Impious

.707 is actually a pretty popular number. It's derived from 1/SQRT(2). In this case, multiplying the voltage by .707 would provide you with the necessary voltage for a -3db decrease in the signal, the -3db point being the crossover point for most amplifier crossovers (or any other Butterworth filter, the crossover point is defined differently for different crossover types). Just as a proof, we can use basic ohms law. Just to make the math simple, lets assume you have a 1ohm load and we'll use your 6V example Power = Voltage^2/Resistance 6V^2/1 = 36w 4.242^2/1 = 18w 10*log(36/18) = 3db .707 is also used to calculate RMS voltage and current from peak voltage and current. Vpeak * .707 = Vrms, Ipeak*.707 = Irms .707 is also used Q of Butterworth filters (crossovers) and Butterworth enclosure alignments. Overall, it just comes up a lot I'll have to ponder this a little. Off hand I'd wonder if maybe you were adjusting the lowpass filter rather than the subsonic.

He doesn't need a PR Dcon. He just needs a PR, which are available from several different vendors. The main "problem" with using a PR is that the PR needs a minimum of 2x the displacement of the subwoofer itself, so not just any ole PR will do. A PR with sufficient displacement is likely going to run you anywhere from $50-100 for the PR alone, which is a pretty significant added cost (nearly 50%+ of the cost of the driver itself).

Well, then you are completely wasting your time. If you are having problem with the "SQ" of your mids, you need to look at your installation, your tuning or the capabilities of the mids themselves. Your amplifier has nothing to do with the "SQ" of your speakers unless you are clipping your amplifier or the amplifier is broken. Using higher powered amplifiers increases your available headroom (<- click the link if you are unsure what I'm referring to) which is the biggest benefit you can gain sound wise from changing amplifiers aside from replacing one that's broken. Not sure who told you that, but that would be about as incorrect as possible. As a matter of fact, the individual who designed the JL Slash amplifiers, Bruce MacMillan, also designed the highly coveted PPI Art line of amplifiers as well as many other well loved "old school" amplifiers from companies such as Xtant. That said, there's no such thing as an "SQ" or "SQL" amplifier. But the man who designed them certainly knows how to design a great amplifier.

What do you mean by "not cutting the signal out"? Is it not affecting the voltage at all? To set the SSF to a specific frequency, turn the filter all the way down (10hz) and disconnect the sub. Turn the volume on the HU up to some arbitrary level (the volume level itself doesn't matter), and play the 33hz test tone (if that is what you are trying to set your SSF to). Measure the voltage output of the amplifier with a DMM. Then multiply this voltage by .707. So if you measure the voltage output and it's 2V, then you would multiply 2 * .707 = 1.414. With the test tone still playing and your HU at the same volume level, turn the SSF knob up until the voltage drops to your calculated voltage, in my example that would be 1.414V. This will set your SSF to 33hz. The SSF is not a brick wall. It will not eliminate the signal below 33hz. It simply attenuates those frequencies at a certain rate based on the slope of the SSF. A SSF is nothing more than a highpass filter.

Depends on your vehicle and the wire you are using. Generally if you are using a single run of 1/0ga wire and your vehicle has a good conductivity, grounding to the frame is the best option. If you are using multiple runs of large gauge wire and/or have a vehicle with poor conductivity, going directly to the battery is the best option

Of those three options, I would go with the JL and bridge the amplifier for 150w x 2. It appears that would give you the most power output. That said, I personally would probably go with another option like the Clarion XH5410 for $220 shipped which would give you an available 320w x 2 for the mids EDIT: Damn, didn't realize you were located overseas Guess that Clarion deal might not work out for you then. But the main point was, I find the most quality power I can for my dollar.

Copper as a metal has less resistance than aluminum. That is completely different than saying "copper coils have less resistance".

Seems like there's something more at play. A driver like the Dcon shouldn't have that appreciable a difference in suspension compliance.....and having used one myself for several weeks, I can honestly say I heard absolutely zero difference in sound (nor have I with any other driver I've used). Regardless, glad to hear your now extremely pleased with the Dcon. 'Tis a great affordable driver.

could you possibly go into more depth with this. Cause i was really fixed on a 2 way active set up and i didnt want to cut anymore into my door panels I believe his point was that "midbass" is a frequency range that, though opinions differ, is generally going to be considered frequencies below ~500hz or so. Given no tweeter is going to realistically play that low, he'll need a speaker that also covers the "midrange" frequencies. More or less, he was just telling him that he used the word, as "midbass" doesn't completely encompass his needs. And yes, it can be an important distinction because a driver that excels in the "midbass" frequencies may not necessarily do well in the "midrange" frequencies.

Sure it can. It may not be as loud as a 6.5 or 8" woofer, but cone size does NOT dictate frequency ability. Cone size (and/or displacement) does dictate realistic frequency limitations and usable bandwidth capabilities. Sure you can get a 4" driver, or a tweeter for that matter, to physically play a 100hz tone....but it would not be logical to expect great midbass performance from a 4" driver because the limited displacement is going to greatly restrict the output capabilities to the point of rendering them virtually useless at that frequency unless 1) you don't plan to listen to them at reasonable levels, 2) you enjoy excessive amounts of distortion, or 3) you plan on using multiple drivers per channel. Even with a "long throw" 4" driver like the underhung TB linked above, the driver is going to be restricted to ~91db of linear output at 100hz. That's with the driver operating at Xmax which is generally going to put the distortion somewhere in the vicinity of 10%. At 80hz it's restricted to ~88db. At 60hz, ~83db. On the opposite end of the frequency spectrum, cone diameter is going to directly affect off-axis response as frequency increases. In addition, generally larger cones are going to experience break-up at a lower frequency than a comparable smaller diameter cone which is also going to restrict usable bandwidth. There are certainly "good ideas" and "bad ideas" in regards to frequency bandwidth that is directly attributable to cone diamater/driver displacement. Using a 4" driver as a midbass would fall in the latter category unless we are discussing extremely unorthodox arrangements/alignments. Your argument would hold some water if we were discussing "woofer speed" or the like, but it misses the mark in this discussion.

