Fi Q

[tmore 0]

Hey guys,

I'm relatively new to car audio and just put an Alpine CDA-117 and RF t1693 speakers in for the mids and highs in my Dodge Charger. I'm planning on putting a t400-4 or t600-4 amp for my mids and highs and just had a question on the Fi Q because I'm sure virtually everyone reading this has more knowledge on it than I do. If I purchase the Fi Q, to what extent is a good ported box louder then a sealed box? Also, to what extent is the SQ improved by using a good sealed enclosure versus a ported? I need to know this because I'm debating whether I want to purchase the high qts or not. I like the Fi Q because it's right in the RMS range I was looking for (1500w, except for the 18?) AND it supposedly has great SQ.

Also, on a side note, if the factory alt putts out 160 amps and I do the Big Three Upgrade, along with a yellow top battery and a 5.0 farad cap, will a RF 1500-1bdcp amp (plus the RF t400-4 or t600-4) suck too much power? Thanks a lot guys, I really appreciate any input

[NDMstang65 403]

They are all 1500 watts, the webmaster missed the 18's when they changed the ratings.

Only thing about the rockford amps is that they don't have an adjustable subsonic filter, if you go ported you will have problems.

[tmore 0]

Ok thanks, the purpose of the subsonic filter is to just filter out notes below 20 hz if im correct. So what you're saying is the RF t series mono amps don't have an adjustable subsonic filter and why again would be bad in only a ported enclosure? Sorry I'm still new to this

[NDMstang65 403]

No.

The purpose of the subsonic filter to act the same as a set of brakes on a car. If you tune your ported enclosure to 32Hz, that means that anything below 32Hz the port no longer resonates or keeps pressure in the enclosure and causes the sub to unload. If the sub unloads, you throw full power to it below the port tuning frequency which locks up the suspension, shred the spiders, pops the surround, and burns the tinsel leads up (look at a tinsel lead as the same as a pop top on a coke can, you can bend it back and forth within its mechanical limitations all day long..until hell freezes over. But, when you start bringing it past the mechanical limitations it begins to generate heat, and fatigues, and eventually rips off..this is what happens to the tinsels)

An adjustable subsonic filter lets you set it at about 2Hz below the port tuning of the box so things roll off nicely. Otherwise, it is like driving your car with no brakes..and trying to stop, which does nothing but either cause you to get into a wreck or wrap your car around a telephone pole.

[tmore 0]

thanks a lot man for sharing that, after reading that comment four or five times I finally understand it. That's strange that what I considered a fairly high end amplifier doesn't have an adjustable subsonic filter, so if your gonna port it, you'd better port it to about 2 hz above the limitation. OK. I just have to badger you with one last question if you don't mind. How much louder is a solid ported enclosure in the trunk of my car going to sound than a sealed enclosure? and to what extent is SQ improved by using a good sealed enclosure on the 15 inch Fi Q then a good ported enclosure?

Thanks

[NDMstang65 403]

Ported box will be louder and not as accurate as a sealed box..that's about what it boils down to.