Impious

JBL makes solid amplifiers. I've ran them in the past with great success. However, your post does not include enough information for us to help you. For starters we would need to know your budget and if you have any space/size constraints.

He said 4ohm each, which wired together in parallel would yield a final 2ohm impedance on the amplifier.

Active crossovers experience phase shift as well.

The ME's are good subs. That amp is fine, set the gain conservatively if necessary and don't use any bass boost/etc.

Depending on where it's installed it also may not be able to cool sufficiently.

Where ever you find it sounds best. If you wanted to only use the HU crossover then yes, set the amp to it's maximum setting. But there's nothing wrong with using them both.

There's nothing wrong with using them both. Yes, the crossovers will be cumulative....in some situations this may be beneficial and achieve better results. The goal is to achieve the best sound for the user, how this is achieved is of little consequence. There are far too many factors involved to say that it would be inappropriate to use them both, either cascaded or staggered. The recommendation for the 1 octave gap doesn't take into account the acoustic response of either the drivers or the vehicle or the slope of the crossovers. I guess off hand I can't say I've seen a crossover theory that recommends a full octave of separation in crossover points. You are going to have a different interaction if you are using a 2nd order filter compared to a 4th order, or if the vehicle and response of the driver result in steeper acoustic slopes than the electrical slopes used which would result in a lull in the that area of separation. In regards to the link; The crossover frequency isn't the point where the crossover begins taking effect.....it begins taking effect before the crossover frequency. The crossover frequency would be the -3db point for a Butterworth filter (-6db for a LR crossover, and different points for other less used crossovers). I'm sure you know this, but the wording is misleading as the response will begin to be attenuated before the crossover frequency. Slope and Q are not the same thing. Slope is expressed in db/octave, Q is a unitless number. The slope is the rolloff of the crossover, the Q describes the shape of the response. If I told you I was using a 4th order filter, you wouldn't be able to tell me the Q of the filter. If I told you I was using a crossover with a Q of .707 or .49, you wouldn't be able to tell me the slope. If they were the same thing, all you would need is one to tell me the other. There are too many factors to take into account to say do this but not that. For the beginner the best thing to do is simply use some familiar music and listen and set them to where sounds best. If it sounds best using both, so be it. Some users have found that the steeper slope has resulted in better results in their vehicle with their particular system.

The knowledgeable members in your other thread told you there was nothing risky about it. The ONLY risk of damaging something in these two scenarios is by trying to run the amps under their rated impedance, there is absolutely ZERO risk of damaging equipment running one amp per coil.

You can use one or the other, or both. If you use them both set to the same frequency, and they are both the same "type" of filter, then the slope will increase to that of the two crossovers combined and the signal will be down -6db at the crossover frequency as opposed to -3db (assuming the crossovers are both down -3db @ the crossover frequency). If you use them both but stagger them as you have them now then it's a little trickier to figure up the exact slope(s), but the jist is that the slope again increases where the 2nd filter begins to affect the signal aswell. Using them both either staggered or stacked can be useful in some scenarios. Or you can try using one and then the other and see which you like best. Generally the xover on the amp will provide a greater selection of frequencies as they use a potentiometer to set the xover point which is "infinitely variable" between the minimum and maximum settings, whereas most HU's generally have a few fixed points you have to select from. But differing slopes may make one a better selection than the other in your particular vehicle with your particular setup. There is no hard and fast rule that can be followed when it comes to setting crossover points in a vehicle as there are too many variables. There is simply no way someone on the internet can tell you the best crossover settings for your stereo. It's simply not possible as there are too many things that need taken into consideration. The best thing to do is simply spend a little time toying around with them on music you are familiar with, and set them to where sounds best. Bass Boost should generally be avoided as it increases the chances or occurrences of clipping the amplifier.

What exactly are your goals or why are you looking specifically for 8" speakers? Hard to answer the second question without really knowing what "differences" you are worried about. As to the first question, the only one that comes to immediate mind is the Dayton 8 MTM; http://www.hometheat...-mtm-rocks.html But then again I'm not deep into the DIY home audio speaker scene

Good to know, I am going to order a couple on Friday. One question for you Sir and sorry to crap OP's thread with a question of my own, but it could be relevant if he goes this route also. Why does Kinetik reccommend 2 of the same batteries? Ex 2 HC2400 vs. 1 HC2000 & 1 HC3800? Would it matter? Do you see that on the website, or read it on a forum? The reason I ask is that it probably depends on the specifics of how/where they were being used. For example, here is an excerpt from their FAQ on the website; As you can see, they recommend two different battery sizes due to the circumstances of one being under the hood and one auxillary in the trunk. If what you are referring to was in regards to two auxillary batteries or the user could fit two of the same batteries in the installation than it was probably for equal discharge/recharge. I wouldn't agree with GlassWolf's opinion.

