quick question about SDX10

[neutron7]

I bought a couple of SDX10s,

I just need to find out what the volume of the driver is, so i can subtract it from my box calculation.

[flatfinger]

Hey Neutron , perhaps tis could help ??


Speaker Driver Displacement Calculator

Speaker Driver Displacement Calculator Help

[neutron7]

That's perfect, thanks, I am glad you pointed that out, my guess was off by quite a bit.

[chrisb]

Originally Posted by neutron7

That's perfect, thanks, I am glad you pointed that out, my guess was off by quite a bit.

Did you mean the (net internal) physical volume the driver would occupy within the enclosure? As the calculator appears to not consider the cast frame, etc (which on the CSS woofers and other biga$$ woofers are quite substantial), that could certainly be a different figure - your initial estimate might be closer than the calculator suggests?

[neutron7]

I thought about that, and the fact that the magnet is hollow, so i guessed they would cancel out, but i added a half liter anyways, which i can always fill with something if it screws up the tuning too much.

[chrisb]

Originally Posted by neutron7

I thought about that, and the fact that the magnet is hollow, so i guessed they would cancel out, but i added a half liter anyways, which i can always fill with something if it screws up the tuning too much.

Why would the "hollow" magnet ( vented for voice coil ) make that much difference? - there's much more "free-air" inside the support arms and cone/rear spider. An easy rule of thumb for a driver of this type is to estimate the internal volume as that of a cylinder the diameter of magnet.

But in any case, the real question might well be what enclosure design did you have in mind? A single of these would work quite well in a simple sealed approx 40liters, (~1.5 ft^3) - just be sure to allow for bracing, including a magnet support if possible - these are very substantial drivers and will definitely benefit from all the bracing you can incorporate.

[neutron7]

I thought the air space in the the hollow magnet would make up (roughly) for the additional volume of the basket compared to a stamped one, which i am guessing that calculator was made for.

using the rule of thumb cylinder calculation gives almost double what the calculator does.

Anyways, today i modeled the cone, magnet, and basket roughly in 3ds MAX, (which has a tool to calculate the volume of things) and it came to roughly 2.1L. closer to the calculator (1.5L) than the cylinder rule of thumb (3L) that is if the cylinder is supposed to be the depth of the driver, i wasnt quite clear on that.

the enclosure is sealed, 24 liters as suggested in the SDX10 PDF. I know its a bit small but that's about as big as i can realistically go (studio monitors). and it has bracing but no magnet support. (i could change that)

they will be crossed over with miniDSP board, so i will be able to use some equalization with that as well.

[chrisb]

Originally Posted by neutron7

I thought the air space in the the hollow magnet would make up (roughly) for the additional volume of the basket compared to a stamped one, which i am guessing that calculator was made for.

using the rule of thumb cylinder calculation gives almost double what the calculator does.

Anyways, today i modeled the cone, magnet, and basket roughly in 3ds MAX, (which has a tool to calculate the volume of things) and it came to roughly 2.1L. closer to the calculator (1.5L) than the cylinder rule of thumb (3L) that is if the cylinder is supposed to be the depth of the driver, i wasnt quite clear on that.

the enclosure is sealed, 24 liters as suggested in the SDX10 PDF. I know its a bit small but that's about as big as i can realistically go (studio monitors). and it has bracing but no magnet support. (i could change that)

they will be crossed over with miniDSP board, so i will be able to use some equalization with that as well.

I've not worked with this driver, but have done with the( much smaller) SDX7 which thrives in very small sealed enclosure, so all theorizing aside, you may well be fine with the 24 liters. Magnet support could be as simple as sitting on a small block of material. With the driver's prodigious power handling ability, and adequate power to support any necessary EQ, you should be able to move some air.

have fun

[planet10]

Originally Posted by neutron7

Anyways, today i modeled the cone, magnet, and basket roughly in 3ds MAX, (which has a tool to calculate the volume of things) and it came to roughly 2.1L. closer to the calculator (1.5L) than the cylinder rule of thumb (3L) that is if the cylinder is supposed to be the depth of the driver, i wasnt quite clear on that.

I take the cylinder only as far as the back of the baffle, which with a double baffle as recommended for SDX10, would be 36-38 mm less than the height of the driver. With the SDX10 i'd probably also consider the last bit of the magnet that is a shallow cone seperately.

the enclosure is sealed, 24 liters as suggested in the SDX10 PDF. I know its a bit small but that's about as big as i can realistically go (studio monitors). and it has bracing but no magnet support. (i could change that)

I have SDX10 for a pair of push-push woofers. So far the plan is to do a sealed 15" square cyclinder of 50-60 litres heavily stuffed with ultratouch. Do install braces. And i'd recommend BB.

dave

[chrisb]

if you haven't already got the box finished, bracing/support for the magnets could be as simple as a square block or curved saddle - these are heavy drivers