Impious

I just finished cutting the speaker rings for them about an hour ago So plan for this weekend is to start work on aiming them in the kicks.

Mine showed up early Sept, about 6 weeks ahead of schedule

Ideally you would make it a part of routine maintenance.

Certainly it's possible. But not everyone has the skill or desire to run an active setup. There are advantages and disadvantages to both active and passive. Active can provide worse results if not setup properly. The user has to determine which route best suits them based on their skill set, knowledge level and wants/needs. And really, going active isn't as cheap an option as it's made out to be after you factor in the cost of the necessary processing and additional amplifier channels, etc. With the added cost of processing, the additional channels required, and the drivers, an active setup would probably cost as much or more than the Bravox passive at full MSRP. But at these current blowout prices, even if someone were to buy them and toss the passives in the trash, they still only have $225 into all of the speakers and an average cost per driver of $56. That's pretty much in-line with the average active driver cost from the DIY market. Certainly it's possible to go cheaper, but results wouldn't be similar.

I guess for starters I really don't see the point behind any of these charts. Not to devalue stephan's work.....but com'on, it's basic math that anyone capable of successfully operating a computer should be able to figure out on their own in a matter of minutes with a calculator. It would probably take more time to pull up a chart than it would to just figure it out by hand. I mean seriously, would people really not be able to figure out the area of more than one circle, then compare that number to another, on their own without use of a chart? Can someone not look on the companies website for Sd, multiply it by the number of drivers they want to use, and do the same for a different sized driver and then compare the two? If someone can't manage to figure out this little bit of information on their own, then they should probably to revisit elementary school as that is where the basic skill sets required to accomplish this feat are acquired. My main issue with the use of that chart, aside from the laziness required to even need to use that chart, is that it is teaching people wrong information. It may be close enough for government work....but it's still wrong. And if it's teaching novices wrong information, then that will simply confuse them more. They'll be missing out on a basic but fundamental concept. Cone area is a simple driver parameter, that is apparently disturbingly misunderstood. It'll only make things worse if we start them off by teaching them wrong information. When you were in school, your educators hopefully didn't teach you that Pi was 3 since that's "close enough" (there have actually been laws passed throughout the years to attempt to change the "officially recognized" value of Pi in various states and localities....ignorance abound). Second, there can actually be a fairly significant difference in Sd between two same sized drivers. If we assume there's no difference by using incorrect values for determining area, then we are again missing important details. A 12W7 for example has approximately 1db worth of additional cone area than the SSA drivers listed above. That's breaching the realm of audibility, due simply to difference in cone area between two different "twelve inch" drivers that the original chart completely ignores. Last, most people interested in cone area are trying to determine potential output differences. Cone area alone is useless for this purpose. For that, you would need to know Vd not just Sd. In order to obtain an accurate Vd, you would need an accurate Sd and Xmax. Using inaccurate Sd will misrepresent potential output capabilities and differences. Again, making the information useless and teaching novices wrong information. Overall, I can't think of a single reason to suggest or recommend the use of wrong information.

Displacement actually needs to quadruple to maintain the same SPL level one octave lower. At one meter; SPL = 102.4dB + 20log(Xmax) + 20log(Sd) + 40log(Freq) or SPL = 102.4db + 20log(Vd) + 40log(Freq)

Here you go: Click Me Gives a brief history of the progress on loudspeaker design, and a more detailed description of the seminal work by Thiele & Small which set forth the set of parameters that define the properties of a loudspeaker, which are still used to this day.

That's how/why I got mine

I do not believe that AC unit will automatically condition the factory signal, which in a highly tuned OEM system would probably be better to have than one requiring manual adjustment, which to a novice can do more harm than good. But on the flip side, it would probably be the last processor he would need as well Assuming the expense is worth it to him in the first place, which I'm still not sure. And while it makes me feel a little lazy, the MS-8 can do more in 5 minutes than I could do in as many days. I really don't think it would be possible for a novice to do manually what the MS-8 can do in minutes. There's some monetary value in that, if the end result aligns with the goals of the user. JL's website only lists one DSP unit, then an add-on module which I really don't think he'd need.

I wouldn't seal the CF's. Pretty high Qts, really designed for operating IB. As Sean and I have said; It all depends on your goals. From what you've said, I'm still not sure With a $600 spread in price between something like the Cleansweep and MS-8, it really depends on how important imaging, etc is to you. Your range so far goes from talking about imaging, to just not wanting it to sound like crap. With the Cleansweep you'll get a conditioned factory signal but without any additional tuning. You'll probably still be able to get a subjectively "good" sounding stereo if certain considerations are taken into account when installing the speakers. Imaging may or may not be good depending on the install. But overall would definitely sound far from "crap", and what you lose in sound you'll make up for with a fatter wallet. With the MS-8 you get the whole deal. Signal condition, processing, and the ability to obtain great frequency response and imaging with a properly installed and setup system. As I said, it's not completely dummy-proof as there are certain things install/setup related that the MS-8 can't fix. But setting up the MS-8 is about as "Idiots Guide to Processing" as it can get. Plug in the mic, setup xover points/slopes, follow the on-screen prompts, turn your head a couple times, and it literally takes care of the rest for you while still giving you some flexibility in level settings and frequency response after it does it's thing. There are some helpful hints and tricks to using it to obtain optimal results, but really as far as processing goes it's the easiest product on the market to use with the best results. So, it's up to. $200 or $800. Good results or better results.

