I know this is an old thread, but feel it is worth resurrecting. FYI, I swap the beryllium tweeters into various Paradigm Signature v1 and Studio speakers. Few of these swaps have included any crossover changes. According to Paradigm a crossover designed for the beryllium tweeter must also be used to get all of the benefits, such as the ability to reproduce up to 45k Hz sounds. I have the utmost respect for Paradigm and believe that they are telling the truth. I also love my cats dearly, but I am playing the music for people, so up into the low 20k hz range is plenty for me (cats hearing goes up to 79k HZ, most humans stop by, or long before 20k).
I have listened to my hybrid speakers next to original Signature v2/v3 speakers and I simply cannot perceive any audible difference between the tweeters with the correct crossover vs the ones designed for PALs (PAL, S-PAL, or G-PAL depending on series and generation). Once again, I am not questioning Paradigm, or the previous poster that wasn't satisfied totally with the swap, but I am completely satisfied, as are all of my customers that have purchased my hybrids, or had me upgrade their personal speakers.
I have swapped beryllium into Signature S8 v1s, Signature C5 v1, Studio 100 v1, v2, and v5, and finally Studio 20 v5. All of those swaps used the original crossovers not designed for beryllium. An interesting case study is the C5, as I did acquire the C5 v2 crossover and upgraded to it later. I didn't perceive any change in the speaker afterward, but assume that its measurements probably changed. I also put beryllium tweeters in Studio 60 v3 and Studio 40 v4 cabinets, but both of those swaps utilized Signature S4 v2 crossovers, which of course were designed for beryllium.
Finally a few last thoughts for anyone considering this swap, including a case study from one of my customers that had me upgrade his own speakers. In my opinion the beryllium tweeters are a big improvement and worth the cost. However, this is relative because I feel once you have entered Paradigm Studio level and above (even Monitor Series 7 for that matter), you have entered the area of diminishing returns. Let's take my Studio 100 v2 customer. His speakers were worth about $800, and he spent $700 for me to swap out his stock PAL tweeters to beryllium and another $100 to upgrade to Studio v3 mids. So he essentially doubled the amount invested in his speakers that were probably 85% as good as S6 v2 to get up to 95% as good. On paper this is kind of a silly investment, but it is the way audio works. If we use the S6 v2 as our 100% mark, the first 50% is pretty cheap, but each 10% gain becomes more and more expensive in a non linear fashion. A pain of 9se mk3 for $200 can get you 50%, Monitor 9 v3 can get you up to 70% for $350, 100 v2 gets 85% for $800, my customer's hybrids get 95% for $1,500 and the S6 v2 are usually in the $2k to $2.5k realm. How about 110%, try Persona 3f for $6k.
So how did my customer feel about his decision. I hooked them up to a mini amp in my driveway and it took less than a minute of a single song for him to smile ear to ear, and be totally glad that he doubled his investment in his speakers. He could have sold his 100s for $800, taken the $800 in upgrade funds, and added another $400 to $900 and actually gotten S6 v2, or of course left his speakers stock. None was a wrong choice, but for him the hybrids were the right call. However, he never even heard the S6 v2, so I have no idea if he would have added an additional (let's say) $800 to trade up to a pair of S6 v2, because I didn't have a pair on hand. The problem is, like him, most have to make these decisions without hearing every option. Even worse, most have to decide with hearing one or less of the options.
In the end you have to decide what you are willing to invest and where you want to end up on the performance scale. The most important variables are your goals and budget. I can try to answer any other questions on this subject or modifying Paradigm speakers in general, but I can only share my opinions, opinions of my friends along with those of my customers.
