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SaltwaterMC
02-28-2007, 06:25 PM
I have a 2007 X-Star that originally had 4 JL tower speakers on it but I had them all taken off when we bought the boat. I am now looking at putting 2 JL tower speakers back on the tower but want the necessary power to handle 4 tower speakers if I decide to add them in the future. With that said, I got into the compartment that houses the stereo and from what I saw there were only two pair of wires instead of four coming from the tower. One set of purple, one set of green. This leads me to believe that the tower speakers are wired parallel. If I am correct, the impedance would then be 2 ohms (two 4 ohm speakers, assuming I use the JL TCS', wired parallel would give you an impedance of 2 ohms)... I am assuming the power going to the amps is 12.5 volts, and if you look at the specs on the JL marine amps, the power output is 75 watts stereo at 2 ohms, and the minimal impedance is 4 ohms if you bridge, so that is out of the question. So it appears to me that if what I think I see is correct, the tower speakers would be significantly underpowered if I were to use one of JL's amps to run tower speakers, considering the RMS of a single speaker is 100w. If I am not seeing something please let me know. Judging from the imprint in the carpet, it appears my X-Star had an M2150 running tower speakers from the factory.

FlatBoard
02-28-2007, 10:17 PM
Just out of curiosity, why did you remove the speakers in the first place. I hear the JL's carry a premium sound.

SaltwaterMC
03-01-2007, 12:49 AM
Just out of curiosity, why did you remove the speakers in the first place. I hear the JL's carry a premium sound.

Too much money at the time.

JBaker
03-01-2007, 05:06 PM
Basically everything you said is correct, although I would not consider them "significantly" underpowered. It would be easy for you to find out how they would sound, just go to a dealer and have a listen, as this is a common setup. Or ask anyone around here what they think of their JL tower speakers. With the exception of the few guys with aftermarket upgrades every JL speaker is being powered by 37W-45W RMS and people seem to be prrrrrrretty happy. Just make sure you turn on the High pass filter on your amp, set it at about 100-120Hz and you will be just fine, IMO. The low frequencies are what eat all the power and they aren't going to make it out to the rider anyway.

FlatBoard
03-01-2007, 09:11 PM
Basically everything you said is correct, although I would not consider them "significantly" underpowered. It would be easy for you to find out how they would sound, just go to a dealer and have a listen, as this is a common setup. Or ask anyone around here what they think of their JL tower speakers. With the exception of the few guys with aftermarket upgrades every JL speaker is being powered by 37W-45W RMS and people seem to be prrrrrrretty happy. Just make sure you turn on the High pass filter on your amp, set it at about 100-120Hz and you will be just fine, IMO. The low frequencies are what eat all the power and they aren't going to make it out to the rider anyway.

JBaker sounds like you really know your stuff. Are you a techy!! So many stereo and power issues being discussed on the site. Must be that upgrade time of year. I too am upgrading my stereo and can't wait to crank it up on the water....

Thanks for all the good advice :D

SaltwaterMC
03-02-2007, 12:29 AM
JBaker, thanks for the response. I actually own a pro audio company, and in our world we believe in overpowering everything significantly because if you know what you are doing and use proper limiting you really can't have too much power. It is typical to provide twice the peak power handling for our boxes, so I am inclined to carry that principle over to the audio system on my boat. I am still pretty hesitant about underpowering the speakers that much even with them crossed over, as underpowering is the cause of the majority of most speaker damage. If you are trying to drive more than the amp can handle it will cause the amp to distort thus causing that distorted signal to be sent the speakers which causes the damage. I don't know though, maybe I'll have to explore other options, but I really do appreciate your help and confirming my apprehensive observations. It's good to know I'm on the right track.

JBaker
03-05-2007, 04:40 PM
JBaker, thanks for the response. I actually own a pro audio company, and in our world we believe in overpowering everything significantly because if you know what you are doing and use proper limiting you really can't have too much power. It is typical to provide twice the peak power handling for our boxes, so I am inclined to carry that principle over to the audio system on my boat. I am still pretty hesitant about underpowering the speakers that much even with them crossed over, as underpowering is the cause of the majority of most speaker damage. If you are trying to drive more than the amp can handle it will cause the amp to distort thus causing that distorted signal to be sent the speakers which causes the damage. I don't know though, maybe I'll have to explore other options, but I really do appreciate your help and confirming my apprehensive observations. It's good to know I'm on the right track.

You've got it figured out. Underpowering is often what destroys speakers...certainly more often than overpowering. You are essentially making the argument for extreme headroom. I have personally found that significantly exceeding max RMS is more necessary when powering subs than full range drivers (especially when you have filtered out low frequencies.) There is a guy on here (TX.X-30 fan I think) who is powering each pair of JL components with a 300/2. That is the closest I have heard to someone doubling the RMS ratings. You would probably have to find a really powerful amp and then bridge it to exceed 200W, unless it was an amp designed to be used w/ subs.

You should also take into consideration how many Amps your alternator is going to put out. Using Ohms law you will find there is a finite amount of wattage you can achieve, assuming say...60 percent efficiency (generous.) It may not even be possible for you to be pumping out the kind of wattage you are thinking with your given power supply.

I don't think anyone would argue with you that you can never have too much power, but at a certain point it may be difficult to justify it. $$

Who called me techy?!

PendO
03-05-2007, 04:51 PM
It is amazing to me ... as expensive of a boat as the X-Star, that they don't do a better job putting the stereo system together ... when we filled out the 04' JD Power questionaire I know that MC did not get high marks for their wiring / amp setup ...