I was just getting ready to say the same thing. The formula they used is to find the area of a circle. Unfortunately you can't calculate cone area by finding the area of a fixed number (8, 10, 12, etc), since only a portion of the surround is considered "cone area" and two different subs will not necessarily have the same physical dimensions. The cone area (Sd) for a loudspeaker is accurately stated as: Sd = (Pi * D^2)/4 Where D is the diameter of the cone plus 1/3 of the surround at both ends of the measurement.* *Some manufacturers will use 1/2 of the surround instead of 1/3 for the measurement, which would make the Sd of the driver appear larger. So in reality, the Sd listed by two different manufacturers is not directly comparable unless you know the same method of measurement (1/3 or 1/2 of the surround) was used for each driver. For example, a 12" Fi BTL has an Sd of 480cm^2, which is 74.4in^2, which according to the chart is less than the Sd of a 10" driver. Work backwards to find the radius, sqrt(74.4/3.14) = 4.87in. Which means that the effective piston diameter of the driver is only ~9.75", not 12" as the chart would want you to use. And if the BTL had a larger or smaller surround, then it's Sd would decrease or increase, respectively. Which means that, unfortunately, those charts are pretty much useless

The MS-8 does accept high level inputs, it's designed to integrate with an OEM system. But with it's cost, it might not be the best solution depending on your goals. If you're just looking for something to do better than an LOC and condition the factory signal, the Cleansweep would perform that job superbly albeit with no other tuning capabilities. I guess the best question is; What are your goals for the system? Are you worried about frequency response, imaging, etc?

I wish I would have dumped money in 18 months to 2yrs ago when everything was bottom of the barrel pricing. So many stocks have doubled, quadrupled or better since then. Though I'm sure millions across America feel the same.....oh well, such is life. I don't have the patience to play the market, and I'm not sure why but it's never really interested me all that much either. Just a bunch of people trying to predict the future, making money by trading money and holding the country's nuts in a vice while they do it. That's not politics, just the way the economy works And although I don't play the market or really understand economics all that well, I have been paying much closer attention over the past 2 years to what's happening on a economic level, as the turbulence has greatly affected things at the workplace and my companies financial stability. I work for a subsidiary of AIG (won't be one for much longer though)......there for a while I thought I was going to be out of a job. Pretty crazy watching the stock drop from nearly $80/share to barely $1.

Moved to the manufacturer-specific forum.

Responded to your PM.

Did anywhere i say that it broke itself? NO and yes thats how it happened just stopped playing one day. And i never said it wasn't my fault, never said it was the company's fault. All i asked was what the procedure was for getting it fixed...... Thats all no more no less I think what he was saying is that "warranty" implies the issue is the result of a manufacturer's defect, which would be fixed for free by the manufacturer. You've owned your subwoofer for over six months, and it just now broke, which means the issue is not one of "warranty". So the question you should have asked should have been simply about repair and not about warranty work, as the two are different things. Regardless, have you tried emailing Fi? That would be the first thing to do. Did you ever have a chance to pull the sub out and see where it broke? That would be helpful to know, that way we can help you avoid from doing the same to the driver once it's fixed.

That's actually a pretty good price for the 8250 nowadays. Wish I would have bought one when SD had them for $300 Though I can't complain, I paid $135 for my 8240, used it for 8 months then turned around and sold it on fleabay for $280

It really depends on what you're looking for. It sounds like you want an actual audio processor for 3-way active (high, mid, sub), but most of the processors you're looking at don't really offer the features you want or will need. The Cleansweep doesn't do anything other than equalize the input signal. It does it's job well, flattening out the response of the incoming factory signal to undo any equalizing the factory system may have built in, but if you want to actually adjust the response of the system then it's not a good option as it doesn't offer any other capabilities to equalize the actual response of the system. It also doesn't offer the crossover features you need. The Re-Q(5) is even more limited than the Cleansweep, it doesn't equalize the input signal over the entire bandwidth, it just restores bass that may be attenuated by the factory system. So it, in essence, doesn't do anything other than increase bass output. It's basically the OEM-integration equivalent of an Epicenter. It also doesn't offer the crossover features you need. I don't know what product you were looking at from Audiocontrol, so I can't comment there. The RF 360.2 is the best of those you've mentioned, offering user-adjustable equalization and crossover capabilities. But.... ....if you could find another $200 in your budget (or look at previously owned products) I think the JBL MS-8 will do everything you are asking for and then some. It will condition the incoming factory signal to undo any factory processing, allows complete active crossover processing (8-channel output), then it also automatically tunes the audio system via binaural microphones, and post-processing still offers a user-adjustable 31 band EQ. It's $800 on Amazon, but used units have been going for under $600. The unit isn't dummy-proof. The quality of your installation and pre-tuning setup is going to determine the quality of the results. Another option is to find a used H701. It won't condition the incoming audio signal from the factory system, but it does offer all of the other tuning features you need for a quality active setup (crossover, EQ, time alignment, etc).

