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Old 01-22-2009, 09:53 AM
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Default 6 Speakers = need 6 channel amp?

Not too knowledgeable on audio equipment. Boat has six 7" speakers. Is a 6 channel amp the best way to go? thank you
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Old 01-22-2009, 03:59 PM
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Default Re: 6 Speakers = need 6 channel amp?

Lot of variables I doubt I would consider just 2ch stereo for 6 speakers though it could be done. Often systems using multiple speakers have a selector switch so you choose which speakers you want running. As in if you have speakers in the cabin and don't want to listen there you switch the speakers off. It would be easier if you listed what all components you currently have and what you want the system to do. Are all the speakers even the same it is possible that 2 of the speakers could be used as subs on a 6 ch system or that you have 2 pairs of 4ohm speakers wired in series in a 4 ch setup there are currently to many unaswered questions as to how to set it up.
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Old 01-22-2009, 04:45 PM
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Default Re: 6 Speakers = need 6 channel amp?

What he said.

A 6 channel amp would be the most straightforward thing to do - but depending on what the speakers are and where they are, you have a lot of options. You might even want to run one pair off the head unit itself and then just use a 4 channel amp.

(a 6 ch amp is a bit much for a boat unless your priority is maximum power to all your speakers)
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Old 01-22-2009, 05:32 PM
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Default Re: 6 Speakers = need 6 channel amp?

I had a 6 speaker amp from JL (6500) and just replaced it with a 4 ch amp from JL (M600/4). The reason was the 4ch has double the power of the 6 ch. I put my bow set and transom speakers on ch 1&2 and my speakers at the midships (where I live) got ch 3 & 4. The fronts and rears are getting 75W a pair and the mids are getting 150W. The new JL amp has it's own fader for front to back level which allows me to really dial in the rear helm sound balance, and turn the fronts down when we have family cruises. I am very satisfied with this arrangement.
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Old 01-22-2009, 05:38 PM
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Default Re: 6 Speakers = need 6 channel amp?

I'm no sound guru..but doesn't putting 6 speakers on a 4 channel amp throw off the impedence/channel? If it does...does that even matter(sound wise)?
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Old 01-22-2009, 07:07 PM
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Default Re: 6 Speakers = need 6 channel amp?

It does not throw off the impedance, it changes it. Most Marine speakers are 4 ohm and if two 4 ohm are wired in parallel the impedance cuts in half to two ohms. Most quality power amps can handle a 2 ohm stereo load without a problem






Quote:
Joe - 1/22/2009 8:38 PMI'm no sound guru..but doesn't putting 6 speakers on a 4 channel amp throw off the impedence/channel? If it does...does that even matter(sound wise)?
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Old 01-22-2009, 07:42 PM
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Default Re: 6 Speakers = need 6 channel amp?

Some times I think yankees and southerners speak the same language, but mean completely different things.

When I said "throws it off"--that's exactly what I meant--"changes it". Sorry for the confusion.
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Old 01-23-2009, 04:30 AM
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Default Re: 6 Speakers = need 6 channel amp?

Quote:
Glen E - 1/22/2009 8:32 PM

I had a 6 speaker amp from JL (6500) and just replaced it with a 4 ch amp from JL (M600/4). The reason was the 4ch has double the power of the 6 ch. I put my bow set and transom speakers on ch 1&2 and my speakers at the midships (where I live) got ch 3 & 4. The fronts and rears are getting 75W a pair and the mids are getting 150W. The new JL amp has it's own fader for front to back level which allows me to really dial in the rear helm sound balance, and turn the fronts down when we have family cruises. I am very satisfied with this arrangement.
There are two potential issues in doing this - first most marine speakers are 4 ohm - putting them in series makes it a 2 ohm load, which if the amp is not rated for 2 ohms will eventually fry it; second, even if it can take a 2 ohm load, all 4 speakers must be the same - ie all Infinity 602M's - otherwise the volume from each pair could be very different based upon efficiency.
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Old 01-23-2009, 06:03 AM
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Default Re: 6 Speakers = need 6 channel amp?

