BillFitzmaurice.info

hello there
after few years of silence, but intensive use of my BF actual rig...i'm giving a chance to the Otop 8.
build has started without any problem but actually something is ticking in my mind:
will i use a piezzo array of compression drivers.

i've always used piezzo in my builds but i think it's time to use something different, just to try.
BUT
i'm questionning myself :
i will use 2 8" speakers wired in serial so 2x4 gives me 8 ohms
i will use 2 compression drivers wired in serial so 2x8 ohms gives me 16 ohms

at the end what will be the electric impedance of my box ? according to the laws i will have something as 5,3 ohms because loads of my speakers and drivers are seen as parallel...right ?
so for the amp it's not 8 or 4...something in between
am i wrong ?

Kranku68 wrote: ↑Mon Oct 02, 2023 3:35 am according to the laws i will have something as 5,3 ohms because loads of my speakers and drivers are seen as parallel...right ?

Wrong. It would be 8 ohms below the crossover frequency, 16 ohms above it.

my god...i feel so stupid

It's not so bad, so long as you don't have a wife to constantly remind you.

so some pictures of the babes :

skeleton is ready


triming the handles:


boxes are closed:

and as usual, too much PU !

i was about to cut the compression horn sides and i noticed something strange in the plans...length is 21 9/16" and the inside vertical length of the cab just 21" (20 7/8)...that won't fit.

Keep reading.

okay i've seen

back bracing...

hey everybody !
autumn is finally here in france...so sunday morning i went for a little mtb ride to celebrate...bad idea.
high speed fall at the end of this little event, way faster than atumn leaves: left clavicle badly broken with no possible surgery, bruises all over the body, helmet destroyed (it's made for that)...the bike 's allright by the way.
i won't get back to work till mid december
So cutting wood will not be not possible for some weeks.
as i don't want to let everything in pieces i decided this morning to give a chance to fusion 360...i'm a f***** newbie on 3D design...after few hours here's my production for the horn diffusion system (just a half cause standard 3D printers are not so big):

some little mods today to have a perfect fit between two half horns...that's gonna be good

After few tries it's on the run for a two days printing marathon:



work in progress...7 hours

Kranku68 wrote: ↑Thu Oct 19, 2023 7:24 am some little mods today to have a perfect fit between two half horns...that's gonna be good

Wicked, keen to see these come together man!
Bummer about the injury though mate.. bikes are like that though, great fun hey

Has anyone else wondered before if the OTop8 cab could be built with a trapezoidal side profile for splaying like the DRs