Ok, juggling several projects now...these long awaited custom crossovers are fabricated. Matched to B&W Midrange and Tweeters for the 4X Doors and 1X Dash Center Channel.
Lots to discuss on this topic, but my next priorities are 1) Spring Install DIY (95% done), 2) Akrapovic Muffler Install, 3) Front F85 Rotors, and then this 3) B&W Speaker Upgrade.
Custom Crossovers's, what am I talking about? Late last year we learned that B&W speakers from the G05, 06, and 07 series were plug and play into the E70 depending on which audio system option you have. I have the S752A Audio option (aka Individual Audio System). I started with the D-pillars and then center dash. Next were the doors, but I got distracted by a post back in Jan-Feb in the General E70 forums where some were discussing crossovers to use with the B&W speakers. I then stumbled across a custom high end speaker designer and crossover fabricator and he agreed to build me some XO's. I sent him a B&W Tweeter and Midrange and he performed a speaker frequency analysis. I also provided him with other details about the upgrade, took measurements, etc. It took him 5 months b/c he was so busy, but he finished this past week. Here's a sneak peek at them...
B&W (Tweeter and Midrange) Speaker Frequency Analysis used for crossover design. He mentioned these were decent or maybe just above average speakers (possibly didn't want to burst my bubble), but not exceptional. However he also said he's seen many high end high dollar speakers on the market fair worse:
Fabricated crossover's w/o lead wires attached:
Custom Crossover Response for all five Crossovers (near perfect match):
Final System Response with XO's attached to the B&W drivers:
I found these Takachi enclosures and the designer made the crossovers to fit in these. They are actually polycarbonate/clear, but I haven't taken the protective film off yet. I will not be using the PCB studs, I will actually be hot melting the board in place. These are actually a VERY NICE kit meant for Raspberries, direct order from Japan. Great customer service, very nice. They sent a questionnaire to gather info that could help with their new enclosure designs.
A lot still to do...I'll need some custom pigtails which I've already designed with OEM connectors, but have to build...still need to buy the rest of the drivers, figure out where/how to mount crossovers, etc. Also, in case you're wondering, I did mention to him that others may be interested in the same and recommended he keep the design, he didn't comment. But given my verbose descriptions and long emails, he was extremely patient, lol.
OH and if you are wondering why I didn't use the Diamond Tweeters, I was talked out of it, FWIW some opinion: "
The main advantage they have is that the membrane works as a piston higher in frequency allowing greater clarity but other than that, they have a rolled off top end and sound harsher than metal. The metal domes can be made thinner and easier to dampen the ringing, also the metal domes weigh less and had more output at the top..........there is much more to be said, but wont go into it too much here. I designed many hi-fi tweeters. Personally, I would go with the metal dome over the diamond dome as the diamond will have a lack of air due to its fall off above 10khz. Since you are listening off axis mostly in a car, you want a boost above 10khz, not a roll-off". . I'm going to go out on a limb and guess that BMW accounts for some of this in their system and amp, but I'm using my S752 amp, so...in the end I didn't need much more rationalization to spend LESS money and use the regular tweeters, lol.
More to come...