Any idea what the T/S parameters of the driver are? Hard to recommend an enclosure without knowing what type of enclosure the driver will perform best in. There can be "SQ" advantages to using a properly designed ported enclosure. Even more if the driver's parameters aren't suited to a sealed enclosure.

Good barrier = high mass, like M5 said. That is why MLV is the "typical" product of choice for such applications, it's one of the more affordable ready-made and readily-available products on the market that has a good mass and is fairly easy to work with. For the barrier to work most effectively, it should be isolated from the surface (which is why Don sells the CCF). Lead is a great option as well due to it's mass, but it's expensive, difficult to work with and hazardous. Really, a quick read of Don's MLV page should answer most of your questions. Users on other forums have tried to get creative, making their own barrier out of high mass and cheap(er) materials they can find at local stores. But if you are looking for a ready-made and easy to use solution, MLV is your best bet.

well im looking for spl but im not looking to enter any comps...so basically the loudest it could possibly be while still being a daily driver Crossover setting basics link read this plaese. set your sub's LPF to 50Hz, 18dB slope. Set your HPF for components to 100Hz, 12dB slope. See how that sounds to you. Worth a try. From a brief read, that crossover link overlooks some important information that is necessary to consider when properly setting crossover points and misstates some information. In our environment, it's usually best to just set them by ear to what sounds best rather than using "rules" which don't really apply in most scenarios.

It might not be so much that it isn't "hitting" in the 45-65hz range, but rather that the response between 30-45hz is so exaggerated that the upper-bass response pales in comparison which is giving you that perception. Basically, it might just be a frequency response problem.....too much on the bottom and not enough on the top. If you had easy access to an EQ (such as one possibly built into your headunit) I would recommend you try decreasing the level of bands in the 30-45hz range and either raise the level of the subwoofer some or use a little more range of your volume knob to get the overall output to the level that you desire. This might help bring the upper-bass to the level you desire while keeping the low end where you want it. Here an excerpt from my Dcon review when I tested it in a ported enclosure that might give you an idea of what I'm talking about; But it would be useful to know what the rest of your system consists of and what settings you are using. It's hard to help without really knowing what you are working with.

I would highly recommend Kinetik. Without knowing more about what you are trying to power, I can't tell you what size battery would work best for your needs.

What exactly are you trying to accomplish? Really need to know your goals to point you in the right direction for the right type of product or what to look for.

This is just a hobby My "day job" is wholly unrelated.

I pronounce it George, like the curious monkey

From what I can tell the former stayed attached to the spider, and the cone stayed attached to the former as well. Another thing to consider is that the 13W7 has dual 1.5ohm coils. If they had wired the coils in parallel, that's a nominal .75ohm. Using basic ohms law, P = V^2/R, that would be 120^2/.75 or 19,200 watts of power to the 13w7. If someone takes a D2 sub and wires the coils in series, that's only 3600w to the driver. If someone takes a D4 driver with coils wired in series, that's only 1800w to the driver. Just because it's a wall socket doesn't mean two different drivers are seeing the same power....which leads me back the internet allowing ignorance to spread throughout the masses by uninformed users not considering all of the necessary information before drawing conclusions. MTX used to have a marketing campaign when they released the 9500 series based on this exact principle.....they showed a Solo X, W7 and 9500 being driven to failure while displaying the voltage each driver was receiving.....ofcourse the Solo X and W7 failed at lower voltages than the 9500.....but they never told you what they had each driver wired to impedance wise, which made it impossible to know which driver was actually receiving the most power. Regardless, I think I've already stated on numerous times that the W7 wasn't intended to handle insane levels of power. If that is your desired application then yes, chose another subwoofer. Yes, there are subwoofers that handle more power than the W7. It doesn't make them better; just the same it doesn't make subwoofers that can't handle as much power as the W7 worse. The W7 is capable of more than the necessary amount of power it needs in order to perform at it's maximum in it's intended application. That's all any driver needs. Eh, isn't that exactly what I said? It appears I used the word "application" atleast 3 times, and the bolded sentence explicit says the only time T/S parameters can have a "superior/inferior" inference is in regards to a specific application. For any given application, yes there are. That's exactly what the T/S parameters tell you.....how the driver will perform in a given application.

