Impious

Not sure who told you that, but it's completely false. Most ported enclosures you see in car audio will have much less "crisp bass" than a good woofer IB. Granted, the IB won't have as much output as ported...but my single 12" subwoofer IB sounds fantastic and has more output than I'll ever use.

http://www.gatelyaudio.com/products.htm

This thread is a year old...understandable how it may be confusing due to it being October of '08.... You may have seen it several times, but it wasn't because they were running separate amps. There was something else at play. False. Another misconception. Even if there were "a slight difference in signal" from the amplifiers (which would be very slight in two even mediocre amplifiers....like, slight enough to possibly be measurable but certainly not audible), the subwoofer would not be damaged. It would play the sum of the signals, not self-destruct. What do you think the original use of DVC was? It was to allow connection of both channels of stereo sound to a single driver (subwoofer, for example) so it could reproduce the signal contained in both channels.

Generally the all-in-one systems from low- and mid-end manufacturers are generally not great (Bazooka, etc). What type of bass are you looking for? Ground-pounder loud or just something to fill out the bottom end? If you are just looking for something to fill out the bottom end without being overbearing, and myself being completely unfamiliar with the trunk of a Cobalt or how much room your mountain bike takes up, I might suggest you investigate an IB setup. No enclosure taking up trunk space...it might be possible to locate the subwoofer somewhere under the rear shelf firing up into the cabin in a location that is out of your mountain bike's way. Hide the amplifier elsewhere in the trunk and you'd have a system that takes up little to no trunk space and you wouldn't have to worry about removing/reinstalling anything.

I never said anything about unloading. An enclosures effect on a woofer and it's various performance aspects runs much deeper than simply when unloading occurs. You are looking in the wrong place. Plain and simple. Just because you heard a similar setup in a different car that happened to have different amps and liked that setups sound better is completely unrelated to the amps. There are a couple dozen variables that could be at play that would cause the differences you noted, all of which have nothing to do with the amplifiers damping factor. A new amplifier is not the fix. It would be helpful if you could go into a little more detail about what it is you are having issues with. Is it like an overhang problem...notes not sounding tight and controlled? I really couldn't get a good handle on what exactly the problem is from your previous description.

Then build a different box. But don't purchase a different amplifier with the single prospect of "better woofer control".....damping factor is completely blown out of proportion as far as importance and impact is concerned.

Buy a monoblock. Bridging a 2chan to 1chan causes a certain distortion. Monoblocks have better powersupplies that can take more beatin. doesnt get as hot, etc. None of your reasoning is really correct. As to the original question...a mono amp would generally be more flexible, and generally more efficient and more cost effective. That's in general, not always the case. If you find a 2-channel amp that fits your goals and budget there is nothing wrong with using it.

Don't pay too much attention to that article, as there's not much worthwhile information contained in it. He's merely contributing to what he's apparently attempting to disspell, as outlined in the opening sentence....All that article proves is he really doesn't understand the function or use of a gain control.

Standing waves are not going to occur within the enclosure due to the small size of the enclosure compared to the wavelength for subbass, unless you have an enclosure the size of a room or are running your subwoofer up to several hundred hz.

http://www.diysubwoofers.org/bnd/4thord1.htm

The son of a lady I used to work with got a ticket for noise ordinance violation with his OEM system. Anyways...as has been stated, good luck getting a judge to believe the officer is in effect lying or mistaken. Won't happen. The officer doesn't really need proof...the ticket is the proof. It'll end up being your job to prove it didn't happen...and even if you could prove it didn't happen with "witnesses" for example, chances of the ticket being dropped are slim. Slightly off-topic but demonstrates my point...young lad that used to work for me was at the lake with some buddies. Him and his buddies were in a few different boats, and one kid tossed a beer can from one boat to another. DNR officer also happened to be on said lake, and the DNR officer claimed he "saw" the beer can not land in the other boat, but land in the lake and wrote the kid a ticket for littering. The can didn't land in the lake, it did in fact land in the boat. But the officer couldn't be persuaded at the scene that it didn't land in the lake, and when they went to court even with the eye witnesses who saw the can land in the boat....the judge upheld the ticket, siding with the officer. Is it fair? Probably not. But it is what it is.

