Sealed Modula MT

[ShaunD]

I am almost finished with my 5 MMT's (gluing up the cabs and routing the driver cutouts today), and I would like--no, have to--wall-mount the rears. I can either make a shelf to mount them on, or mount directly to the wall. Which means they won't be too far from the wall in any direction. So, my question is, should I or should I not port (rear, side, top, anywhere) them? Thanks in advance.

[KeithM]

They should work decent withouit modifying the crossover by putting the port on the front. They still won't sound as good as if there was 2 feet or so behind the speaker, but we all have to make sacrifices.

[ThomasW]

The ports need clearance so that eliminates rear mounting. Avoid putting the port near the tweeter, any other sufrace is fine.......

Generally speaking one runs the effects speaker as 'small', this means a higher crossover point, so there's no real benefit to having them ported, unless in the future you anticipate running them fullrange.

[Jim Holtz]

The ports need clearance so that eliminates rear mounting. Avoid putting the port near the tweeter, any other sufrace is fine.......

Generally speaking one runs the effects speaker as 'small', this means a higher crossover point, so there's no real benefit to having them ported, unless in the future you anticipate running them fullrange.

Hi Thomas,

Question. When you said to not put the port near the tweeter, you meant next to it on the front baffle, correct? I thought directly behind the tweeter on the back baffle was the ideal placement for a port, assuming sufficient clearance between the speaker and the wall. Am I incorrect in my thinking?

Thanks!

Jim

[ThomasW]

When you said to not put the port near the tweeter, you meant next to it on the front baffle, correct?

Correct.

I thought directly behind the tweeter on the back baffle was the ideal placement for a port, assuming sufficient clearance between the speaker and the wall.

I'm not sure that's 'ideal', it's certanly convenient for those using the premade PE boxes

[ShaunD]

Thanks for the replies. I think I will go ahead and leave them sealed because they will only be for movie surround. Since they will be sealed should I stuff 'em with polyfil?

[ThomasW]

You bet.

[dawaro]

I built my set sealed to use for rear surrounds and I had absolutely no complaints. Being that the receiver is going to cut the frequencies below 60-80hz I doubt you will ever notice the difference.

Dave

[ShaunD]

Is there an easier way to laminate the front baffle? It's quite hard to center the inner part on the outer part after I put the glue on, because if I clamp or put weight on it, the wood just slides around. Maybe using a different glue? I've been using titebond II. I tried searching here and google but the only things that came up were about veneer.

[ThomasW]

Build the outer shell first, then put in the inner layers

[ShaunD]

I should have been clearer. I mean laminating two pieces of mdf together for the front baffle, so it will be 1.5" thick. The inner is smaller in both directions than the outer.

[ThomasW]

I guessed as much. You sort of painted yourself into a corner.

If the rest of the box is built, glue in the inner piece. Then you can align the top piece to the outer edges of the box.

Otherwise draw diagonal lines on each piece. Align them and attach together with screws or nails you'll remove after the glue dries. You might want to cut down the inner piece just slightly so make sure it will slide in of your alignment is off.

For future reference it's best to cut the outer piece oversized. Then trim to fit using a flush trim router bit after everything is glued in. That way slight problems with aligning the two pieces isn't a big deal

[ShaunD]

Thomas, thanks for the help. I did what you said; using screws to align them. That worked great. The outters are cut oversize, but only by about .125".

[ShaunD]

How much stuffing for Modula MT

For my rear surrounds I'm leaving the speakers sealed. How much stuffing (polyfil) should I use? I think I read somewhere 0.5lb/cu ft? Also for the ported ones, I know I should just put a blob of dacron/polyfil behind the midwoofer, should I also dampen the cab with carpet padding or similar? Thanks.

[ThomasW]

One doesn't stuff ported cabinets, instead the interior surfaces are lined

Please don't start separate threads for questions about a project that has an existing thread.

[WLF1]

One other way to align the two baffle pieces is to use 1/4" dowels. If you drill the location holes from the back, you can maintain a finished front baffle (like a hardwood baffle) by holding the hole depth to something less than the thickness of the front baffle.