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The biggest problem with the non-infinity deck is the lack of adequate processing. The biggest problem with the infinity deck is the crappy processing by the processor. At least on the infinity system, they play some mediocre door speakers down to 50hz. In truth, only the best 6.5" speakers can be played down to 50hz, and to do that in a door, the door must be absolutely solid and dead. The biggest problem with the sub is simply it's size and it's not mounted in a solid enough baffle.

As far as options, with the non-infinity deck there are a number of processors that can use the rear speaker signal to process the sound, and send it to the new amps. With the infinity system, the best option is to use a processor with optical input and get the signal from the head unit before processing. You will lose all stock audio and volume adjustments this way, but the sound will be much better, and you can adjust the volume with the processor
 

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If your just looking to install a sub, the alpine type r is a great sub for a car audio branded sub. Klippel optimized, which is THE definitive measurement device for speakers. The audio control would work. That's the way I would go if you don't plan on replacing any other speakers. If you do think you'd replace the other speakers, I would look more towards a C-DSP from MiniDSP.
 

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Simply put, a sealed box will provide the smoothest in car response, at the trade off of being less efficient than a ported box. It will also have more distortion at the low end of its frequency range.

Ported boxes can be more efficient, and reduce distortion at the tuning frequency, but they roll off faster past the tuning point, and need eq to smooth out the response.

My last car used a ported 10, and eq to fix the frequency response. I generally listen to Metal, Rock, Classical, and Rap. With the occasional tuning sessions using extremely well recorded reference material.

My wife's Optima will have a sealed 12" sub, fully sealed and enclosed 8" midbass in the doors, infinite baffle 4.5" midranges in the dash, and tweeters in the sail panels. This is only for simplicity and to avoid obstructing her view.

My personal next car, will have four sealed 12" subwoofers, ported 8" midbass in the kick panels, sealed 4.5" midranges on the dash on axis, and full format tweeters on axis on the dash.
 

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Oh boy.

Class d does not mean it can handle lower ohm loads. Class d means the amp uses a switching power supply. That's it.

Dual voice coils doesn't mean better bang for your buck either. You can have great subs that are single or dual voice coil. Dual voice coil can sometimes increase power handling which lowers power compression. Other times, as in an xbl2 motor design, they use the second coil to significantly lower distortion.


Ported boxes only sound sloppy if they are poorly built, and you don't have good eq capability. Ported boxes actually lower distortion near the tuning frequency by limiting cone excursion. Single reflex bandpass boxes limit distortion above the tuning frequency. And dual reflex bandpass boxes roll off distortion above the upper tuning frequency, and lower distortion near the lower tuning frequency. Band pass boxes are the ONLY way to filter out harmonic distortion.

And last but not least, capacitors are just a bandaid for a poor electrical system. Upgrade your big three. If you still have dimming issues, you need a bigger battery and a high output alternator.

I ran 1000 watts to my last sub, 125 watts to each midrange, and 70 watts to each tweeter in my last build. It was a 98 dodge neon with the stock alternator, cheapie walmart battery, and 0 gauge wires. And not even on the most bass heavy of music did my lights dim.
 

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I never said a 2 channel bridged to 1 ohm was better than a 1 ohm stable class d. I clarified what class d actually menat, because in your post, you very clearly said that class d was preferred and that that was because it meant it could handle lower ohm loads.

I still don't see how dvc is the best bang for your buck. Best bang for your buck, to me, means getting the sub and amplifier combination that does what you want for the least money. That could be svc or dvc, depending on what you want.

Ported boxes are actually more accurate if designed right. As said earlier, they lower distortion. If they are designed right, they will take the transfer function of the car it is installed in into account, and the peak in response will smoothly roll into the cabin gain. Furthermore, ported are on frequency range limited if they are purposely designed as one note wonders. One of the best subwoofer set ups I've ever heard was a 6th order bandpass box with two jbl 15"s. It was impressive enough to win a state sound quality championship in meca's extreme class, and would have been in th fight for a world championship had the transmission not failed.

Like I said, dead stock 12 year old alternator, 0ga big three, 0ga wire to the amps. No dimming. I could play skrillex at full tilt or the telarc 1812 recording and not once did the lights dim. Class ab on the front stage, class d on the sub. If your lights are dimming from music in a sound quality based build, something with the cars electrical is wrong.
 
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