Speakers for leading edge, transients, speed and big sound

@larryi 

I hear you and I respect your sonic preferences, but how does low xmax translate into clean, and especially fast, bass? Especially when paired with a 15" paper cone?

I have a question about the JBL K2 S9900.

TMR just listed a pair, and I was looking into it to see if it’s something I should be interested in.

According to their datasheet, bass extends to... 33 Hz @ -10 dB? Really? Are they some kind of Cerwin-Vega tribute? Lots of folks talk about them like they’re the second coming though, so what am I missing?

So, guys, wait a second. The JBL K2s have big honkin 15" woofers mounted in big-arse bass reflex cabinets like it’s 1975, but they’ve got no bass. No bass. And a used pair is asking $18K. Am I reading this right? Can someone please describe what makes these speakers attractive?

Mike, that old Lansing Heritage paper is a very good and very approachable analysis of woofer design, with the caveat of course that it is limited to JBL products (naturally).

That other article is just one man’s opinionated screed. While I’ll be the last to dismiss the importance of a seamless and harmonious woofer-midrange integration (why so many planars fail), it isn’t the be-all and end-all and woofer quality does matter.

Since we’re on the subject of "fast" bass I just want t point out that it is generally understood as not just how fast a woofer can accelerate to, say, 30 Hz (a low bar for sure), but perhaps more importantly how fast it stops.

Hence the servo systems developed by Arnie Nudell and others that employed piezo accelerometers mounted on individual woofers to feed acceleration data to circuitry that controlled cone excursion in real time.

@larryi I completely get your point. I guess it’s like tubes and vinyl in a way; despite the mess of stunted frequency responses, low channel separation and massive distortion they sound delightful. I get that the same goes for woofers.

I strongly suspect that I couldn’t live happily with speakers that are down 6 dB at 55 Hz (JBL’s spec), but I respect those who see beyond that. An additional caveat is that I have not auditioned the K2, and I am open to the possibility that their sound somehow transcends their underwhelming spec. Wouldn’t be the first time such a thing happens 🙂

I'm kind of curious about the JBL M2 though. On paper, they look more like my cup of tea.

OP didn't say why he got rid of his, did he?

@phusis 

Thank you for your response. Your point about "hifi" bass and what it is / should be about is well taken. I do agree in principle, but I do like some slam too, and I'm not resigned to the two being mutually exclusive.

I suspect that listening tastes play a part. For instance, I listen to a lot of electronic music.

In any event, I was curious about this:

to those of us who are not bothered by larger size and that dare to look outside the accepted brands, hifi segment and high price dogma, not to mention embracing actively configured speakers, there are even better options out there - and cheaper to boot.

Wondering if you would care to elaborate on some specific options you have in mind? Thanks!