Jordan MLTL Enclosure Sealing

[LizardBrain]

Hello:

I am in the middle of building the cabinets for the GM MLTL 48", triangle cross-section. Have the boxes together without the tops or bottoms on yet. I have used 3/4" Birch plywood.

As this is my first build, and I have the enclosures still open at this point, is there anything I should do to treat the inside of the cabinets that would help acoustically. Paint? Some sort of resin? Anything? Just leave the bare wood alone?

Looking for some experienced opinions.

cheers

 

[Colin]

You could try running a thin bead of sealant or wood glue up the inside joins, just as belt and braces approach to sealing where the walls meet. Painting or otherwise sealing the inside surfaces won't make any difference.

Don't overstuff the top section (from just below the driver to the top) - I found with mine that lightly filling this section worked well. (Although you can adjust to suit.)

Look forward to hearing your impressions (and seeing any pics).

 

[LizardBrain]

Thanks. I have applied sealant to the inside seams.

I will post pics and my listening impression when they are finished.

 

[LizardBrain]

One other newbie question. Does the material the port tube is made out of matter. I immediately answered no, but then thought I should check with you experts. I have the standard plastic tubes, but also have some copper pipe that would work too. Is metal a bad idea?

 

[Colin]

It may resonate, so I'd stick with the plastic. Some designs even use a cardboard tube. Alternatively, keep the cross-sectional area of the port the same and make a square-section port from wood.

 

[LizardBrain]

Hey Colin:

Thanks for your help. Sounds like you have made these. Did you veneer them? Do you have pictures? I made them out of Birch ply, but I am going to have to use veneer if I want them to look decent.

 

[Colin]

Yes I have built them - I assembled mine about a year ago, meaning to finish them off and haven't felt inclined to take them apart and veneer yet. The cabinets are a bit rough so I may have another go. Here's a pic, with their smaller siblings, the new JXR6.

 

[LizardBrain]

Thanks Colin:

One more questions that I can't tell from the picture. Did you rebate the drivers or just mount them flush?

 

[Colin]

I mounted the drivers flush but ideally they should be rebated (I didn't have the facility to do this). Rounding out the back of the driver hole will also help prevent reflections from the inside of the front panel.

 

[thinkbad]

Sharp edges cause irregular response at medium to high freq.
If you don`t have the facility to rebate, you can cover the baffle with felt, or use a mousepad with a cutout for the driver.

JB

 

[Colin]

The effect is slightly less with the Jordan drivers, as they are quite directional from 2kHz up. The felt idea is a good one, though. Another option is to make a ring of 4mm ply or mdf and place round the driver, rounding off the outer edge.

BTW, I recommend devising a cover or some form of protection for the drivers when the system is up and running. People love to poke their fingers at them - they exert an attraction second only to LCD computer screens - and the cones are very fragile.