Impious

The science books say it's impossible or improbable.....because it's impossible or improbable. There is nothing that changes in this particular scenario between the science theory and reality that would make the latter different than the former. The signal transmission is simply too fast to make any noticeable difference at the distances we are discussing. If you think the Bronco somehow defied the laws of physics, I'm sorry to disappoint you....but it did not. If what you are claiming is true, there are a hundred different scenarios in audio applications where this would rear it's ugly head. Helotaxi listed one such aspect above. Another issue would be with amplifier RCA pass-through outputs....you wouldn't be able to use them due to the time delay involved. Overall this issue of time delay would be a significant factor in every system design. The fact is that it isn't. And the reason it isn't is because of the physics involved, and these physics are the same between the science books and the "real world". It's simply too quick of a signal transfer to make any noticeable difference. I'm sure there were some bugs in the system in the Bronco. And I'm sure you made some changes that corrected them. I'm not disagreeing with that aspect of your experience. What I am saying, however, is that you are ascribing the differences that existed to the wrong variable. It wasn't due to a time delay resulting from a difference in RCA/speaker wire. It's simply not possible according to the laws of physics.

Impedance changes based on frequency, enclosure, temperature of the voice coil, etc etc. But the goal of the DMM method isn't to set the gain based on the impedance of your subwoofer. What you are attempting to accomplish with the DMM method is setting the gain based on the output voltage of the amplifier at a known power output at a known impedance, namely the impedance the amplifier's output power was rated at. If the amplifier is rated 100 @ 4ohm and you are attempting to set the gain....in theory it doesn't matter if your subwoofer is 4ohm, 3ohm, 2ohm, 1.3ohm, 3.6ohm, etc. What you need to know is what rail voltage the amplifier should be operating at, and adjusting the gain control of the amplifier to achieve that rail voltage. Ideally the output voltage of the amplifier would actually be independent of impedance. If the amplifier is rated at 100w @ 4ohm, that means the amplifier is capable of operating with a 20v rail voltage. In a perfect world, this voltage (20V) would remain the same no matter what impedance load was connected to the other side. The actual power output would depend on the load, as that determines the current output and ultimately the power output, but the rail voltage itself wouldn't change. So, in a perfect world, all we need to know is where the output voltage of the amplifier should be, and we determine this based on the rated power (which is a specific power output into a specific impedance load) and not what the impedance of the load is that is actually being connected. In practice it does matter as there are some design features and losses that occur within an amplifier that affect it's ability to maintain that rail voltage at higher power/higher current output situations. In many amplifiers the output voltage will decrease as impedance decreases, which decreases it's power output (normally due to current output constraints, power supply constraints, etc etc). But, again, we can use the rated power to approximate where the rail voltage should be for the approximate nominal impedance of the load we are connecting. It won't be perfect, but it doesn't need to be as small differences won't be noticeable in either direction. Another issue is where rated power falls in relation to actual power output. The amp might be capable of more or less power than it's actually rated for into the specific impedance it was rated at. In all but the most extreme circumstances they will be different but not by an excessively large amount. That means the voltage setting could be a little high or a little low....but again, small differences won't matter. The larger issue for me is the level of the test tone. If you use a 0db test tone (which most people use/recommend), 90% of people will end up unhappy with the result and think the need to buy a more powerful amplifier. Since music hardly spends any time at 0db, you will have a very low average power output from the amplifier. With a -6db or -10db test tone (depending on circumstances), the DMM method is good enough to get the gain set to a level that is relatively safe and leave most people happy. The problem is, you could probably do just as well by setting it by ear....so why bother? There are other issues as well that overall just make setting the gain by ear the easiest and best solution a majority of the time.

For some "real world tests", let's consider the speed of signal transfer. The speed of electric signal transmission depends on construction and materials of the copper wire, with co-axial cable being on the low end at ~66% the speed of light. I'm going to round this to 70% because I was able to find a wikipedia page that already has already used that number, so it saves me the time of having to manually calculate anything. With a signal transfer of 70% the speed of light, it would take a signal 4.76 nanoseconds to travel 1m. That's 0.00000000476 seconds to travel ~3 feet. I'll leave it to the reader to calculate the associated phase shift resulting from a 0.00000000476 second signal delay. And for reference, that's also many orders of magnitude below the audibility of human hearing for signal delay. I'll defer to your experience with "real world tests" and await an explanation as to how a 0.00000000476 second delay resulting from extra RCA cable length or speaker cable length is going to cause an audible delay or audible phase shift within the system.

Unless he is wrapping the speaker wire around his car a few times first, which I doubt, then I seriously doubt a foot or two difference of speaker/RCA cable is going to make any audible difference at all. I would question your test methods.

That right there would keep me from ever recommending you. I'm not going to recommend anything that directly or indirectly supports AT or uses his products.

