OnYrMrk wrote:well I like to be the odd man out sometimes. How will this compare to say the Focal KX series of subs?
It's not an odd comparison by any means... but it doesn't make the best comparison either.
And by that, I mean flattering towards us in every way.
Fortunately, I've worked with Focal for years, in a retail shop.
The KX line I always thought to be a little odd...having a very high Fs, but not the low Qts [you'd expect them to be shooting for a vented alignment compatibility, given that high Fs and the limitation on sealed extension].
The Polyglass line (V2 series) IMO more represents the "traditional SQ purist sub".
Let's draw comparison to both, for the heck of it.
Them: Traditional overhung designs.
Ours: XBL^2 - no intermodulation distortion.
Them: KX uses multi-element magnet elements. V2 uses ferrite ring magnets.
Ours: Uses ferrite ring magnets.
Comment: This is mostly one of those "heritage" things - it looks cool, but came about necessity back in the day - large diameter ferrite ring magnets didn't exist - this was their solution for increasing magnetic flux.
Today, they look cool, but technically don't represent an advantage. Something Focal has been using for years, as a tie to their heritage.
Note their BL of about 16 that they can reach with a motor capable of about 11mm of excursion. Ours is about 15, that we can acheive with over 30mm of excursion. Polyglass V2 BL is under 10.
Them: Kevlar/foam composite on KX. Proprietary "Polyglass" cone on V2.
Ours: Carbon fiberglass/paper composite, or kevlar reenforced paper cone. I was sold on the carbon/paper cone until I got my hands on the kevlar paper cone and saw how unbelievably rigid it was as well. Undecided now, may come down to cosmetics - advantage carbon/paper cone with the woven appearance on the front side. Both are tremendously rigid and meet moving mass goals.
Comment: This is a subwoofer - primarily rigidity is the issue, although you want to meet moving mass goals as well with respect to the overall balance of the design. Resonances are a consideration, and a sharp flick of a fingernail seems to indicate superior damping properties of this paper cone compared to a V2 - not terribly surprising. I'd expect the KX to have good damping too, I don't have one handy at the moment - but largely in reality, a fancy cone isn't of significant benefit to a subwoofer.
Them: Inductance at 12.5uH for V2, at 4.3uH (impressively low for an overhung) for the KX. Likely explains much of the clarity.
Ours: Inductance at less than 1.5uH.
Them: Couldn't find any documentation on any implementation of copper shorting rings, or pole caps, or anything of the sort - I'm surprised since that's often a feature of a purist-SQ sub like these.
Ours: Includes a copper shorting ring, fitted into what otherwise is wasted space - the XBL^2 rebate groove - and lets it work without reducing efficiency.
Comment: Copper shorting ring smooths magnetic flux jumping the gap. It exists purely for sound quality purposes.
Them: Woven tinsel leads on KX, not on V2.
Ours: Fearing tinsel fatigue failures when woven in, but also fearing the possibility of 'tapping' due to our high excurision capabilities, we have ours tied down to a couple of the spider peaks.
Them: KX claims sealed and vented compatibility. V2 claims sealed.
Ours: This is the cool part. Middle of the road Qts, middle of the road EBP, pretty low Fs. Normally, this means you've compromised the sub to be "not really ideal" in either one.
We're using XBL^2 to boost performance in vented enclosures (not only is the sub inherently lower in distortion, but behaves "stronger" with respect to excursion levels acheived, than specs indicate ]Comment:[/b] Compromise?
Plus, it'll handle a ton more power than a purist SQ sub.
Bottom line is a question:
Would you rather run a purist SQ sub that's limiting in terms of output...
...or would you rather run a "new SQ" sub that exceeds it in all the traditional "SQ purist ways" of looking at performance, plus offers you the excursion to drive the thing to ludicrous levels of output?