Quote:
LI32 - 1/23/2009 7:30 AM

There are two potential issues in doing this - first most marine speakers are 4 ohm - putting them in series makes it a 2 ohm load, which if the amp is not rated for 2 ohms will eventually fry it; second, even if it can take a 2 ohm load, all 4 speakers must be the same - ie all Infinity 602M's - otherwise the volume from each pair could be very different based upon efficiency.
Wiring two 4 ohm speakers in series will result in an impedance of eight ohms, not two. Wiring them in parallel will result in an impedance of two ohms.

The equipment's specifications will state the minimum load (impedance). Your point on efficiency is valid, but most speakers intended for boats will be about the same efficiency.

Something I've never seen mentioned when discussing multiple speakers is "phase". A speaker's cone moves in and out when producing sound. If one connects two speakers "out of phase" with each other, one cone will be moving in while the other moves out. The most obvious result will be a loss of bass frequencies. Less obvious will be a subtle change in sound as one moves around the listening area. Using the same brand and model speakers and paying close attention to the wiring is the simplest way to avoid this problem. It's also possible to compare the phase of different speakers with a "D" cell and a pair of clip leads.
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Old 01-23-2009, 10:24 AM
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Default Re: 6 Speakers = need 6 channel amp?

Please...no armchair experts on this...everything I do is run by JL tech and they are wiring their 4 ch amps all over the country like this. It may be "your opinion" but it's not fact...one 2 channel source is feeding 4 identical JL speakers
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Old 01-23-2009, 05:19 PM
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Default Re: 6 Speakers = need 6 channel amp?

Not doubting you Glen. Like I said..I'm no sound guru. If your way works, seems okay to me !
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Old 01-23-2009, 05:24 PM
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Default Re: 6 Speakers = need 6 channel amp?

Quote:
Joe - 1/23/2009 8:19 PM

Not doubting you Glen. Like I said..I'm no sound guru. If your way works, seems okay to me !

not you joe....
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Old 01-23-2009, 05:49 PM
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Default Re: 6 Speakers = need 6 channel amp?

Running a two ohm load(two 4ohm spkrs in parallel) on an amplifier whose output is rated to drive a 4 ohm load can cause damage as you are causing the amplifier to try to push more current. P = I^2 * R. The safer avenue is to run the speakers in series. This will cause a loss in volume, but will not destabilize the amp by asking it to output more than it's designed to. I'd continue, but the wine is starting to destabilize me.
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Old 01-23-2009, 09:58 PM
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Default Re: 6 Speakers = need 6 channel amp?

Quote:
LI32 - 1/23/2009 7:30 AM

Quote:
Glen E - 1/22/2009 8:32 PM

I had a 6 speaker amp from JL (6500) and just replaced it with a 4 ch amp from JL (M600/4). The reason was the 4ch has double the power of the 6 ch. I put my bow set and transom speakers on ch 1&2 and my speakers at the midships (where I live) got ch 3 & 4. The fronts and rears are getting 75W a pair and the mids are getting 150W. The new JL amp has it's own fader for front to back level which allows me to really dial in the rear helm sound balance, and turn the fronts down when we have family cruises. I am very satisfied with this arrangement.
There are two potential issues in doing this - first most marine speakers are 4 ohm - putting them in series makes it a 2 ohm load, which if the amp is not rated for 2 ohms will eventually fry it; second, even if it can take a 2 ohm load, all 4 speakers must be the same - ie all Infinity 602M's - otherwise the volume from each pair could be very different based upon efficiency.


putting two 4 ohm speakers in "series" would give you an 8 ohm load. putting them in parallel would give you a 2 ohm load.

and it really doesnt make that big of a difference if the speakers are different if you wire them in parallel. sure they may sound different, but so long as they are similar sized speakers, i really doubt you would see a difference in power between the sets to really notice.

by the way, i havent seen a multichannel amp built in the last 10 years that wasnt at least 2 ohm stable

i just finished wiring up a boat the exact same way as Glen E has his setup. all 4 bridge speakers on the front 2 channels, the cockpit speakers on the rear. fade to front and you get all the flybridge speaker, fade to back and you get cockpit. keep it in the middle and all of them play. it's a pretty common way to wire a setup like that.
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Old 01-24-2009, 05:53 PM
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Default Re: 6 Speakers = need 6 channel amp?

Quote:
Glen E - 1/23/2009 8:24 PM

Quote:
Joe - 1/23/2009 8:19 PM

Not doubting you Glen. Like I said..I'm no sound guru. If your way works, seems okay to me !

not you joe....
Me?

