Well that figures, lol. I ended up calling the place that I ordered my Focal 165CA1 speakers from to get their thoughts. I will be running the RF PBR300x4 amp. They said I should be fine as long as I don't have the gain cranked on the amp. I was planning on setting the gains individually for each speaker to set below distortion level. Hopefully the speakers will be OK.

 

JB , they said , as you have that the speakers would live with the 75 watt RMS of the PBR300X4 , as long as you keep the gain down , but the 100 watts of the PBR300X2 that I'm running would kill them in no time... and actually the MM165 Polks I'm getting are rated at 100 watts each , but they are 3 ohm so my amp should be putting out about 125watts to each speaker, instead of the 100 watts at 4 ohms.... but as long as i didn't keep it wide open all the time I should be safe ... good luck with your install... if my RG inner fairing wasnt already painted I would have taken it off and installed 4 speakers in it and used the 300X4 myself....but I hate to go thru that again ...LOL

 

I'm not sure the guy you spoke to knows what he is talking about. The gain control/function does not decrease power at all- it just basically changes how loud the amp will get how fast on the volume dial- it compensates for different signal voltages from your source (head-unit).

And it is far better to drive a speaker higher than rated RMS power than lower. The higher power will drive the speaker at higher volumes without clipping (which comes from the amp and not the speaker). Someone might tell me I'm full of sh*t but this is what I was taught.... You'll blow a quality speaker/driver faster by underpowering it than overpowering it.

<added> a link from Crutchfield with thoughts on matching amp and speaker power:

http://www.crutchfield.com/learn/vid...ml?g=100&tp=14#

 

That is the first thing the person I spoke with told me.

Does cranking the gain lead to distortion? I think I read that the distortion is what kills the speaker. Thanks for bearing with me since I'm below a novice with this stuff.

 

Great link. Thanks. Too bad I have all these posts thinking that I screwed up. I could have claimed I knew what I was doing by ordering speakers rated less than my amp.

 

Where do u guys ground your amp, do u clean some paint off inside the fairing and just find a bolt or is there a good spot. I haven't taken the fairing off yet but all of the kits I see have a 3ft ground wire

 

yeah , maybe I should just get some 40 watt speakers and drive em wide open with a 300 watt per side amp ....that way they will be overpowered and not underpowered and will last forever ....sounds logical.......

 

Thats what would happen with the factory junk but you are taking the theory a little far <g>. As I was taught (and again, I'm by no means an expert, just a hobbyist) that its not the power per se that is going to blow a speaker. Its typically distortion and clipping that'll do it in. And another caveat- I'm talking about clean, high current power, not a cheapo, low grade brand mega-watt amp. You know, 1,500 watts for $200 as seen on eBay!

I guarantee that about anybody thats messed around with audio gear long enough has blown speakers powered right off the deck. I know I have. If the deck is only kicking out a measly 15 watts but the speaker was rated for 60, what happened?

Now if you pummel a speaker with multiples of the power its rated for, for an extended period of time, yeah, you'll probably fry it and it'd be silly to think you wouldn't, they are rated for a reason. But I'd rather feed slightly more power and underdrive the amp than keep it maxed out where its clipping and distorting the signal.

YMMV....

 

The power output of the amp remains the same regardless of the gain and distortion is a product of overdriving the amp (listening at too high a volume) The gain is only there to compensate for the varying line-in signal voltages to get the amp in its happy range. (check specs on head units and they'll list how many volts the preouts are). It'll seem like its distorting sooner but you've just maxed out the volume earlier on the dial.

When I was setting the gain on my amp I initially had it too high and at only 1 bar on the radio volume display it was blasting. It'd sounded impressive as hell (wow! look how loud!) but would max out at about 3-4 bars. I turned it down to get a more useful range (I don't need the same volume sitting at a redlight as I do at 80 mph on the interstate) and now the radio pretty much maxes out around 3/4 of the volume scale.

 

that was just an exageration of the low speaker /high amp theory to show that a person has to have a little common sense of course when matching components , and that theory can be misconstrued... As the man from Crutchfield told me ... 100 watts is too much for a 60 watt speaker , and 125 watts would work great on my 100 watt speaker as long as I didnt run it wide open forever.... because the high powered amp will produce a better cleaner sound and in effect will not have to be cranked wide open to produce the quality , distortion free sound we are looking for... I cant wait until my setup gets here so I can see how it sounds.. I took the new bike out for a ride today and the stock setup/speakers turn into pure crap at anything above 1/2 volume... you'd think for $20+ K , you could get a decent set of speakers ... but we wouldnt want to cut into Willie G's wine and caviar fund now would we ..I am not a stereo pro by any means and I'm sure I'll have a question or 2 for the gurus on here before its all said and done... good people on here , great place to learn...