49 cent wonder mounting question

[mazeroth]

Turning the 49 cent 4" over it looks like it could be a little complicated to mount properly in MDF. When you guys cut the holes for it did you cut a hole so only the metal flaps touch the outer MDF or also the ring that's about 1/16th of an inch lower than it? If the latter, when you screw it in the flaps will probably bend down to the MDF.

I'm hoping to get proper measurements for the hole that goes all the way through the MDF, and for the smaller inner ring that I could hopefully route out, however deep it needs to be. Anyone have accurate measurements? Sorry if I'm babbling!

[chipco3434]

What? You haven't built those yet?

Drill 3-3/4" diameter holes on 4-1/16" centers. On the front side, you will need to use a piloted router to get it out to 4" "plus" to a depth of about 1/8". You can go deeper becaue these will be bedded in rope caulk. I then routed out the back of the holes with a 1/2" radius tool. best I can tell you was it was "purdy deep" ~ 1/2" or so.

Get it done!

[cytokine]

This is one of the thing I'm considering as well.

When you say "use a piloted router ..." are you talking about a Rabbeting bit or did you build a jig to cut that extra bit out? Doing it freehand would be a bit of a risk considering how long it has taken me to cut the 16 holes in the baffles I've made.

Oh yeah and mazeroth... get busy . You inquired when I started my thread which was easily a week ago.

chip;

Why rope caulk? Although mazeroth is right about the flaps, once you rout out the extra little bit they will mount flush. Any reason you can think of not to use screws?

Sure, this is an experiment but I still want mine to look good just in case they are keepers.

[Luke (Uof Iowa)]

If you drill holes less than 4", what about the terminals? They stick out to the outer edge.

[chipco3434]

Why rope caulk? Although mazeroth is right about the flaps, once you rout out the extra little bit they will mount flush. Any reason you can think of not to use screws?

You will still use the screws but the caulk just dampens any vibration.

"use a piloted router ..."

A router bit with a bearing on the end to run on the ID of the 3-3/4" holes.

If you drill holes less than 4", what about the terminals? They stick out to the outer edge.

Bend 'em out of the way!

[BillFitzmaurice]

The better way is to drill 4" holes and then rout from the rear a 1/2"radius quarter-roundover; that opens up access from the rear and you can fill the joint between the frame and baffle with silicone sealant, since the frame is too small for a decent gasket anyway. And yes, bend the lugs out of the way.

[chipco3434]

Bill... I think that with a 4" hole, there's just not enough "meat" between centers. This might lead to a breakout during the hole sawing operation. Sure, the top routing is an added step, but no chance of busted wall.

I chose the rope caulk because it 1) doesn't drip 2) doesn't harden.

[BillFitzmaurice]

You do have to leave about 1/2"- 5/8" of wood between the holes but it doesn't affect the response, assuming you don't try to crossover above 6kHz, which you shouldn't anyway with these drivers.

[johninCR]

Ah, the holes, thats the hardest part of the hole thing. On my first one I used a 2"x6" of some nice hardwood for the front baffle. It came out looking great but I'll NEVER do that again.

If you are going OB, you don't have to worry about a perfect seal. If you are closing it up, Bill's advice is the only way to get a good seal. If you use silicone, make sure you let it fully cure before closing it up as the acid released will eat you drivers.

I've found the easiest method is to mount them and finish the wiring before attaching the baffle to the rest of the structure. You have to be more careful with glue drips etc, but it's much easier to do everything with room to work. Solder the wires on the drivers before mounting them, it's a lot less tedious. Make sure you use phillips head screws and have a screwdriver bit for your drill. Flat head screws will mean the death of at least 1 driver and are a real pain. Use a driver as a template and drill pilot holes for the screws first.

The more things you can do assembly line fashion, the faster it will all go.

[ralph-bway]

HI,

This thread shows a way to deal with mounting the 4" drivers.

http://ceramicsubs.web1000.com/4x4x42/index.htm

I used two 3/4" thick boards for the baffle. The front baffle cutouts were close enough so that the frames of the drivers were touching. The back baffle cutouts were just large enough so the rear of the driver fit through. In short 4" holes over 3 3/8" holes. This gave me more than enough strength & stability for the front baffle with the closest spacing possible.

Hope this was some help.