cyber1ed

I have just completed installing Kicker's RMB8 with a Rockford 200M amplifier - everything works and sounds great at lower volume levels, but when I turn it up, the sub begins to break up/bottom out/pop at the higher dB levels. Has anyone else had this problem? How do I fix it?

I used 12 gauge stranded to the battery and for ground - no cap installed yet. Shielded RCA cables for the inputs (no engine noise what so ever). 16 gauge from the amp to the speaker. For now, I had to bypass the stock remote wire, as it didn't have enough power to turn on the amp (just wired the 12V power into the remote - the amps on all the time).

Thanks for your help!

drcookie

The sub is not designed to handle a lot of low end power eventhough it is rated 175W RMS. I have hit the bottom a few times when I turned up the volume more than half. One way to get the music loud without having the sub hitting the bottom is to decrease the bass.

The other way I might try is to add a cross over which cut off some of the lows frequency (below 50Hz) to see the sub can still handle it or not.

It's a trade off between easy swap out with the stock and the loudness of the sub.

Hope this helps.

Cheers !!!

shawhite

if you cut the all freq below 50hz your music will not sound right... i still never understood why people replaced the stock sub with a mid bass.... i still have not seen anyone use the illusion audio sub... it is really thin as well and would probably sound better than these kickers everyone is using...

cyber1ed

Dr. Cookie - If I understand you correctly, the Kicker RMB8 is not able to handle the 100W delivered by the 200M? Why is it rated at 175W RMS then?

shawwhite - Have you tried the Illusion sub? Can it handle the 100W?

shawhite

yeah i believe the illusion sub was rated for 250w... but i forgot illusion audio went out of business so they might be a little difficult to find now...

drcookie

cyber1ed,
It might handle 175W RMS but not at low frequency... may be 100 Hz and above. RMB8 is a cheap and easy replacement, not a perfect replacement.

I managed to get my hand on a Illusion Audio Luccent 10" sub (not ND-10). The sub is a little bigger than the plastic frame that attached to the center break light. It might not fit without some modification. I will figure out when I have some time later.

As for Illusion Audio 8" sub ? I believe it pretty much the same as the kicker ... no guts ...

Cheers !!!

rmarin2

I'm glad I decided to go with the Pioneer 10" free-air sub. Its rated for 250W RMS and I'm powering it with a 300W RMS amp and have a crossover filtering at 50hz and I can turn the volume all the way up and have yet to hear the sub shut off!

cyber1ed

What a huge let down! The Kicker can't handle 100W of low end power?!!!! Wow, did I learn the hard way.

randomwalk101

Illusion 8" is 170watts (or was it 150w) at freq 30 - 500hz like rmb8. So Illusion in this case won't do any good.

Turn DOWN the GAIN in your amp!!! One way is to turn your music loud GRADUALLY when you play...when you hear the sub distort sound..turn the GAIN DOWN....distortion should go away..then continue turning up the volume (and adjusting the gain on amp as you hear distortion)...when you hit the max vol level that you like at no distortion on the sub..you can stop tuning there.

randomwalk101

What's the model of your Pioneer 10" sub? What's the mounting depth of it? What did u have to do to get it fit cuz the stock hole is only for 8" sub. Pls let us know.

cyber1ed

On any music with a lot of deep, low bass, I have to turn the gain down on the amp so it is practically off at the upper volume limits. I believe the RMB8 is being overpowered by the amplifier's below 100Hz frequency response as dr.cookie indicated. Unfortunately, the 200M only has a low pass filter from 210Hz down - I need a band pass to try and cut off those lower frequencies and determine if that is the cause of the distortion/popping/bottoming out.

But then again, by cutting off those sub 50~100Hz frequencies, isn't that defeating the whole purpose of a sub woofer?

Brewboy

When in IB, it'll take less than rated power to reach full driver excursion. If your amp doesn't have a subsonic filter on it, you could add a Harrison's Lab 30hz Hi-Pass FMOD to you RCA's to your sub amp. They cost about $28/pr or so at thezeb.com