1 Amp or 2? *Short Version*

[Wrecked Rooster]

Would y'all recommend a single 5 channel amp or a 4 channel amp and a separate amp for a sub, possibly 2 subs and 4 6.5 speakers? Both amps have the RMS wattage to drive the subs. 350 watts at 4Ω and 600 at 2Ω. Subs I'm looking at are 175 watts 4Ω speakers. It should be okay to have the extra wattage at the amp over what the speakers can handle right? Just turn the gain down? Never installed an amp in my life. Going to have a local shop tune it after I install everything.

And which sub would you recommend? Both are Free Air subs that I plan on installing under the bench of my AR210:

• Subwoofer options:
  1. JL Audio MX10IB3 (discontinued model) - 175w RMS at 4 Ω
  2. Kicker KMF10 - 175w RMS at 4 Ω

Kickers are $30 more than the discontinued JL's. Also with 4 6.5's and 1 sub, would that be "enough" to have decent sound while under way, or would it be suggested to add an additional sub? And possibly some 8's in the middle of the boat? When we anchor off, I usually turn the boat off and have a JBL speaker we listen to on the back deck. Thanks!

 

[Wrecked Rooster]

Got rid of the long winded post (sorry, I get in the weeds sometimes) and got it down to the nuts and bolts. Thanks for any help!

 

[jcyamaharider]

As far as amps go I have never like the multi use amps. You just seem to get more out of a dedicated mono black amp for subs. Just personal preference.

I cannot speak to the Kicker subs but I do have 2 of the JL audio subs in my boat and it sounds good. If you are looking for the shake yourself to the bones bass, it will not do that, but it a good all around stereo.

 

[Wrecked Rooster]

As far as amps go I have never like the multi use amps. You just seem to get more out of a dedicated mono black amp for subs. Just personal preference.

I cannot speak to the Kicker subs but I do have 2 of the JL audio subs in my boat and it sounds good. If you are looking for the shake yourself to the bones bass, it will not do that, but it a good all around stereo.

Thanks for the info! I might buy 2 to save on shipping and install one to see how I like it. Cutting large holes in the boat is a little nerve racking. I just want to add some depth (not sure if that's the right word) to the system. With just the 4 6.5" speakers, everything seems kind of high pitched I guess.

 

[kgower]

Short answer 2. As far as cutting holes, I totally understand. So far, I have cut 4 holes. 2 for 6.5 mid cabin speakers, 1 for a ten-inch sub port helm and 1 for a Nocco port plug for charging the batteries.

 

[Wrecked Rooster]

@jcyamaharider @kgower

Seems like a little overkill on the power, but if I won't damage anything, I'm good. I'm installing and having a local audio shop tune everything. Would this be okay? Mixed reviews on the internet about over/under power on the amp.

Mono amp specs:

350 watts at 4Ω
600 at 2Ω
800 at 1Ω

Subs I'm looking at are both 175 watts 4Ω speakers. Free air.

 

[Bruce]

Mono amp specs:

Who manufacturers the amplifier? There is a lot of variation in claimed wattage versus reality.

 

[Wrecked Rooster]

Who manufacturers the amplifier? There is a lot of variation in claimed wattage versus reality.

This is the one I'm looking at:

https://www.skaraudio.com/collections/marine-amplifiers/products/rp-800-1dm-marine-amplifier

 

[Bruce]

This is the one I'm looking at:

https://www.skaraudio.com/collections/marine-amplifiers/products/rp-800-1dm-marine-amplifier

Here is a dyno test of that amplifier

Remarkable output for such an inexpensive amplifier!

What will you do for batteries to keep the amplifiers fed?

 

[Wrecked Rooster]

Here is a dyno test of that amplifier

Remarkable output for such an inexpensive amplifier!

What will you do for batteries to keep the amplifiers fed?

Skar seems to be making some good stuff and figure it's worth a shot. 2 year warranty is a little nice too. I installed their 6.5" speakers and they seem like good quality. I bought a dual battery setup (switch and ACR from bluesea) and another battery that's rated at 65 AH. However, listening to the system with the boat turned off wouldn't be more than an hour max at a time. When we anchor off, we kill the boat and use a bluetooth speaker for tunes.

 

[Bruce]

listening to the system with the boat turned off wouldn't be more than an hour max at a time. When we anchor off, we kill the boat and use a bluetooth speaker for tunes.

That will reduce usage during the day but even with the engines running you are likely to be consuming more power that the stators are producing.

A 65 AH lead acid battery has 32.5 AH of usable power before you damage it.

The RP-800.1D appears to be capable of consuming close to 80 AH per hour. Realistically it will consume much less than that but you could drain two 65AH batteries. I suggest putting an amp clamp meter on your positive cable when the stereo is running at a typical volume to get an estimate of what the draw will be.

 

[Wrecked Rooster]

That will reduce usage during the day but even with the engines running you are likely to be consuming more power that the stators are producing.

A 65 AH lead acid battery has 32.5 AH of usable power before you damage it.

The RP-800.1D appears to be capable of consuming close to 80 AH per hour. Realistically it will consume much less than that but you could drain two 65AH batteries. I suggest putting an amp clamp meter on your positive cable when the stereo is running at a typical volume to get an estimate of what the draw will be.

