hole size for 12" alnico blue dog speaker

[blindopher]

Hi,

 

How big should the hole in the baffle board be for a speaker of the following diameter: 12-1/8" (30.79cm)?

 

Do I need to measure or can i just cut an 11" hole and not worry about it? The driver in question is a Weber Alnico Blue Dog.

 

thanx!

[isaac42]

Look at the back of the driver. There should be a lip, where the bolt circle is, then a place where the frame starts to go backward. You know the outside diameter (12 1/8"). How wide is the lip? Double that and subtract it from the outside diameter. That gives you the driver cutout diameter.

[Goddess of '93]

Whatever you do, dont trace around the outside and cut on the line!

[blindopher]

thanx Isaac42, that is the way to go.

[WRGKMC]

If you're doing this without a radius tool, What I do is draw a circle round the speaker.

I know I cant get near that line. I then take a large round dinner plate to act as a curved edge to trace an inside line

I make sure I have about 3/4" or so and draw a line inside the first and have enough space to mount the speaker.

 

Then when I cut the hole with a jig saw I make sure I stay inside the inside line.

 

You can also do this using a large compass or whatever you have on hand that will act as a compass.

A piece of metal or wood that has holes in it will work. The wood gets tacked down in the center with a single nail,

then you drill a hole for the pencil at the radius mark. You then just rind the pencil around the center like the hour hand on a clock

and you have your circle.

 

I just use the dish plate thing because drawing a circle around the speaker is easier and i'm pretty good at drawing the inner circle

by eye. I only need a guide and the rest is just eyeballing the cut with the saw.

 

One word of advice is, you can always take off more material so if anything make the hole slightly smaller vs too large,

If you cut too large, the job is ruined.

 

Also if this is a front mount, the hole has to be very exact or you can have air leakage.

If its a back mount and you go a little small the speaker will still safely mount because you'll have some extra meat fro the mounting bolts. .