Nominal Vs Overall Diameter

[pjoseph]

Looking on the JL audio site it shows a Nominal of 13.5 and Overall of 14in
I am wondering what is the difference.
I am looking to make a front panel to make the sub flush mounted not sure which diameter to use?

 

[TLS Guy]

Looking on the JL audio site it shows a Nominal of 13.5 and Overall of 14in
I am wondering what is the difference.
I am looking to make a front panel to make the sub flush mounted not sure which diameter to use?

Before you make ANY holes make sure you have the driver in your hand, or a detailed mechanical drawing.

If you make the hole 14" the driver will drop right through. The nominal diameter, will be the best estimate of SD, for box design purposes.

You will need the hole, so the driver is a snug fit, and then use the router, so the driver can be set flush.

 

[MidnightSensi]

Nominal sizes are rough or rounded dimensions, often used to refer to something simpler (like a 2x4 isn't actually 2"x4", that's a nominal dimension).

Double check with them before cutting, because it would make more sense if the nominal size was 14" and actual was 13.5" Generally a nominal size is a simpler dimension used to identify something. So, double check with them. Ask for a CAD drawing of exterior geometry. A lot of times they won't give you actual CAD drawings, obviously, but most manufacturers have exterior geometry CAD sheets for manufacturers to fit using.

 

[pjoseph]

They are listed on the JL site I have the mounting hole diameter but i want to lay a piece over that which goes around the sub but not sure which to use.

 

[pjoseph]

Yea i just emailed them I will let you know what they say.

thanks

 

[MidnightSensi]

*edit* Ah, you were typing as I was.. yeah let us know what they say!

They are listed on the JL site I have the mounting hole diameter but i want to lay a piece over that which goes around the sub but not sure which to use.

14" sounds like a nominal diameter to me and 13.5" sounds like the actual, its likely they have this backwards where you are reading so I think you should check with them.

Like a 3/4" ANSI/ASME taper shank drill bit is .7480" .... .75" is the nominal and .7480" is the actual. (I didn't pull this off the top of my head, I have Machinery's Handbook in front of me haha)

You see why I think JL might have swapped them by accident?

 

[pjoseph]

quick reply over at JL
here is what they say
" If you plan to flush mount the woofer you need to go by the overall diameter. The nominal diameter is the description of the size of the surface area of the woofer. Overall diameter is the size including the edge of the basket."

 

[annunaki]

Please keep in mind with the W7 that you will be unable to mount the driver if you plan to flush it. The reason being is the mounting system. Your flush panel cannot be a part of the enclosure, but a removable panel.

The actual diameter of the driver is 14". You will want to go slightly bigger than that, probably 14.25" or so for a nice snug look.

Please check out how the driver mounts and you will see what I mean. You will be unable to put the metal trim ring onto the driver that holds the surround pin ring to the drivers chasis.

 

[mike c]

nominal is what you call the driver ... like: "hey man, what size driver you have in your sub?" "13.5"

overall diameter is the overall diameter!

mounting hole diameter is the diameter you need to make a hole to hold the driver on the box.

http://mobile.jlaudio.com/products_subs.php?series_id=10

 

[Warpdrv]

Please keep in mind with the W7 that you will be unable to mount the driver if you plan to flush it. The reason being is the mounting system. Your flush panel cannot be a part of the enclosure, but a removable panel.

The actual diameter of the driver is 14". You will want to go slightly bigger than that, probably 14.25" or so for a nice snug look.

Please check out how the driver mounts and you will see what I mean. You will be unable to put the metal trim ring onto the driver that holds the surround pin ring to the drivers chasis.

Good point.... I have looked at the install of that driver, and I kept looking at the front of my F112 with that stupid look on my face... The actual posts that stick out to hold the grill get unscrewed to access the driver removal process.... that was pretty cool I thought....