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Post by fishnfool on Feb 17, 2019 10:55:58 GMT -5
Can someone explain what this means and dumb it down real good? This is from an amp spec sheet...
Channel Class D Power Amp 2 ohm stable stereo outputs Bridgeable outputs Variable input level controls for each pair of channels Variable High-pass, Low-pass and All-pass crossover Variable Bass Boost circuit Thermal and overload protection circuitry Gold-plated RCA jacks and terminals
Idling Current: 0.8A Idling Current when off: <0.001mA Output Power (RMS)@14.4V/4ohms: 125W x 4CH Output Power (RMS)@14.4V/2ohms: 200W x 4CH Output Power (max)@14.4V/4ohms: 250W x 4CH Output Power (max)@14.4V/2ohms: 400W x 4CH Fuse Rating: 25A x 3 Dims (LxWxH) inches: 10 7/8″ x6 3/4″ x 1 7/8″
I am looking at this in the context of driving 2 4ohm coaxle speakers.
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Post by finatic on Feb 17, 2019 11:02:20 GMT -5
Its written in Chinese,, so I can't be of much help. lol Sorry buddy can't help myself.
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Post by fishnfool on Feb 17, 2019 11:39:08 GMT -5
Its written in Chinese,, so I can't be of much help. lol Sorry buddy can't help myself. I thought it was Korean lol Paging Captn Ron!
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Post by fishnfool on Feb 17, 2019 11:43:15 GMT -5
Basically I was looking to pick up another 4 channel amp exactly like the one I have for purposes of driving the 3rd set of speakers.
I am not 100% sure how my speakers are wire now - 6 speakers and only a 4 channel amp. Pretty sure theres only wires for 2 sets of speakers connected to my amp.
The stern and bow speakers are loud the mid ship speakers are not nearly as loud. So what is powering these mid ship speakers?
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Post by Team Ruby on Feb 17, 2019 13:27:26 GMT -5
Is it possible that the midship speakers are powered by the amp from your head unit? A quick test would be to pull the fuses on your amp and then turn the head unit on and see if any speakers play. If nothing plays you might then have two speakers wired to half of your four channel amp and the remaining four probably wired in parallel to the other two channels. The remaining four could also be wired in series, but based on what you have said so far I wouldn't think that they are. Also, if you have a fader control in the system somewhere what speakers are effected when you shift from front to rear?
At one time home audio amplifier power output was measured in RMS, root mean square. RMS is nothing more than a value used to multiply the peak of sine wave when the amp was brought to full power and within specified distortion limits. Some manufacturers want to see bigger numbers for the power output of an amp and use terms like peak or max power output. One thing not mentioned above was any mention of a percentage of distortion. Back when I was into this distortion was listed as Total Harmonic Distortion, THD and Intermodulation Distortion.
So in your case I'm assuming that your amp is seeing a four ohm load and the amp produces 125 watts RMS or 250 watts max, tow different ways to measure power output into a four ohm load. It's kind of like saying a car produces 400 HP at the crank or 300 HP at the wheels. The engine is producing the same amount of power, the difference is where and how are you measuring the power.
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Post by fishnfool on Feb 17, 2019 14:15:16 GMT -5
As far as I know there are no speaker wires attached to my head unit. I put it in. There is rca cable with a splitter from the head unit to the amp and all speaker wires are attached to the amp. I installed the amp when my last one blew but all I did was plugged the existing wires back in.
Is it possible the mid ship is jumped with the forward or stern wires/speakers?
As to the amp it says 2 ohm stable but the speakers are 4 ohm. Then is says 4 ohm in the description along with 2 ohm.
How do I wire the amp so that it is putting out 4 ohm and not 2? So confusing...