While I agree it's a stupid idea, yes you could technically make it "work" by properly matching the gains and xover settings. It would simply make much more logical sense and be a much simpler install to use a single amp. Not to mention you are relying on the shops ability to perform these settings, which may or may not be within their capabilities. Being "the best in the area" doesn't mean a whole lot. They can be "the best in the area" and still not be the sharpest knives in the drawer...it's all relative to what else is in your area. Also, you asked earlier about how much louder.....ideally, assuming you maintained the same alignment, I believe you'd be looking at a difference of ~3.5db. So an audible difference, but not dramatically louder. A DMM and common sense should be enough to get them set close enough not to matter. No way in hell there is not going to be enough of a difference to matter. That one's kind of out there.

Then keep the rears stock ran off of HU power and put all of your amplifier power and $$ to the front speakers. Do you have any sound deadening installed?

Don't install anything in the rear. Put all of your speaker funds towards the front speakers. If you absolutely must have rear speakers, just keep the stock speakers. Also, don't use the amp on the rear speakers. Bridge it to the front speakers. If you must use rear speakers, just power them off of the headunit.

That is pretty well the antithesis of your originally stated goals. Supertweeters have no purpose being in a vehicle, IMO.

A few potential problems I see. First, where does the AP mat vent to? It should vent into a large open area, just the same as IB. It looks like it simply vents into the floor of the car, which would be far less than ideal and cause it not to function properly. Second, AP isn't as simple as using a predesigned mat/vent, such as that Scanspeak piece. The amount of resistance provided by the AP mat needs to be "tuned" to the loudspeaker just like any other enclosure. The goal of AP is to flatten the impedance peak, and the thickness/resistance of the mat needs to be designed specifically for the driver and it's particular impedance peak. Last, I personally think you have insufficient AP mat area. That AP mat you have is designed to be used with smaller diameter drivers. Also, what was the reason for going AP? What were you hoping to gain? I think your driver selection is probably fine. I think the problem is the implementation of the AP.

Horn Loaded Compression Drivers and 8" - 10" pro audio midbass drivers. I honestly think this is about the only logical means by which to reach the goals you are aiming for. It is NOT a beginner system, so I hesitated in suggesting it....but IMO most of the tuning issues with this system comes mostly from the EQ adjustment rather than crossover selection and other issues like the other options. It would have the output and impact to make your chest feel like it was collapsing and with properly adjusted EQ selection and installation it would still be capable of high fidelity, great detail and good imaging at normally listening levels.

You can get NPR pretty much anywhere in the country.....what else do you need to listen to ??

Some of vehicles people describe as some of the "best" "sound quality" (both in quotes) vehicles are also the vehicles where you don't realize how loud the stereo is until you try to talk to the guy in the seat next to you....and realize you can't hear your own voice. Certainly it's possible.....but it also entails A LOT of knowledge and skill because you have to understand proper driver selection, have pretty in-depth tuning skills, excellent installation skills (not necessarily in form, but in function), an understanding of the human hearing mechanisms, etc etc. It's not easy, and it's more dependent on the installation and tuning skills as well as knowledge than it is on what speakers are purchased. Ideally a true "sound quality" stereo will have the ability to play as loud as an accurate representation of the source material requires. This entails large amounts of transient headroom and high but clean and undistorted output requirements. If you can feel the snare and cymbal hits from the drums in your chest when listening to a live (unamplified) concert, then the stereo should give you this same feeling. They should play loud, but it's a different kind of loud than most bassheads relate to. This ofcourse isn't the only requirement, but it's one that's often overlooked.

Process of elimination. Check to verify the RCA cables have voltage. Check to make sure the fuse isn't blown. Check your speaker wire connections. Check to make sure the REM wire has 12V. That's in no particular order. But some things to check.

Yes. I should add that kicks are a good idea IF they are properly aimed, are of solid construction and have sufficient airspace. So that rules out Qlogics and the like. Pretty well requires something custom built.

Yes.

Is this for competition or daily driving?

I really think a 2-way active front stage is a great place to start. The learning curve on properly tuning an active setup can be steep. You learn with the 2-way active then progress to a 3-way active. It sounds easy, but getting it right and maximizing performance isn't as simple as setting the crossover and calling it done. Coupling little to no experience with a 3-way active front stage is a great way to end up with a stereo that never really sounds goods. Also, the DQL-8 is not going to be a good processor for 2-way active, and from what I can find isn't capable of 3-way active. For starters, it has no means by which to bandpass an output other than the sub channel.

Aaron responded to the thread on crapaudio.com "I think someone lied to you. We are not switching manufacturers." My guess would be someone tried to get a recone and Fi was waiting on a parts delivery or something so it wasn't immediately available, and the guy misunderstood what was going on. But that's only a guess.

Noise Troubleshooting Guide Follow the guide, you will eventually locate the noise. More often than not it's either a poor ground at the amplifiers or at the headunit. Though my guess would be that he's had some alternator whine the entire time, but the sensitivity of the horns & supertweeters coupled with the added amplifiers in the system simply made it much more audible/prevalent. Also, for reference, that's a terrible speaker setup.

And what do you plan to use for processing?

