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Recommendations on amp for marine stereo (and battery requirements)

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Recommendations on amp for marine stereo (and battery requirements)

Old 07-09-2012, 11:56 PM
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Default Recommendations on amp for marine stereo (and battery requirements)

I'm replacing a stereo in a 24' pontoon used on fresh water lakes and rivers. I'm considering the following head unit/speakers.

- Fusion MS-IP700 head unit

- JL Audio M770 Coaxial speakers (x2)
- 100 watts RMS, 4 ohm, 40 watt minimum amp, 75+ watt recommended amp
- JL Audio M10IB5 Subwoofer
- 75-250 watts RMS, 4 ohm
I'm not sure about the amp. What would you recommend? I'd like to leave room for the possibility of adding two more M770 speakers after I hear how things sound on the boat.

Should I be considering a 4+1 channel amp or a 4 channel and a separate sub amp?

Here are some I have on my list. I'd like to hear about others too or why these would be a bad/good match for the speakers.

- Alpine PDX-5M
- @14.4 Volts, 75 watts RMS x4 @4 ohm, 300 watts RMS x1 @2 ohm or 300 watts RMS x1 @4 ohm
- Alpine PDX-4.100M + a sub amp
- @14.4 Volts, 100 watts RMS x4 @4 ohm
- JL Audio M700/5
- @14.4 Volts, 75 watts RMSx4 @4 ohm, 300 watts RMS x1 @2 ohm or 180 watts RMS x1 @4 ohm
I should mention that the goal is not to annoy other boaters by blasting the stereo. I'd like to have a system that sounds clean at lower volumes and is also clean at speed, being heard above the engine. The boat is in the shop now, as I'm replacing a Mercury 90 carb 2-stroke with a Mercury Optimax 150. While it is in there, I want to have them replace the stereo system too.

Thanks for any feedback you can give me.

David

Last edited by x_david_x; 07-10-2012 at 11:05 PM. Reason: Changed title to reflect discussion of battery requirements added later.
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Old 07-10-2012, 03:03 AM
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Get a 5 channel.
I would go with either JL or Fusion. They both sound great.
JL is slightly better sound but Fusion is also good at a lower price.
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Old 07-10-2012, 06:29 AM
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+1 for the Fusion 5-channel.

And while you might be able to tell the difference between the JL and Fusion speakers, you won't be able to tell the difference listening to Fusion's amp vs JL's (assuming both under rated power levels)
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Old 07-10-2012, 06:47 AM
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I've got a similar system (ip600, 4 770s, 2 10 inch jl subs) and I run a MHD 900/5 JL. I finally had an audio guy really tune my system 4th of July. Holy smokes! It will meet all the requirements you've laid out...and will run you out of the boat if you want it to. If you're only running one sub the 700/5 is probably plenty.
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Old 07-10-2012, 07:16 AM
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The Fusion MS-DA51600 5 channel amp is the way to go. You will get more RMS power out of a single amp by going with the Fusion without breaking the bank. We use this amp all the time and never have any complaints! Great amp at a nice price point. THT members get an additional 10% off your entire order on our site by entering the code "THT" in the coupon code box at checkout! The Fusion also gives you enough back up power to allow for running more speakers in the future!

http://store.mbmarineelectronics.com...watt-amplifier
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Old 07-10-2012, 11:04 PM
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Wow, thanks for all the feedback!

If the JL Audio amp is better, how much difference is there between that and the Fusion amp? I've read others (very few, however) mention the sound won't be as clean from the Fusion amps vs the JL Audio amps. In the real world, on a boat, do you think it would be a noticeable difference?

Anyone want to weigh in on the Alpine PDX-5M?

One other question related to the amp. I'm planning on having the electronics on the boat (stereo, bilge pump, lights, horn, fish finder) on their own battery. The spare battery I have for this is a Sears Platinum Marine Battery - size 34M. The reserve capacity is 135.

I know converting reserve capacity to amp hours is a risky business, but just for the sake of discussion, if I divide RC by 2 to get a rough AH, I get 67.5 AH. I also realize that if it did have a true AH rating on the battery, it would probably be under the assumption of using those amp hours over about a 20 hour period. However, if I ignore that and start adding up the numbers for my theoretical usage, here's what I find.

