Like I said "....but you can't really tell a difference when done. ...".
You know, one thing that makes comments far more helpful is when the commenter displays rudimentary reading comp skills.
The person you quote made the referenced statement in reply to a question about
physically mounting a very deep drive-unit in the factory subwoofer cabinet. You know, the actual reason this thread exists.
The statement was completely orthogonal to your misguided crusade, and no competent read of the statement could find otherwise.
While the rest of your comments are out of the scope of the thread, there’s enough misinformation in there that some reply is warranted.
Replace the front door speakers with a good co-axial or tri-axial speaker
There’s no such thing as a “good triaxial.” I don’t care if you’re talking about some dinky car-fi thing or the very expensive 8” Cabasse unit. There are expensive ones sold by “high end” brands, but that’s quite different from “good.”
Furthermore, the only good “coaxials” are
concentric drivers that use the midrange or midwoofer cone as a waveguide, such as a Tannoy Dual Concentric, KEF Uni-Q, or TAD/Pioneer CST. There have been a few such drivers marketed for car-fi, but they’re rare because many of the features needed to make a smooth transition from tweeter to waveguide/cone are locked up in patents by KEF, Tannoy, and Pioneer. (One
really good set marketed for car-fi were the KEF KAR units designed by Andrew Jones and made in the UK in the early 1990s.)
Never mind that one thing the CT200h “premium” system really gets right – due to very good LCR speaker placement, not parts quality – is imaging. Ditching the dash speakers for full-range units low in the doors ruins that. It seems to me the best solution is to upgrade the parts in the stock LCR dash positions, and fit dedicated midbasses in the doors. FWIW, I plan to use some 3” KEF Uni-Qs I have on hand in my dash. They’re not expensive; one can often find the little eggs I from which I pulled these drivers for under $200/trio shipped on eBay, and with suitable processing the stock passive should be adequate. True, they’re far from KEF’s best drivers, but they’re still a marked improvement over most 3” coaxes marketed for car-fi, and the polymer basket + neo magnets for both midrange and tweeter makes them fairly light.
such as JL Audio 8W7AE ( 16-80,100Hz,120Hz, even up to 150 Hz depending on the Cross-over)
You’ve obviously never played with a Jello W7, because while your crossover recommendations would be great for some long throw 8” drivers (e.g. ScanSpeak Revelator, Alpine Type R, Peerless XLS, Dayton Reference, TangBand W8-740) they’re inappropriate for the W7.
Yes, the W7 are probably the best air pumps for their size in the world. However, for some reason JL refuses to join the rest of the world and design shorting rings into their woofer motors. So the W7s have very high inductance. Unfortunately, that means their frequency response has a big hump in the 50-100Hz octave and a steep rolloff above that. So they’re best limited to below 80Hz or so in a car, and below 40Hz or so in a home system. It’s a pity, because I don’t think there’s another driver on the market that has both such a long stroke and such incredible motor linearity over that stroke. A Jello W7 with a copper sleeve on the motor (like the Aurasound drivers I use in my multisub system at home, and that Magico uses in their five-figure subwoofers) would probably be the best bass driver in the world.