Again, ditch the 2nd pair of tweeters in the kicks. Completely unnecessary and will make things worse instead of better. Also, a 5.25" midrange isn't of much use in a 3-way front stage. It sort of defeats the purpose of a 3-way to start with. If you must go 3-way, drop the midrange down to a 3"-4" midrange. It will have better high frequency extension and response. Although I still say stick with either 2-way front stage or a 3-way passive setup. I can tell just from your postings in this thread that a 3-way active frontstage is going to be well beyond your capabilities. I know active is all the rage anymore....but the advantages of active will only become relevant when the active setup is properly tuned and installed. A poorly installed and tuned active front stage will sound worse than reasonably well installed passive setup. So, 2-way active or 3-way passive front stage is for you. Personally, I would high suggest you consider the more simple 2-way front stage idea. Unnecessary. A reasonable quality co-axial speaker will be more than satisfactory back there. When no one is back there, they will be muted anyways. All it has to do is play just audible enough for the rear seat passengers to hear it. That's it. It doesn't need to be loud, and with as quiet as these speakers will be a basic co-axial will sound fine. Although I haven't had rear speakers in a decade and I've never had anyone sit in my rear seat have a problem hearing the front speakers. I still say they are unnecessary overall. But if you feel you must, a basic co-axial is more than sufficient. Unnecessary and you won't have the necessary processing or skill level to properly utilize them. It will make things worse instead of better. No. Bad idea and poor implementation. Scratch this from the board. Not going to happen. 1/4 wave you mean a T-line? Unnecessary. Basic sealed or ported will do everything you need. Again, start over. The entire system design needs rethought. Your original plan is just not an implementation that will allow you to achieve the goals you indicated in the original post and thread title.

First, you have too many speakers up front. You only need/want one pair of tweeters up front, not two. You also will not want both the 6.5" in the doors and the 5.25" in the kicks, both playing midrange and midbass (which I'm guessing was your plan). If you want to do a 3-way up front, do a true 3-way up front. If doing a 3-way front stage, in my opinion there's no point in using a 6.5" midbass and a 5.25" midrange. If you plan on using a 6.5" mid in the door, decrease the size of the midrange to 3"-4" to gain some advantage there from the 3-way system design. Though based on your post I'm not sure you have the skill set at the moment to pull off a properly tuned 3-way active front stage. My suggestion would be to stick with a simple 2-way or passive 3-way. Second, I would still forgo rear speakers. Properly setup the rear passengers will have no problem hearing the front speakers. If you must have rear speakers, I would just go with a simple co-axial and have them faded off when no one is back there. When someone is back there, just bring them up enough to be audible. You are overcomplicating the rear speaker setup. Last, I'm not sure what you mean by "Pro Audio 8in subwoofer", but using a true Pro Audio style 8" driver as a subwoofer is not going to work. They are going to need a largish ported enclosure to even begin to perform properly, and even then the low frequency response is going to be anemic. Overall, I would say start over from scratch on the system design. What is your budget and what is your goal? What equipment do you have right now you plan to use, and what equipment you were looking to use?

The only person making it an issue is you. The only person bringing it up on a weekly basis is you. The only person posting it in every thread about SSA subwoofers is you. The only person who fails to understand they are not rebadged Fi subwoofers is you. The problem.....is you. Nick's post above demonstrates that they are not copies as the differences he outlined are everything that matters in a subwoofer, and proves you are wrong. That is coming straight from the guy who built them. Now if you could kindly wipe the sand from your vagina and stop bringing it up constantly as you've just been proven wrong, that would be great.

Actually he said outwardly the motors appeared to be similar. That says nothing about similarities within the motor, and frankly he doesn't even give any external measurements of the motor itself to confirm they are anything more than similar in appearance. Also, if you look at the actual measured T/S parameters you can see they are different drivers. The Xcon has a higher Q, lower Fs, lower Le and higher Mms. Plus the Xcon has slightly more linear excursion and I believe higher thermal power handling as well. It is still an Fi copy with a couple alterations. Quoted "Any differences from the Q are probably in the voice coil itself and the gap geometry and possibly the pole piece machining." Are the external dimensions of the motor identical? He doesn't say, and I don't honestly know. I'm guessing you don't either. So it appears both you and he are basing that on nothing more than the outward appearance of the motor. Even if the outward dimensions are similar doesn't mean they are identical. T/S parameters show they aren't identical. Thermal power ratings show they aren't identical. The voice coil, gap geometry and pole machining and other features are what matters in the motor, not how similar they look externally. Yes, there is going to be some similarities. That doesn't make them copies. I don't understand why you feel the need to bring this up on a weekly basis? We get it. You think they are copies just because they are built at the same buildhouse, even though they are clearly not identical drivers. Did you do this to Sundown when they were using off the shelf boards? Follow Jacob around and post in every thread about how it's a copy of XYZ? Do you tell Kevin at Skar about how similiar his subs are to Sundown because they are designed by the same person? Or post in every Arc thread about all of the other brands that use their boards? Or is this a special fetish you have for SSA?