I still feel the OP's issues are his midbass, not his subs.
I normally reside in the car audio camp and subwoofers are par for the course.
The normal issue with "slow" sounding bass is the integration between the bass woofer and the mid-woofer. Why does it sound slow? Normally because the subwoofer will easily over power the midwoofer, the crossover is set at low volumes (normally picked 60-80Hz 'cause that's what everyone else does and it must be right) then the system is turned up and the user wants more bass, so the gain on the amp is whacked up and the crossover is left in the same place-this is where the issue lies.
If you look at my very crude illustration below (and ignore I can't draw in paint for toffee and have no scale to work with) you'll see that line A represents a subwoofer in a 3-way set up, crossed over at 40Hz. You'll also see that line B represents the same sub, crossed over at 40Hz too-but with the gain massively turned up so the actual crossover point doubles to 80Hz-hence the muddy sound.
IMO the OP is wasting time/money/effort trying to get his subs/new sub to play higher up the freq range-what he actually needs is mids that can play as loud as he wants in the 80-120Hz range-or to turn his subs down so his mids can keep up...
I normally reside in the car audio camp and subwoofers are par for the course.
The normal issue with "slow" sounding bass is the integration between the bass woofer and the mid-woofer. Why does it sound slow? Normally because the subwoofer will easily over power the midwoofer, the crossover is set at low volumes (normally picked 60-80Hz 'cause that's what everyone else does and it must be right) then the system is turned up and the user wants more bass, so the gain on the amp is whacked up and the crossover is left in the same place-this is where the issue lies.
If you look at my very crude illustration below (and ignore I can't draw in paint for toffee and have no scale to work with) you'll see that line A represents a subwoofer in a 3-way set up, crossed over at 40Hz. You'll also see that line B represents the same sub, crossed over at 40Hz too-but with the gain massively turned up so the actual crossover point doubles to 80Hz-hence the muddy sound.
IMO the OP is wasting time/money/effort trying to get his subs/new sub to play higher up the freq range-what he actually needs is mids that can play as loud as he wants in the 80-120Hz range-or to turn his subs down so his mids can keep up...
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Have you considered switching to a sealed subwoofer arrangement? May require different drivers, and probable crossover adjustment, but you could do a "quick + dirty" test by adequately blocking/stuffing the ports to see if things tighten up. If so, there's a clue as to what direction to take next with the sub-bass frequencies.
I would use different terminology to describe bass notes and characteristics, but to me "slow" is akin to "loose". If that's a correct assumption, sealed sub drivers (and possibly your full-range main speakers) are tighter (= "faster"). The main speakers may be contributing to an overlap area if they have reasonable LF output alone, so taming the port resonance frequency of the mains might help by reducing overlap with the sub. A lower x-over to the sub might also be worth exploring to the same end.
Regardless of whether that helps or not, consider:
I agree that there will still be issues with midbass drivers/crossover to fully resolve the issue, and I also agree that you shouldn't be raising the sub x-over point above perhaps 80 Hz. However you could consider adjusting the slope of the low-pass (sub)x-over to a steeper one. This may allow you to raise the x-over point a bit.
Hving said that, don't be afraid to use a lower x-over point; depending on the response of the full rangers, 80 Hz can be too high.
For reference: Low E on a bass guitar and Lowest note on a grand piano fundamental is 41 Hz. The second harmonic is 82, third 164. The bass "quality" is often related to second and third harmonic output, an area where the sub should not really be contributing much, if at all. Many recording techniques rely on manipulating the 2nd and 3rd harmonics to give the impression of strong bass output. This is really the job of the mains, not the sub.
I prefer the sub to be totally non-localized. In other words if you can tell where the sub is from audio cues, the x-over is too high or the slope is too gentle. Test for this by playing music through the sub only (no other speakers playing).
Also, I agree that the room nodes could be an issue. Again you could try the "quick + dirty" assessment method whereby you move the sub to your listening position, play music, and walk around the room (don't be afraid to get on your hands and knees either; it will be different and after all, most subs sit at floor level).
