I wanted to know if it is possible to run a 4-channel (Legacy 1200watt) amplifier on a dual voice coil subwoofer (Ma Audio 15" 800watt). Each coil is 4 ohms which is perfectly matched with the amp's impedance when the amp's four channels are bridged in to two which gives four ohms each two channels bridged. I wanted to know if it is ok to run one voice coil with a different wattage than the other coil.
no you need to run the same power to both voice coils. if you have just 1 sub you need to bridge the 4 ch's to 2 ch's and run 1 ch to 1 coil and the other ch to the other coil.
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Big Dave
I am not sure if I am understanding this right or if there is something I don't know that bigdave does. I thought you should run one channel to both coils. I would bridge the amp into 2 channels and run one channel into the sub. Then I would run the same set of wires to the second voice coil, wiring the speaker in parallel is what that is called. It should give you a 2 ohm load but be sure your amp can handle it. If you ran the voice coils in a series it would give you an 8 ohm load which is way to high and you wouldn't achieve any substantle output. If your amp can't handle a 2 ohm load you could always buy a second speaker of the same kind and run the speakers in parallel and the voice coils in a series which would give your amp a 4 ohm load. This site has wiring diagrams that will walk you through the process. Good luck.
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J. Mike Perkins
No, it is not ok to run 1 coil of a DVC sub with a different wattage then the other. What speedway suggested
is not recommended (even though it is possible to do). Read
this for more info on the drawbacks of "independant wiring". Sending different wattage (even small differences) to the coils of a DVC sub can end up cancelling out the signals, making the sub perform poorly, and even damaging the sub itself.
Since you have a single 4ohm DVC, you can wire into 2 or 8ohms safely. Unfortunately, since you say your amp is 2ohms/channel, and 4ohms bridged, you've got some issues to deal with. First, if you wire your sub in parallel to a 2ohm load your amp is not rated for that bridged. So you look at you amp possibly shutting down or going into protect mode. Second, if you wire your sub in parallel and only use 1 of the 4 channels (not bridged) then you will be underpowering your sub, and I don't think that you would be happy with the sound. Third, if you wire in series into an 8ohm load you can still run it bridged, but again I don't think that you would be happy with the sound.
IMO, if you exchanged your sub for a 2ohm DVC model then you would be better off. With a 2ohm DVC you could wire in series to a 4ohm load and bridge the amp safely.
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Squirrel
"No more Cpt. Kirk chit chat"
If its too loud, then you're too old
Donate to the12volt.comI think maybe wvsquirrel meant to say "different input signals" instead of "different input wattages", as they are not the same thing. I guess a difference in wattage kinda does mean both signals are not gonna be the same depending on how you look at it. But not in such a way that would make one voice coil cancel out the other as would occur if you had different signals. At least that's the way I look at it.
I got the sense from the JL page and from personal experience that it's more harmful when the signals are completely different (left channel and right channel of a stereo input, for example) than when they are both summed mono but possibly at slightly different volume/gain levels. As the last paragraph of that page says:
"If a dual voice coil subwoofer must be wired to two independent channels, the inputs to both channels should ideally be the same (summed mono) and every effort should be made to match the gains of both channels as closely as possible."
Here is the bottom line: As far as I know, 4-channel amps cannot be bridged in such a way as to offer a single output. You can bridge the 2 front channels to a 4-ohm load and the 2 rear channels to another 4-ohm load, but you can't take that one step further and bridge them again. This is why when you see the specs for a 4-channel amp they'll show you power ratings for 4-channel setups and 2-channel setups, but not 1-channel setups.
What this means for you is that in order to hook up your DVC sub to the 4-channel amp and be able to fully utilize all 4 channels of the amp's power, one voice coil has to run off of the front channels and another voice coil off of the rear channels. Remember that when you hook it up in this manner, the amp is taking care of summing up the left and right channels into a single bridged output for each set of channels (front and rear). Almost all 4-channel amps do not have separate left and right gain controls; therefore the only thing you really have to take care of is making sure those front/rear gains are set to the same.
The ideal situation is to have a 2-channel amp and either two 4-ohm DVC subs (2 ohm stereo load) or one 2-ohm DVC sub (4 ohm mono load). If you can return the amp and sub then you might want to think about doing that as it really is the simplest and best way to hook it up. But i realize that a lot of times people, for whatever reason, are unable to return/exchange equipment and that's why I'm trying to inform you of all possibilities.
Whatever you decide to do, be sure to let us all know how it turns out.
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Ethan
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"Patience, persistence, and perspiration make an unbeatable combination for success"
Donate to the12volt.comThanks esmith69 for the correction, I did mean to say different signals. Although different wattages can play a factor as well, I was refering to what you mentioned about the left and right inputs and gains.
I agree with your ideal situatition (a 2-channel amp and either two 4-ohm DVC subs (2 ohm stereo load) or one 2-ohm DVC sub (4 ohm mono load)) for this situatition, but I would also like to add Mono amps to that suggestion. IMO a strong, well built class D or BD mono amp will give better performance (and more options) if you can afford one. By more options I mean that I have not seen that many 2 or 4 channel amps that are 1ohm stable. But since most places will not allow you to trade a 4-channel amp for a mono amp, it's kind of a mute point now!
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Squirrel
"No more Cpt. Kirk chit chat"
If its too loud, then you're too old
Donate to the12volt.comThanks for the suggestion. I have no idea why I didn't at least mention mono amps in my reply!
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Ethan
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"Patience, persistence, and perspiration make an unbeatable combination for success"
Donate to the12volt.com