stereo question

[Z28Johnny]

My ar240 came with a 600 watt 6 channel jl audio amp running 4 jl audio 6.5 boat speakers and 2 jl audio 7.5 tower speakers... And a 200 watt jl audio amp running a 12" sub. It seems like the driver of the boat misses out on the sound. The speakers are all 4ohm and the 6 channel is 2 ohm stable... question... from what I know of 12 volt stereos I can add 2 more towers and 4 more boat speakers and the amp would put out 100 watts per channel instead of 75 watts... At the same time adding more sound. It would drive the amp harder, but it is capable. Is it worth adding the extra speakers?

 

[MikeyL]

@Z28Johnny - You have made an EXCELLENT point !
"It seems like the driver of the boat misses out on the sound."

It has to do with SPEAKER LOCATION - not more "amps."
We are gonna haveta design more speakers (in a 24' 2015 Yamaha) which are more "ear friendly" to the driver's ears.
In my opinion, the problem is not POWER - It is LOCATION.

Hope this helps a little. Mikey Lulejian - Lake Oconee, GA

 

[txav8r]

I agree, you need mid cabin speakers (2). I am adding them in my JL upgrade. You have a solid system there, but it is set up to run the system you have. Adding two more speakers may require trading one of the amps to accommodate another 200w of capability, or changing the wiring in the setup you have. IMO, you are definitely underpowered if you add more tower speakers, but you may be able to accommodate the two additional in boat speakers. The tower speakers need to be driven with more than the in boat speakers. You can drive the in boat speakers optimally with 75w each, but the 7.7's need closer to 100w. Division of power is the key, and there are many threads dealing with that as well as dealing with the atmospherical difference between boats and automobiles, and magnify that in the difference between an atmosphere inside an open boat, and the atmosphere a tower speaker has to play to. You have a solid system there, very solid. And all the speakers are being powered to their optimum except the tower's right now. At 2 ohms or at 4, you don't have the amp reserve to add 4 or 6 more speakers. I doubt that you can add two more without giving up something somewhere. You mentioned you have a 12" sub and a 200w amp powering it. 200w sounds very low for a 12" sub. My 10" JL sub has a 250w "continuous" RMS power requirement, and if you were to put 250w to it, the excursions might run it over IMO. I don't put that much power on my sub, but I am suspecting if yours is a 12" sub, you may want more power to it anyway. One thing you could do is sell the 200W amp and get what you need for the upgrade to cover additional tower speakers if you so desire, and the sub, and channel the 600/6 to the 6 in boat speakers, after you add two mid cockpit speakers. It is tough to find a perfect place to add these mid cabin speakers. The available surface is more restrictive than it appears. I am adding mine in the combing pocket port side where the depth requirement of 2.75" is available, and below the combing pocket and forward of the throttles on the sidewall in front of the drivers legs. It won't fit behind or in front of the throttles in the combing pocket, and aft of the throttles it must be built out with a supporting bezel over 1.5" thick. My preference is forward. Those two speakers will fill in the loss of what your hearing (not hearing) at cruise. The choice on additional tower speakers is up to you, but if distance is important to you, you need different speakers up there, not more coaxials, if overall near range sound is important, then maybe additional might help. One size definitely does not fit all...it is all based on your needs and expectations, but it is all doable!

 

[brockhals]

I'd bridge (if possible) two channels on the 6 channel to run both tower speakers at 2 ohnm. and add mid cabin mids as mentioned above

 

[txav8r]

@brockhals , if bridged, won't he lose the number of channels he needs to power 6 in boat speakers and 2 tower speakers (4 - 60w optimum and 2 - 100w optimum), plus the sub? He needs a total of 9 channels IMO, to maximize the output of all of those drivers. You can change the output some, but adding two speakers will reduce output somewhere to share. He could share the load the way we do at times with fade or switching, but that means all 8 coaxials are not playing at once. That may be fine with him, and tower speakers play when the bow speakers don't for example...but the load, and the supply are still limited by amp output into however many channels it can deliver to. You guys know me, I only know simple, so when it gets complex, you gotta "splain" it to me!

 

[brockhals]

What I'd do is add the mid cabins to the "rear" channel on the amp with the other cockpit speakers, thus putting this channel into a 2 ohm load. Then bridge the "tower" channel to two ohm as well, so only the bow speakers will be running at a 4 ohm load. The sub is on another amp so I'd leave it as is. You'll sacrifice a bit of power to the rear speakers now since the 2ohm load will be split by 4 speakers now, but the drop in power will be made up by the addition of two speakers.

Now that I think more though, I wouldn't bridge the tower speakers and that will create a 1 ohm load on those channels...not safe. You could however add them to the bow channel possibly, presumming they'd be playing the same frequencies. As the driver, you wouldn't get much/any benefit from towers anyway as they are designed to project behind the boat.

