MJ18 Enclosure for Music

[mlstrass 1]

Haven't built anything in a few months, so I've got the itch. Decided I want to do an MJ18 to add to my set up in the gym. Simple 2 channel set up with some Klipsch Legends and a Denon receiver that mostly plays 80's metal or 80's old school/dance stuff to get me fired up.

Looks like 4.5^3 @ 30Hz is pretty popular for music, so that's what I plan on doing. Don't need any low freq stuff, just some nice punch for kick drums, etc... Box will be slot ported and downfiring and will also have a TV stand built on top of it, so it's functional.

I'm used to building car boxes and normally do 12" of port area per cube of box. How much port area do I need for the MJ in a 4.5^3 box, 54^2 like a car set up? Have searched and searched but couldn't find anything. Much appreciated...

[smokinkane 0]

We did the mj18 in a 3.5cf sealed box, you get plenty of punch and the extension is good 90hz down to 20hz.

Haven't built anything in a few months, so I've got the itch. Decided I want to do an MJ18 to add to my set up in the gym. Simple 2 channel set up with some Klipsch Legends and a Denon receiver that mostly plays 80's metal or 80's old school/dance stuff to get me fired up.

Looks like 4.5^3 @ 30Hz is pretty popular for music, so that's what I plan on doing. Don't need any low freq stuff, just some nice punch for kick drums, etc... Box will be slot ported and downfiring and will also have a TV stand built on top of it, so it's functional.

I'm used to building car boxes and normally do 12" of port area per cube of box. How much port area do I need for the MJ in a 4.5^3 box, 54^2 like a car set up? Have searched and searched but couldn't find anything. Much appreciated...

[Viperoni 0]

3.5-4cf sealed would do very nicely for music, but I think the 4.5 @ 30hz would also do well.

I'd also increase the port area a bit, but unfortunately, 50sqin already needs a 27" long port...

[mlstrass 1]

3.5-4cf sealed would do very nicely for music, but I think the 4.5 @ 30hz would also do well.

I'd also increase the port area a bit, but unfortunately, 50sqin already needs a 27" long port...

Thanks for the replies. Just worked up another box with 61.5^2 of port area for 4.5cubes. Still considering sealed as I don't need killer bass since this is just a gym stereo in a 24x20 room with cement walls and floor, so ultimate SQ isn't the goal.

[Viperoni 0]

3.5-4cf sealed would do very nicely for music, but I think the 4.5 @ 30hz would also do well.

I'd also increase the port area a bit, but unfortunately, 50sqin already needs a 27" long port...

Thanks for the replies. Just worked up another box with 61.5^2 of port area for 4.5cubes. Still considering sealed as I don't need killer bass since this is just a gym stereo in a 24x20 room with cement walls and floor, so ultimate SQ isn't the goal.

Ah, then you should be fine with that, I like the 61" of port area better. It should be able to pump out a lot of bass, you should be fine. The concrete should help as well.

Have fun with it

[mlstrass 1]

Plan on ordering later this week and also getting an EP2500 to power the RL-P's in the HT and moving the Hypex downstairs for the MJ18. Either going to do Baltic Birch and stain it or Trupan with paint, not decided yet, but I want it lighter than MDF.

I'll post some pics of the build when it happens.

[mach5audio18 0]

i just bought a mj18 4ohm. anybody have drawn out plans for a ported box?

[mlstrass 1]

How would the MJ18 do off a 300w BASH plate amp? Is that enough power to get it moving decently in a ported enclosure?

Edited February 18, 2008 by mlstrass

[mlstrass 1]

i just bought a mj18 4ohm. anybody have drawn out plans for a ported box?

I worked up plans for a 4.5^3 @ 30Hz box. Slot ported and down firing. I have it saved on the PC at home if you want a link let me know...

[mach5audio18 0]

yeah ill definitly take that link if u dont care