Underdamped response = missing sound quality?

[voodooless]

Just tune to 30Hz and the rest will follow.

Sort off. Indeed you can get away with some wacky alignments and some EQ. But indeed, the point here is that you can optimize for efficiency, max output and/or wide bandwidth, and largely ignore the exact response, because that is something you can fix later, the other things, not so much.

 

[Heinrich]

Sort off. Indeed you can get away with some wacky alignments and some EQ. But indeed, the point here is that you can optimize for efficiency, max output and/or wide bandwidth, and largely ignore the exact response, because that is something you can fix later, the other things, not so much.

Sure, sort of. I mean, the time of over-problematizing are long gone. Ports need to be big enough in order to avoid noises. Drones/passiv radiators can‘t be made arbitrarily heavy, which was my first concern when choosing a particular internal volume. The secondary aspects of the past, whilst frequency response being prime, are today‘s most relevant obstacles.

Maybe the original poster is going to figure it out, eventually.

 

[bachatero]

Seems I made it to the ‚ignore list‘. Fair enough. What „we“ are talking about in harmonious loops is the very foundation of bass alignment, well understood since the 60s of the last century (Thiele/Small), but tainted by myths and misconceptions fueled by the advertising. It appears less promising to me to pick one buzz word, or the other, and trying to figure it all out from there. Better to take a thorough read of the vast literature before to get a full picture of the landscape.

I don't know what the fuss is here. My Kali sub is far from a powerful sub, so it makes sense to hear distortion when plugging its port and compensating for that with EQ.

 

[Heinrich]

I don't know what the fuss is here. My Kali sub is far from a powerful sub, so it makes sense to hear distortion when plugging its port and compensating for that with EQ.

Most likely it is the language barrier, there is not the least of "fuss" (negative, exaggerated exitement, anger) around.

It is only so that you start your thread with a complaint targeting the KH150, now it is about the Kali (6.2 type, not 6.5, correct?). And all the in betweens. You suspect that "underdamped" makes bad sound, and you see that feature in some graph but you also claim, that you can't hear it. And finally you ask for a solution.

Maybe I got it all wrong. In either case, what you see in the graph and address as "underdamped" is group delay that is with full mathematical rigor unavoidable. Because the universe exsists only for so long .. really .. there IS a low frequency cut-off, and that makes the group delay all for its own. There would be "DC", no cut-off that is, possible only if there is no limit in time, and here the big bang chimes in.**

I'm NOT making fun of you. I told you that the logical (!) cross connections of time, frequency and all are well understood, even for loudspeakers. That big bang of a theory, Thiele/Small'S namely, took place in the 60s of the last century.

In practical terms the problem is considered solved, at least by me. I personally equalize, using two subs, for a reasonable flat in-room response at a variety of listening positions. That was it, because I take care of the excursion limits and power hunger of the devices. To design such a solution needs a littel bit of expertise, admitted, but only so little. The optimal starting point would be to engage the contemporary simulation tools, maybe under assistance by the DIY board here. To speculate about "underdamped" is not as promising, since we have that "Thiele/Small" complex around.

**You may "correct" for the group delay in bass, but that is only possible if you delay all the other frequencies as much; you essentially worsen the other, but not correct the group delay in the bass.

 

[levimax]

"that you first need to EQ the sealed system to the same FR as the ported system before seeing if there were any residual time domain changes."

While I understand wanting to match the FR response of the 2 systems in order to isolate any time domain differences, from a "sound quality/ preference" comparison perspective I am not sure this makes sense. I am not sure it is "settled science" but everything I have read about both psychoacoustics and subjective listening would indicate that a 2nd order roll off is generally preferred compared to a 4th order roll off. The way I see it 2nd order roll off is an inherent advantage of a sealed system just like LF extension is an inherent advantage of a ported system. In general (assuming not too much DSP mischief) sealed systems have better time domain performance, a 2nd order roll off (an advantage I think), are less efficient, have a higher F3, and have more distortion. Ported systems are more efficient, have a lower F3, have lower distortion, have worse time domain performance, and a 4th order roll off (disadvantage I think). Either ported or sealed systems can be used very effectively if their inherent advantages and disadvantages are taken into account and allowed for.

 

[Marin]

While I understand wanting to match the FR response of the 2 systems in order to isolate any time domain differences, from a "sound quality/ preference" comparison perspective I am not sure this makes sense. I am not sure it is "settled science" but everything I have read about both psychoacoustics and subjective listening would indicate that a 2nd order roll off is generally preferred compared to a 4th order roll off. The way I see it 2nd order roll off is an inherent advantage of a sealed system just like LF extension is an inherent advantage of a ported system. In general (assuming not too much DSP mischief) sealed systems have better time domain performance, a 2nd order roll off (an advantage I think), are less efficient, have a higher F3, and have more distortion. Ported systems are more efficient, have a lower F3, have lower distortion, have worse time domain performance, and a 4th order roll off (disadvantage I think). Either ported or sealed systems can be used very effectively if their inherent advantages and disadvantages are taken into account and allowed for.

Yes, but that order drop from the 4th order, happens at the low end of ported "resonance", maybe 30hz and lower if the peak of port is 45 top end,till then it's 6 order and that is why I love ported box design, also less distortion.

 

[Marin]

Yes, but that order drop from the 4th order, happens at the low end of ported "resonance", maybe 30hz and lower if the peak of port is 45 top end,till then it's 6 order and that is why I love ported box design, also less distortion.

Of course, if the bass port is set up correctly, some smaller speakers with a small drivers one to get some dynamics and tune peak port resonance at 100hz even 120 that is totally wrong...
About group bass delay, in stereo and even more so in multi-channel even more there are no chance you can hear it, with your room singing along and you hear cacophony of the room (reflections 1,2,3..), but the direct sound is dominant, that's why it's important to have a flat frequency response and good dispersion.