Rf pbr300x2
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From: North Carolina
Rf pbr300x2
Heres a question for you audio guru's. I'm looking at the RF PBR300X2 for my upgrade that I just started. Got the Polk MM651's going in the fairing this week. I don't run my lower fairing a lot, mainly the couple months it gets cool and rains I'll put them on. Anyways, if I were to say put the MM651 in the lowers and wired them in series, would the amp still see the speakers as 2ohms or would that change them to 4ohms? Was thinking if this can be done and not mess with the amp I might try it.
Tim
Tim
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From: East of the Sun, West of the Moon
running speakers in series effectively doubles the impedance the amp sees, so yes it would double it (or close to it) to proably about 5.4 or so ohms.
Last edited by UltraNutZ; Dec 7, 2012 at 10:30 AM.
Thread Starter
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Intermediate
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From: North Carolina
Tim
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well kinda sorta not really I'm afraid. :-)
The diagram above is for a dual voice coil speaker DVC.
If you run your MM651s which are single voice coil in parallel then you effectively drop the impedance in half bringing your load down to about 1.3 ohms. This will make that RF amp clip because it will get hot very quickly. Essentially what's happening is the impedance is driving the output of the amp at a certain level. Throughout that level there is a constant supply of AC voltage (contrary to popular belief it's not DC voltage). The closer you bring an amp to a 0 ohm load the closer you take it to a direct short.
here's my suggestion.
wire it up in series but make the connections "quick connects" for your lowers. this way when you're running both pair of speakers, you're at an approximate 4ohm load. This will sound just fine. When you disconnect your lowers tuck the wires up out of the way somewhere and you're back at a 2 ohm load because the lowers are no longer in the circuit.
The diagram above is for a dual voice coil speaker DVC.
If you run your MM651s which are single voice coil in parallel then you effectively drop the impedance in half bringing your load down to about 1.3 ohms. This will make that RF amp clip because it will get hot very quickly. Essentially what's happening is the impedance is driving the output of the amp at a certain level. Throughout that level there is a constant supply of AC voltage (contrary to popular belief it's not DC voltage). The closer you bring an amp to a 0 ohm load the closer you take it to a direct short.
here's my suggestion.
wire it up in series but make the connections "quick connects" for your lowers. this way when you're running both pair of speakers, you're at an approximate 4ohm load. This will sound just fine. When you disconnect your lowers tuck the wires up out of the way somewhere and you're back at a 2 ohm load because the lowers are no longer in the circuit.
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From: East of the Sun, West of the Moon
see diagram attached...
what I meant to say was when you take your lowers off, take the red wire in the diagram going to the lower speaker + and plug it to the green wire of fairing speaker and tuck your wires up out of the way. Now you're back to a 2 ohm load with just the fairing speakers.
sorry for the confusion
what I meant to say was when you take your lowers off, take the red wire in the diagram going to the lower speaker + and plug it to the green wire of fairing speaker and tuck your wires up out of the way. Now you're back to a 2 ohm load with just the fairing speakers.
sorry for the confusion
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Went back and checked and your right about the DVC and didn't see anything that really addresses my question on the RF site. I went back to check the specs on the PBRX2 and it will run 4ohms speaker with about 50watts RMS drop from the 2ohm set up.
Rated Power
(RMS Continuous Power):
100 Watts x 2 @ 4-Ohm
150 Watts x 2 @ 2-Ohm
300 Watts x 1 @ 4-Ohm Bridged.
The MM651's are rated at 100watt RMS with 200watt peak. So I may do it and see what happens, doesn't look like it will hurt anything if I do. Not looking for a parking lot bumper, just something with a little better sound and volume at highway speed. Last ride the wife was on, she said she couldn't really hear the radio and it was pretty well cranked. Either way its a win for me, get to upgrade the stereo and the wife's not bitching about it.
Rated Power
(RMS Continuous Power):
100 Watts x 2 @ 4-Ohm
150 Watts x 2 @ 2-Ohm
300 Watts x 1 @ 4-Ohm Bridged.
The MM651's are rated at 100watt RMS with 200watt peak. So I may do it and see what happens, doesn't look like it will hurt anything if I do. Not looking for a parking lot bumper, just something with a little better sound and volume at highway speed. Last ride the wife was on, she said she couldn't really hear the radio and it was pretty well cranked. Either way its a win for me, get to upgrade the stereo and the wife's not bitching about it.
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Extreme HDF Member
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From: East of the Sun, West of the Moon
running speakers in series definitely will not hurt anything; it's when you get to running them in parallel that you start running into heat issues and clipping which eventually destroys the amp or radio. have fun and yes I 100% feel ya about the wife bitching. always a good thing to be able to shut them up on a ride. :-) I love talking to my wife but I do not want to have a conversation with her cruising down the road at 80 and she feels like talking about one of the kiddos teachers! LOL
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Question. The polk MM651's are 2.7 ohms each. Wouldn't putting 2 of them in series make the total resistance 5.4 ohms, thus decreasing the total output wattage to the speakers below 100 watts per channel?
