Been thinking again...

[Jim Robeson]

Okay, I'm just about to add speakers to the swim deck...behind the backrest cushions. Got to thinking about the hole that I was going to need for these 6 1/2 inch speakers and wondered if I just drilled several small holes right where the speaker would mount. You wouldn't have to remove the backrest cushion to install the speaker, just mount it to the fiberglass on the inside of the engine compartment. My question is, and I know I would have to have several small holes, would the sound be too muffled that way. In a sense I would be using the fiberglass as the speaker grill if that makes sense.

 

[Bruce]

Why not hole saw a single hole the size of the speaker cone from the inside of engine bay going out. Then drill each of the screw holes to attach the speaker. Reaching through the large hole place bolts with 3M 5200 or another suitable adhesive in the holes with the thread facing in. After the adhesive dries thread the speaker over the bolts and use nuts to secure it in place.

If you do this please be very careful drilling as there is not much room between the fiberglass and the seat back.

 

[Jim Robeson]

@Bruce ... I like that idea but what would you use to protect the speaker?? Or does the cushion to a good enough job of that??

 

[brockhals]

Then your screws are going into the pad and someone could lay back into one...or four

 

[Bruce]

This is what I did.

They sound great and have held up to fresh and salt water usage this year.

I also did some testing before and after reinstalling the seat back

I finished my behind the seats speaker install this afternoon. Before installing the seat back I setup a decibel meter on a tripod 7 feet in front of and slightly below the speaker. Seven feet seemed like a comfortable position for hanging out behind the boat.

Before installing the seat back I saw decibel readings primarily in the 82 to 87 range.

I then installed the seat back and repeated the test without moving the meter or adjusting the volume control playing the same portion of the same song. The meter continued to show similar readings with peaks of 87.

The highs were diminished but the bass maintained its volume. I prefer the sound with the seat backs on. It had a fuller deeper sound.

They also provide a slight back massage.

 

[maboat]

Then your screws are going into the pad and someone could lay back into one...or four

... Use shorter screws....

 

[jcyamaharider]

Then your screws are going into the pad and someone could lay back into one...or four

Bruce is talking about using bolts and the head would be towards the back rest. the threaded part would be toward the engine bay and easy to slide a speaker over and then install 4 nuts to tighten down the speaker. Very easy to do and a great idea @Bruce !!!

 

[0627Devildog]

@Jim Robeson - re: "Been thinking again" . . . . . .You didn't hurt yourself did you?

 

[Jim Robeson]

@0627Devildog ... yeah, my wife really gets worried when I start a conversation with "I've been thinking". No, I was worried about pulling the backrest so I could insert the speaker and use the grill to protect the speaker. Then I thought about just drilling the smaller holes and just use the fiberglass as the speaker grill. But now that @Bruce has given me the idea to insert the bolts through I think I could actually put them through the speaker grill too. Unless you all think that the speaker is protected enough without it.

 

[0627Devildog]

@0627Devildog ... yeah, my wife really gets worried when I start a conversation with "I've been thinking". No, I was worried about pulling the backrest so I could insert the speaker and use the grill to protect the speaker. Then I thought about just drilling the smaller holes and just use the fiberglass as the speaker grill. But now that @Bruce has given me the idea to insert the bolts through I think I could actually put them through the speaker grill too. Unless you all think that the speaker is protected enough without it.

As stated above, with the speaker behind the seat there would be no reason for a protective grill. . . . .

 

[Julian]

Just make sure if there is a raised tweeter that the hole is big enough for it to fit through and sound to pass around.

 

[Bruce]

Just make sure if there is a raised tweeter that the hole is big enough for it to fit through and sound to pass around.

My suggestion is to hole saw a hole slightly larger than the speaker cone.

 

[Julian]

My suggestion is to hole saw a hole slightly larger than the speaker cone.

That would be perfect....rear mounting would be perfect in this location!

 

[Jim Robeson]

Yep. I have a 5 inch hole saw..could use a 5 1/4 but couldn't find one. I think I will see what the 5 inch hole looks like and if I need to grind out a little more I can.

 

[bucks448]

As stated above, with the speaker behind the seat there would be no reason for a protective grill. . . . .

X2, the speaker grill provides little protection as it is from the elements, and many have installed them on the lower swim deck.

 

[Jim Robeson]

Installed my speakers last night. I think they turned out okay. Spliced into the rear speakers and will use the fade function on the head unit to put more sound out the back when we are in the water. Only took about two hours and three cold ones!

 

[cwoav8r]

Next on my list... I'm thinking about two JBL 6.5's.

So that was a 5 inch hole... did you bolt thru or just use screws?

How do they sound?

 

[cwoav8r]

Oh, and were you able to install without removing the seat backs?

 

[zelone]

This is what I did on my 212 SS. Sounded great when swimming out back.

 

[txav8r]

Looks to me like @Jim Robeson had to actually mount the speakers inside the engine compartment instead of mounting to the underseat side of that wall, because you would have to move the seatback to place the speaker thru the hole and mount to the wall. Cutting and installing from the back is a way to keep from removing the seatbacks, but the speaker will be mounted with it against the hole, not mounted through it. The speaker is approx 6.5" and the hole is only 5", so getting it through the hole from the engine compartment isn't possible. But what a workaround Jim! Looks like you did a great job there! Can you describe your steps so everyone can understand how you drilled and attached the speakers inside and how you secured them like that? Great mod!