beady

Thanks Joe. Why does the frequency response for the 4th stay so flat, so low? Is cabin gain added in that curve? Since the sub models well ported, what about a 6th order? I probably won’t run the box forever, I’ve just never had a 15 or 18, so just wanted to try it. Could be the shop sub in a corner or HT sub in the room over the garage eventually and I could put a more modest sub in. I have an old EQX I could use to bring down some peaks… Mike

Hi all, not new to audio stuff, but it’s been a good while. My son wanted a sub, so I am back dabbling. Got him some Kicker C12a’s and picked up a 4-ohm 18” Rockford Fosgate RFP-2418 on a whim for me. I measured the XLC parameters with a parts express DATS V2, and tried modeling a largish 4-th order bandpass for it (going in an oldschool OBS suburban, so have room). The weird thing is that it doesn’t model wider, deeper, or more efficient on the whole than a plain ported enclosure of similar volume. And the 4th order I had for the Kickers waaay back in the day models a decent gain in efficiency while still going nice and low. I guess I’d rather lean towards SQ than SPL at this point (whatever that means for this sun, like I said I bought it on a whim without researching) as I’m rarely ever going to run it full tilt. We have a small farm and 3 kids, so quite often there’s a ton of crap in the back of the suburban, hay, feed, lumber, etc., which is partly why I want to go 4th order (physical protection). Also, I had a 4th order with pair of Kicker C12’s back in college which sounded killer. Going to run the 4-ohm 18 off one of several amps, Punch 30HD (would be cool to shock ppl with what “30 watts” can do), Punch 75HD, Punch 250.2, or maybe MTX 3002. So can either lean towards super efficient, or less so, and still be OK. I’m attaching pics of the measurements, and the simulation I’m thinking of going with graphed with sealed and ported enclosures of about the same size for comparison. Oh yeah, I like deep bass, electronica, old school bass like dj magic Mike, techmasyer peb, etc. Would also like to have good kick drum kick if possible, is why I’m thinking larger, lower efficiency, and wider pass band may be where I need to be. Constructive input is welcomed. Thanks, Mike