SaltwaterMC
03-05-2007, 05:07 PM
I am not necessarily trying to double the RMS for the JL tower speakers, but would certainly like to see more than 37.5 watts going to each speaker. I would like to stick with the JL products simply because that is what is in there now from the factory, but given the way it is wired I would not be able to get any more power out of the JL marine amplifiers. So I guess my only option would be to run individual pairs of wires to each tower speaker, allowing me to rid of the parallel wiring but JL still doesn't make a marine amp that would provide ample power. I don't know how one of their mobile amps would hold up in a saltwater environment, but I am guessing not too well. If anyone has any suggestions feel free to let me know.

Archimedes
03-05-2007, 05:28 PM
I'm just a caveman and I'm confused by your talk about ohms and amps and such, but what I do know is... the new 6 channel JL M6450 amp I put in my X-1 last fall powers four JL cockpit speakers and two JL tower speakers, sounds awesome and gets louder than one would ever need.

'course if my goal was to serenade the whole lake and surrounding valley, I might need more, but the set up I've got sounds great for everything else.

PendO
03-05-2007, 05:30 PM
I am not necessarily trying to double the RMS for the JL tower speakers, but would certainly like to see more than 37.5 watts going to each speaker. I would like to stick with the JL products simply because that is what is in there now from the factory, but given the way it is wired I would not be able to get any more power out of the JL marine amplifiers. So I guess my only option would be to run individual pairs of wires to each tower speaker, allowing me to rid of the parallel wiring but JL still doesn't make a marine amp that would provide ample power. I don't know how one of their mobile amps would hold up in a saltwater environment, but I am guessing not too well. If anyone has any suggestions feel free to let me know.

with ours we replaced the factory wiring, put 1 crossover per speaker down by the amp (didn't care for the integrated crossovers), and ran a total of 8 pairs of wires up to the tower (two pair from each of the 4 crossovers, with power to the crossovers from a 4 channel amp)... replaced the speakers with some MB Quarts speakers ... I will look for pictures on my home computer and post them up this evening (I say "we" like my brother and I did it ... in actuality we had a top notch steroe shop rewire it and just stood around watching them) ... the stock speakers were removed at the time of purchase and sold by my brother IIRC - but he can post and refresh my memory.

JBaker
03-05-2007, 05:38 PM
Bridge the JL M series marine amps. I have seen/heard this a few times. It is basically the best you can do while staying in the marine line. You would get 150W @ 12.5v to each speaker, or if you wanted to compare that rating to other amplifiers that are rated at 14.4v, you would get 220W.

I have seen this done where a guy absolutely loaded himself up with e4300-Ms (predecessor to M4300.) He had one for every pair, so 4, plus a sub amp. Nice system-he had to run power and ground wire that looked more like anacondas after a feast.

SaltwaterMC
03-05-2007, 06:50 PM
I thought of that but I was hoping to get by with one amp to power a potential 4 tower speakers, but the M4300 would only allow me to power 2 tower speakers if I were to bridge it so I guess I better learn to be satisfied with 2 tower speakers or accept the fact that I would need 2 amps to run 4 speakers. I just don't know why they don't make a 4 channel amp that puts out more than 75 watts when you bridge channels, or a 2 channel amp that puts out more than 45 watts stereo.

ProTour X9
03-05-2007, 07:13 PM
Off topic but, DANG YOUR BOATS COOL!!!

SaltwaterMC
03-05-2007, 07:29 PM
ProTour X9, if that comment was to me thanks, if not... sorry.

TX.X-30 fan
03-05-2007, 07:42 PM
with ours we replaced the factory wiring, put 1 crossover per speaker down by the amp (didn't care for the integrated crossovers), and ran a total of 8 pairs of wires up to the tower (two pair from each of the 4 crossovers, with power to the crossovers from a 4 channel amp)... replaced the speakers with some MB Quarts speakers ... I will look for pictures on my home computer and post them up this evening (I say "we" like my brother and I did it ... in actuality we had a top notch steroe shop rewire it and just stood around watching them) ... the stock speakers were removed at the time of purchase and sold by my brother IIRC - but he can post and refresh my memory.


Here's a dumb question, why did you replace all the factory wires? And was it expensive to fish new wires to the tower?

ProTour X9
03-05-2007, 07:53 PM
It was to you Saltwater.

JBaker
03-05-2007, 10:19 PM
I just don't know why they don't make a 4 channel amp that puts out more than 75 watts when you bridge channels, or a 2 channel amp that puts out more than 45 watts stereo.

Well the Clarion APX480M offers 80W a channel, 4 ohms @ 14.4v.

Did you mean 75W a channel when running in 2 ohm mode? You can't really take the bridged output power and cut it in half and say that is what each channel is putting out. In bridged operation, one channel is responsible for a given polarity.

There is a very small market for marine amps with the kind of wattage you are looking for. In car audio, all manufacturers have to be concerned with is what is going to sell at the retail level. In marine, they have to take in to consideration what boat builders are going to buy. I doubt many boat builders would want to pony up for the cost of not only the more powerful amp itself, but also the larger power/ground wire with the price of copper these days.

JBaker
03-05-2007, 10:22 PM
Let me also second the hooray for Salt's GORGEOUS MC!

SaltwaterMC
03-05-2007, 11:48 PM
That was my mistake, I see that it puts out 150 W in bridge mode at 4 ohms. JBaker thanks for the compliment!