Wylie_Tunes

I have not gutted a Roswell/Centurion downfire pod, so just a hunch here. I would fully expect those drivers to have a proprietary basket size, shape and or bolt pattern. So this would limit you to the manufacturer. 5 seasons is not a lot of time, so I would also want to revisit the amp settings, to make sure theres not a reason for a blown speaker that would repeat itself. The woofer is a 10" IIRC. Its in a small sealed enclosure I believe. There are better build woofers, but id want to know what my enclosure volume was first, unless the plan is to scrap the entire setup and start fresh. At that point, move up to a 12. Even consider a ported enclosure. Need to take the available amp wattage into account also. Want to get the most out of the amp, but at a safe impedance. Here again, buzzing is not normal from a woofer, so id want to try and isolate the noise and make sure its not going to be there with the new woofer.

If the OP has a blue sea dual circuit plus switch and ACR, any diagram from Perko will get you in trouble. Need to clarify the switch type.

Amplifier output is dependent upon voltage, so engine off v's engine on can make a difference. Gain level also. A larger factor is a difference in voltage at each amp. Its very rare to have the DC voltage input, bleed into the AC voltage audio output due to cable routing.

I dont recall which media source unit the 2020 has, but good bet its the only thing all of those modes have in common.

Different gauge is not an issue, but incorrect gauge, as in too small, can cause issue. Have you checked voltage at all the audio components, and compared them? I do suspect something wrong with the amp, if the noise is present with no audio cables connected to the amp inputs. Take a short RCA and connect both ends to any and all RCA inputs on the amp. This basically shorts the inputs, preventing noise from entering. If noise is present and the gains are not excessive, this pretty much points to the amp.

Try starting with a different phone.

Most any unit with USB, should be compatible with the apple protocol with a lightening x USB cable.

A woofer change will not address this, as the current enclosure is the biggest factor in how the woofer sounds. You would need to change the enclosure volume. If the woofer is whats making all the unwanted noise, then you need to first determine if any external factor was the root case, before installing a new woofer.

It can. In not a fan of point a woofer up. Many woofers have whats called a dust cap in the cent of the cone. Its where the cone connects to the motor structure and they glue a cap over that point. With the woofer up, if water collects in the woofer, it will find its way into the motor after awhile. If you have a ported enclosure, this is an entry point for water to also collect and stay in the enclosure. If you can spare another 3" of height, consider inverting the enclosure and make it a down-fire by making a couple of risers.

Alternators are typically wired to the starter's main post, as its the shortest, most direct route.

You can use a multi meter and measure the woofer's coil and circuit at the amp. If you know which model woofer it is, you can look the specs up to see what its impedance is. Other wise, id bet its either a 4 ohm or 2 ohm woofer. So the complete circuit would be close to that by a couple tenths of an ohm. Say 3.8 to 4.2 would be normal for a 4 ohm and 1.8 to 2.2 for a 2 ohm. What you are looking for is the meter to be wildly off or showing OL.

Battery voltage, battery voltage battery voltage. Got to start here. Whats the battery voltage at the batteries, then at the back of the head, then again with engine running. IIRC, the 2014 would the dual circuit plus switch and ACR. Where the batteries removed or disconnected for winter layup? If so, gut says the ground for the ACR was left off or the ground link between the banks was left off.

To truly get the most, the Kicker KXMA1200.2 would be the top choice. It will deliver up to 300W rms x 2 @ 4 ohm. This well above each pod's 150W RMS, but it equals a ton of head room. Your gains are going to be super low, so the amp runs real conservative, which yields better sound quality overall. While a bridged 4 chnl will typically give you more wattage p/$$$, these multi-driver pods are known to dip well below their rate 4 ohm nominal impedance. This can put some bridged 4 chnls into protect mode intermittently.

At the least, I would separate the two batteries into a main cranking and house bank, with a dual bank battery switch. I would want a cranking on one side and deep-cycle on the other side. Then, depending on how much anchor play time you wanted, then you can calculate the need for additional battery amp hours.

It definitely sounds like the amp is driving the tower pods on chnls 1 & 2 i.e. AMP-1. It then sounds like chnls 3 & 4 i.e. AMP-2 is power some in-boats but maybe not all. This leaves 1 or 2 pair still on the head unit. The best improvement you can do is to install a new (2nd) and dedicated to the tower speakers. Then, rewire the existing amp and in-boats so ALL in-boats are driven by the existing amp. based on the online specs, those speakers have a 3 ohm nominal impedance, you would be best to go with a 2 chnl amp. id want to be in the 150W to 200W rms @ 4 ohm range, which will = a little more to a 3 ohm speaker.