RF300x4 Speaker Choice

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Sep 7, 2012 | 04:33 PM

Pioneer74

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From: Michigan

RF300x4 Speaker Choice

I posted this in the Touring section thinking I would get a better response there. Surprise! No answer yet, so here it is:

I will be adding 2 RF300x4 amps to my Limited. The first will power the fairing speakers in the batwing and I will be adding the CVO lower speaker boxes. The second amp will power the Tour Pak pods and later on I will add saddlebag lids.

Need some help deciding what brand/model speakers to go with. I kinda like the idea of using marine certified speakers in case I get caught in the rain. Another thing I am concerned about is I work a midnight shift and there are times I come out in the morning after work and there is a lot of condensation on the bike. Would hate for that to ruin them. The only thing I don't like about the marine certified speakers is they seem to have lower wattage than the PBR300x4 puts out per channel.

Here are the models I am looking at:

Infinity 612M - 4 ohm - 75 watt RMS - marine certified

Polk DB651 - 4 ohm - 60 watt RMS - marine certified

Polk Dxi - 4 ohm - 60 watt RMS - marine certified

Alpine SPS-610 - 4 ohm - 80 watt RMS

Infinity Kappa 62.9 - 4 ohm - 75 watt RMS

Kenwood Excelon KFCX173 - 4 ohm - 80 watt RMS

Rockford Fosgate Power T165 - 4 ohm - 70 watt RMS

I would have liked to have gone with the Polk MM651's, but they are 2.7 ohm speakers and the amp isn't rated for anything less than 4 ohm. I thought about running them off the PBR300x2, but when you paralell them it drops the load below 2 ohm.

Thoughts? Suggestions?

Sep 7, 2012 | 08:51 PM

FLHX_Tim

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From: North Carolina

Man I know this is not going to help but the MM651's sound pretty dam good. I still haven't pulled the trigger on a amp yet. Still fighting with which one to go with, but even un-amped they sound much better than the stock ones and clear as a bell even when they are cranked. Good Luck

Sep 7, 2012 | 09:44 PM

Pioneer74

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From: Michigan

Quote:

Originally Posted by FLHX_Tim

If they were 4 ohm I wouldn't have needed to make this thread. Series, to me, is too much resistance and the available wattage will drop. 2.7 is only good for one per channel on the pbr300x2. I want at least 6 speakers, so that would mean 3 amps. I'd rather only have two so I can put them under the fairing.

I'm leaning toward the db651's. I have everything I need sitting in my Amazon cart, minus the saddlebag lids, and its less than $700. Two pbr300x4 amps, two 10 gauge install kits, Arc Audio adaptor rings for the fairing speakers, 3 pairs of Polk 6.5's and a pair of Polk 6x9's.

Sep 8, 2012 | 08:01 PM

Pioneer74

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From: Michigan

Might have found an alternative so I can use the MM series speakers. Still have to pull the outer fairing off to see if it fits, unless somebody that has already mounted two PBR's on top of thier radio can comment. Not much size difference between 2 PBR's and this amp. I would just have to send my radio to Iron Cross to get some pre amp outs installed.

JL Audio M600/6 6 channel amp. 100 watts a channel at 2 ohms. I would just not get the saddlebag speakers.

http://www.crutchfield.com/p_136M600...ml#details-tab

Sep 9, 2012 | 05:40 PM

GLACIERPEARL

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From: OHIO......UGH !!

You need to learn more about speaker wiring. Parallel versus series, and the load it puts on the amp. You are making this WAY harder than it has to be ! You don't have to have 1 channel for each speaker.

This is Carl's favorite link !!

http://www.termpro.com/asp/pubs.asp?ID=124

Sep 9, 2012 | 07:54 PM

Pioneer74

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From: Michigan

Quote:

Originally Posted by GLACIERPEARL

I think I understand it enough. I never said each speaker had to have it's own channel.

In a series circuit, you add the resistance. The greater resistance, the less wattage that will be available per channel.

In a paralell circuit, the resistance is lowered (by a formula that escapes me right now). The lower the resistance, the greater the wattage per channel.

2 2.7 ohm Polk MM speakers in series on a PBR300x2 amp will create 5.4 ohms per channel of resistance, which will decrease the rated 100W per channel at 4 ohms and the speakers will be underpowered.

Using the same amp, but putting the speakers in paralell, will result in 1.6 ohms of resistance and will make the amp unstable because it isn't rated below a 2 ohm load.

You can't use the MM series speakers with the PBR300x4 because it isn't rated below a 4 ohm load. Adding two per channel will decrease the available 75 watts at 4 ohms because you are back to putting 5.4 ohms per channel resistance to the amp, thus underpowerig the speakers.

Like I said, the JL Audio amp might solve all of my problems. It will be able to handle the load of the MM speakers that I want. I might be overthinking my speakers, if anything. I just feel that I need a marine rated speaker because of the condensation the bike has on it after working my overnight shift. I just have to see if the JL Audio fits in the fairing.

I would love to have a stereo like yours, GP, but I like to remove my tour pak and run "solo", so I can't put the amps in there. I guess if I had to I could put it in one of my saddlebags, but then I would have to put everything on quick disconnects for maintenance purposes.

Oct 29, 2012 | 05:58 PM

renfroeinc

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I have the polks and the pbr300x4 and it cuts out all the time. I need another amp option as well. I also wonder if the JL Audio marine speakers will fit in the lowers as nicely as the polks