Impious

You can add SDS to that list That's because he's tried to fling his bullshit around here, and we didn't let that shit fly

log(1000/400)*10 = 3.9794dB However speakers aren't very efficient, and they have their limitations. To be a little more specific, that is the maximum theoretical difference. The actual difference in output will be less due to power compression, which means that the subwoofer (or any speaker) is not converting the same percentage of that additional power into acoustic output due to various reasons. I don't know the power handling limits of the RF sub or how it responds to that enclosure, but it's entirely possible that power compression would reduce the actual increase in output by 1db or more. As was mentioned, the amount of perceived difference depends on many different factors, including frequency. A ~4db difference in the bass would be noticeable but not dramatic. But that's before power compression, realistically the difference would be something less than ~4db. On top of that, you don't actually know how much power you were applying to the subwoofer. So it's all a moot point anyways.

You're asking an extremely vague question that would require an extremely long and detailed explanation. The short of it is that it sound is created by the movement of air. The more air you move, the louder the sound will be. With bass it's a little more difficult to fill a large listening space with sound than it is a smaller listening space, which means if you are in a large listening space (like your van) you generally need to move more air to have the same output as a smaller listening space (like a compact car). If you took a 12" subwoofer and put it in compact car & measured it's output and then put that 12" subwoofer in your van and measured the output again, the output when in the compact car would end up being louder. The amount of air a subwoofer can move is called it's displacement, and it's determined by the size of the cone and the amount of excursion the subwoofer is capable of. So a subwoofer with a larger diameter cone, like an 18", is going to move more air than a subwoofer with a smaller cone, which means more potential output (assuming excursion and listening space are equivalent). However, large diameter drivers generally require a larger enclosure volume than smaller speakers, so you need to have more room available for the enclosure with a larger diameter subwoofer. In your van you have the advantage of having enough airspace to allow you to properly fit a pair of large diameter subwoofers, which is good. On the down side, and you also have more listening space to deal with when trying to create bass. If your goal was to create loud bass, your best option would be to use large diameter subwoofers with decent amount of excursion to create more air movement inside your large listening space which will allow you the ability to create louder bass. That's Bass 101 in a nutshell. Obviously there is much more to it, but that's the very basics in layman's terms.

How much port area do you have? Looks on the smaller side in the pics.

yeah sad to see Jacob fuller promote a crappy product. Especially from a kid that trash talked sundown publicly. Jacob used to recommend Peel N Seal as an effective sound deadener. Just because he owns Sundown doesn't mean he knows or understands anything about sound deadener. The owner of AT has a history of dishonesty and demonstrated idiocy. Don't know why people are surprised when his product fails to perform any better than his character & behavior would indicate. I would never use nor recommend the product. I wasn't saying he knew anything about deadener but he has a long trail of lemmings that follow his every word and now he's promoting a shitty product. I know, I'm agreeing with you. My response was pointing out that Jacob obviously doesn't understand sound deadening, so don't follow his recommendations. It wasn't pointed at you but the lemmings that follow his every word. That said, the owner of AT doesn't understand sound deadener either......LOL. And he's an asshat on top of it. Sorry to hear the OP spent hard earned money and ended up with a substandard product....but it's no surprise, and glad to see the truth being told.

yeah sad to see Jacob fuller promote a crappy product. Especially from a kid that trash talked sundown publicly. Jacob used to recommend Peel N Seal as an effective sound deadener. Just because he owns Sundown doesn't mean he knows or understands anything about sound deadener. The owner of AT has a history of dishonesty and demonstrated idiocy. Don't know why people are surprised when his product fails to perform any better than his character & behavior would indicate. I would never use nor recommend the product.

Am I the only one who finds it hilarious that Facebook stock has been sucking goat nuts since it's IPO?

