"Crossover Design for New Project"

[Panomaniac]

For $80 you can get a well calibrated ECM8000 here:
www.cross-spectrum.com

You'll only need the basic.

[Altec Best]

For $80 you can get a well calibrated ECM8000 here:
www.cross-spectrum.com

You'll only need the basic.

Cool I'll put one of those in my cart Thanks Pano

[Altec Best]

I have been thinking about housing the woofers horizontally now that a few guys said it would sound better in that config. Original width was to be 34" I can increase abit if I pull out from the corner.If I make the baffle 36" with 2 416's at 32" that would leave 4" to play with maybe 2" in between the woofers and a inch on each side.My question would this baffle work.I could increase the baffle to a 1" Baltic birch and the sides will remain 3/4".I would still like to keep the woofers off the bottom of the cabinet with them at least 16-24" from the floor.And the horns directly above them as close as Poss.Would this be a better config.or would they be too close together.I can't go any wider than that otherwise I will have to continue with the over under config. The cabinet will remain triangular per GM's recommendation I need to get this finished so I can get the drawing done.Thanks for any help

[GM]

You can/want to jam the drivers within a hair's width of each other to minimize any sonic parallax error and since you're going to run a vertically oriented board brace centered between them (notched as required to clear) to the rear that combined with some other bracing there's no need for a 1" thick baffle.

Right, we want the woofers at the extreme top to minimize the vertical distance between the horn/woofer acoustic centers. The vent will be near/at the bottom.

GM

[SOOTSHE]

You can/want to jam the drivers within a hair's width of each other to minimize any sonic parallax error and since you're going to run a vertically oriented board brace centered between them (notched as required to clear) to the rear that combined with some other bracing there's no need for a 1" thick baffle.

Right, we want the woofers at the extreme top to minimize the vertical distance between the horn/woofer acoustic centers. The vent will be near/at the bottom.

GM

Sounds like a plan.

[Altec Best]

You can/want to jam the drivers within a hair's width of each other to minimize any sonic parallax error and since you're going to run a vertically oriented board brace centered between them (notched as required to clear) to the rear that combined with some other bracing there's no need for a 1" thick baffle.

Right, we want the woofers at the extreme top to minimize the vertical distance between the horn/woofer acoustic centers. The vent will be near/at the bottom.

GM

Thanks GM, my concerns too are that the max baffle height can only be 60" and as discussed to get to our desired tuning of 30 Hz we had to extend the box(Internal Volume) to 70-74" With 3/4" BB coming in only 5x5 sheets the max height in any direction is going to be 60" one piece.Now the 1" BB comes in 4x8 sheets but is 5 times the cost too unfortuantely.I can get the 3/4" for $39 sheet the 1" is $190 sheet.With the woofers in the horizontal config. will that enable us to shrink the cabinet down a bit.I'm going to do a quick drawing using the paint program then a more 3 dimensional one once I reach the desired Dimensions and configuration. :thankU:

Sounds like a plan.

Yes it Does !! My new measuring equipment is arriving painfully one piece at a time but I'm getting close He-Haw

[GM]

You're welcome!

You lost me........ If the baffle height is 60" max, then how does one extend the internal volume (net Vb) to 70-74"?!

Regardless, I previously noted that since a large baffle needs bracing and cabs usually need some in-room fine tuning, best to make a separate woofer and vent baffle, so 5x5 ft panels are plenty large enough to make the cab from since the side panels need bracing that can double as multiple panel joints.

WRT net Vb, for a given height, width, then obviously the only way to increase it is by increasing depth, though again, Olson's work indicates up to 10.5" regular depth was acceptable, so the theoretical max depth will be a 10.5" o.d. front extension from the wall and the distance from the wall to the corner apex.

Note that room corners around these parts are rarely exactly 90? or perpendicular to the floor, so best to make a cardboard cutout of the ideal size to check at both the floor and at the 60"/whatever height to see what, if any adjustments must be made to the cab's design lest you not be able to slide it all the way in.

GM

[SOOTSHE]

Now the 1" BB comes in 4x8 sheets but is 5 times the cost too unfortuantely.I can get the 3/4" for $39 sheet the 1" is $190 sheet.

Have you considered using double thicknesses of 3/4 ply? I used this method with great results on my LS W bins. I used "Green Glue" between the 2 layers (noiseproofing, adhesive sealant) & it really brought the bottom end alive. This would save on your timber costs & give you a far stiffer cabinet.

[GM]

Why waste the $$$/weight penalty? Minimally braced 19 mm BB or Apple ply is more than adequate to control dual 15"s flexing only a few mm.

GM

[SOOTSHE]

Why waste the $$$/weight penalty? Minimally braced 19 mm BB or Apple ply is more than adequate to control dual 15"s flexing only a few mm.

GM

With all due respect......my experience is all I can pass on & that was that I had my cabs built by a professional cabinet maker who fully understands the design & construction of loudspeaker cabinets. He made them from 3/4 ply & braced the heck out of them.
All I can say is I heard a world of difference when I added the extra layer of 3/4 ply.