Question about installing speakers in swim platform

[PEARCE]

I replaced my stock speakers with MM651UM and installed two extra by the swim deck.
(did not caulk, just used a waterproof foam tape behind speaker lip, I liked the access to area).
All the information I found said the speakers are marine nature in design and can get wet.View attachment 3087 ubmerged without problems.

I have the same speakers in the boat as well as on the swimdeck. They sound great! I have a dedicated 2 channel amp for the swimdeck speakers and a 5 channel for the rest of the boat speakers.

 

[paul075]

Here are mine. You could put tweeters here. They are 3" Poly Planars and sound good. The bass carries from the subwoofer, so I didn't need large speakers back there.

 

[SCSTWG]

I think the next time I go out, Ill do some hard stops and see how much water comes back on to the platform. Ill have to think about which would be a better install. I like the speaker being protected behind the seat back, and can keep the tweeter close to the woofer.

I am not saying it will be an issue, but they will be submerged often. When you stop relatively quick, the lower portion of the swim deck is a complete washout.

 

[octavio3311]

That area can take on a lot of water. Even more so when my ballasts are full and the boat is squated lower - I'd be concerned about how well/how long the speakers would last in that lower area.

 

[JWPrendergast]

It really is too bad there isnt a simple solution on the rear of this boat.

 

[jcyamaharider]

For this reason I love my tower speakers.

If I were to do it I would put them behind the seat back, I like Bruces install.

 

[txav8r]

If I had a 240 without the room like my 230 had, I would just take my seat backs down I believe, and have the cut and refitted with room for the speaker. That is what they do on the 242. No reason that a good upholstry shop couldn't do this pretty easy without materials needed, just loosen the fabric on that end, cut the support back to shape, cut back the padding, trim the upholstry to fit, reattach and use the leftover piping to trim. Install the speaker. Another thing to consider besides the need to increase volume 4 times the level to get the desired level behind the seat cushion, is that it drains your battery 4 times faster, in addition to the muffled and flat sound that it produces.

 

[Bruce]

@txav8r, where does this four times figure come from?

Many quality speakers use chamber designs to improve sound quality. The fiberglass and the seat backs are hard surfaces that should direct the sound rather than absorb it.

Speakers mounted high on a tower will project rearward better than any mounting on the boat. But I bet the 6x9s behind the seats will sound better to tubers than the smaller angle mounted speakers often used.

 

[jcyamaharider]

I agree that behind the seatback is not optimal but working with what you have , it protects the speakers from the elements and water on the swim platform. It is also better than speakers in the cabin as you are relaxing in a quiet cove.

 

[David Analog]

"....four times...." would actually be a conservative estimate. Remove the subjective and use common sense.
A 6dB decrease in amplitude would require four times the power to correct. 6 dB is less than what would be perceived as half the volume.
The seat cushion has a hard HDPE or similar structural back, plus very thick foam padding, plus vinyl. No different than a rear bulkhead that is intended to attenuate engine noise.
From behind the solid seat cushion you might get the bandwidth of a telephone and perhaps the top end of musical fundamentals although greatly reduced in amplitude.

 

[txav8r]

I wouldn't be concerned with transom splash with a true marine speaker. I wouldn't use a speaker with an open midbass voice coil (one with a tweeter mounting post) because debris will get in the VC gap and corrosion will also be an issue.
If the position of the transom speaker (any speaker) is too low and just barely above the swimdeck, sudden stops and the back wash can represent major displacement (ie: the lake) and is enough force to eventually tear the outer surround away from the cone. So heavy splash and wash is okay. Totally submerged for a brief moment definitely is not.
Placing a speaker behind a thick and dense cushion will have that speaker and amplifier playing perhaps four+ times harder to even approach the same output level. And the high frequencies will be totally lost. At the same time, the cushion will also mute some of the distortion.
Using a separate tweeter with a significant positional advantage to augment a buried fullrange speaker will create a very abrupt change in treble, which can sound extremely strident, kind of like fingernails on a chalkboard, especially on female vocals. You can obtain and add a supplemental tweeter to any speaker but I would pad the tweeter with an attenuation circuit, unless you have already suffered permanent hearing damage.

