Enlarging Speaker Hole

[DJ Bebop]

Or the most constructive in the right hands.
Make a template out of MDF. Cut a circle in MDF and Check that the driver fits.
Cut it to size to fit inside the baffle edge.
The MDF can be made thicker than the lip of the baffle backset so the router base doesn't hit the lip.

Or the template can put temporarily put on top of the existing baffle as somebody already mentioned.
Test/prototype before you cut. Test if it's even worth it.

 

[DJ Bebop]

 

[seamonkey]

View attachment 3245766

There are piloted drum sanders also - they also work with templates

 

[agedhorse]

Templates seem to be a waste of time on such a one-off.

I have a drum sander set up that I use when prototyping with different drivers and find the need to adjust the top radius of the hole. Takes about 2 minutes total to do this with the right equipment IME.

I also have a half-round rasp I can do the same thing with in about 4 minutes.

 

[beans-on-toast]

There’s a tool called a drum rasp. Tape off where you want to stop on the baffle, work slowly, finish with a drum sander.

 

[DJ Bebop]

There’s a tool called a drum rasp. Tape off where you want to stop on the baffle, work slowly, finish with a drum sander.

View attachment 3245795

That may be too much, a little sanding works wonders. We are talking about a 1/8 of an inch total, 1/16 of the edge. Plus if it's plywood it can chip.

 

[DJ Bebop]

View attachment 3245769
There are piloted drum sanders also - they also work with templates

I would use that without a template, chuck it up in a drill, just use the hole itself and go round and round in the hole against the rotation of the drum.

 

[beans-on-toast]

Rather than hand sanding, maybe foot sanding would work.

 

[DJ Bebop]

Rather than hand sanding, maybe foot sanding would work.

View attachment 3245802

I would use that before I'd use a router and a template

 

[Mike Arnopol]

For 1/16" of removal---use the drum. For a bit bigger---rasp then drum. If I have 1/4" or more---here's what I do.
Using a compass with a pencil, make a circle the exact cutout size on heavier paper or cardboard. I just use manilla folder stock. Cut it out exactly. I use a silver paint Sharpee and place the carboard centered over the existing hole and trace around--the tip is thick so it gets on the template and baffle. Now you know how much exactly you need to remove.

 

[Redbrangus]

Meanwhile, to address the OP's additional concern: don't worry about it...you're not going to blow your speakers up. You could put them in those enclosures as they are and would be extremely unlikely to endanger the drivers. The worst that will happen is you'll get sub-optimal performance. And listen to it some...your ears will tell you if the speakers are being driven beyond their excursion limit. If you hear the speakers starting to crap out, stop. But just eye-balling it, I'd wager that box would load a 15B sufficiently enough that you're not going to blow the voice coil out of the gap, or cause similar mechanical damage from over-excursion.

In this thread are contained the driver model number, the external dimensions of the enclosure, and the duct dimensions. Seem like some pretty simple arithmetic to calculate the internal volume and plug the variables into a bass-reflex enclosure calculator program. Someone?

IIRC, the referenced EV TL606 enclosure had an optional plug that reduced the port (duct) opening by about a third, enabling you to tailor the LF roll-off curve, somewhat.

 

[Bill Whitehurst]

Yes they did.

Just eyeballing the ports, they look like they might be somewhat close to the size of the
TL606 ports with the center port blocked.
Likely not optimal, but close enough to try out.

I'd use a rotary sander.
The baffles look like MDF, which can want to come out in chunks if try to remove too much too fast.

On a related side note, this same situation can come up if you ever want to use Altec Lansings in a cab made for some other speaker.

 

[BogeyBass]

I'm taking a wild guess the cab is tuned to 40/45 hz and will be completely fine

 

[DJ Bebop]

Did you get that speaker in there yet?

 

[Plain Old Barry]

Router will work until it bumps into the edges of the cabinet. The baffle is recessed over an inch...

Use a small router like a laminate trimmer, Bosch Colt or Dewalt 611 (below), or carpet tape some MDF to the baffle board to raise the router base over the lip.

So little material is being removed the smallest routers would do fine.

Next?

 

[agedhorse]

Use a small router like a laminate trimmer, Bosch Colt or Dewalt 611 (below), or carpet tape some MDF to the baffle board to raise the router base over the lip.

View attachment 3246326


So little material is being removed the smallest routers would do fine.

Next?

Like making a thick template to remove <1/8" roundover to clear the return on the basket? Seems like a lot more work than a couple minutes it's a hand tool.

 

[gregmari]

I'm taking a wild guess the cab is tuned to 40/45 hz and will be completely fine

Yes tuned down to 40 Hz per Hartke specs.

 

[gregmari]

Did you get that speaker in there yet?

Not yet. I'm hoping to have some time this weekend to play around with it.

 

[Plain Old Barry]

Like making a thick template to remove <1/8" roundover to clear the return on the basket?

Nope... If needed to clear the edge of the cab because only a large router is available, random pieces of MDF taped in place, to either the baffle or router base itself to support the router base and allow part of it to overhang the raised cabinet lip.

But with a palm router or laminate trimmer, none of that is needed based on the photo, just a multi-bearing rabbeting bit, as the base of the router will clear. Again, pass #1 uses half of the existing hole to cut a rabbet to new size. Pass #2 is with a flush trim bit, using the newly cut rabbet as a guide, leaving a straight sided hole of the new dimension.

This is the rabbet bit, changing the bearing sets the rabbet width, the largest bearing makes it trim flush.

This is a flush trim bit that can be used from the front of the cabinet. The bit above can also flush trim, but from inside the cabinet only, due to the bearing location.

This is a 5 minute job including putting the bits away when you're done, and it'll be perfect.

If you only need a rabbet, skip step 2.

Templates are great for ports and cutting speaker holes from scratch, but totally unnecessary here.

 

[agedhorse]

Most baffles are recessed over an inch, and the hole openings at the edges are within an inch of the edge of the cabinet (or grille batten) I don't see how these suggestions can help unless I'm missing something in your explanation.