I'll use the Fusion amp for this. 80 watts RMS x4 @4 ohm @14.4 volts and 250 watts RMS x1 @4 ohm @14.4 volts. I'm assuming those are the 14.4 volt figures, as their website didn't distinguish. If I use an 80% rule for running at 12.5 volts instead of 14.4 volts, that brings us down to 64 watts and 200 watts, respectively.

I'll be running 2 coax speakers and 1 sub. At max level of the amp, that would be 328 watts (64 + 64 + 200). 328 watts at 12.5 volts = 26.24 amps.

67.5 AH / 26.24 amps = 2.57 hours

However, assuming the battery shouldn't be discharged that much, let's give me 25% of that figure, or .6425 hours = 38.55 minutes.

Now, I certainly hope that I don't need to run the amp at full power to hear what is coming out of the speakers when sitting still. What I don't know is what percentage of max will represent typical use. Any ideas?

If I use 20% of max (1/5th power), that gets me up to .6425 * 5 = 3.2125 hours.

If all those unknowns in the math go my way, I could certainly live with 3 hours of usage. What are your thoughts on the math used?

I should mention that I plan on having a battery switch installed between the motor and the starting battery and dedicated electronics battery so that I can, if needed, put a little juice back into the electronics battery by bringing the boat up to speed. I haven't done the research to even begin to determine how long it would take to recharge the electronics battery. A big for anyone who'd like to take a stab at that. The motor is an Optimax 150. Assume it is splitting the charge between the starting battery and the electronics battery, as I don't want to risk getting the starting battery down so far that I'm stranded.

I doubt there will be too many times for our type of usage that we'll be sitting still for 3 hours. Of course, if we are at speed, then the wattage usage may go up to overcome the ambient noise, leaving even less time. At a minimum, if the electronics battery is drained, I should be able to get enough juice back into it with the battery switch so that I can use the fish finder's GPS to get me home in the dark. Or at the bare minimum, power the running lights!!

I do have another option. I'll have 3 group 31 M batteries (sears platinum again) in the boat for the 36 volt trolling motor. If I really had to, I suppose I could wire those in parallel to the amp with some sort of switch so that I could use those for when there is a lot of stereo usage (which is generally mutually exclusive with a lot of trolling motor usage, for us).

Thoughts?

If anyone has any real world hours they get out of their 3 speaker setup with a similar amp and could include what battery(ies) they are using, that would be great.

Thanks again!
David
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Old 07-11-2012, 06:28 AM
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I'm not a fan of doing all my calculating at my desk and like real world tests to see how long things last. I always simulate real world worst case testing on a new setup. Tied to the dock with engines off, I turn on the system to the max loudness I'll ever use and come back every 2 hours and take batt voltages. I know I personally will not do more than 6 hours drifting so that's the limit.
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Old 07-11-2012, 06:46 AM
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[quote=Glen E;4757186] I always simulate real world worst case testing on a new setup. Tied to the dock with engines off, I turn on the system to the max loudness I'll ever use and come back every 2 hours and take batt voltages. [quote]

Your neighbors must love you!
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Old 07-11-2012, 06:52 AM
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Glen - That was good timing and a solid plan. I am an empirical guy myself. I was mulling this over this morning and came up with basically the same plan. Run it on dry land and check voltages periodically. I then plan on taking it on the water and running the motor, checking the voltage of the house battery periodically to see how long it takes for the motor to recharge it when set to charge both batteries.

However, it would be great if someone could tell me how long they get out of their battery(ies) when running a similar amp. That will give me a rough idea of where I stand.

Glen - Do you remember what you found in your previous testing? What type of amplifier load did you have and what type of battery?

I'm also getting into trying to determine the best way to wire things together and my head is swimming with battery switches, ACRs, multiple battery banks, electrical isolation, dissimilar batteries being charged at the same time by the motor, etc. I think I'll open a new thread specifically on those items. I know there are many threads out there on that, but it seems like each situation is unique. They provide a good starting point though.

Thanks again,
David

Last edited by x_david_x; 07-11-2012 at 06:53 AM. Reason: changed amp to amplifier to avoid confusion
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Old 07-11-2012, 07:04 AM
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I'm running a JL mhd750/1 for my subs(2) and a MHD 600/4 for my 6 JL 770's......I think I got about 3 hours at my max volume I like, before reading 12.0 which is my lowest I will go. I also max drift 2 hours and really don't do any sand bar work anymore.
My amps run direct from two odyssey pc1500 house batts, connected to engine batts via blue seas ACR'S

The reason you really can't compare here is every has a diff max volume and loads from other things.

