I was looking at the 9500 today, and am a little confused about the design. It has a super tiny Vas (30L for the 12) so it requires a super small enclosure to keep a decent alignment. Because of this they have horrible efficiency (84 dB). It is so bad, they had to put on their main page a 2.83 volt rating to make it look good. :no: So because of this, you would expect a pretty low Fs right? Well it's Fs is 34.3 Hz. Ok, so I figure it's an SPL sub, and probably won't work great for SQ. A low efficiency and small box isnt' a good choice for that, but oh well. So then I looked at the BL. It's up at 18.73 which is pretty good. But when you look at the Qts, you see a .568 which is pretty high, showing it won't work well in a ported enclosure. In fact it's Qes is at .7. This means they had to use a super tight suspension (.0075mm/N Cms). Anyway, I'm confused. What application would this driver work best in?
BTW, this isn't supposed to be an attack on MTX, or their sub. I'm just trying to understand the point of the design. I was hoping that maybe some of you guys had some thoughts.
Well, the design from a mechanical/electrical/thermal standpoint looks great, simply. The design from an alignment standpoint, possibly more questionable... But I'd wager that it's just as you speak of... small enclosures are desirable, and always have been. Remember, powerhandling and thermal efficiency are apparantly two big goals of this sub... so who cares about power efficiency? Fs might be up there at least in part (if intentionally) as a goal to maximize efficiency in the 40-80hz range (Hoffman's Iron Law, compromising low frequency response to gain efficiency and small enclosure size). In terms of Hoffman's Iron Law... My guess is their #1 goal was Small Enclosure Size. They traded off a good deal of Efficiency by design apparantly... so they sacrificed a bit of Low Frequency Extension to gain back a little of that Efficiency, albeit in the 40-80hz range. How's that for a guess on a sub that I've never modeled up or seen a plot on? :lol: I'm only making these statements based on what you've said here, btw... and what I know of the sub's construction (which looks very impressive, if not sexy). B)
Thanks Chris. I guess that makes sense. I just noticed, I was wrong with the Vas. It is low, but not as low as I was thinking. But I should say that I haven't modeled it up either............till now. Here's a link to the data sheet on the single voice coil 12. I am surprised that WinISD (that's all I have at home) shows a 2 cubic foot enclosure for a .71 alignment. Hmmmm, now I'm totally confused.
