Sub enclosure for a boat using exotic materials

[Arthur79]

Bass for a boat!

 

 

This is another box build I did for the local shop before I had the CNC router.  The shop did rear facing cans on the wakeboard bar, speakers in the boat cabin and some LED lighting.  The shop owner took the initial measurements for the box size.  It is located in a large L-shaped cubie on the port side (what would be drivers side of a car in the US) of the boat.  The customer brought the boat in to have measurements taken but only had it at the shop for less than an hour before taking it out on the water for the weekend.  I couldn't make it up to the shop to confirm measurements so I took what the owner provided for measurements and got started.

 

For the enclosure, the shop wanted to build the box out of 3/4" expanded PVC and acrylic instead of MDF or birch ply with a resin sealer coat.  The expanded PVC is super light by comparison, and small pieces are pretty rigid, but longer pieces can have a fair amount of flex and require bracing to stiffen up.  For the glue joints, I used a thick CA glue (mobile solutions I think) and accelerator.  Just have to make sure you scuff the PVC where the glue joints come together.  I got to find out first hand how strong the glue joints were later in the build.

 

Finally since the top was the only part you would be able to see once the enclosure was installed into the cubie, they wanted the entire top of the box to be acrylic with red LED lighting and the shop wanted their logo somewhere visible.

 

The enclosure was for a pair of DD Audio 610D subs wired down to final impedance of 1 Ω.

 

I modeled the enclosure up in WinISD based on the measurements I had shooting for a tuning frequency of 34Hz

 

Braces using template tape and scraps (my go to for router work) and a shot of my ancient Ryobi router table.  This thing just refuses to quit

 

 

Mocking up the box

 

 

Gluing up the baffles

 

 

 

Here you can see all the threaded inserts for 10/32 hardware to mount the acrylic

 

 

 

Adding foam gasket tape.  I used a soldering iron to create holes in the tape for the mounting hardware to pass through

 

 

 

The acrylic top for the box

 

 

 

So at this point the boat was back at my buddies shop and we could test fit the box.  You'll never guess...  The damned thing flat wouldn't fit.  My buddy had taken measurements inside the cubie, not the opening in the cubie.  Width-wise we were ok (as long as you didn't mind the sub surrounds rubbing a little bit while you put the box in) but length-wise it was a total FAIL.

 

So back to my shop to try and fix it.  This is where I got to find out just how strong the CA glue joints were.  We had to salvage the existing box and make use of the left over material if at all possible because the expanded PVC and Plexi were both expensive and the shop didn't have budget to buy more (or at least really didn't want to)

 

Here is a shot of the box getting moded to fit into the boat

 

 

Just like tightbond and MDF, if done right the joints were stronger than the material.  You can see some of the crap material that was torn out to the right on the floor.  I had to do a ton of sanding to get back down to the base and you can still see where the glue chemically altered the material.  I was able to get it all cleaned up, just a lot more priming and painting.

 

Here is the final box with the acrylic top and the inside finished in flat white.  Drilling and countersinking all of those mounting holes in the acrylic took a few months off my life I'm sure.  There wasn't enough acrylic left to cut another piece if I f'ed it up and hand tools on acrylic give me heartburn but the audio gods were smiling that day I suppose and there were not catastrophic failures.

 

 

 

 

 

You can see the 3D printed shop logo epoxied in place in this shot, along with the ledges opposite the subs that the lights were mounted under to try and create an indirect lighting effect

 

 

 

When I cut the acrylic I oversized it ever so slightly so I could run a flush trim bit around it, sizing it to the box as accurately as possible.  I learned the hard way that you need something like painters tape or some other substrate to let the bearing ride along.  I got the flush trim done, but the bearing didn't like riding along that PVC and that bit was RIP after this job.  It sucks to as it was a spiral flush bit I had ordered from mobile solutions and they aren't cheap.

 

The subs were powered off a DD D5.1500 and the audio shop added a flared port to the seat cubie to crate a sort of 6th order bandpass effect in the boat.  I know the box sounded pretty good on the bench, but I didn't get to hear it in the boat.  I'm told it sounds really good on the water.

 

I'll add a couple of short videos as well.  Seems like LED lights never look true in the photos / videos but it'll give you an idea.

 

 

[Arthur79]

A couple of short videos of the finished box before it went into the boat:

 

Box walk around with the shop lights off

 

 

Walk around with the shop lights on

 

 

Again, nobody was concerned with the finish on the outside of the enclosure as you really never see it once it's installed in the boat.  Hell the only way to appreciate the acrylic top is if you pull the seats, but it still came out pretty alright.

 

 

[Dafaseles]

12 minutes ago, Arthur79 said:

Bass for a boat!

