Vanharca

When I purchased my boat, a Powerquest 260 Legend, it had a stereo already installed, but currently has no subs. As I have been looking into adding a couple, I dug into the current system layout and have some questions.

Here is what is currently installed:

Head Unit: Kenwood KDC-400U (22Wx4 RMS), Front/Rear/Sub Preamp Outputs
Amp 1: Alpine MRV-F450 (50Wx4 + 200Wx1)
Amp 2: Alpine MRP-F240 (40Wx4 or 100Wx2)
Speakers A: Qty. 4 - Alpine SPR-M700 Coaxial, Mounted on the sides of the cockpit, 2 in front of the bolsters, 2 behind. These are powered by the MRV-F450.
Speakers B: Qty. 4 - JBL MS 6200 Coaxial, Mounted under the rear bench. These are powered by the MRP-F240.
Speakers C: Qty. 2 - Alpine Coaxials, not sure of the model, but they are small and in the cuddy. These are currently powered by the head unit.

Right now there is no ability to fade. While re-wiring I would like to gain the ability to fade the cuddy speakers on or off in case the kids are in there.

I would like to add a couple of subs relatively cheaply, but want decent components. I'm not after perfect sound quality or being the loudest stereo out there, just something decent. I am looking at adding these:
Amp: JL Audio MHX 300/1 (300Wx1 Bridged at 2 Ohms)
Subs: JL Audio MX10IB3, Qty. 2

Now here are my questions:
1) Mono Channel: There is a single 200W channel on the MRV-F450 not being utilized right now, but it is only stable at 4 Ohms. I'm not 100% on 2 subs and could get away just adding 1 on this channel. Will 2 Subs be that much better than just 1? Are there any other ways to utilize this?

2) 2 or 4 JBL: I don't think the JBL Speakers are that great and I'm not a huge fan of adding new/unnecessary holes to the boat. I am thinking about removing the 2 central speakers and mounting the subs in their place. If I did this I would probably bridge the MRP-F240 to the two remaining speakers. In this configuration there would be both subs and coaxial speakers using the same air space under the rear bench, does that cause problems or being different frequencies is it ok?

3) Fade: In order to gain the ability to fade, I was thinking about running the two speakers in the cuddy off of either the front or rear outputs from the head unit. I would then use the opposite pre amp output to signal the amps powering the speakers in the cockpit. Does it matter if I use front or rear for either of these? As I understand it both are full range signals to the pre amp outputs, but not sure about speaker level.

4) Pre amp outputs: I would use the sub pre amp outputs to the JL amp, that is the easy part. As mentioned in the fade question, I would potentially only have one more set of outputs to run the other 2 amps. The MRP-F240 does have a pre amp output. In order to get the best signal, is it better to y the output from the head unit to the front/rear channels on the MRP-F240 then use the pre amp output on that amp and y that to the front/rear channels of the second amp? The other option would be to y the output from the head unit to each amp, then y the signal again to provide a front/rear input to each amp. Of course my understanding is that each amp requires a front and rear input, even if they are the exact same signal with no desire to fade.

Sorry about the long drawn out post, I just wanted to be clear and detailed. Any input or suggestions would be great!

Thanks,

Craig

Diamond Dave

1. Do not use this channel.

2. I would run two subs for sure. If you wanted to you could use the Alpine MRP-F240 bridged stereo for two of your "front" channels that you felt would benefit the most from the higher wattage and then use the output of the Alpine MRV-F450 to power the rest.

3. Your deck has the option in the menu to turn off its internal amp thus muting your cabin speakers for the kids. Hook them up to the front speaker line level outputs. As long as you are happy with the output of those speakers I would use that feature rather than adding another amp or rewiring anything.

4.Use the front and rear pre outs on the deck (assuming you do what I suggested in #3)

Vanharca

This makes sense. I didn't realize the head unit had that function, but it certainly would be better to use both front and rear outputs knowing that it does.

As far as the subs, does anyone have any experience with that model and or amp? I know they are the lower end JL, but for the price I'm not sure what may be a better option.

Thanks

Diamond Dave

I do not have experience with that series of amp specifically but do with JL's HD series which are great amps. Most threads I have read about the JL subs are regarding the M series and people are extremely happy with them. Where are your amps mounted in your application? You may not need "marine" versions which can save you some money also. The amp you are looking at has the remote gain capability http://www.jlaudio.com/m-rbc-1-marin...essories-98404 so you can remotely control the sub gain with a dash mounted knob which is a very handy feature.

Jonesyfxr

iTrader: (1)

Even though the subs you spec'd are JL's lower line, don't let that discourage you. They are a great sub.

Vanharca

Thanks for the replies so far.

My amps are both mounted in the cuddy. The MRV-F450 is in the top of a storage compartment, with very little to no chance of exposure to water. The MRP-F240 is mounted in a compartment underneath the v-berth. There is a possibility of moisture in this compartment draining through from the anchor locker, but no splashing and it hasn't been a concern this far.

Based on what I have heard, I think the plan would be to use the JL subs mentioned above in the location of two of the JBL speakers. I will keep the cuddy speakers wired as is along with the 4 alpine speakers and consider bridging the MRP-F240 to a pair of speakers, though I'm not sure which at this point. I do have a set of JL C5 coaxial speakers in my garage just sitting there, so I could install them if there was any benefit, but not being marine speakers would be concerning depending on where they went.

As far as amps go, I think I would be fine without a marine rated amp because it would probably go in the same storage compartment as the MRV-F450. With that said, should I consider anything in place of the JL MHX 300/1? The non marine version is the same price so there is no benefit there, but just browsing crutchfield there are some lower priced amps out there that seem to have plenty of power for these subs. I've been out of the audio world for awhile so I'm really not sure who makes decent equipment any more. There are some Kenwood Excelon amps that are fairly low priced along with some others, but I am assuming its a get what you pay for scenario. I do want to make sure I get something that can take the vibration and hits from the waves that a boat sees. Should I just stick with the JL amp and not worry about it?

Craig

Diamond Dave

I would bridge the MRP-240 to whatever speakers it would do the most good. I am unfamiliar with your boats acoustics but "generally" speaking this should help figure it out what I mean.

1. Do you primarily value the loudness and clarity while you are driving at speed? If so I would say the two "front" speakers in front of the seats would benefit this situation most.
2. Do you primarily sit on the beach and listen to the music play? If so I would bridge the two channels to the speakers that were the highest and projected in the direction you want the music to be best heard.
3. If none of that works trial and error! Acoustics can be tricky for the best results sometimes....

There are a lot of great amps out there and I have had great luck with a lot of different brands over the years. I would probably just stick with what you listed already unless you can find a deal on something higher power for the same money... just don't go swap meet on your amps just because they say they have more power.

288sunny

I have 2 brand new JL 10's, sealed enclosure type I'll sell. Still in box's. $250 each

288sunny

Might have some used clarion speakers and subs for sale, will know more on Monday.
Sony amp as well

US1 Fountain

iTrader: (1)

I have 2) JL M10IB subs and a 300/4 amp.
The subs are the higher end for infinite baffle use.
The amp is an older 300/4 Slash series I used for 4) 7.7's. I replaced the subs with one for a sealed box use. The amp I replaced with an HD600/4. The amp did drop a channel a few times. Maybe once or twice a yr for a couple min. then back on. Might have been speaker wiring. Didn't really look into it. It was always the same speaker that cut out. Wanted bigger amp, so out it came. I assume it could be used as a single channel to power both subs. I used a 250/1 for both subs. I'd sell subs and amp for $200 plus shipping.Shoot me a pm if interested.