I have 4 polk MoMo 8s in a sealed enclosure and had been unhappy with the output. I dug up a copy of BassBox Pro and discovered that I had enough airspace to go ported. I have the subs grouped in 2s with about 1.1 cubes per 2. I used 2 3"x15" ports per 2 subs and the difference is unbelievable. I did not expect that much of a difference. The SQ remained as well, still tight and clean. I can finally move on to the rest of my system!
i was trying to see if my theory of less than recommended airspace using a ported box could work well and to me it seems you proved to me it CAN. I think it all has to do with what frequency you port it too.
I agree. I still have some tuning to do though, I think I can get it a little better still. I also need to get some donuts on the intakes and flare the outputs. There is much more airflow that I expected. BassBox Pro calculated the velocity and its really not that bad but, might as well do it the right way. One other note, when I switched to ported, I did enable a 24db subsonic filter but its way down at 15Hz. (Just trying to protect my investment from any "wayward knob turners" )
Nope, those specs are real. I looked long and hard to find a decent 8. There are a few "entry level" 8s here and there and a few destined for SPL only. The Momo can talk the talk and walk the walk, with the right enclosures of course.
well I havent run your box size with your port demensions but if you go below port tune you can damage them very easily just keep that in mind. The subsonic filter is good for just that 15 hz and down if thats where you have it set and anything above that can get through unfiltered. If you want to protect the subs the best you want to filter them just below your port tune.
Unfortunately my subsonic is only selectable at 15Hz or 30Hz. I'll eventually bump it to 30, it's just a real pain to get to. Most of what I listen to dosen't get that low anyway.
andy roang
Unregistered guest
Posted on
what kind of retarded person has 4 8" subs!!!! why not go with 2 12's or 2 15's