I monitor my batt levels with a sep voltage and amp gauge on my dash called a Newmar DCE gauge- google it....
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Old 07-11-2012, 05:53 PM
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Those PC1500s look like they have the same reserve capacity as my Sears Platinum 34M, at 135 minutes. You have more speakers, but that should mean you'd run each individual speaker at a lower level to get the same total sound output as I would with fewer speakers (assuming we want the sound output to be the same). You have two batteries though, so you'd get at least twice the duration if other things are equal.

Thanks for the DCE information. I looked and can't find another device that quite does what it does. It is expensive, but it may be worth it.

The DCE information says it works on up to 3 banks of 12 volt or 24 volt. With my currently planned system, I'll have the following banks:

- 1 AGM starting battery (12 volts)
- 1 AGM house battery (12 volts)
- 3 AGM trolling motor batteries (36 volts)

If I hook up the DCE to 1 battery in the 36 volt bank, will it work, but I'll just need to multiply by 3 for amp-hours remaining shown on the monitor?

Thanks,
David
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Old 07-11-2012, 06:00 PM
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No Idea, might Ask newmar
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Old 07-11-2012, 06:26 PM
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Just an FYI - Most chart plotters can show the voltage on the circuit they're connected to, and usually you can set alarms on the value as well. If you have one that does so, you may be able to use it instead of buying a separate gauge. My NSE can even plot graphs over time, though I haven't actually tried to set up a graph for the voltage.
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Old 07-11-2012, 06:44 PM
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Originally Posted by LMychajluk View Post
Just an FYI - Most chart plotters can show the voltage on the circuit they're connected to, and usually you can set alarms on the value as well. If you have one that does so, you may be able to use it instead of buying a separate gauge. My NSE can even plot graphs over time, though I haven't actually tried to set up a graph for the voltage.

I have that as wel but the gps voltage readings are not pure.... the DCE Is something quite different....And reading without the gps on....
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Old 07-11-2012, 07:07 PM
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Originally Posted by x_david_x View Post
Thanks for the DCE information. I looked and can't find another device that quite does what it does. It is expensive, but it may be worth it.

The DCE information says it works on up to 3 banks of 12 volt or 24 volt. With my currently planned system, I'll have the following banks:

- 1 AGM starting battery (12 volts)
- 1 AGM house battery (12 volts)
- 3 AGM trolling motor batteries (36 volts)

If I hook up the DCE to 1 battery in the 36 volt bank, will it work, but I'll just need to multiply by 3 for amp-hours remaining shown on the monitor?

Thanks,
David
The DCE is not unique, the Xantrex LinkLite and LinkPro are the common ones. Neither the DCE nor the Xantrex products are capable of operating on a 36v bank. There is also no "hooking it up" to a single battery... all current passes through each battery. There may be a solution for 36v, but I would just use a simple voltage gauge to determine battery health on the trolling bank... most people have nothing at all.
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Old 07-11-2012, 07:17 PM
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Update on my proposed speakers. I stopped by to take some measurements of my boat at the dealer today. The existing two speakers, mounted under one of the seats, have 5.75" diameter grills (5" speakers). Unfortunately, I only have about 1/2" space on the bottom of the speaker and maybe a little over 1" above the speaker (which to take advantage of would require moving the hole). That means I'm back to 6.5" speakers instead of the 7.7".

The maximum grill size would be about 6.75" before it hangs past the plastic seat base and could get snagged, kicked, etc. If I go with 7.7" speakers, the grill would hang down almost a half an inch.

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Do you think hanging over that much (red circle) is enough to switch from the 7.7" speakers to the 6.5" speakers?

Hmm, looking at the picture, and thinking about the fact that the 7.7" speakers need a bigger mounting hole, maybe the whole thing could be shifted up? That might allow for the overhang to be closer to 1/3".

I think I'll need to go back to the dealer and measure and see exactly what I have to work with. When I was there today, I was assuming it would use the same hole and would hang over a lot more.

I've read on here in other posts that the M650s are recommended over the MX650s when using an amp, so those are probably what I'd go with if I downsize.