I will be adding the Differential Drive (aka Dual Gap) technology when I get a chance. Though it does allow for some flexiblity in terms of keeping BL linear, it shows more benefits in power handling by increasing surface area and air flow over the coil substantially. The W7 is a very simple method: it's a standard overhung design with some machining done in the pole piece. If the right amount is done in the right places, you can achieve surprisingly linear BL, but it becomes increasingly more challenging to achieve this at very high levels of excursion. Of course, I'm of the opinion that a speaker that takes 1kW with 30mm of Xmax is more than enough for my ears. I think your due for a write up on dual gap motors! JBL does have a white paper on the technology; http://www.jblpro.com/catalog/support/getfile.aspx?docid=1253&doctype=3

Damp Pro was the overall winner. Raammat was listed as being a good alternative "value" deadener.

The Kinetik KCIB12-35 is a sturdily built "intelligent" 12V battery charger with 2/10/20/35 Amp charge rates, alternator voltage check and battery recondition/desulfation functions. It features an easy to read 3-character display, four clearly marked push buttons for on/off and accessing the functions, and 4 LED indicators. It also features a heatsink that covers the majority of the front section, a built in cooling fan and the rear of the unit also functions as a storage compartment for the wires. Recondition According to the literature, as lead acid batteries discharge sulfate can build up on the plates, causing them to not fully accept a charge. Reconditioning (Desulfation) of the battery is accomplished by sending electrical impulses to the battery over a given period of time to break down this build up and allows the battery to better accept a charge and release energy more quickly. This seems to be a useful feature for not only under-hood batteries but also auxiliary batteries that may repeatedly be discharged. Very simple process. Just connect the charger to the battery and press the button! The large teeth and strong springs keep a tight clamp on the terminals. The downside is that this is a long procedure, however there's no way around this as it's simply a long process. The manual states it takes up to 24 hours. When using this mode on an HC1800 I had in the garage it seemed to take around 20 hours.....which while a long time, was shorter than anticipated. Charging The 2/10/20/35 amp charging allows you to select charging rate based on the size of the battery. The 2/10 are of course for smaller batteries, 20 for normal auto batteries, and the 35A rate is for large truck batteries or banks of batteries. It charges in three stages; Rapid Start Charge delivers maximum charging amperage (also allows for quick engine starting in as little as 2 minutes) Absorption Charge maintains the maximum possible charge at a constant voltage Top-off Charge voltage is automatically maintained and reduced to a predetermined level while current is adjusted to a safe battery charge level This process as well as the actual battery charge rate are monitored and adjusted automatically by the microprocessor. After desulfating the battery, I topped it off with a charge using the 20A setting. Again a very simple and surprisingly quick operation. Press the rate selector button until the desired rate of charge is displayed and let it do it's thing. The display will read "FUL" when the battery is fully charged. While I didn't watch it like a hawk, the process took less than a 4 hour interval. The charger appeared to stay nice and cool throughout the entire process. Alternator Check With the car running and charger connected, the manual asks you leave all accessories off and press the Alternator Check button, and then turn all accessories on a perform the same test. If the charger determines that the alternator is okay, the Alternator Good LED lights. Checked it on my car with the stock alt, and both times it indicated my alt was A-OK :thumbup: Overall, I would say this is a great charger. Useful features for the car audio crowd in the desulfator and higher 35A charge for battery banks, convenient storage and carrying handle, all built into a fairly compact case. It's extremely easy to use, stays cool while in use and quick charging times.

Somebody PM me and tell me about robotunderground. I always see their stuff for sale on ebay, never bought from them though. For when you're bored; http://www.diymobile...nderground.html (this one gets pretty entertaining, actually) http://www.diymobile...nderground.html

If it's 1.4ohm/coil, that would be a D2. He said each coil was .7 No, he asked if you could wire to 1ohm or if the only option was to wire to .7, which for a single sub would mean each coil is 1.4 Learn to read n00b

Adding mass lowers resonant frequency, stiffening a panel raises the resonant frequency. So if you add some mass and lower the Fs a little, but at the same time stiffen the panel some which raises the Fs a little, then the net result is virtually no change in Fs If you add mass without stiffening, then Fs will decrease. It takes a 4x increase in mass to decrease Fs by one octave. If you stiffen without adding mass, then Fs increases. As for results with weather stripping......Don has mentioned over the years as well as in this thread that the viscoelastic properties of the adhesive layer are going determine it's effectiveness as a vibration damper (in addition to some other things). My guess would be that a material designed for the construction industry is probably not going to utilize a compound ideally suited to vibration damping, and that's before we even discuss differences in the other important factors to CLD performance. But Don could go into much more detail. Great thread Don!! Sound deadening is one of the areas in this hobby that needs a lot more accurate information being presented and a lot less voodoo and mysticism about what works and why. Glad it was you who stepped up to fill that role extremely well for the past few years.

If it's 1.4ohm/coil, that would be a D2.