I finished my install of the RF 300.2 and MM651's. It was all working fine with the fairing lid off and no Poly-fil. I played it at full volume for several hours on and off without the poly-fil and it worked and sounded great to me! Never cut out.

Today, I went to Walmart and bought the suggested poly-fil and installed it. Then I installed the fairing lid. I know I need to open it back up and adjust the gain as I have some distortion. I had adjusted it initially without the poly-fil and forgot to readjust after it was installed.

Now, on certain music, at even a mid volume, the amp cuts out. I assume it's going into overload protection because as soon as I reduce the volume it comes back on.

I am considering removing the poly-fil. My initial goal in installing the amp was volume and clarity at highway speeds. I wasn't looking for a home stereo sound.

Anybody have any thoughts on what I am seeing/hearing?

 

The Poly-fil should not have any effect on where the gain is set. It just tightens up over-all sound quality. You should be able to set your gain then wrap the speakers with Poly-fil and be done. I would try removing the Poly-fil to see if the amp still cuts out and narrow it down to that. Where is the gain set now?

 

I set it to 5 and the switch to HP and around 80 or so on the frequency. I think I got that from one of your post. Like I said it just cut out on a couple of songs. I really don't remember if it was when it had a lot of highs or lows. I just know it was some hard rock as I was tuning through the FM channels. The bike was just in accessory as it was before. All my wires are soldered, heat shrink and tied way out of the way so the fairing or headlight would not interfere. I know the combination of the poly and the fairing going back on caused the problem. It was plenty loud and sounded great to me without the poly so that is where I am going to start. I am thinking it is putting too much of a back pressure on the Polk speakers and over driving the amp. We will see tomorrow.

 

I forgot to say that now it distorts at lower volumes. I probably should have set the gain again after I added the poly.

 

Sorry you're having issues. I've had mine set-up the same way since March with no problems (knock on wood). If you're sure it's the Poly, I'd take it out for now. Maybe UltaNutZ will have a suggestion?

 

I had a similar issue. If you read back a few days, the symptoms were pretty close. I added a line output converter and the problem went away.

 

see my response to your other post. Too much polyfil is just as bad as not enough. What you're using is 1/4" thick so only 1 layer for fairing speakers and this stuff is too thick for lowers and rear pods. need the thinner 1/6" thick polyfil for those.

 

I just spent about 20 minutes with the tech support guy at RF. he seemed pretty knowledgable about motorcycle audio.

He said the current Harley stock head unit will start to distort at where the bars are at the end of the word volume on the screen. He said to not go past the letter E.

Also he said the MM651's on only rated at 100 watts continuous. The RF PBR300x2 amp with a 2.7 ohm speaker will easily produce more power than the speakers can handle over time. He said the amp gain should be somewhere between 3 and 4 for these speakers if you want them to last. Also he felt the addition of the poly could also cause some problems with the coils in the speakers overheating and causing the amp to fault. He also said that the poly doesn't do you much good at highway speeds because in an open air environment most of the base you are trying to achieve cannot be heard anyway. As a side note RF doesn't even make any speakers that will handle the gain level most of us are using. I am just the messenger here so if you disagree don't beat up on me. I do plan on following his advice especially as many speakers as I read about that are blown or whatever you choose to call it. For information I spoke with a guy named Rico at 800-669-9899 if you want to talk to him. He said all he talked to me about was from their testing with the current Harley radios.

So when and if it cools down this evening I am going to make some changes. Will report back.

 

precisely why I said "too much polyfil is just as bad as not enough." You're not trying to force all sound out the front of the speaker therefore smothering it, you're simply trying to slow the sound waves down so when it starts moving forward again, it's not cancelling out the woofer of the speaker moving backwards at the same time. The right amount of polyfil is essential. Also, do not tape up polyfil. Defeats the whole purpose of allowing it to breathe...

And FWIW, I disagree with a couple of things here.
1.) no way in hell I'd turn those gains up to 3 or 4 in this setup. 11 should be in the neighborhood of where it should be.
2.) the comment about not using polyfil in an open air environment. Their own testing shows it to be beneficial

 

I think I am trying to make this harder than it is. I took off the fairing lid and took all the poly off and still had it cut out or should I say off. I was able to look at the power light when it went off and it was not going into fault it was going off. For the last few days when I was working on it I had my battery tender hooked up but for the last day I forgot to hook it up while running the system. I suspect it was cutting off due to low voltage. I put my poly back (reduced the amount per your suggestion), tighten the screws on the power plug and closed it up. I tested it with the bike running at idle and it fine. I think the battery was just run down a bit. I forgot how much current this sucked draws.

I did turn the gain up a bit to 6 because the XM output is probably 25% lower that the normal FM radio. I know I have read around somewhere about this being a problem. XM is really all I listen to so I should be ok with the gain up but time will tell.

I am going to leave it alone now and take a day ride tomorrow and see how it sounds and holds up.