David

Last edited by x_david_x; 07-11-2012 at 08:01 PM. Reason: Pictures didn't show up right the first time.
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Old 07-11-2012, 07:57 PM
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Originally Posted by TheLucille View Post
The DCE is not unique, the Xantrex LinkLite and LinkPro are the common ones. Neither the DCE nor the Xantrex products are capable of operating on a 36v bank. There is also no "hooking it up" to a single battery... all current passes through each battery. There may be a solution for 36v, but I would just use a simple voltage gauge to determine battery health on the trolling bank... most people have nothing at all.
Thanks for the information on the Xantrex devices. The LinkLite is a little more reasonably priced than the Newmar DCE. Does anyone have any experience with the LinkLite? It only supports two batteries, from what I can tell, however. I don't see anything about it being water resistant/waterproof.

So if I hook up the monitor to the positive and negative post of one battery in the 36 volt bank (let's say the one that has its negative post connected to the trolling motor), it will sense the full amps going through all 3 batteries that are wired in series?

Thanks,
David
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Old 07-12-2012, 10:55 AM
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Glen - I looked at the online operation manual for the Newmar DCE device. It looks like there are various options for recalibrating it. My initial reaction is, "How in the heck would I know what to change the values to!?"

This is just one example:

"If the displayed amp-hours is drifting down faster than actual
amp-hours, increase the drift compensation value slightly. If
it is drifting upward faster, then decrease the value slightly."

How does one know if amp-hours displayed is accurate or not?

I also found out that most functions only work on one bank, with the other two banks only having voltage displayed:

"The unit displays voltage for three banks and amps or amp-hours for
your house bank. It tracks all current entering and leaving
the house bank and applies Peukert's and efficiency factors."

Thanks,
David
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Old 07-12-2012, 01:46 PM
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See post #12
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Old 07-12-2012, 11:40 PM
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Originally Posted by Glen E View Post
See post #12


Well, I did ask them about the 36 volt system today, via email:

...
Hello,

I'm considering buying a Newmar DCE energy monitor for my boat. I'm making some changes and plan to have 3 banks of batteries:

- 1 AGM house battery (stereo, horn, bilge, lights, etc.)
- 1 AGM starting battery for an outboard motor
- 3 AGM batteries (36 volt bank) for electric trolling motor

The literature says that the DCE works for 12 volt and 24 volt banks. If I wire to the positive post of one of the 36 volt bank batteries, what will the device display?

Thanks,
David
...

If I buy the device, I'll ask them about recalibration. My hope is that recalibration is seldom needed, but I do still wonder how one would know how to set some of those values.

The dealer that is installing everything said they were looking at the Xantrex LinkLite and they were going to call Xantrex to see what they had to say about a 36 volt system. Xantrex only supports 2 banks, but if neither end up being useful for the 36 volt bank, then maybe the Xantrex is worth the money savings. Hard to say from pictures, but for some reason I like the look of the Xantrex more. The red back lighting of the Newmar gauge seems harsh from the pictures. Does it look that way in real life?

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Two other products have come to my attention:

DOC Wattson model R102 digital panel meter, which appears to support 36 volt banks (even up to 60 volts):

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Victron BMV-602s, which appears to be less expensive than the Newmar/Xantrex products, and will support monitoring my house battery (AH, percent used, etc.) and the starting battery (voltage). I did find a review online stating that it wasn't waterproof (holes in the back of the device where water could enter).

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If it wasn't for the lack of waterproofing on the Victron, I might consider it. I think it is between the Newmar DCE and the Xantrex LinkLite or LinkPro (LinkPro has historical information). The DCE has an NMEA 0183 interface, so I could really get fancy and log the output to a laptop.

Hmm..this just in. I found the company that makes the monitors for Xantrex. They have a monitor that will work with banks up to 70 volts. It looks very similar to the LinkLite/LinkPro. It is called the E-xpert Pro-HV (non-HV pictured here):

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The E-xpert Pro (non-HV) is for 12-24 volt systems.

Looking like either a combination of Doc Wattson and LinkLite/DCE, or two E-xpert Pro-HVs. That would give me a good view of my trolling motor battery bank (36 volt) and a good view of my house battery, and still give me an accurate measurement of voltage on the starting battery.

Now if I could just figure out how to rig my 36-volt bank to be switched to (could be manual) if the house battery is low and have it disconnect (preferably automatically) the series connections and switch to parallel connections, we'd have little worry about running out of power! I'm sure there is a way with enough relays, but that fun will have to wait for another night.

If anyone has any pictures of the various screens on the DCE, please post them.

Thanks,
David
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