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Post by finatic on Feb 17, 2019 16:13:04 GMT -5
Is it possible that the midship speakers are powered by the amp from your head unit? A quick test would be to pull the fuses on your amp and then turn the head unit on and see if any speakers play. If nothing plays you might then have two speakers wired to half of your four channel amp and the remaining four probably wired in parallel to the other two channels. The remaining four could also be wired in series, but based on what you have said so far I wouldn't think that they are. Also, if you have a fader control in the system somewhere what speakers are effected when you shift from front to rear? At one time home audio amplifier power output was measured in RMS, root mean square. RMS is nothing more than a value used to multiply the peak of sine wave when the amp was brought to full power and within specified distortion limits. Some manufacturers want to see bigger numbers for the power output of an amp and use terms like peak or max power output. One thing not mentioned above was any mention of a percentage of distortion. Back when I was into this distortion was listed as Total Harmonic Distortion, THD and Intermodulation Distortion. So in your case I'm assuming that your amp is seeing a four ohm load and the amp produces 125 watts RMS or 250 watts max, tow different ways to measure power output into a four ohm load. It's kind of like saying a car produces 400 HP at the crank or 300 HP at the wheels. The engine is producing the same amount of power, the difference is where and how are you measuring the power. Now that's a mouth full. Hay Capt Ron he's going the chase every Rockfish out of the bay with this system.
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Post by Team Ruby on Feb 17, 2019 17:11:09 GMT -5
In your situation you have all four ohm speakers. If you wire a single pair of speakers to one set of speaker outputs the amp is seeing a four ohm load, the speakers make up the load and determine what kind of power the amp can make. In this case the amp is seeing a four ohm load and can make 125 watts RMS. If you take and wire four of your four ohm speakers and wire them in parallel, so that you have two sets of speakers each with two speakers the combined impedance (or load) that the amp sees is now 2 ohms. So now with four speakers connected to two channels of the amp you're able to generate 200 watts RMS.
So, technically to answer your question, "How do I wire the amp so that it is putting out 4 ohm and not 2? So confusing", the answer is connect one speaker to each speaker output. Since you have 6 four ohm speakers though all wired to the amp, four of them must be wired in parallel, so half of your amp is running at 2 ohms, which your amp can handle and the remaining two are connected to the other half of the amp and that side of the amp is running at a four ohm load. You're still within the limits of the amp.
Are all 6 speakers the same?
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Post by fishnfool on Feb 17, 2019 18:30:33 GMT -5
Thanks Ron, clear as mud! Lol So I went ahead and purchased this amp... www.jlaudio.com/m200-2-marine-audio-m-series-amplifiers-98270Thought being I would dedicate this amp to running a set of JLA M880's. I could run it bridged at 4 ohms to produce 200w. The other 4 speakers I would power with my existing 4 channel amp (specs above). These are JLA M770's. Does that sound like a good plan?
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Post by Ol Mucky on Feb 17, 2019 19:28:48 GMT -5
My head hurts now.
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Post by fishnfool on Feb 17, 2019 19:31:12 GMT -5
Yea who knew this shit would be so complicated! I just want to plug shit in and GO.
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Post by ragtop409 on Feb 17, 2019 22:05:33 GMT -5
Fishin, are you adding 2 more speakers for a total of 8? I would say in most cases it is best to keep 1 speaker on each channel. I would also say that 2nd amp puts out less power per Chanel then the first so you would want to hook the 8” speakers to it and the 7” to the smaller amp. But a phone call to Ron might be the best corse of action. Rag’s
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Post by fishnfool on Feb 17, 2019 23:38:12 GMT -5
Ok thinking of this amp instead for the 8's.
HTX Series 2-Channel Class D Marine Amplifier RMS Power Rating: 4 ohms: 150 watts x 2 chan. 2 ohms: 300 watts x 2 chan. Bridged, 4 ohms: 600 watts x 1 chan.
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Post by Team Ruby on Feb 17, 2019 23:52:02 GMT -5
I like it for the M880's.
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Post by fishnfool on Feb 17, 2019 23:53:52 GMT -5
It's weird, my head unit has 4 zones and thus 4 rca outs, but for some reason I have 2 Y splitter rca cables going into the 4 inputs on the amp.
Seems like each set of speakers on its own zone and tossing the Y splitters would make the most sense?
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