I like a moderately loud level for this test; it's easier to hear what you're listening for but in any case you want it at least loud enough to get to the flatter portion of your hearing (Fletcher-Munson curve).
At the point(s) where the sound is to your liking, move the sub to that location. You can choose a "second-best" or "third best" location if the best one is inconvenient; ie moving the sub there would be "in the way".
Finally, perhaps just turning the sub level down a bit might help. Try it for a few hours or days of listening; you might be surprised to learn you prefer it to the current level, even if your initial instincts are to have it set higher.
I would use different terminology to describe bass notes and characteristics, but to me "slow" is akin to "loose". If that's a correct assumption, sealed sub drivers (and possibly your full-range main speakers) are tighter (= "faster"). The main speakers may be contributing to an overlap area if they have reasonable LF output alone, so taming the port resonance frequency of the mains might help by reducing overlap with the sub. A lower x-over to the sub might also be worth exploring to the same end.
Regardless of whether that helps or not, consider:
I agree that there will still be issues with midbass drivers/crossover to fully resolve the issue, and I also agree that you shouldn't be raising the sub x-over point above perhaps 80 Hz. However you could consider adjusting the slope of the low-pass (sub)x-over to a steeper one. This may allow you to raise the x-over point a bit.
Hving said that, don't be afraid to use a lower x-over point; depending on the response of the full rangers, 80 Hz can be too high.
For reference: Low E on a bass guitar and Lowest note on a grand piano fundamental is 41 Hz. The second harmonic is 82, third 164. The bass "quality" is often related to second and third harmonic output, an area where the sub should not really be contributing much, if at all. Many recording techniques rely on manipulating the 2nd and 3rd harmonics to give the impression of strong bass output. This is really the job of the mains, not the sub.
I prefer the sub to be totally non-localized. In other words if you can tell where the sub is from audio cues, the x-over is too high or the slope is too gentle. Test for this by playing music through the sub only (no other speakers playing).
Also, I agree that the room nodes could be an issue. Again you could try the "quick + dirty" assessment method whereby you move the sub to your listening position, play music, and walk around the room (don't be afraid to get on your hands and knees either; it will be different and after all, most subs sit at floor level).
I like a moderately loud level for this test; it's easier to hear what you're listening for but in any case you want it at least loud enough to get to the flatter portion of your hearing (Fletcher-Munson curve).
At the point(s) where the sound is to your liking, move the sub to that location. You can choose a "second-best" or "third best" location if the best one is inconvenient; ie moving the sub there would be "in the way".
Finally, perhaps just turning the sub level down a bit might help. Try it for a few hours or days of listening; you might be surprised to learn you prefer it to the current level, even if your initial instincts are to have it set higher.
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Correction to my previous post (it's early)
3rd harmonic is at 3x fundamental or 123 Hz; 164 is the 4th.
You can come across music with "Low B" (5 string bass) @ 30.5 Hz w/A-440 tuning or drop-tuned E (reducing the tune of the E string on a 4-string bass) which is ideally the same as Low B but most 4-string bass guitars can't really do that well, so perhaps mid 30's.
3rd harmonic is at 3x fundamental or 123 Hz; 164 is the 4th.
You can come across music with "Low B" (5 string bass) @ 30.5 Hz w/A-440 tuning or drop-tuned E (reducing the tune of the E string on a 4-string bass) which is ideally the same as Low B but most 4-string bass guitars can't really do that well, so perhaps mid 30's.
Sorry to resurrect this thread but after a lot of experimenting I eventually found out what was wrong in my sub setup. I think my findings can help to clearify things for other people who has similar problems with their subs or want more punch from them.
Since my mids\bass is only 6.5" I wanted more bass to fill the large livingroom at louder music levels. So I turned to my subs to see if they could help out a little more
The problems that I encountered when turning the sub level up where as follows:
A massive room node in the 40Hz region.. I eventually I made 8 cm tall spikes for them to get rid of the floor coupling effect. That made a huge difference! The worst of the deep rumbling disappeared!
