Just started digging into the 2021 SX250/AR250 audio system

[Wheelspin]

It's pretty meager. Amp is the Wet Sounds HTX4. (DSP)The speakers are 25w RMS Jensen MS650s. So they've got a 400W RMS (100x4 @4ohm) amp driving 150w RMS worth of speakers total. Or, taken another way, $650 worth of amp driving about $125 worth of speakers total. DSP must be seriously cutting the gain to keep from smoking the little plastic fantastics.
I can also see from equalizing the input and observing the output the DSP has pretty much entirely cut off everything from about 80 hz and below. I haven't chased wires back yet to see if perhaps some are wired in series as well to lower the output. It wouldn't surprise me.
The end result is that it can put out an acceptable volume. It would play loud enough to hear ok even at speed I think. But it's very compressed. If horribly compressed Sirius satellite audio through an economy car stereo is not annoying to you, this will probably work just fine. Think music playing through an Amazon Echo sound quality.

 

[Wheelspin]

I pinned out the wiring harness. The good news Connext is feeding the HTX4 through low level inputs. The bad news is they are hard pinned to a connector instead of RCA. I'm just going to cut the plug off, and getting RCA to bare wire ends to solder onto then to feed a new amp.
Plug 1 is input. Plug 2 is output.

 

[Wheelspin]

White wires are channel 1.
Gray is channel 2.
Green is channel 3.
Purple is channel 4.
Blue is the remote turn on lead.

 

[NewGuy]

Great work Wheelspin! Those Jensen’s bring me back to the garbage Kraco days, compliments of every cheap domestic car or truck at that time. What are you going to replace those with?

 

[Jeebus]

So, the HTX4 amp, that is powering all 6 speakers in the boat? I assume the cabin 4 speakers are bridged and running "front" and the swim deck is "rear"?

 

[Wheelspin]

Jeebus, Yes, all 6. Parallel on the cabins was my thought before I dug into it too. But parallel to 2 ohms with 25W speakers and feeding them 150w instead of 100w seems sketchy. Bridged would actually feed them 300w! Would be a smoke show. heh heh. That's why I am wondering if maybe they wired the 4 cabins in series instead actually. I don't *need* to know the answer since I am not using the wiring, but I am going to chase the wiring down to find out anyway out of sheer curiosity.

New Guy, I just got my replacement HTX6 amp, and I already have a Clarion marine amp from my old boat. I am planning to run the cabin speakers off the HTX6, and the 2 Wet Sounds 10 inch subs I just got off the Clarion.
I haven't ordered the cabin speakers yet, as I have been mulling several options. Right now I am leaning towards trying the Audio Legion MR6Ns. They are carbon fiber marine speakers, high efficiency, high power, and would give me a bunch of bridging and/or parallel wiring options. I might order a single pair just to hear them since I don't know anywhere local that has them to try them out. They are popular in the Harley Bagger community.

I am looking at a Rockford DSP right now as well. It looks really user friendly, handles 8 channels IIRC, and can be run via a bluetooth and smart phone app.

 

[Wheelspin]

So popped out a couple more speakers. The cabins are wired with the same colors on the 2 left cabin speakers and 2 right cabin speakers. They are on the front 2 channels. The swim platform speakers are on the rear 2 channels. I disconnected one of the cabin speakers and it's mate continued to play, so they are definitely wired parallel. So the factory setup is 150w @ 2 ohms to both left speakers and 150w @ 2 ohms to both right speakers. And 100w each @ 4 ohms to each swim platform speaker.

All into plastic 25w speakers. What a waste of potential on that amp...

 

[NewGuy]

So popped out a couple more speakers. The cabins are wired with the same colors on the 2 left cabin speakers and 2 right cabin speakers. They are on the front 2 channels. The swim platform speakers are on the rear 2 channels. I disconnected one of the cabin speakers and it's mate continued to play, so they are definitely wired parallel. So the factory setup is 150w @ 2 ohms to both left speakers and 150w @ 2 ohms to both right speakers. And 100w each @ 4 ohms to each swim platform speaker.

All into plastic 25w speakers. What a waste of potential on that amp...

Thank you for sharing the knowledge Wheelspin! I too am now scratching my head on what the amp is pushing, but glad to know that's also an easy fix - just money, but easy DIY. Please go pic heavy when you bridge the second amp and subs.

 

[Jeebus]

So, the stock amp... does it have any gain control or frequency control on it at all? If I were to simply put speakers with higher rms capacity in the stock locations, would I be able to gain any volume or sound quality? I’m understanding that there is no eq adjustment anywhere in the boat?

