Bose Speakers in the Cockpit


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Jan 2003 -- The old cockpit speakers, in addition to being cheap
and sounding lousy, are basically just cones in 5 inch holes.
If anything happens, I'll have a 5 inch hole in the cockpit...

Really, I just want better speakers!

I like to sail close hauled into a really stiff breeze with the stereo cranked.

This solution wouldn't be my first choice... but the holes are already there!

Here's how the layers will be put together.

The black ring
is normally is on
the outside of the
bulkhead, but I'm
going to move it inside.
The speakers bolt onto it.

The modified
smaller grill
fits very tightly
into the ring.

A thin (1/8" thick)
ring made of
prefab fiberglass
(from McMaster-Carr)
goes on top
of the Bose ring,
to protect it and
cover some unused
mounting holes.

A thicker (3/8" thick)
ring will mount on top
of this, and will fit
up against the inside
of the boat. It's this
thick because the
Beckson port flanges
are 1/2" wide, but the
area where I'm going
to mount it is only
1/4" thick.

Making the rings was time consuming, since they don't make hole saws that big! (Well I saw one but I'm not spending $60
on a single-use tool.) I had to hack the inside part out with a handheld grinder and sand it into shape with a drum sander.
If I had to do it again I'd probably use
Starboard or thin polyethylene!

The Bose speaker cones are rather small,
but they have a huge grill that's
designed to cover a big black mounting ring.

Bose never envisioned what I'm about to do!

I trimmed the grill down to just cover the speaker, using a saber saw and bench belt sander.
It was tricky to get it just right.

The Beckson port
will fit snugly inside that ring.
After some adjustment with my Handy Dremel Tool, the holes on the port match the mounting holes on the Bose Ring.

After cutting the heads off some 8/32 2" bolts with my Handy Dremel Tool, I dipped them in vegetable oil, then epoxied the whole assembly together.

I was careful to pack the nuts in epoxy (below left) so they'll be
permanently attached.
This is going to make the
installation a lot easier.

Bose provides cheap wire and these twist-on connectors,
but that's silly.

After covering the whole thing with wax paper, I slipped the Beckson port ring over the bolts. This is a critical step, else it won't all line up! The wax paper keeps the ring from sticking to the epoxy.

If you're going to put Bose speakers on a boat, then it makes sense to use good wire and connections. So I'm using 16 gauge wire and splicing it on like any electrical connection. There are holes in the speaker housings that can be used for strain relief.

The screws made the installation incredibly easy! I just reached through the hole, pulled the speaker up and fit them into the bolt holes in the 'bulkhead', fit the Beckson port on top, then slipped normal machine screws into
the other three holes. Then I used Vice Grips to remove the three headless screws
and replaced them with normal ones.
Since the nuts are epoxied onto the back side, the whole installation took about 10 minutes and I didn't have to crawl under the cockpit
or fuss with dropped nuts!

After tightening everything down, I masked it off and backed the screws out 4 full turns.

That left enough room to take a plastic syringe full of LifeSeal and inject it into the joint. Very clean and easy. Then I tightened them back 2 full turns and will let the LifeSeal cure before really tightening it down.

LifeSeal is a silicone polyurethane
that's safe for all plastics.

I labeled the wire all over the length of it.
In a year I won't be able to tell this wire from all the rest of them, so I'm doing this to make my own life easier.

The ring assembly is painted and the edges ground down a bit in case there's an issue with the interior corners.
(That turned out not to matter.)
Three of the headless screws are back in, and the speaker is bolted to the rings.

Tucked back
under the cockpit,
the wire mounts
are attached with
epoxy, after wiping
the small area with
acetone. I don't always trust
the peel-n-stick adhesive.

Here's a good laugh.

While running the wires back
I found my needle nosed vice grips.
I've been looking for them for the last year...
since I installed the amidships deck cleats.
They've just been clamped onto that nut ever since.

I think this is what happens when you have
too many projects going on at once...
but if I hadn't lost them
I wouldn't have experienced
the happiness of finding them.
(Welcome to California.)

Here's the final result.

The break in the threads for the cover are located at the bottom, so water can run out.

January 2003 --
There was an unexpected problem. The sound coming from the new Bose in back didn't match the 20 year old Pioneer speakers in the cabin, and it was really annoying. My Sony stereo was able to make the old Pioneer speakers
sound really good, since it has all these electronic equalization and effect settings. However, the Bose don't need any of that, and switching between cabin and cockpit speakers also meant fiddling with the stereo for 5 minutes to retune it. So I replaced the cabin speakers with Bose 151's.