Greetings to the experts on the BIB design,
There doesn't seem to be much info about the two fold BIB online so I thought to seek the inputs of the experts here. Was messing around with the two-fold BIB calculator. The Z-driver came out to be around 25 inches. The external height is around 64 inches. To raise the driver to around ear level, say about 38 inches, is it as simple as adding a sand/damping filled chamber underneath the BIB cabinet (25" Z-driver BIB + 13" chamber)? I guess this also would raise the two fold BIB cabinet higher towards the ceiling, a good thing?
Thanks for the advice.
There doesn't seem to be much info about the two fold BIB online so I thought to seek the inputs of the experts here. Was messing around with the two-fold BIB calculator. The Z-driver came out to be around 25 inches. The external height is around 64 inches. To raise the driver to around ear level, say about 38 inches, is it as simple as adding a sand/damping filled chamber underneath the BIB cabinet (25" Z-driver BIB + 13" chamber)? I guess this also would raise the two fold BIB cabinet higher towards the ceiling, a good thing?
Thanks for the advice.
Interesting! Wasn't aware of this. Without good ceiling or floor loading the driver can be very poorly protected since normally the cab will be tuned a full octave below Fs, which equates to 4x the excursion [6 dB] above and beyond whatever it needs above Fs, so be forewarned.
Yes, it's as simple as that, just make sure it's about as resonant as a block of concrete or so rigd the driver can't excite it. 😉
Yes, it's as simple as that, just make sure it's about as resonant as a block of concrete or so rigd the driver can't excite it. 😉
Two fold BIB follow up
Thank you very much for the advice on the two fold BIB.
Is there a rule of thumb for determining whether the top of the speaker cabinet is close enough to the ceiling to have the protection against excessive speaker excursion? My sample two fold BIB calculation has the cabinet height at 64 inches, raising by @13inches would make it 77 inches. The floor to ceiling distance is about 97 inches, so there is a 20-inch space.
Thank you
Thank you very much for the advice on the two fold BIB.
Is there a rule of thumb for determining whether the top of the speaker cabinet is close enough to the ceiling to have the protection against excessive speaker excursion? My sample two fold BIB calculation has the cabinet height at 64 inches, raising by @13inches would make it 77 inches. The floor to ceiling distance is about 97 inches, so there is a 20-inch space.
Thank you
You're welcome!
Once upon a time I made a calculation and posted it 'somewhere', presumably in the huge BIB thread and if I saved it, it's on a damaged BU HD, so you'll have to search or hopefully someone will post it.
That said, I know I've many? times recommended adding a simple removable/gasketed 'top hat' with slotted sides that sum to the horn's mouth area [Sm] to bridge the gap, leaving a little room between it and the ceiling for relatively easy install.
Once upon a time I made a calculation and posted it 'somewhere', presumably in the huge BIB thread and if I saved it, it's on a damaged BU HD, so you'll have to search or hopefully someone will post it.
That said, I know I've many? times recommended adding a simple removable/gasketed 'top hat' with slotted sides that sum to the horn's mouth area [Sm] to bridge the gap, leaving a little room between it and the ceiling for relatively easy install.
Greetings, GM. May be this is it?
Terry Cain's BIB -why does it work and does anyone have those Fostex Craft Handbooks?
Terry Cain's BIB -why does it work and does anyone have those Fostex Craft Handbooks?