What T/S are you shooting for on this driver?

Not unless your amplifier is sub-par. In which case, the best course of action is to change amplifiers. Assuming we are talking about the same amplifier, the increased power output at 2ohm compared to 8ohm would potentially improve "sound quality". (or if it was not designed to operate at 2ohms, which of course would be a problem as well)

I haven't, but JBL has Here's a plot of a dozen or so vehicles from Andy Wehmeyer; http://farm4.static....0d155d5ac_o.jpg Unfortunately when people say "you can't model these drivers", they mean don't use the programs suggested enclosure and tuning. But people take the statement literally and think the drivers somehow defy physics and aren't capable of being modeled I recently tried to explain this in another thread; Win ISD parameters for BTL 15 - SSA Car Audio Forum

Not sure why the "lows would slam" after break-in compared to now when the response will be virtually identical. Also, no need to wait weeks for break-in. Run the driver at high excursion for a few hours....job is done.

What is your subsonic filter set to? I know it's fixed, but what is the frequency? Have you verified the enclosure volume and tuning frequency? What was your prior subwoofer? Do they "feel" stronger than your prior setup, just not as loud to the ear? How low of frequencies are we talking about?

While I agree with your premise (having available headroom is important), wiring to a higher impedance does not help one achieve that goal. If you gain "headroom" in the amplifier by wiring to a higher impedance, then the amplifier has a weak power supply that's not able to support the higher power output at the lower impedances. The amplifier itself should have zero headroom, unless it has a unique technology built into it like the RF T15kw. Otherwise, headroom in the amplifier itself is simply an indication of a weak power supply. So if you gain "headroom" in the amplifier by wiring to a higher impedance, I'd suggest you look for a new amplifier rather than change your wiring.

Yes, the Fs may drop some as a result of the Cms increasing. However, since Fs or Cms are also used to calculate Vas, Qes, Qms, and hence Qts, the net change in in-box performance will be completely inaudible. We are talking a difference in response in the same enclosure of tenths of a decibel and a tenths of hertz. So while yes, the Fs may drop some....you can not attribute a change in sound to this phenomenon since all of the other determinant parameters change in proportion to Fs aswell.

This would be why no one t/s parameter can be relied on to determine woofer quality? Also why there's no "perfect" woofer? Short answer because I'm tired; Pretty much. I'll try to help if I can

Ultimately you can't just arbitrarily adjust Cms without consequence even if it doesn't directly impact sensitivity. If you look at the BTL example I posted earlier, the Fs jumped by nearly a half octave when we halved Cms. So the engineer is going to have to balance Cms (and sensitivity) with the other performance goals for the driver.

I would rather have a pair ported than a trio sealed.

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Nope, efficiency would remain the same aswell. Sensitivity is based on the relationships between motor force, cone area and moving mass.

Nope, efficiency would remain the same aswell. Sensitivity is based on the relationships between motor force, cone area and moving mass.

Meh, I guess if I were re-running all of the wiring anyways I would spend the extra couple minutes and hard-wire the 12V switched (ignition) wire. I don't care how fancy of a plug you get.....IMO tapping the fuse box is a little ghetto and lazy. For quick-fix scenarios or short term temporary use, sure. But for a permanent install.....no. If all of the factory wiring is intact you should be able to trace the OEM wire back to it's origin.

Clamping the DC side of the amp would tell you how much power the amplifier is drawing from the electrical system, not outputting to the speaker. When someone "clamps" an amp they are measuring the output side of the amp, which is AC. They normally keep a DMM on the power input side to monitor what the input voltage is dropping to, but that's not how they are deriving their power output figures. Anyways.....many people fall under this delusion that they are performing some meaningful act by "clamping" their amplifiers. As Crazy said, they connect their amplifier to a load (normally just a subwoofer in most cases) and play a test tone. They then use a DMM to measure the voltage output from the amplifier and a clamp meter to measure the current on the output side of the amplifier while playing the test tone. They then use basic ohms law to calculate power (Voltage * Amps = Power) and the impedance of the load (Voltage/Amps = Resistance). As I previously mentioned, most people will also use a DMM on the power input side of the amplifier to monitor the voltage drop the electrical supply is experiencing. The problem is, 99% of the time people are simply wasting their time. It's a mostly meaningless endeavor that has been perpetually (and incorrectly) promoted on the internet as having actual relevance. There are several problems with this method. Along with being able to question the accuracy of the measurements themselves for various reasons (accuracy of the devices, the type of measurement being conducted, the varying impedance of the load, the varying stability of the supply, etc), many people try to compare these "clamp test" results to the manufacturer rated power. The problem is, the manufacturer's rated power is specified at a certain distortion level. Nobody performing these clamp tests are measuring distortion. One could make any amplifier appear highly underrated very easily in one of these "clamp" tests as there is a total disregard of distortion.