After all this, I'd just add the mid cabins and tie them in with your cockpit speakers at a 2ohm load on those channels.

 

[Williamsone46]

Leave the amp alone and put the two rear cabin and the new mid cabin speakers in series. That's how the do it on the 242 LS with the transom speakers.

 

[brockhals]

You could, but then you're splitting the 4 ohm power in two with no additional benefit.

 

[kthrash]

I'd bridge (if possible) two channels on the 6 channel to run both tower speakers at 2 ohnm. and add mid cabin mids as mentioned above

I may be misunderstanding what you are saying here... but, when you bridge two channels the resistance stays the same however the output goes up... so the tower speakers would still be 4 ohm but driven by more wattage.. Now if he added two more tower speakers and had 4 and ran them in parallel, then the resistance would drop to 2 Ohm..

I would wire in 2 more speakers to what are in the boat like others have said.. leave the Amp wiring alone..

 

[brockhals]

I was saying that if he were to bridge two channels, he'd then wire the towers in parallel creating a 2 ohm load, however the amp would then 1/2 that so 1 ohm for each channel which isn't stable.

 

[kthrash]

I was saying that if he were to bridge two channels, he'd then wire the towers in parallel creating a 2 ohm load, however the amp would then 1/2 that so 1 ohm for each channel which isn't stable.

Wouldnt that kill the whole Stereo L/R sounds though.. I think it would leave it sounding dead... like listening to one side of a headphone..

 

[brockhals]

It would, but for tower speakers would it really matter? You don't really benefit from left/right when you're behind the boat.

 

[kthrash]

I'm just thinking tone in general, if you completely cut out one of the channels of music I would think you would lose some of the sounds..

 

[Williamsone46]

 

[redthumper9]

I'm in the process of adding mid cabin speakers to my AR240 now. In fact, they are installed, just not finished wiring my new amps. Should be an easy fix for you. Wire the front channels into a 2 ohm stereo load (4 speakers, each channel in parallel).....Wire the rear channels into 2 ohm load (4 speakers, each channel in parallel)......Wire tower channel into 2 ohm load (4 speakers, each channel in parallel). Yes it will increase the amplifiers output, but it will be splitting the power between more speakers. That amp probably has plenty of headroom in the power department, so I would worry about under powering anything. Leave the Sub amp alone and you'll be good to go. I'm curious as to where you plan to add the extra 4 speakers in the cabin or are you planning some for the transom. I think some are getting confused using the word "bridged". It usually refers to combining two channels into one......not the same as paralleling a channel for a 2 ohm load.

 

[Z28Johnny]

I'll probably just add two in the middle of the boat for now... The pic that williamsone46 is showing even shows you can run 4 speakers off of two of the channels putting them down to 2ohms. This question goes to show that there is a lot of confusion sometimes about ohms, watts, bridging, etc. I feel I know quite a bit and I still get confused sometimes.

 

[David Analog]

It is probably not a good idea to load any multi-channel amplifier down to its lowest stable impedance load on ALL channels. Four of six channels, sure. Six of six channels, probably not. That's stretching your power supply and your heatsink to the max. Power distribution may also impact the decision. Towers and subs are usually driven the hardest. The workload of in-boat coaxials is easier. So bridging a 6-channel into a 3-channel on tower and sub is not a good idea. Mix it up with the in-boat coaxials and the load is better balanced. The amplifier will certainly run more efficiently at a higher impedance load. But economics often dictate that you run some of the channels at 2-ohm stereo or 4-ohm bridged in order to derive the extra power needed or to save on the number of channels needed.
Having four total coaxials within the cockpit, excluding the bow zone, is really important if it's possible. The boat doesn't always cooperate. The added midbass surface area of those extra coaxials significantly improves the integration with the subwoofer.
A 12-inch sub typically will handle more power than a 10-inch sub. But power handling and size alone does not necessarily dictate that you need more sub power. After all, a 12" sub within the same series, having more surface area, will also be more sensitive than the corresponding 10" sub. I think it is more a matter of fulfilling potential than need.
Regardless of how you configure it, no more than two tower speakers on two channels unless those are some really BIG channels. The demand that tower speakers place on the power to project a long range with noise competition is just too great for the modest power that works so well with the in-boat speakers.
Can't bridge into a 2-ohm load. In the bridge mode you actually have TWO inverted positive channels working in a push-pull arrangement and passing TWICE the current. So the 4-ohm speaker termination is actually the ""equivalent"" of half that impedance.
When four channels are bridged into two channels correctly with a fullrange or highpass speaker, you will not sum L & R and you will not drop one channel. You will maintain stereo.