Impious

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.

What is sensitivity? The sensitivity of a driver is typically defined as the sound pressure level of the loudspeaker given 1 watt of power input, measured at a distance of 1 meter, measured on-axis with the loudspeaker and measured in infinite space with the loudspeaker mounted to an infinite baffle. While the later part is typically assumed but not stated, the former part is the reason you generally see “1w/1m” or “2.83V/1m” stated along with the sensitivity specification. But wait, is 1w/1m equal to 2.83V/1m? The answer is only for an 8ohm impedance driver. We know this because of ohms law, where Power = Voltage^2/Resistance. If the load is anything other than 8ohm then the resulting sensitivity rating will not be a 1w measurement! If the driver is 4ohm and the measurement is a 2.83V measurement, we can find the amount of power input with the formula 2.83^2/4 = 2w. This means that sensitivity will be overstated by 3db compared to a true 1w measurement. I have seen many unscrupulous companies take a dual 2ohm/coil subwoofer, wire the coils in parallel and then rate sensitivity at 2.83V, overstating sensitivity by 9db! Due to these and other variations in rating methods and some manufacturers not even stating a method, it can often be difficult to directly compare one subwoofer’s sensitivity to another’s. However, if you are able to obtain the Thiele-Small parameters for the subwoofer there is one surefire way to calculate an accurate sensitivity measurement for a driver. And that is with the following formulas; Efficiency (N0) = 9.64 * 10^(-10) * Fs^3 * Vas / Qes *To express as a percent, multiply by 100 *Vas in liters Sensitivity (SPL) = 112 + 10*Log(N0) The Efficiency (N0) calculation expresses, typically as a percentage, the amount of power input that is converted to acoustic power. With the sensitivity calculation we can convert the efficiency of the driver to a 1w/1m sensitivity rating. As long as the T/S parameters are accurate, utilizing this formula will put any two drivers on a level playing field and allow you to directly and accurately compare sensitivity (or efficiency) between drivers. Okay, but higher is still better because higher means it’s louder, right? Not necessarily the case. There are a few issues here that need to be discussed to better understand why. From a driver design perspective, we can see from the above formulas that there are two ways in which to increase sensitivity for a given driver diameter; increasing Fs or decreasing Qes (or both). Adjusting either of these two parameters, however, is ultimately going to affect how the driver responds in a given enclosure. And this relationship, as it relates to enclosure size, sensitivity and low frequency extension, has been defined through a rule known as Hoffman’s Iron Law. As you can see from the link (which I highly suggest you read), it’s already been covered in relative detail elsewhere on the site. But it’s important to us here, so it’s worth touching on again. In short, Hoffmans Iron Law states that we can only have two of the following three; Low frequency extensionSmall enclosureHigh sensitivity What’s important to take away from this is that if you want high sensitivity and a small enclosure, you will necessarily sacrifice low frequency extension. Or, conversely, if you desire extended low frequency output from a small enclosure, you must necessarily sacrifice sensitivity. While a given driver may have a higher rated sensitivity, that driver may actually have less output in the subbass region once the effects of the enclosure are taken into consideration since it may begin it’s rolloff at a higher frequency. And given in car audio we typically require reasonable enclosure volumes, having a high sensitivity can actually be disadvantageous. The second factor we need to consider is how output is achieved. Sensitivity isn’t what determines maximum output. Output is a function of air displacement. The maximum amount of linear displacement (Vd) you can achieve is limited by your cone area (Sd) and linear excursion (Xmax). As you increase the amount of displacement at your disposal, you increase the potential linear output you can achieve. Even though a driver may have a higher sensitivity, if it’s maximum linear displacement (Vd) is less than that of a driver with a lower sensitivity, the lower sensitivity driver will have the potential for higher levels of output. We also have to consider the effects of Power Compression (and I again urge you to read the link). Consider the effects of power compression applied to our scenario. A higher sensitivity driver may, for example, begin to experience more power compression at a lower output level than a lower sensitivity driver. If this is the case, then as output is increased beyond that level the higher sensitivity driver would gain less output for each increase in power and experience more parameter shift. The basic summary is that after many factors are taken into consideration, it is impossible to state unilaterally that higher sensitivity drivers will better than lower sensitivity drivers. Generally choosing one driver over another based on sensitivity alone is a bad path to follow. Sensitivity is just one of a multitude of parameters that all conspire together to define the performance of a loudspeaker. And in my humble opinion, it is one of the less important factors to consider. As with anything, there are compromises to be made and it's necessary to find the best set of compromises for your particular situation.