This is where it comes from Bruce. And while the 4 times harder may be a wag...it may be MORE! No doubt it will muffle it. But like stated, if it is all you have to work with, so be it. I can tell you that hearing over the wind, water, engines, at tube length on a rope isn't happening, except to maybe know someone, somewhere, is playing some music, but you won't hear the music clearly at that distance even if they are mounted on the transom or on a tower for that matter...if they are not high power HDCL horns. Coaxials are not projection speakers, they are near range speakers meant for immediate area sound reproduction. Hey, not trying to be a knowitall here, ask the guys with the wakeboard boats. Yes, you can hear some music out at 60', but not clear music. I could hear some music in my boat too without an amp or upgraded speakers, while underway, but it was just more noise, not music. And that is what you get with coaxials cranked to try to project. They are near range. And putting them in a cabinet, even vented (behind the seatback), will require driving them much harder to produce the same level of sound.

 

[jcyamaharider]

Wait a minute David you do relize these seatbacks are open at the bottom correct, which is basically a big port.

 

[JWPrendergast]

My goal is to have sound at the platform when sitting and chillaxing. Im sure we will eventually do some watersports, but thats not the main focus of the boat.

That said, jcyamaharider is correct, there is a sizeable opening at the bottom of the cushion. Im sure sound will be somewhat impeded, but not as much as everyone is thinking.

 

[David Analog]

Wait a minute David you do relize these seatbacks are open at the bottom correct, which is basically a big port.

Yes, a big port. Effectively you have a speaker in bottle....a chamber and a mouth. Every port is a filter. It passes different frequencies with bias. So while you are passing a narrow bandwidth with some success, you are attenuating a much broader range. You are going to have major amplitude losses and major SQ losses as compared to a direct-radiated speaker. The speaker and amplifier will be working harder to create the same output over a limited range. And you are less likely to hear the distortion in this arrangement.
Having stated that, it still remains an option for some. People who are considering this route need to know all the trade-offs beforehand. Certainly the larger surface area of a 6X9 helps. Behind a solid bolster and squirting the sound through a slot hurts.

 

[David Analog]

My goal is to have sound at the platform when sitting and chillaxing. Im sure we will eventually do some watersports, but thats not the main focus of the boat.

That said, jcyamaharider is correct, there is a sizeable opening at the bottom of the cushion. Im sure sound will be somewhat impeded, but not as much as everyone is thinking.

And expectations are a big part of this. If your intention is to just get sound at the swim deck perimeter when at rest and still be able to converse, that's easy enough. If you need projection, sorry, you'll be disappointed. None of the flush transom options are going to be able to project at distance (watersports) with any degree of authority or intelligibility using a speaker that is designed for near field applications.
Everyone of these options is still better by a good margin than trying to use the in-boat system to project out of the bathtub, over the gunnel and down at water level, let alone at distance.

 

[jcyamaharider]

As always good information David. Thanks!

 

[SCSTWG]

Here are mine. You could put tweeters here. They are 3" Poly Planars and sound good. The bass carries from the subwoofer, so I didn't need large speakers back there.View attachment 3139View attachment 3140

While I would like something a little larger, these have a very nice factory look to them. Nice work on the install.

 

[Bruce]

I will get the decibel meter out and get some readings with and without the seat next week.

 

[JWPrendergast]

Paul, I looked up those speakers and I think that might be the best solution here. I can use the bass from the boat to supplement these little guys. As much as I really want to put bigger speakers in, I think these will have to do the trick. Ill probably hook em up to the head unit with a switch to turn em on and off, then use the amp for 3 sets in the boat.

 

[octavio3311]

JW,
Paul's speaker do blend in nicely. But another option may be 4" Polk's. The 14' 212x's now come with the 4"ers on the transom.They probably will fit the same location as Paul's.