Hey, I've got 2 infinity kappa 122.7's, switched to 4 ohms each, parallel to 2 ohms to the amp in a bassworx double 12 ported box, its running on a 500 watt alpine MRP M500 monoblock amp, it pounds pretty hard, but i feel it could pound even harder, and i know those subs can handle alot more, problem is, the freqency **** does nothing and the subs have this sound like "flapping" like the dust cover is coming loose and vibrating almost, now i know its not the dust covers, i just think the subs are underpowered... i was thinking of purchasing the MRP M1000 amp, running the subs the same way, just with the bigger amp...does anyone think it will get rid of the flapping noise? it sounds like there just slightly underpowered, any input would be amazing, thank you

 

If the subs are "flapping" it sounds like they are unloading below the port frequency. I didn't look up your amp but does it have a subsonic filter? If so it might not be set high enough. It's hard to say what frequency them Bassworks boxes are tuned to. You can likely take port and box measurements and input them here. This will at least give you an idea of where you stand box wise. Maybe a new custom box?

 

The amp does have a subsonic filter however it's fixed at 15hz.

 

15hz.... OUCH! That's going to make just about any sub unload in a ported box. Sounds like the Bassworkx is ported high and the subsonic is not effective. I think your problem could be the subs unloading. I'd look at a good amp with adjustable subsonic filter.

 

most of the bassworx boxes are tuned between 42 and 48hz. The infinity Kappas mechanical power handling isn't too great in a ported application as they unload very easily.

 

And sounds like a new box. 42-48 ... that is pretty high for a 15 hz subsonic filter. Would make a good burp box??

 

Not reall, not enough port area. I've measured a few of their ported enclosures, all seem to be tuned in the 42-48hz area. the 10's are usually .9 cu.ft the 12's 1.2-1.4 depending on the enclosure.