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.

If I ever get around to figuring out how it works, I should have a crude measurement setup.

You would have to ask all of the former-owners of now defunct internet-based car audio businesses who proceed him A lot of them burned down in a blaze of ignorance and misdirection. Or you can ask Ben Milne how he's managed to lie and cheat for nearly a decade yet still remain in business. Oh, and not all forums are educated. Have you visited some of the others?.....

95db w/ response down to 50hz and 250w continuous power handling and clean response to 5khz+ is still pretty....umm, extreme, for an 8" driver. well honestly I dont know what to look for on how to tell if a speaker set is good or not. I know with subwoofers but speaker set's are totally different. What stats should I be looking at? As far as low frequency response, a speaker is exactly the same as subwoofers. They are all the same thing. And the same set of parameters define their low frequency performance. You'll just be dealing with a different bandwidth of frequencies. As far as midrange performance, there's no real "stats" to look at as the T/S parameters define the low frequency response of a driver only. One indicator would be inductance, as a driver's inductance and resistance work together to basically form a classic first order lowpass filter. So if, for example, the driver's inductance induces roll-off beginning around 2khz....you can pretty much rule out performance up to 5khz. Beyond that, it's really beneficial to see the actual measured performance of the driver.....frequency response, impedance curve, distortion measurements, etc. But there are some things to "expect".....I would reasonable expect an 8" cone to experience some break-up issues somewhere below 5khz, for example.

You do realize the only reason I'm planning to purchase a pair is frankly because I don't believe the claims, correct ? The comment was made tongue-in-cheek. But if they end up as cheap as people are saying, I'll buy a pair to see how they hold up to the claims....again, because I don't really believe it. EDIT: Oh, and no response to the email yet But I don't know what their turn around time on emails are.

95db w/ response down to 50hz and 250w continuous power handling plus clean response to 5khz+ is still pretty....umm, extreme, for an 8" driver.

What equipment do you have currently? Unless your amplifier is junk or severely underpowered, you're best bet for (potentially) significantly improving performance is to change out the subwoofer. If your prefab box is appropriately sized and appropriately constructed it won't hurt anything to use it.

Can you recommend a car that's really fast but also handles well in a wide variety of situations? Attn NOOBS!!!! SSA Guidelines to Effectively Answer Your Questions

that was a beat that we downloaded from a website called freesound.org I was just being a smart ass because of the comment made in the video

Audax PR170M0 6.5" Midrange - 100dB from Madisound 100db sensitivity. But with .5mm Xmax you aren't going to get much midbass out of them IIRC companies like B&C, 18sound, Eminence and Faital all have high sensitivity 6.5" mids. But.... We have that stinking Hoffman's Law to contend with. Problem with small drivers is their small cone area, so you really need to give up the ghost in low frequency performance in order to gain efficiency. So how they were able to get 50hz performance out of a 6.5" with 94db sensitivity and 250w continuous power handling (which will be put to the test if I remember to get a pair).....I'll be very interested to find out. BTW, I have an email dispatched to them to try to get a little more info. We'll see if they divulge.

Nice video. What song was that?

Clicked the link expecting to see a video of 20 people climbing out of the car

Hmmm....so now we have a high efficiency driver than can play down to 50hz and handle a continuous 250w? I'm going to have to buy me a pair of these. When are they going to be available again?

Technically yes, but why in the world would he spend $100+ on a Maxxlink when he can accomplish exactly what he wants with a $1.50 part from Radio Shack ? But is a line driver too. You also get pretty chrome too.$80 online all day long. He doesn't need a line driver. Waste-O-Money no matter what it costs as long as it's more than a couple bucks, which is all he needs to solve his problem.

There's no reason with today's technology to look at big, low impedance class A/B amplifiers when you can get exactly the same performance in a potentially smaller and more efficient package with other amplifier classes. While it may be big in Italy for whatever reason (can't say I can understand the appeal of the systems in the above links personally), the rest of the world is advancing with technology into the future with amplifier designs that provide more benefits than class A/B has to offer. I've really yet to see any valid reasoning as to why you feel the need for the amplifiers to be class A/B as opposed to other topologies other than "because it's the big thing in Italy right now". That's not really valid reasoning, that's just following the herd. Class A/B has it's place as a topology.....big, high powered, low impedance amplifiers isn't really that place anymore.

Technically yes, but why in the world would he spend $100+ on a Maxxlink when he can accomplish exactly what he wants with a $1.50 part from Radio Shack ?