imply that, but rather I was intending to point out the increased cone movement which means more frequency modulation distortion (doppler effect). I find it ironic that horns are praised for lowering FMD while subs don't recieve that same hardcore praise (even on this forum). I firmly believe that for the same driver and cabinet size that a properly implemented ported cabinet is the better bang for the buck. If you feel otherwise, then by all means plug your ports and A/B the difference. Quote Link to comment Share on other sites More sharing options...
InnovaZero Posted January 12, 2005 Share Posted January 12, 2005 I firmly believe that for the same driver and cabinet size that a properly implemented ported cabinet is the better bang for the buck. If you feel otherwise, then by all means plug your ports and A/B the difference. ---------------- I agree, I like my increased volume down low that you get with a proper ported system. By the way, anyone know a good program that I can use to help me with my car subs. I know for a fact that the ports are wrong in the sized boxes given. I built the box, and it just seems like something is wrong down low (like 25-30hz area) Quote Link to comment Share on other sites More sharing options...
DrWho Posted January 13, 2005 Share Posted January 13, 2005 http://www.linearteam.dk/default.aspx?pageid=winisdpro The best part is that it's free Quote Link to comment Share on other sites More sharing options...
johnyholiday Posted January 13, 2005 Share Posted January 13, 2005 an were does a stuffed port fall in all this FMD Quote Link to comment Share on other sites More sharing options...
InnovaZero Posted January 13, 2005 Share Posted January 13, 2005 ---------------- On 1/13/2005 1:53:08 AM DrWho wrote: http://www.linearteam.dk/default.aspx?pageid=winisdpro The best part is that it's free ---------------- Awesome, thanks! Quote Link to comment Share on other sites More sharing options...
formica Posted January 13, 2005 Share Posted January 13, 2005 ---------------- On 1/12/2005 8:10:40 PM TheEAR wrote: Ported more often will reach deeper with power (port tuning) and fall very fast below. Sealed will be capable of deeper extension but the rolloff starts early and slowly continues with freq. going down. ---------------- Yes, but just to avoid confusion about which will produce useable lower output... I think that needs a little clarification. A ported sub will roll-off at 24db/octave while a sealed sub will roll-off at (about) 12db/octave. The catch is the sealed sub can easily begin to roll off a full octave higher (same driver in the same sized box) . This means the sealed sub will already be at f10 (-10db is often referred to lowest useable output) even before the ported system begins to drop. Note that this is only theoretical. Obviously a subwoofer design probably wouldn't use the same driver... and would apply more EQ to the sealed unit to help compensate. What does that mean in layman terms? The ported system will play lower than a sealed system without any special tricks. Later... Rob Quote Link to comment Share on other sites More sharing options...
TheEAR Posted January 13, 2005 Share Posted January 13, 2005 Any special tricks like...heavy EQ use.For example All compact sealed subs use some form of EQ to compensate. Quote Link to comment Share on other sites More sharing options...
CAS Posted January 14, 2005 Share Posted January 14, 2005 ---------------- On 1/13/2005 8:20:04 AM johnyholiday wrote: an were does a stuffed port fall in all this FMD ---------------- Stuffing a port is essentially removing it. Quote Link to comment Share on other sites More sharing options...
John Warren Posted January 20, 2005 Share Posted January 20, 2005 Ported subs, for the same cabinet size, have lower useful bass extension, higher efficiency and lower distortion than a sealed design. Lower distortion is a consequence of the port (usually a ducted port) which "takes over" for the woofer as the frequencies approach the enclosure tuning frequency which, in some designs, can be as low as the free air resonance of the driver (recall that the free air resonance defines the lower limit of the useful LF extension of the driver). The higher efficiency is a due to the fact that ported designs use drivers that have relatively high electrical damping (large motor structures) and high electrical damping translates into high electro-acoustic efficiency.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> Sealed subs use the air volume contained in the enclosure to provide system damping. Since the system damping in a sealed sub is defined by both the driver total damping AND the damping provided by the sealed air in the enclosure, the electrical component of damping is lower in a driver designed for a sealed system relative to the corresponding vented system. Which one's is better depends on what the design goal is. Loudspeaker systems, regardless of the design however, are constrained to an efficiency-bandwidth-size relationship. You can have any two and the third becomes "fixed". The vented and sealed subs are embodiments of this relationship. Quote Link to comment Share on other sites More sharing options...
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