Because each individual subwoofer's coils are wired in series. So each subwoofer will be wired in series for 4ohm per subwoofer. The subwoofers are then wired in parallel to the amplifier resulting in 2ohm final load. This is actually the preferred method as opposed to wiring the subwoofers coils in parallel (1ohm per sub) and then wired in series to the amp for a 2ohm final load. holy crap.. So they way I have it is correct? 4 ohms each works out to 2 ohm final load. So each sub will see 1 ohm? so 2 subs will give me the 2 ohm load for strapping From your description it sounds like you have them wired properly. The subs don't "see" anything. They present the load to the amplifier. And yes, wiring the subwoofers in series-parallel results in a final 2ohm load at the amplifier(s). Series-parallel wiring is what is shown in the picture posted earlier. Generally speaking if you can avoid wiring two or more speakers/subwoofers in series with each other, you want to. Coils on the same subwoofer wiring in series is not an issue. But two different speakers should be avoided when possible. If strapping is causing part of your issues (confusion on how to wire them), you could always just NOT strap the amplifiers and wire one subwoofer per amplifier. In your situation there's no benefit to strapping other than having a "master" control, but it's a simple matter to match the amplifiers with a basic DMM and test tones and it makes the wiring less confusing.

Because each individual subwoofer's coils are wired in series. So each subwoofer will be wired in series for 4ohm per subwoofer. The subwoofers are then wired in parallel to the amplifier resulting in 2ohm final load. This is actually the preferred method as opposed to wiring the subwoofers coils in parallel (1ohm per sub) and then wired in series to the amp for a 2ohm final load.

Nobody here thinks you're tough. So just stop. Also, this isn't twitter. Use actual words when you type, please.

By the time you account for the enclosure material and driver displacement (assuming you will have the driver in the enclosure & not inverted) I don't see that airspace feasibly working. Honestly in a convertible I don't see a single 6.5" "subwoofer" having enough displacement to make the endeavor worthwhile. Even a single 8" driver is going to be a questionable improvement. IMO you need to find more space somewhere, maybe find somewhere you can run a larger diameter driver (i.e. a 12") infinite baffle so you don't have to worry about enclosure airspace, just enough room to fit the driver itself and a baffle?

Glad you're okay! Do as your mother told you and stop playing in the street

Next time wear socks please.

What is your budget? What are the available xover points/slopes on your HU? Where are they being mounted and how much room do you have available? Glad you decided against a supertweeter There is really very few applications where they make sense in an automobile despite the widespread use (read: misapplication) by SPL guys.

What are you looking at for xover point? 3800 Hz -- which I suppose isn't high per-se but not low either That's pretty high for a 6.5" driver. Beaming will be pretty well in affect at that point, which considering these are primarily mounted off-axis in a door I'd be a little worried about a hole in the midrange response. Have you measured the FR in a typical installation from the listening position yet?

Generally it's best to separate the enclosure into separate chambers for two reasons: First, that divider acts as a brace for the enclosure and helps strengthen the structure of the enclosure. Second, in the event one driver fails it protects the second driver a little more for subsequently being damaged. If one driver fails the 2nd driver would then "see" an enclosure twice the volume as intended which would increase the efficiency and could potentially result in the driver being overpowered if you are already running close to the limit. Other than that, there won't be any performance differences.

First, you have to wait more than 8 minutes for a reply. Second, what exactly is it you need or that you're trying to do? RCA jumper cable is a very vague term.

Good progress so far. I agree with both of Sean's points, although you said you have to cut some spacer rings still so I'm thinking you might be adding some more layers to the baffle?

I wasn't trying to insinuate you were generally unknowledgeable, rather this is not your area of expertise. It wasn't based on your posting status, but rather the questions you were asking. If you really want to pursue this, there are some general guidelines. Look at what most SPL guys have to give you some clues. Large enclosures with tons of port area generally arranged in a manor to minimize cabin space. So, first this should tell you that you would want to avoid a high vent mach. High vent mach/port velocity will lead to compression of the air in the port, which will cause large amounts of port noise and reduce the efficiency with which the air in the port can oscillate. So you want to use a port with large area to reduce port velocity, but on the other hand if you go too large the mass of the air in the port can become too much for the driver to effectively utilize. It's a balancing act. Second, you want to create a "path of least resistance" for the air in the port to more or less reduce drag on the air as it oscillates within the port. Also, port design/shape will have an affect on the turbulence within the port, which is one of the reasons many people use aeroports, flares, and 45's or PVC in the corners of their enclosures and ports. To reduce turbulence. As for the enclosure, generally you want the enclosure on the larger side. Larger enclosure = more efficient enclosure with a larger peak at tuning. Yes, you want increased cone excursion as more excursion equals more air movement. Load a driver in WinISD and compare the cone excursion graph of various enclosure sizes of the same tuning on the same power. You'll notice as the enclosure size increases the cone excursion increases as well. For tuning, you will want to tune higher. You'll gain peak output and better match the resonant frequency of your vehicle. You're not going to be doing hair tricks with a 30hz tone, especially with your setup. It will be more in the 40's and 50's. Tuning high will obviously cause your low frequency response to suffer, but that's the trade off. From there, it's all about experimentation and what works for your subwoofers in your vehicle. Those are just basic generalizations. I still believe you are searching for a unicorn here, you don't have the basic foundation upon which those types of systems are built. But if you want to spend a bunch of time and money (MDF, glue, screws, etc will add up quickly, you'll need to build and test and build and test and build and test) to pursue this endeavor, there's some basics to get you started.