Fair enough. The 12W7 has an Xmax of 29mm. But Xmax by itself is irrelevant, since we are concerned with the total amount of air capable of being displaced linearly.....otherwise known as Vd. Due to the design of the 12W7's cone and surround it has 542cm^2 of cone area compared to 480cm^2 on the Xcon. So the 12W7 has a total Vd of 1.57L, whereas the Xcon as a Vd of 1.49L. Displacement advantage: 12W7 A driver only needs to have enough power handling to achieve it's intended level of performance in it's intended application. Just because a driver wasn't intended for the application you desire is not a problem with the driver.....it's simply the wrong driver for the application. The Xcon wasn't designed to excel in sealed enclosures. Do I hold this against the Xcon, or simply decide instead to chose the proper driver for the application? The point being there are different applications, and no driver is going to excel at all of them. You are choosing to place significance on power handling for your own personal reasons.....not everybody does, nor should they. So while higher power handling may be a "plus" for your desired applications, it is irrelevant to most others. Last, simply looking at rated power isn't really a valid means by which to even compare power handling capabilities. While the 12W7 may not be "rated" to handle the same amount of power and it may void the warranty, it's design may allow it to do so. So really, the entire topic is moot without more information about the actual ability of both drivers to actually sustain certain levels of power.......other than the fact that running a 12W7 @ 1750w will void your warranty. Herein lies the problem.....you CAN NOT have two drivers with identical parameters other than sensitivity. It's not physically possible. So your hypothetical scenario is completely irrelevant as you can not "choose" an identical driver with higher sensitivity. If you really want to know why sensitivity is NOT a "higher is better" type of specification, here is an article in the tech center that will help you understand the trade-offs associated with increasing sensitivity; Subwoofer Sensitivity - SSA Car Audio Forum Exactly. That's not evidence of anything other than your own personal opinion, which is irrelevant to the discussion of the performance of a driver. Even then, we could question the validity of the experiences which you used to form your opinion. The performance of a driver is impacted more by the system, enclosure and environment than the actual driver itself. If your experiences with the W7 were heavily influenced by those factors (i.e. listening to a W7 in someone's vehicle, in a showroom, etc) then you honestly do not have enough experience with the W7 in order to form a valid conclusion and comparison of it's performance to any other driver. So, have you ever compared the W7 to a Xcon in identical environments and identical alignments and identical systems in order to form a valid comparison of the two drivers subjective performance relative to each other? If the answer is no, then "your opinion" is quite simply irrelevant and your experiences are inconclusive. That says nothing negative about you personally, it's simply a matter of fact. All opinions are not equal, and all opinions are not valid. Despite popular belief, an opinion can indeed be wrong.....or atleast, be based on faulty information. T/S parameters are not a "superior/inferior" type of parameter. They simply describe the low frequency performance of a driver, which assists the user in determining which driver best suits their application or what application would be most appropriate for a certain driver. The only relevance T/S parameters have in a "superior/inferior" inference is with respect to a given application. Look at the video closer. They don't have the ring on the surround, which means the surround is not attached to the basket. It appears when they applied power the coil rocked as a result, which hit the gap and began to bounce around thereafter. That video doesn't show anything other than a broken driver doesn't function properly. THIS is a prime example of the problem with the internet. People "see" something without fully analyzing the situation or circumstances and then use this misinformation to draw conclusions.

That they don't deserve? The W7 is worthy of every educated compliment thrown it's way. It set the standard for low distortion high output drivers. The W7 never claimed to be a SPL sub. That was never it's intended application. To use that against the W7 is a little like complaining that you can't take a Corvette rock climbing. It was intended to be a high output low distortion subwoofer for use in accurate music reproduction. Not a single tone fart cannon. Though IIRC Nate Munson said he put a W7 in car and only lost around 1db compared to the DD 9510 he had in there at the time. Arguable. What measurements do you have to support that the Avalanche and Tumult are far and away superior performers to the W7 in distortion and other "sound quality" parameters? Make it look retarded? No. Not happening. Sorry. How is it superior in every way? I hope your list gets better than this; Irrelevant....and actually higher sensitivity can be detrimental for a subwoofer. Sensitivity isn't a "higher is better" spec....and if you think it is, you have some learning to do. Irrelevant again. Having a higher rated power handling again isn't a "higher is better" spec.......and if you think it is, you have some more learning to do. The W7 has sufficient power handling for it's intended application, that is all that matters. If you want to go rock climbing, don't buy a Corvette. A little more relevant. But IIRC the Xcon is rated at 31mm Xmax, correct? 13W7 is rated @ 32mm Xmax and was Dumax'd at 33-34mm.. They are close enough that I wouldn't say excursion is in either driver's favor. Subjective, which makes it only relevant to you and no one else. Another person may think the W7 sounds better than your Xcon. Indeed it is. You finally got one right! Congrats!

Don't base anything about an amplifier's capabilities on the "tests" you see on the forum. They are irrelevant and essentially useless. Oh, and LOL at trying to have an argument in youtube's comments.

Is that intentional, as in THD is greater than or equal to 1%, or does someone @ AQ not understand their greater than/less than signs from grade school?

Whether or not they are "worth it" really depends on your factory system and what exactly it is you are trying to accomplish. Without more details about what you are trying to accomplish and what system you are trying to integrate, it's going to be difficult to really provide meaningful information.