The other guy. If I'm understanding your post, you would be correct in that sealed enclosures don't have the unloading issue that ported enclosures have.

They certainly aren't the norm, but they have been around here and there. More than just the Focal for certain.

Those low notes are put out by the excursion of the sub. A sealed box makes the pressure that the sub exerts force back onto itself, making it rebound faster and not allowing for that full excursion, unless you are using a very large sealed enclosure. ported lets the sub "breathe" so to speak and allows for more and deeper movement of the cone. (as far as my understanding goes) Not really.

Not looking up all of those amps. Got any links?

Flexibility in wiring options. SVC doesn't offer any flexibility, DVC/QVC does.

You didn't think to verify the amplifier would handle the load before you purchased the amplifier?

First you need to explain why you think you need a capacitor. What exactly is it that you are trying to "fix"?

Keep in mind that impedance is also heat and frequency dependent. So it would be impossible to choose any particular impedance based on measurements as the measurements will be all over the place depending how and when you measure. Some people don't like the DMM method. But I think it sets a reasonable baseline for someone not familiar with gain setting/structure.

I wouldn't recommend you actually drive a subwoofer to it's mechanical limits, however...

Keep in mind that you have to quadruple displacement to maintain the same SPL for every octave decrease in frequency. So that means, for example, that if your mids are moving 3mm at 50hz to produce a given SPL level, they must excurt 12mm at 25hz to output the same SPL. Given the generally limited excursion of the majority of mids...this isn't really a good situation to put your speakers in. It's certainly possible to listen to the stereo with no HPF, but you're mainly gambling that you have the self control to always keep the volume at a level where this doesn't become dangerous.

Plug 'em into an enclosure program and play around.

The bridge you are referring to (as pointed out by M5) failed not necessarily because it was excited at resonance, but because it was excited at resonance and driven beyond it's mechanical limitations. Just the same a subwoofer would be damaged if you drove it past it's mechanical limits. But going back to our weight on a spring...what happens when the weight is pulled downward and released? Does the spring oscillate until it self destructs, or does it oscillate until it's energy is expended? So, how do we determine the time it takes a subwoofer excited at resonance to dissipate it's energy and cease oscillation? By the Q factor. The Q of the driver describes the amount of damping provided at resonance, or for how long after the signal is removed the driver will continue to "ring". (The terms "overshoot" and "ringing" are commonly used to express the amount of damping a driver has.) Qms is mechanical damping (i.e. the suspension). Qes is the electrical damping (i.e. the motor). And Qts is the total Q of the driver (Qts = Qms * Qes/Qms + Qes). A high Q indicates a driver that is underdamped, meaning it will "ring" for a longer period of time or that it has more "overshoot". A low Q indicates a driver is more overdamped, meaning it will have less "ringing" or less "overshoot". So the Qts tells us how a driver will behave at Fs based on the damping provided by the motor and the suspension. And, in case you've never noticed...in the vast majority of drivers on the market, the Qms is much higher than the Qes. Likewise, the total Q of the driver (Qts) is typically just slightly lower than the Qes and significantly lower than Qms. So what does this mean? It tells us that the motor provides much more damping and control over the motion of the cone than the suspension. Well, the impedance does increase but I don't believe "rise" is typically the word used to express that idea as that's most associated with enclosure and heat effects, again as M5 pointed out.

My first question is, why do you think a speaker would be damaged by playing at it's Fs? The woofer doesn't self-destruct at Fs. Think of a weight at the end of a spring, with the spring being suspended vertically and the weight attached at the bottom of the spring. If you grab the weight, pull it down and then release it, the spring will rebound and continue oscillating up and down at a specific rate. In speaker terms, the mass of the soft parts would be the weight and the suspension would be the spring. At some specific frequency, the weight of the moving mass will be in balance with the compliance of the suspension and there will be a natural oscillation of the "weight on the spring" (the moving mass on the suspension). This is the Fs, and can be identified by a peak in the driver's impedance.

what should i look for in a good amp? The amplifier that has the most power within your budget, has the features you desire, cosmetics you can live with and a warranty that satisfies you.