Eminence 18 Scoop

ok but with a proper negative expansion?

bitzo wrote: ok but with a proper negative expansion?

EXACTLY AS PLANS STATE, but with previous mentioned external dimensions + 45° deflectors/braces added.

Can assure you, the only 18" scoops I have heard to match this design in terms of depth, SPL,throw are ASS S118, Stravens, or this design built full size.

EDIT:(Not heard wattcos yet)

aye aye sir

bitzo wrote: aye aye sir

That's "MR Sir", if you don't mind... :lol:

OK thats easy Lev, too wide though.
How much we losing if it's 636 wide?, ie 600 mouth

nickyburnell wrote: OK thats easy Lev, too wide though.
How much we losing if it's 636 wide?, ie 600 mouth

levyte357 wrote:

bitzo wrote: Prototyping is the definitive way to learn but a bit expensive for just an hobby.

When this cab is built H48", W24", 29"D, with approx 5" gap below rear baffle + corner bracing/deflectors, it gives stunning performance with these drivers and many similiar,

24"W is 610mm wide.. :lol:

25"W (636mm) would be even better.

ok internal width 60 cm, depth from baffle 68.8 (72.5 minus 3*woodthickness). I modeled a duct to have the cornered negative expansion on the top right corner brace.
I put the eminence sim just for reference. 2pi sim pd1850 loaded.
[attachment=0:2gmjdjp6]<!-- ia0 -->eminence.jpg<!-- ia0 -->[/attachment:2gmjdjp6]

bitzo wrote: ok internal width 60 cm, depth from baffle 68.8 (72.5 minus 3*woodthickness). I modeled a duct to have the cornered negative expansion on the top right corner brace.

I estimate internal chamber depth to be: 245 - (30+18) = 197mm, is this what you're using to estimate chamber volume ?

Would leave the duct out of sim for now, and just model scoop in 3 segments,

throat to first corner
first corner to start of horn mouth
mouth start to end of horn mouth

Graph should basically say small peak around 43hz, dip 50-65, steeply rising to huge peak at 80hz.

However excursion graph should state minimum excursion at 40hz, which is why small chamber scoops like pre-amps.. smiley23

Did this once.
was great[attachment=0:20itcavz]<!-- ia0 -->untitled.jpg<!-- ia0 -->[/attachment:20itcavz]

nickyburnell wrote: Did this once.
was great

Note the similarity to Eminence Design.