I'll be sure to do that. I have a buddy with one of those tools I believe. Worst case, I have a 100 AH LiFePO4 battery I'm not using that could replace the 65AH AGM. It's just a space thing. There's a storage compartment built into the boat, made for 2 batteries in the 24 size range.

 

[Wrecked Rooster]

That will reduce usage during the day but even with the engines running you are likely to be consuming more power that the stators are producing.

A 65 AH lead acid battery has 32.5 AH of usable power before you damage it.

The RP-800.1D appears to be capable of consuming close to 80 AH per hour. Realistically it will consume much less than that but you could drain two 65AH batteries. I suggest putting an amp clamp meter on your positive cable when the stereo is running at a typical volume to get an estimate of what the draw will be.

Also, I was using a formula I found on crutchfield to determine amp draw. Says to take the RMS for the amp, divide by .75 then divide by 13.8 to get a more realistic rating. With 2 subs in parallel at 2 OHM the speaker rating would be at 350 watts RMS but the amp is capable of 600 watts RMS. Using the speaker numbers I get 34 amps and using the amplifier numbers, I get 58 amps. Definitely worth checking with a meter. But those are the numbers I should be getting in theory, correct? The 80 amps would be if I was fully driving the amp at 1 OHM right? What kind of power do the stators produce?

 

[OB WI]

Would y'all recommend a single 5 channel amp or a 4 channel amp and a separate amp for a sub, possibly 2 subs and 4 6.5 speakers? Both amps have the RMS wattage to drive the subs. 350 watts at 4Ω and 600 at 2Ω. Subs I'm looking at are 175 watts 4Ω speakers. It should be okay to have the extra wattage at the amp over what the speakers can handle right? Just turn the gain down? Never installed an amp in my life. Going to have a local shop tune it after I install everything.

And which sub would you recommend? Both are Free Air subs that I plan on installing under the bench of my AR210:

• Subwoofer options:
  1. JL Audio MX10IB3 (discontinued model) - 175w RMS at 4 Ω
  2. Kicker KMF10 - 175w RMS at 4 Ω

Kickers are $30 more than the discontinued JL's. Also with 4 6.5's and 1 sub, would that be "enough" to have decent sound while under way, or would it be suggested to add an additional sub? And possibly some 8's in the middle of the boat? When we anchor off, I usually turn the boat off and have a JBL speaker we listen to on the back deck. Thanks!

Last year I upgraded the 6 interior speakers to Kicker 6.5 replacements and then added two Kicker 10 free air and one Stinger SPX 1000x5 w/ bass knob amp. Nice to turn down the subs as needed. It sounds pretty good for the cost. It never overheated even with 6 plus hours of use. If I add tower speakers or anything else I will definitely be adding a 2nd amp.

 

[Bruce]

The 80 amps would be if I was fully driving the amp at 1 OHM right? What kind of power do the stators produce?

From an electrical engineering perspective wattage = voltage x amperage. But with audio the amplifier will not be drawing power most of the time and capacitors in the amplifier allow peak output to be higher than current draw.

An averaging multimeter will give you a good indication of how much your amps are drawing.

I am uncertain what the output is of the stators on the TR-1s. I would guess 30 amps or less each but it should be documented in the owners manual.

 

[212s]

Remarkable output for such an inexpensive amplifier!

@Wrecked Rooster Have you seen the inside? It's a cheap design which is why it's not expensive. While it will output decent power, it likely can't do it sustained or in hot or moist environments. And it's not a marine rated amp so no coatings on the board to protect it from moisture. Also the "dyno run" Bruce linked to is by Skar so it's not going to be...to spec. Where's the 2/3/4 ohm results?
After 20 years of doing this, I've learned you generally do get what you pay for...

 

[212s]

And which sub would you recommend? Both are Free Air subs that I plan on installing under the bench of my AR210:

• Subwoofer options:
  1. JL Audio MX10IB3 (discontinued model) - 175w RMS at 4 Ω
  2. Kicker KMF10 - 175w RMS at 4 Ω

I'd go for the JL sub in a heartbeat...much deeper and cleaner output. And they can handle a good 25% or more over ratings if you plan to push it hard.

 

[kgower]

@jcyamaharider @kgower

Seems like a little overkill on the power, but if I won't damage anything, I'm good. I'm installing and having a local audio shop tune everything. Would this be okay? Mixed reviews on the internet about over/under power on the amp.

Mono amp specs:

350 watts at 4Ω
600 at 2Ω
800 at 1Ω

Subs I'm looking at are both 175 watts 4Ω speakers. Free air.

I have one amp for the 6 cabin spears and sub and one amp for the tower speakers. If you want to see an impressive set up check out @Sotally Tober https://jetboaters.net/threads/sotally-tober-5s-completed-build-pic-heavy.31483/

 

[Julian]

I'm the wrong guy to ask....(three amps in my boat)

 

[Wrecked Rooster]

@Wrecked Rooster Have you seen the inside? It's a cheap design which is why it's not expensive. While it will output decent power, it likely can't do it sustained or in hot or moist environments. And it's not a marine rated amp so no coatings on the board to protect it from moisture. Also the "dyno run" Bruce linked to is by Skar so it's not going to be...to spec. Where's the 2/3/4 ohm results?
After 20 years of doing this, I've learned you generally do get what you pay for...

I know you said the inside looked cheap on the Skar (pic attached with red board), how does the other one attached compare? I don't know anything about what a good amp looks like based on its internals. Thanks for any help.