I did this stuff for a living for twenty years or so. And for side work before that. Fooled enough people and made enough money to retire and buy the boat pictured.

I could make your head spin, but how you have your speakers wired is fine, no need to change anything.
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Old 01-24-2009, 05:58 PM
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Default Re: 6 Speakers = need 6 channel amp?

Quote:
Glen E - 1/23/2009 1:24 PM

Please...no armchair experts on this...everything I do is run by JL tech and they are wiring their 4 ch amps all over the country like this. It may be "your opinion" but it's not fact...one 2 channel source is feeding 4 identical JL speakers
are these the same JL techs that suggested you use the 7.7" midrange from the component set as a subwoofer?

you might want to take your chances with the armchair experts
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Old 08-09-2010, 03:55 PM
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Default speakers/amps HELP!! :(

Kind of a long story but bare with me...i need your advice!

I have a 2006 22' mastercraft x-star wakeboarding boat that came stock with a 6 channel JL audio m6450 amp that runs 6 JL audio 6.5" 150w interior speakers AS WELL AS a 10" sub woofer.

The boat also has a JL marine amp that runs 4 JL audio 6.5" 150w tower speakers.

And lastly i added an additional 10" sub woofer powered by a 1996 Sony mobile ES car amplifier model XM-5046.

Last week the JL 6 channel amp and sony amp stopped getting power...so my boat guy said both amps were shot and replaces the JL 6 channel with a 2010 rockford fosgate t600-4 amp that runs ONLY the 6 interior speakers and replaced the sony amp with a 2010 rockford fosgate p400-2 amp which now runs BOTH 10" sub woofers...

i take the "broken" JL 6 channel m6450 and the 1996 Sony mobile ES car amplifier model XM-5046 to AL and ED's autosound where they both pass a bench test and work fine!!!!???

not to mention im getting a buzzing sound in the speakers with these new rockford fosgate amps and i know the pre-amp output on my head unit wasnt used because the sub woofers only fade and work with the "REAR" tower speakers.

So...given that i have the Clarion cmd4 head unit (which has a pre-amp output but no sub control option) how exactly should i configure the 5 available working amps i have with the 12 total speakers in the boat?

(and whatever i dont use i will just sell on ebay)
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Old 06-17-2013, 09:29 AM
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Hi Glen,

I haven't been around much lately, but I just did the same thing you did with the Mean Kitty's stereo and I lost quite a bit of volume. I say the same thing, but my tech was just a general electronics guy -- there are no JL techs near me.

I sent a email to JL's tech support (see below) with no response. If you or anyone else has any ideas -- I'm "all ears"...

Thanks,
Dave


I have a 33 Hydrasports with a Clarion CMD7 head unit front ending all JL audio amps and speakers. The set up is 6 years old and originally I had a M6450/6 connected to 6 M770 (with the front 4 set up as the front fade on the CMD7 and the back 2 as the rear) and a M1400 driving 2 M10B subs. It worked fine and sounded quite loud.

Last year I started getting crackling at low volume in the two rear speakers and the installer (who is not very audio savvy) said that the speaker leads on the M6450 were severely corroded making it impossible to isolate the problem as being speakers or amp. So over the winter, I had my boat dealer replace the M6450 with a M400/4 and both of the M770 rears. I went with a more powerful 4 channel versus a 6 because I seldom need as
much volume in the front 4 as I do in the back 2. The installer twisted the speaker leads together from the 2 front sets (R&L) into one and connected those to the front speaker output on the M400.

My problem is that the entire system is no where near as loud as the old one and based on the specs I think it should be louder. The old one was 6X45W and I had it set up with 4 channels going to the front 4 speakers and 2 going to the back where I also have 2 subs. The new one is 4X75W and it was suppose to share the frot 2 channels between the 4 front speakers and then give me 2 dedicated 75 watt channels for the rears. When I fade
everything to the rear, I should have 2X75 vs. 2X45, which should be louder -- but it isn't.

Am I wrong -- are there settings that my untrained installer could have messed up or did we do something wrong by splicing the front speaker wires?
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Old 06-17-2013, 09:55 AM
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Mean Kitty - Have you tried playing with the gain?
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Old 06-17-2013, 11:21 AM
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There isn't any Gain adjustment on the M400/4
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