DevilDriver

Without even modelling things up, you can make pretty good guesses based on what most 12" drivers work best in. Expect .8-1.5 sealed and 1.8-2.5 ported, tuned 28-33 Hz. Something along those lines. As far as port size goes, go with 12-16 square inches per cubic foot, so if you do 2.5 cubes ported tuned to 30 Hz (a very good starting point), you should have at least 30 square inches of port area. I don't have the time to calculate port length from there, but it's pretty easy to do so.

I'm sure that will take you far, Jim.

Glad you're liking it. Imagine what will happen when you put them in a more suitable enclosure that won't limit output.

And you disappeared into a website that doesn't exist.

I sneak in my posts like I sneak in my engineers. How I stole you from RE, I'll never know.

If you must know the truth, I am the majority owner of Fi.

Get some pictures up ASAP. Glad you're digging it. About 30 minutes after I shipped mine, I regretted it. Maybe I'll get another again on Thursday....who knows? Any tracks worth mentioning in particular?

http://oink.cd/details.php?id=757378 http://oink.cd/details.php?id=838534 http://oink.cd/details.php?id=1324831 http://oink.cd/details.php?id=1324838 http://oink.cd/details.php?id=1266069 http://oink.cd/details.php?id=1056776 http://oink.cd/details.php?id=757190 The first two are an absolute must. Absolutely.

Sound that good, Scott?

An NDA is a Non-Disclosure Agreement. It's quite typical that an OEM agrees to not discuss any specifics of their agreement with their clients. As for what Circuit City brands have XBL^2, I couldn't tell you, and I'm not totally sure how factual that is. If you have a few thousand dollars, let's go down there together and we'll cut some motors open.

Haha. These are definitely considerations I had made, but I was hoping someone would surprise me with a cheap, viable, and attractive solution that no one had ever heard of. Dream a little dream.

Have you confirmed my invitation to OiNK that I sent you?

Excited to start learning Japanese.

From personal experience in a Blazer, you're probably better off firing towards the rear of the vehicle.

They say that if you teach a man to fish, he learns to feed himself. 12" Atlas Xmax = 18mm Cms = 0.395mm/N = 0.000395m/N Mms = 119g = 0.119kg g = 9.81m/s Sag = Cms * Mms * g Sag = 0.000395m/N * 0.119kg * 9.81m/s Sag = 0.000461m = .461mm % Sag = Sag/Xmax*100 % Sag = 2.56% On the topic of positioning, there are a couple reasons why firing to the rear hatch often works best. First, you are loading off of a boundary. Second, the pathlength from the pointsource to your ears becomes longer and the frequency at which the first null cancellations occurs at a lower frequency (all nulls are usually shifted lower in frequency). This usually leads to improved output. Downfiring provides a similar effect in respect to the former (boundary loading) and but often lacks the increased pathlength. However, downfiring does have an added advantage: the boundary you are loading off of is usually much more rigid, dense, and stores less energy. Each have their own advantages. What vehicle will this be in?

Nope, that should work just fine. I think you've drawn the correlation well: the sonic characteristics (including the "tightness" you mentioned) are largely controlled by the enclosure. You're going down the right path.

You can find a lot of textbooks online via various torrent sites, totally for free.

Driver sag is strictly a function of the suspension stiffness and the mass of the moving assembly. This is very intuitive: a stiffer suspension will decrease sag, while more mass will increase sag. How much sag is acceptable? This will vary from opinion to opinion, but usually no more than 10% of Xmax should be considered acceptable. Where: Sag = distance from rest that diaphragm sags (m) Cms = stiffness of suspension Mms = mass of moving assembly (g) g = the rate of acceleration of gravity, which is 9.81 m/s Sag = Cms * Mms *g If the value of Sag is less than 10% of your total Xmax, then it is fairly suitable for downfiring. The less sag, the better, in my opinion. Kind of an off-topic but interesting note as well: the concept of sag applies in virtually every direction, to a certain extent anyways. This is kind of hard to see with your eyes, but if you use a speaker in a sealed enclosure (particularly with a Qtc that would be considered underdamped) and play sinewaves through it over extended periods of time, you'll see the assembly slowly creep forward.

They'll work just fine in both. They have the linear stroke for good low frequency performance in a sealed enclosure and the electrical damping to achieve good output in a ported enclosure around resonance.

Depends what MK Brahma it is. MKI was not a 12 spoke, iirc. And just to clarify, I believe the original poster is asking if he can use his 12" basket from a Brahma, his BL motor from his 10" sub, and get a 12" recone kit from Fi.

If I may add something for a moment.... If you go the powered subwoofer route (which is simply a great idea), maybe add an onboard EQ system or something similar. Kevin Haskins of DIYCable/Exodus Audio has an OEM solution in place at very affordable rates that is all analog. Here's a quote from him that I still have: edit: This is also something that can be used on a full range design as well.

Just over an hour till I'm out of here. I have a couple of cases of beer that will be in trouble tonight. What's everyone else doing?

Going to see it tonight. I love everything Seth Rogen has ever done.