Impious

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.

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.

Keep an eye out for a Rockford Fosgate RFX-8240. It's a rebadged Denon and can normally be found for $250 or so when they come back up for sale. I can't recall which Denon model it is off hand, but it was one of the better models and had an MSRP of $900-$1k. The RFX-8250 was a slightly "upgraded" model, but they are normally in the $500+ range now (MSRP was something like $1300). They were blown out by desertaudio on ebay as well as sounddomain a few years ago at ridiculous prices, and as a result still go pretty cheap (albeit not blowout cheap anymore) when they come up for sale. Neither are a Z1, but still quality Denon decks that have "Rockford" screened on the face.

The RCA knob is more than likely a simple attenuator. So all it can do is turn the volume "down", but can never turn it "up" past the original level being output from the headunit (that's assuming it doesn't offer any sort of bass boost circuitry...most of them don't). Without knowing what amp you have, I have no idea what the knob actually controls. If it's a remote gain control, then those are usually basically the same thing....an attenuator that can only turn the volume "down" but not "up". However, if it controls the bass boost or something of that sort, then you could be in trouble using it. If they are both just attenuators, then there's nothing really wrong with just leaving them both installed. It'd be a little redundant to leave them both in, but sometimes it's a bigger PITA to remove something from a system than it's worth due to having to rewire. If they are both just attenuators, then you can basically continue doing what you're doing, leave one all the way up and use the other one as the control.

It's basically a matter of relative source levels. Some headunits offer source level adjustment, others don't. With all of the things a CarPC can offer, I'm sure there's probably some sort of input loudness/volume control software that would be available or built into certain programs.

It won't

It would be helpful to know what you already know and what you don't. Or, what exactly it is you need to know. There can be entire books written on the specifics of enclosure design and the physics of how they work and why. And after all, this sounds like a business class not an engineering class. At some point even the business people say "go ask the engineers".

Yes, for gain setting ACV is correct. But I would try to find a way to verify the ACV readings of the electrical system. If they really are outside of the normal range (~1V), you may have a problem that needs fixed......so it might have been a lucky mistake.

You have the DMM on the wrong setting. Battery and your car's electrical system is DC voltage, you have the DMM set to ACV. Although I'm not sure why it's showing 30V AC, that's more than a bit out of the norm. Your alternator produces AC voltage which is then rectified into DC voltage. You may have an issue with your alternators rectifier? That or your DMM is freaking out. The rectifiers don't completely remove the AC ripple, so I wouldn't have been surprised if it had read a volt or two of AC.....but 30V has be a bit confused. I would imagine you would be having serious problems with the vehicle if the electronics were getting hit with 30V AC.

Sounds like a good alternative

All of the amplifiers are sufficient to power your subwoofers and of good build quality. If you want a little more versatility, the Sundown does offer 1ohm stability which neither of the other amplifiers offer, and a little more power output at that lower impedance. But for anything 2ohm or above, I'd just stick with the least expensive option. How do you know that? I just recently had to contact JBL's customer service, there were no deficiencies in the service they provided. What is your experience with the CS of Pioneer and JBL to determine the CS from Sundown is vastly superior? I picked up the phone, called JBL and had my issue resolved in under 10 minutes. Sundown on the other hand has explicitly stated they often can't reach the phones in time (a phone number is not even published on their website) so the best method to contact them is via email , which normally means you are waiting much longer than 10 minutes for a response. How is that "far better" than the service I received from JBL in under 10 minutes?