Lusima31 wrote: "I found the same with my 4 AK subs, without the port plugs they sound very good so the sealed vs vented sub dilemma I have a feeling it depends on other things, maybe the dimensions (length and diameter) of the port in proportion to the enclosure? Not saying sealed is not good, just that I assumed for music sealed was always better and Duke prove otherwise."
Thank you Luis!
Arguably what matters most is the in-room frequency response. The ear is far more sensitive to frequency response than to time-domain response in the bass region, so the superior group delay behavior of a sealed sub is not a significant factor in sealed vs ported. (This is somewhat counter-intuitive, and is among the things I learned from Earl Geddes.)
Imo the correct "target response" for a subwoofer would take into account the effects of boundary reinforcement. "Typical" room gain from boundary reinforcement is about +3 dB per octave south of 100 Hz, according to a couple of different sources, but obviously it will vary with the specific acoustic conditions.
So let me try to explain what I believe to be the primary reason why sealed subs tend to sound better than vented subs: In general a sealed sub starts rolling off higher than a vented sub, but its rolloff is more gentle; whereas a vented sub is "flat" down to a lower frequency, then rolls off rapidly. Factor in room gain, and vented subs tend to have exaggerated low end above their inherent rapid rolloff, which tends to sound "boomy" and/or "slow"; on the other hand, room gain synergizes pretty well with the gentle rolloff of sealed subs. (This is all without factoring in EQ.)
The target response for my Swarm units in ported mode is the approximate inverse of room gain: They gently roll off at about 3 dB per octave from 80 Hz down to about 20 Hz, and then the rolloff accelerates rapidly below 20 Hz. Not saying this is the only valid approach, but it seems to work pretty well.
Luis again: "Just that Duke of AudioKinesis if I’m not mistaken was the 1st "commercially" to approach the array, the concept and theory comes from Geddes I believe?"
That’s correct. When Earl described his subwoofer concept to me, I immediately asked him if I could license it. He said no, that I could just use it. So the Swarm uses Earl’s ideas with his permission... but anyone else can use them as well, no permission required. He has trade secrets which he keeps to himself, but the distributed multi-sub concept is not among them.
Duke
Thank you Luis!
Arguably what matters most is the in-room frequency response. The ear is far more sensitive to frequency response than to time-domain response in the bass region, so the superior group delay behavior of a sealed sub is not a significant factor in sealed vs ported. (This is somewhat counter-intuitive, and is among the things I learned from Earl Geddes.)
Imo the correct "target response" for a subwoofer would take into account the effects of boundary reinforcement. "Typical" room gain from boundary reinforcement is about +3 dB per octave south of 100 Hz, according to a couple of different sources, but obviously it will vary with the specific acoustic conditions.
So let me try to explain what I believe to be the primary reason why sealed subs tend to sound better than vented subs: In general a sealed sub starts rolling off higher than a vented sub, but its rolloff is more gentle; whereas a vented sub is "flat" down to a lower frequency, then rolls off rapidly. Factor in room gain, and vented subs tend to have exaggerated low end above their inherent rapid rolloff, which tends to sound "boomy" and/or "slow"; on the other hand, room gain synergizes pretty well with the gentle rolloff of sealed subs. (This is all without factoring in EQ.)
The target response for my Swarm units in ported mode is the approximate inverse of room gain: They gently roll off at about 3 dB per octave from 80 Hz down to about 20 Hz, and then the rolloff accelerates rapidly below 20 Hz. Not saying this is the only valid approach, but it seems to work pretty well.
Luis again: "Just that Duke of AudioKinesis if I’m not mistaken was the 1st "commercially" to approach the array, the concept and theory comes from Geddes I believe?"
That’s correct. When Earl described his subwoofer concept to me, I immediately asked him if I could license it. He said no, that I could just use it. So the Swarm uses Earl’s ideas with his permission... but anyone else can use them as well, no permission required. He has trade secrets which he keeps to himself, but the distributed multi-sub concept is not among them.
Duke