Primarily your limited cone area and enclosure placement/cabin space. Majority of the people doing the massive hair tricks have walls and/or multiple times more cone area. Two 10's from a trunk in a sedan aren't going to do the hair tricks you see on YouTube, atleast in any manageable installation. If "hair tricks" are your goal (given your line of questioning, I'm assuming it is), then you need to entirely redesign your system and given the size of the trunk in a Cavalier, you would need to step up to a wall. Then I would suggest you look into increasing your cone area as well and fit the largest quantity/largest diameter drivers you can fit in the airspace. Granted given proper enclosure design and construction as well as driver selection 1900w would probably achieve your goal, again most of the people doing the YouTube hairtricks are running 3x or more that power. Based on your line of questioning, I would suggest you refocus your goals. Designing and installing those types of systems take a significant amount of knowledge and experience to properly setup. It doesn't appear you are there yet.

Find the size of your stock alt. Get an ammeter, turn on all of you accessories (headlights/high beams, AC, etc) and see how much current is being pulled from the alt. The difference is roughly how much "available" current draw you have available from the alt.

What is your budget? What the hell is a midbass sub? How much space are you willing to allocate? "Small as possible" isn't an answer. We need an actual volume. What amplifier are you using?

I understood what you meant. Using an 8" driver up to 3khz is not a good idea for many reasons. Since you are using your receiver, you will want to make sure you find a set of speakers that is an 8ohm nominal impedance, and that the impedance curve doesn't drop too low. Otherwise your receiver will have a very difficult time driving them.

I would recommend against crossing an 8" driver @ 3khz. It is going to be beaming heavily at that point, and you are more than likely going to encounter the driver's cone break up nodes among other issues. What is your budget, and what are you powering them with? Do you need to maintain a certain nominal or minimum impedance? Honestly, there are so many DIY projects out there, my suggestion would be to search around and find a project that generally fits your goals & budget with products that are available to you. The Beta 8" & 10" are actually fairly popular in the DIY community. While I don't have any specific projects handy, I'm sure if you searched around you could find plenty of projects that meet your goals & budget, and they will generally have detailed plans of the enclosure as well as crossover. Both of which take a certain degree of knowledge, experience and time to design. In home audio it's not as easy as just finding a good enclosure volume and tuning....baffle width & design (woofer/tweeter location and spacing, etc) need to be carefully considered and integrated into the crossover design to achieve a good frequency response, for just one example. Unless you have a lot of experience in designing speakers specifically for home audio, it is best to find something with complete plans already available rather than try to design your own from scratch.

I never said "up front speakers" were a marketing ploy (whatever "up front speakers" means?), I said all of the "add ons" they try to sell you are a marketing ploy...such as their center stage kit, their upstage kit, etc. If you would like me to explain why I think it's a bad idea from an acoustics point of view, then I would be happy to do so. I already told you what I don't like about CDT. The value isn't there. The cost of the speakers are not in line with their performance. They aren't "bad" per say, you will probably be happy with their sound. But you could have purchased different speakers for less money and been just has happy, and not spent the money on the center stage kit. Specs and objective measurements tell you a lot if you have the right objective information and understand how to interpret it. More than any subjective review or subjective evaluation could ever hope to obtain. There's absolutely nothing wrong with asking questions and "questioning authority", if that's how this instance is viewed.