Afterwords I decided to stuff both subs heavily to make the cabs smaller internally to decrease efficiency in the low end. That way the room node would't be triggered as much as before. (The stuffing mod is reversable so it can be taken out if I move to another room).
Now the the subs sounded more articulate and less boomy.. (It gave the effect of increasing the Q factor).
But the subs still didn't blend perfectly at very high music levels, so I decided to add in -line filters to get even more tuning control. With the new filters added to the existing filters in the sub amp I now got 24db lowpass 120hz and a 24db higpass 70hz or so.. (The filters are tunable but unmarked, so I'm uncertain of the excact frequencies they work at.) That got rid of the hollow sound that came with the higher crossover point.
The end result is now a sound which is similar to a good 3 way speaker and plays plenty loud down to say 30hz or so. Because of the aggressive filters I can now turn the level way up on the sub amp without having the music getting too muddy Nirvana now plays with plenty of punch, and the subs still perform decent when playing movie effects. My next improvement would be to buy an DSP but so far I'm really happy with the new sound!
At last I would like to point out that my high xo point works so well since the subs are placed directly under my fronts..
I would like to thank everybody in this thread for helping me understand what's going on in the bass domain and the importance of equalizing subs to get the most out of them!
Since my mids\bass is only 6.5" I wanted more bass to fill the large livingroom at louder music levels. So I turned to my subs to see if they could help out a little more
The problems that I encountered when turning the sub level up where as follows:
A massive room node in the 40Hz region.. I eventually I made 8 cm tall spikes for them to get rid of the floor coupling effect. That made a huge difference! The worst of the deep rumbling disappeared!
Afterwords I decided to stuff both subs heavily to make the cabs smaller internally to decrease efficiency in the low end. That way the room node would't be triggered as much as before. (The stuffing mod is reversable so it can be taken out if I move to another room).
Now the the subs sounded more articulate and less boomy.. (It gave the effect of increasing the Q factor).
But the subs still didn't blend perfectly at very high music levels, so I decided to add in -line filters to get even more tuning control. With the new filters added to the existing filters in the sub amp I now got 24db lowpass 120hz and a 24db higpass 70hz or so.. (The filters are tunable but unmarked, so I'm uncertain of the excact frequencies they work at.) That got rid of the hollow sound that came with the higher crossover point.
The end result is now a sound which is similar to a good 3 way speaker and plays plenty loud down to say 30hz or so. Because of the aggressive filters I can now turn the level way up on the sub amp without having the music getting too muddy
Nirvana now plays with plenty of punch, and the subs still perform decent when playing movie effects. My next improvement would be to buy an DSP but so far I'm really happy with the new sound! At last I would like to point out that my high xo point works so well since the subs are placed directly under my fronts..
I would like to thank everybody in this thread for helping me understand what's going on in the bass domain and the importance of equalizing subs to get the most out of them!
Hi,(Impuls60) What did you finally settle on to get the 10 inch defined subwoofer sound quality you were after. Also I say your post in a class D versus class ab thread ,and you said you were using class D for your car audio. Is that for the midranges and tweeters.If so What was the brand of the class D amp you, and power you were using . I was looking to hopefully change out my alpine 3544 amplifiers for 600 watt class D amplifiers,but was scareed the class D would not deliver the sound quality at the very high volume listen. Tell me your experiences with high end car audio class D amp,and if they will sound equally as good as my oldschool class AB amps or even better than them. I like the alpine 3544 amp sound quality. It just heats up too quickly,Drastically shortening my listening experience. I want to listen to loud crystal clear music at high volumes,without having to shut down because the amps are getting too hot. Have you tested high power 600 + class D 2 channel amplifiers to know which one can deliver the 600 Rms power that I desire,and yet sound like or better than the class AB. This would be a life changer for me,since I immensely enjoy high fidelity ,high volume listening in the car,but never get to listen to it long enough. Please help me.Thanks
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