 

[212s]

So popped out a couple more speakers. The cabins are wired with the same colors on the 2 left cabin speakers and 2 right cabin speakers. They are on the front 2 channels. The swim platform speakers are on the rear 2 channels. I disconnected one of the cabin speakers and it's mate continued to play, so they are definitely wired parallel. So the factory setup is 150w @ 2 ohms to both left speakers and 150w @ 2 ohms to both right speakers. And 100w each @ 4 ohms to each swim platform speaker.

All into plastic 25w speakers. What a waste of potential on that amp...

A waste yes...they must have de-tuned the amp a lot...would have made more sense to put in decent speakers with that amp but I guess they had to work with what they had for suppliers.

Oh and just to clarify, when you parallel speakers you divide the output into each speaker so 150w at 2 ohms is 75w to each speaker as they share the 2 ohm load output from the amp.

 

[212s]

So, the stock amp... does it have any gain control or frequency control on it at all? If I were to simply put speakers with higher rms capacity in the stock locations, would I be able to gain any volume or sound quality? I’m understanding that there is no eq adjustment anywhere in the boat?

No adjustments on the DSP versions - they are custom tuned for each boat model. In this scenario, they're probably tured down to 25w per speaker. I guess they didn't have a supplier with a smaller amp for these boat models and just de-tuned instead.

 

[Jeebus]

Okay, so its a total replace... thats fine i suppose. So, is anyone offering a plug that converts the inputs on this amp to useable RCA ends?

 

[Wheelspin]

Yep, total replace I am afraid. Better speakers wouldn't help much with the way the amp is hobbled. It's pretty trivial to solve for RCAs. I ordered these:

https://www.amazon.com/gp/product/B08PRY6Q34/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

Then it's just cut the black input plug I posted a picture of at the amp side and connect RCA lines instead like the ones I posted above. No more complicated than wiring a speaker. The blue wire remaining will be your remote turn on lead.
I also pulled the 10 gauge or so amp power wire and ground out of the plug at the boat side of the wiring harness as well. There is a little pin shoved into the rubber sealing it. Pull that out and back the rubber out and you can easily de-pin the weenie power wires.

 

[Wheelspin]

You can see the little pin that holds the rubber seal in on the #2 plug in this picture.

 

[Wheelspin]

The power and ground wires are retained by little barbs. You can see them in this pic. There's a de-pin tool you can use, but with the rubber backed out, *solidly* pulling at the wire, and picking at the little barbs with a small screwdriver or pick, it will come out without too much fuss.

 

[Cambo]

The one thing that I have learned from doing multiple stereo set ups in boats is the best piece to add is an EQ with amps . The wet sounds eq really helps balance out things and allows easy upgrades. One day some manufacture will hopefully build a system and post easily up gradable

 

[Jeebus]

Okay, its been years since ive had to splice rca onto speaker leads, used to have to do that pretty reguarly back in the car stereo days of the late 90s lol

Okay, so im on the same page here, there are 4 "plugs" on this amp, two black plugs and two white plugs. the white plugs hold the "input" signal to the amplifier, correct? Connector 1 specifically. So i splice my RCA ends onto that plugs signal wires for audio. That is the only plug i will need for the system, as the rest is just for power, ground, remote and output.

Thanks for all the help!! ordering stuff today

 

[1WetBoat]

Great info @Wheelspin. I haven't had a chance to tear into mine too much but I could have sworn I saw a set of RCA's coming out of the connext. I could be mistaken, will take a closer look this weekend.

 

[Wheelspin]

1wetboat, the RCAs you saw are coming from the aux port on the helm into the connext system. I was hopefully when I saw them until I chased the wire back.

Jeebus, 2 black plugs on the amp. Then that harness goes about 2 feet back to the 2 white plugs, which connect into the boat harness. I de-pinned the power wires on the white harness, and am cutting off the input black plug to wire to the RCAs. (#1 written in marker on the pic of the amp) I am not gong to use the stock wiring so I will just leave that plug (#2 written in marker on the amp pic) going to nowhere.

Cambo, agreed. That's why I decided to go with the Rockford DSP. Let's me split 4 channels to 8, and configure crossover and EQ individually for each channel. All with just a smartphone connection. Seems like a winner, we'll see.

 

[Jeebus]

Last question.... since i dont have my boat here yet with me, i cannot see if this would work or not, but do any of the speaker openings inside the cabin have space to fit an 8" speaker instead of the stock 6.5"? I would love to swap these all out with 8" component sets.