The Titans were designed, from the get-go, around the KappaLite 3015LF for the T48, and the BassLite 2010 and 2012. Then, Bill helped design the HL10C, and it worked perfectly in slim models of Titans. Then, the KappaLite 3012LF was introduced, and its specs were PERFECT for Titans, especially the T39. Fast forward to ~2009 or so, and China decides it is going to cut neodymium magnet production WAY down, to artificially raise the market prices, because China has the only working mine that produces material for neo magnets. BOOM! Prices for neo drivers skyrocket! Since Bill's designs are all about using inexpensive drivers, he modified
the Titan designs to make the Lab drivers work. That is the only reason they are in the plans.
I don't know much about actual speaker applications, but is the sensitivity of the 3012LF the reason for the same output as the LAB12? or are there other factors?
In these designs, raw open-air driver sensitivity doesn't mean much. Fs is the factor at play here. Bill said it elsewhere on the forum. I don't really care for the Labs, simply because they don't offer anything but headaches and backaches in the end. I don't think they are a bad driver, for the THT, they are the $hit! It's just my opinion, YMMV.
Grant Bunter wrote:
There is a whole host of TS parameters that are involved in calculating voltage displacement limits for horn loaded cabs, in a decreasing order of significance.
The top two factors are Xmax and impedance.
The 3012lf has lower Xmax than the Lab 12, but higher impedance, so they work out to be the same in horn loaded cabs when it comes to output.
I'll just throw in at this point that, the lab 12 has significantly higher Vd than the 3012lf, but ends up with the same voltage displacement limit, so, while it is often stated here in the forum "displacement is king", Vd is only useful in many cases to compare one driver to another (usually to a smaller diameter driver).
It's the design that dictates response. It's the driver that dictates output...