DevilDriver

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.

1. www.creativesound.ca (also sold through www.acoustic-visions.com) - Most notably the FR125 (a 4.5" full range design), WR125 (the original wide range version of the FR), and the SDX15 (great value; in terms of performance, falls between the Brahma and the Tumult but costs way less). Bob Reimer will also be offering a 7" driver similar to the Extremis (named the SDX7, I believe). 2. www.hempacoustics.com - I don't believe any of their products currently employ XBL^2 and it is quite possible there might not be any due to the fallout between Adire and Hemp, but they have long been publishing that they will be using XBL^2 in their products. Maybe the site needs a bit of an update. 3. www.diycable.com - Sold under the Exodus Audio brand. Kevin Haskins has had the XJ line (also sold through acoustic-visions) and intends to offer a 6.5" driver that should be better for 2 ways than the Extremis was, but with all of the low bass performance. There should also be some other subs in the not-too-distant future. 4. www.gr-research.com - A slightly smaller company I'm not as familiar with. They offer a 130X and 165X (130mm and 165mm in diameter with XBL^2 motors) at very good prices. John Krukte from Zaph Audio reviewed the 165X and seemed to find it acceptable. There have been many other companies that have offered XBL^2 at one point or another, including Ascendant Audio and Resonant Engineering, but the above list is of those manufacturers that I know for a fact use the design currently. Dan Wiggins has mentioned many times that there are other companies who utilize XBL^2 that he cannot speak of due to an NDA. How many companies that is, I'm not sure, but he has mentioned that you can go to Circuit City and pick up something with XBL^2 in it.

Take a look in the Technical section here and read the thread called "Hoffman's Iron Law"....I think you'll find it a little interesting. To answer the question directly, increasing enclosure size will generally Increase: 1. Efficiency 2. Excursion 3. Output 4. Low frequency extension Decrease: 1. Mechanical power handling 2. System Q (ie. decrease the damping effects of the enclosure on the sub) These are all good things, in my opinion.

It's another Death Cab For Cutie night.

Welcome. I own an S-10 with the Xtreme package and don't really care for it, but a good sport truck can be quite beautiful. I have considered a B2200 a few times but don't have the time or money to do what I'd like with it.

Beer usually motivates me to listen to music some more; I don't get much done when I'm having a few beers.

Shon is a good guy. Hopefully both sides can see some gains from this venture.

Can you expand on this at all? Are we looking at a full merger, or just offering assistance on RoE by answering emails and posting in their forum?

I know that Scott said before he would only be slightly changing the amount and location of copper in the motor; however, it would be nice if there was some review of the cone (notice there are quite a number out there that are Carbon Fiber that weren't officially "sold") and surround geometry to maybe push the slightly rough response on the Poly above 2-3 kHz. BTW, I believe AA is looking at the home audio market quite a bit, perhaps more so than the car audio market (that's Fi's world and I think Home Audio is Scott's first love). We'll see where things go.

Personally, I would say setting by ear is more than appropriate for most. A little clipping probably won't bother most (by which I mean won't be audible) and a lot of clipping will be quite noticeable, although not as much in a subwoofer. Obviously, you need to be more sensitive to clipping in some circumstances than others, but it's not the instant destroyer of worlds it is often touted as. For sheer accuracy, use an oscilloscope, then a DMM. For ease of use, use your ears. My opinion only.

They're coming...eventually. Word on the street is that the dealer network has not expressed that much interest in them so they're not a big concern right now.

I was getting up at 5AM every morning for about a week and half to do my brother's papers while he was in New Brunswick; don't want to do that again for about a century or so.

The shirts that were only available for a short period of time were ridiculously good looking. Wish I would have got my hands on a couple of those.

Yes. The pole chamfer is very different than a pole vent; in a sub like the BTL, you don't want a pole vent.

I believe Kevin from Low-Hz was offering their remaining 15" Mags for $375 shipped.