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If you're really worried about the scratches, you might be able to polish them with some emery cloth or some high-grit sandpaper, and then mask off the cone part with some painter's tape and spray the aluminum dustcap with some clear polyurethane lacquer or something similar to prevent further...

That's actually not a terrible amount of gain for a subwoofer amplifier. I'm not sure what the power output of yours is, but it's generally taken to be an axiom that the voltage input to an amplifier from the line-level signal is between 0.1V and 1V RMS. Given that you have a total gain of 46...

John, Best of luck with getting everything sorted out. I've had experience trying to get things done right and on schedule when coordinating efforts in north america and overseas, and I know it can be difficult. :) I've got one AV15 on preorder, and I don't personally care if it takes until...

Sorry to interject here, but I feel obliged to clarify a few things: First off - the rail voltages on the AVA250 should be much higher than 28V each. If they were indeed +/28V, (note that the power supply rails should be DC, or very close to it, so there's no need to specify RMS here) the...

I have an AV15 on the way - destined for a large (~6-8 cubic feet) vented cabinet.

That's a heck of a loaded question that's going to cause a ruckus if answered. ;)

Whew - I'm 100% for no logo. :) I'll be ordering mine without it. For what it's worth - logos are fine on the back plate, on a magnet boot, or anywhere rear of the mounting flange (along the side of the basket would be fine if it's the venezuela style basket, for example. However, I've...

I talked to John last night - he said that the AV12/15, like all TC drivers, use the spiders with the tinsel leads woven into them, like the MASS 2012, et al. If they're the same as the ones in the MASS, they follow more of a linear (parabolic kms curve) law than a true progresive spider (which...

If the output is highly distorted at that level, then it's highly likely you've driven your amplififier far into clipping. You're probably giving your sub closer to 300-350W RMS, and if there's audible nasty distortion, you're likely feeing your sub what amount to square waves. And no, I...

Jack's right - it has nothing to do with the driver. It's the sum of the resistance of the speaker wire and the output impedance of the amplifier. In most cases, especially with subwoofers, this will be in the realm of 0.1 ohm or so. If you really like, you can look up the output impedance in...

Well, if you're replacing the woofers, the tweeters, and the crossovers, you might as well do it right and replace the box as well. Which would mean of course, building your own speakers. There are many kits out there that are ideal for a first-timer, or if you're already fairly well-versed in...

Well, the strictest definition of bottoming (and the correct one, I believe), would be when the voice coil former contacts the back plate. My comment about bottoming in the earlier posts was not directed specifically at the MASS woofer though - it was a general statment with regards to the Kms...

While I'm not a driver engineer, I think that the fact that the surround is made of rubber isn't by itself a major factor. The particular surround profile Audiomobile chose may very well be limiting the excursion, but I have a feeling that the excursion limits would be very similar for foam and...

Sure, Jack. Most of the time, xmac and xmax are indeed one and the same, at least per DUMAX. When finding the final xmax for a driver, DUMAX takes the lower of xmax, and xsus. For most drivers, xsus is higher than xmag, so xmax just becomes equal to xmag. In this case, the audiomobile motors...

http://www.audiomobileinc.com/xfiles.htm Check them out - some interesting information in there. Not the least of which is that some of Audiomobile's motors have more xmag than Blueprint's mighty '03 series motor design - what's holding them back right now seems to tbe the suspension more...

I agree 100% that cost isn't much of an issue. Many of the ultra-low end car subwoofers use rubber surrounds - I have a couple of 10's I bought with rubber surrounds for $18cdn each! If the entire driver is $18cdn, including retail markup, shipping from overseas, and assembly costs, I can...

I don't see what's stopping anyone from using metallic spray paint, either solid, or textured, such as Hammerite, to make their own "aluminum" port flares. I'm willing to bet with a little sanding/finish work, you can get a heck of a convincing replica. - Rick

Rubber is more durable, but in pretty much every other aspect, foam is superior. 1) Foam is lighter, which reduces your moving mass and increases efficency. 2) Foam is much better at terminating the edge of the cone, to reduce the amplitude of any resonances that exist. 3) It's easier to make...

Adire's PR-15 is indeed probably the best 15" PR in existance right now. For cheaper PRs, with a little less claimed displacement, try www.stryke.com. Stryke's PRs are excellent. Lambda Acoustics (www.lambdacoustics.com) does produce some of their own as well - you might want to ask them if...

They "cheated" and listed the BL for the coils in series. They say that their Re is for the coils in series as well, but with a listed Re of 1.5 ohms, it's obvious they screwed that up - the Re is for the parallel coils, not series. Even so, by running the numbers myself, I only get a BL...

http://www.audiomobileinc.com/evo-rsubs.htm

One other thing to consider - cone breakup modes in a driver like that are likely to be down real close to the sub's usable bandwidth, and considering that 30" cones are hard to come by, I'm willing to bet that the technology and manufacturing for it aren't very mature. If you like high-Q...

Well, I ran the numbers and with that Qes, Fs, and Vas, (which are all from their website), I get an efficiency of 84.4dB/W/M. For a subwoofer that large, that's pitiful. Even if you assume that it can handle the 5000W RMS that they claim, you're still thermally limited to 121.4dB in a sealed...

Just an FYI... Blueprint has posted a message on their website (Link Removed - Rick

By the way, Mark: Link Removed There's your impedance graph. I love the fact that google caches everything. I wonder what kind of ungodly huge storage array they must have? - Rick

Guys.. for all who haven't read it yet. Link Removed I also remember reading, somewhere... out there... that the p-p xmax number given by Blueprint is simply (VC length - gap height)/2. I wish. If this were the case, the REAL xmax would end up being close to 40mm one way. Long magnetic gap...

Dan: first off, thanks for coming in and laying it down like it is. We all appreciate the help you give to the DIY community. I'm actually amazed that Dumax testing is that cheap. For the record, my posts on the PE board about not having Dumax testing due to cost issues was just speculation...

Tyler, you're in Mission, BC, right? National Concrete Accessories in Burnaby has lots. They're in the phone book. Look 'em up. :)