Audio Systems: subs, fiberglass boxes, pioneer products

Question
i saw some guy one time with this one fiberglass or maybe plastic box(not sure but it wasnt like the regular ones) for his speakers..it said something like power bass or super bass or something on it..he had 2 memphis' but the watts werent all that high on them and they still thumped like crazy..they sounded louder than one of my friends solobaric 12" L7s..they parked next to each other and compared..and the memphis guy smoked him..do fiberglass boxes really make a difference?  and what kind of box should i get so i get the most out of these subs?...thanks again.
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-----Question-----
i really wanna buy these TS-W3004SPL Pioneer premier subs..their 12' and have 3000 watts..i wanna stick to pioneer on everything in my car except for maybe the amps cause pioneer amps arent so strong but everything else yea..well before i buy them i just wanted to ask if they were even good..the magnet on them is huge and they look great but looks arent everything..i found out the hard way..i have a friend that could hook me up with 2 of these and a box for like 240 or so but yea i just wanted to know your opinion about these speakers and if it was a good deal or not..well thanks for your help..bye.
-----Answer-----
I donot have experience with these models. However, I am a great fan of Pioneer products.  It is a grand company with excellent engineering. I know personally many of the engineers who design their products and have high regard for them.

As a general rule, I am always confident of their products.

I wish you the best results; however, much of the final outcome is in the installation and attention to detail in the design of the boxes the subs will be mounted in.

All the best,

Cleggsan


Answer
The box design is critical, but the governing factors are the box size and rigidity of the materials used.  Then, performance is also greatly effected by the location or mounting within the acoustic space.  In other words, the vehicle they are mounted in will make a big difference in the low frequency radiation.

AND: Another great factor in the "loudness" is the spl rating of the sub. For example, a sensitivity of 97db is twice as powerful as one with a 94db rating.  3db denotes a 2 to 1 power difference.  9 db denotes a 2 to 1 loudness difference; in other words, a 9db difference in sensitivity will produce a 2 to 1 loudness difference to the ear and will take almost 10 times the power to produce it.  That is the non-linearity of audio power and aural acoustics relationships.

Hope this helps to explain what may be going on with the systems you are comparing.
Cleggsan