Jl Audio HD600/4 vs HD750/1 for a Pair of REV10s

[House324]

Looking for advice on new system.

I have 2 JL MHD amps that I'm removing from my old boat and will use in my new boat. I'm planning on buying a pair of Wetsounds REV10s for the tower. If you had a choice, would you use a 750/1 or a 600/4 to power the speakers? I've seen seen expert recommendations from David Analog who often recommends using the 750/1 for REV10s. And he addresses the insignificane of "stereo" channels in two hlcd speakers closely mounted on the tower. But I've never seen a comparison between the 600 vs a 750. Is the power difference noticeable, or any other advantages between the two?

BTW, my new boat is a 2011 Sport Nautique 200 and I will be swapping my stock Polk amps into my old boat.

My new system "plans" are:

* I have 1 MHD600/4 to power 8 stock Polk in-boat speakers. All are Polk MM650s: 4 cockpit, 2 bow, 2 rotating cans on sides of the fct3 tower.

* I have 1 MHD750 for ported sub under observer seat. My current Sub is a Line-X coated factory JL Audio ported MicroSub, single 12TW1. The box is nearly direct-radiating via stock 10" speaker grill opening in the walkway. I mounted the sub speaker facing the stock opening and glued in some speaker cloth so it looks like the stock Polk 10" sub opening. The 750/1 will be gained down for the 300watt rms specs of the sub. It's overkill for my current sub, but I like having an efficient, regulated amp that I can stack and save space. And maybe room to grow to a larger sub latter on.

* Need to buy 1 MHD750 (or MHD600) for a pair of REV10s on the tower.

I have a WS420 for control which will be mounted near the driver's helm. And powered directly from Iphone, using a Wetsounds inline RCA volume control between phone and WS420. I want to mount the volume control right next to the throttle for fast volume control when towing so I don't have to fumble for volume when watching everything else. I think I'll prefer the inline RCA control because its faster than having to wait a second for the VC-BT Bluetooth version to change the volume. But both options are cheap enough that I can switch them out if I decide to use the VC-BT control which is nice for BT and track control.

I'm planning on upgrading the stock Group 24 battery to an Odessey group 31 which is mounted in the rear port compartment. I'm planning on bypassing the factory multi-fuse configuration and using an inline 120amp switchable fuse mounted near the battery. Positive/Negative ground to battery for all of the system to prevent ground loop noise. About a 10' run from battery to distribution blocks near the amps that will be mounted under the observer seat. Will a "real" 4 gauge main wire be enough for power. JL Audio's wire guide says 4 gauge is sufficient for 20' based on their numbers...Or should I just use 0 gauge? FYI, I already have enough 4ga OFC and 4 ga dist blocks so it would save me money.

Sorry for the long post, but any help or suggestions will be appreciated.

Thanks, Jeff

[David Analog]

The JL Audio HD750/1 is 25% more power and costs less than the HD600/4. With the HD600/4 you would be paying for complexity that you wouldn't need or use in this application.
Be careful about stacking amplifiers since this isn't an air-conditioned cab.

[distinguishedmotorsports]

regarding the amps i really don't have much to say. i could understand the cost saving measures.


in regards to the wire, high quality OFC 4 gauge should be good for around 150 amps at that length, you should be fine. but typically any more than two additional amps and you will need the 0 gauge. i added two more to my boat, a sub amp and a 4 channel and i'm using about 140 amps of it. KnuKoncepts OFC wire, did both the power and grounds to the battery. you may still want to ground all the amps and head unit together via 16 gauge to prevent noise.

[nyryan2001]

I stack my 750/1 on a 900/5.... I run them hard and they get hot... But have never cut out

[MLA]

Is that 20ft one way or both ways?

For me, no, I would not use 4ga trunk line for any combination of those amps. If you look at the overall cost of this build, cable is the small investment. Even if 20ft was the round trip, id build it with 1/0 trunk. Sounds like you are not using a dual battery or bypassing it with the audio?

[House324]

Thank you guys for the input.

I installed most of my stereo today. I'll buy a MHD750, REV10s and 0 gauge wire next week.

I spent a considerable amount of time identifying speaker wires and labeling. I disconnected the factory 6 gauge main lines from rear locker. I temporarily used my 4 gauge wire till next week. Now + and - are direct from wired battery to distribution blocks with a 150 amp Bussmann breaker near the battery. 9' of wire run (18' round trip).

I ran all the wiring and RCAs and WS420.

I discovered the factory Roswell tower wires are 16 gauge. Will that be enough for a pair of REV 10s?

[David Analog]

16-gauge isn't horrible but it is certainly less than optimum for this use. If you have (8) factory 16-ga. conductors in the tower then double up for (4) total conductors, which will work out fine, however, the quality of the connections is very important.

[MLA]

Not really the speaker that dictates the wire gauge.

[House324]

Thanks David, that's a good idea to double by using two pair of wires per speaker. Now I just need to check if I have another pair available. If not, I may just run a larger wire through the tower.

[toomuchuv]

I use a HD1200/1 to power my Roswell Neptunes. They sound pretty darn good, and loud! I use the wired remote to turn them down when needed....

[toomuchuv]

16-gauge isn't horrible but it is certainly less than optimum for this use. If you have (8) factory 16-ga. conductors in the tower then double up for (4) total conductors, which will work out fine, however, the quality of the connections is very important.

Interesting.....Do the lengths have to be EXACTLY the same?

[David Analog]

Interesting.....Do the lengths have to be EXACTLY the same?

Absolutely, they must be EXACTLY the same only if you are OCD.

[Kporsch]

I really like the JL MHD line of amps. I am close to finishing the install on my 17 G23. Just need to wire tower speaker amp (750/1) and put my Roswell box in place of the stock JL sub.


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