Happy Holidays All!
Over winter break I plan to build a pair of B&C Sub 15s I'm going to slightly modify the design to incorporate an extension around the enclosure about 40mm to countersink a flush grill. I want the vents covered also as these will live in my garage when not in use and I live rural so rodents are a real thing. Given that the enclosure is on the smaller side and the vent is fairly sizeable, small differences in length seems to make big differences in tuning. The flange will extend the vent on 3 sides, since it is only 3 sides, how do I account for/calculate the amount if vent I have to leave off internally?
Thanks!
Chad
Over winter break I plan to build a pair of B&C Sub 15s I'm going to slightly modify the design to incorporate an extension around the enclosure about 40mm to countersink a flush grill. I want the vents covered also as these will live in my garage when not in use and I live rural so rodents are a real thing. Given that the enclosure is on the smaller side and the vent is fairly sizeable, small differences in length seems to make big differences in tuning. The flange will extend the vent on 3 sides, since it is only 3 sides, how do I account for/calculate the amount if vent I have to leave off internally?
Thanks!
Chad
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Chad,
The vent is already extended infinitely on the bottom side when on the ground, no problem there.
The other two sides- not much of an issue at all.
A sketch of what you plan to do would help understand any issues that might arise from your particular build.
The vent is already extended infinitely on the bottom side when on the ground, no problem there.
The other two sides- not much of an issue at all.
A sketch of what you plan to do would help understand any issues that might arise from your particular build.
Thanks Art,
Well, they will probably only be stored with the vent down as I plan to lay them on their "side" for use as that will make a better footing (there will be a pole mount on the "side."
I'll try to get a rough sketch posted, but it's basically the top, bottom and sides 40mm longer with the baffle and vent brace inset 40mm.
The bottom photos on this page is exactly my thoughts.
Chad
Well, they will probably only be stored with the vent down as I plan to lay them on their "side" for use as that will make a better footing (there will be a pole mount on the "side."
I'll try to get a rough sketch posted, but it's basically the top, bottom and sides 40mm longer with the baffle and vent brace inset 40mm.
The bottom photos on this page is exactly my thoughts.
Chad
The 40mm depth extension won't affect the Fb, but a grill frame over the port may slightly affect Fb and turbulence.
The grill will be "frame-less" for the most part as it will be full steel with a 90 degree bend. The biggest concern will be how open the grill is as the only thing impeding the edge of the vent will be the thickness of the sheet metal. And 2-3 rivnuts. the fasteners for the grill will come in from the outside of the lip.
Not even to the grill design in terms of how open yet, because I have yet to see if this cabinet sucks. 😀
Not even to the grill design in terms of how open yet, because I have yet to see if this cabinet sucks. 😀
A perforated steel grill as you describe won't be a concern as far as the port tuning, but ringing can be.
thouught about that a bit, probably wont be playing anything high enough to get it exited at resonance, but, a center post is not out of the question.
Leave enough room so the cone surround won't hit the post at Xlim, which could be around 30mm from the resting position.