 

 

This is another box build I did for the local shop before I had the CNC router.  The shop did rear facing cans on the wakeboard bar, speakers in the boat cabin and some LED lighting.  The shop owner took the initial measurements for the box size.  It is located in a large L-shaped cubie on the port side (what would be drivers side of a car in the US) of the boat.  The customer brought the boat in to have measurements taken but only had it at the shop for less than an hour before taking it out on the water for the weekend.  I couldn't make it up to the shop to confirm measurements so I took what the owner provided for measurements and got started.

 

For the enclosure, the shop wanted to build the box out of 3/4" expanded PVC and acrylic instead of MDF or birch ply with a resin sealer coat.  The expanded PVC is super light by comparison, and small pieces are pretty rigid, but longer pieces can have a fair amount of flex and require bracing to stiffen up.  For the glue joints, I used a thick CA glue (mobile solutions I think) and accelerator.  Just have to make sure you scuff the PVC where the glue joints come together.  I got to find out first hand how strong the glue joints were later in the build.

 

Finally since the top was the only part you would be able to see once the enclosure was installed into the cubie, they wanted the entire top of the box to be acrylic with red LED lighting and the shop wanted their logo somewhere visible.

 

The enclosure was for a pair of DD Audio 610D subs wired down to final impedance of 1 Ω.

 

I modeled the enclosure up in WinISD based on the measurements I had shooting for a tuning frequency of 34Hz

 

Braces using template tape and scraps (my go to for router work) and a shot of my ancient Ryobi router table.  This thing just refuses to quit

 

 

Mocking up the box

 

 

Gluing up the baffles

 

 

 

Here you can see all the threaded inserts for 10/32 hardware to mount the acrylic

 

 

 

Adding foam gasket tape.  I used a soldering iron to create holes in the tape for the mounting hardware to pass through

 

 

 

The acrylic top for the box

 

 

 

So at this point the boat was back at my buddies shop and we could test fit the box.  You'll never guess...  The damned thing flat wouldn't fit.  My buddy had taken measurements inside the cubie, not the opening in the cubie.  Width-wise we were ok (as long as you didn't mind the sub surrounds rubbing a little bit while you put the box in) but length-wise it was a total FAIL.

 

So back to my shop to try and fix it.  This is where I got to find out just how strong the CA glue joints were.  We had to salvage the existing box and make use of the left over material if at all possible because the expanded PVC and Plexi were both expensive and the shop didn't have budget to buy more (or at least really didn't want to)

 

Here is a shot of the box getting moded to fit into the boat

 

 

Just like tightbond and MDF, if done right the joints were stronger than the material.  You can see some of the crap material that was torn out to the right on the floor.  I had to do a ton of sanding to get back down to the base and you can still see where the glue chemically altered the material.  I was able to get it all cleaned up, just a lot more priming and painting.

 

Here is the final box with the acrylic top and the inside finished in flat white.  Drilling and countersinking all of those mounting holes in the acrylic took a few months off my life I'm sure.  There wasn't enough acrylic left to cut another piece if I f'ed it up and hand tools on acrylic give me heartburn but the audio gods were smiling that day I suppose and there were not catastrophic failures.

 

 

 

 

 

You can see the 3D printed shop logo epoxied in place in this shot, along with the ledges opposite the subs that the lights were mounted under to try and create an indirect lighting effect

 

 

 

When I cut the acrylic I oversized it ever so slightly so I could run a flush trim bit around it, sizing it to the box as accurately as possible.  I learned the hard way that you need something like painters tape or some other substrate to let the bearing ride along.  I got the flush trim done, but the bearing didn't like riding along that PVC and that bit was RIP after this job.  It sucks to as it was a spiral flush bit I had ordered from mobile solutions and they aren't cheap.

 

The subs were powered off a DD D5.1500 and the audio shop added a flared port to the seat cubie to crate a sort of 6th order bandpass effect in the boat.  I know the box sounded pretty good on the bench, but I didn't get to hear it in the boat.  I'm told it sounds really good on the water.

 

I'll add a couple of short videos as well.  Seems like LED lights never look true in the photos / videos but it'll give you an idea.

 

 

Nice box!

[Arthur79]

8 minutes ago, Dafaseles said:

Nice box!

Thanks!  It was the first time I'd done something with the expanded PVC, I think it worked out well and it is perfect for marine stuff - it's plastic!

[Arthur79]

Just for grins and not worth another build post, but here is cutting out a box with expanded PVC using the shop CNC.  I know access to a CNC is definitely a luxury, but this thing makes my life SO much easier for box builds and saves so much time.

 

This was another enclosure for a boat.  If I remember correctly, it was a single 12 that went in, but this was in January and I've slept a few times since then...