View Full Version : SI Mag v3 Box, Need some guidance

02-26-2009, 01:36 PM
Ok, so real good local guy had my car yesterday to build me a box for my SI Mag v3 (built my last sealed enclosure, came out nice and was very affordable). Shortly after I dropped the car off he called me and asked about the tuning (32hz) suggesting that I should do something higher for better SQ:crap: (unless I had some good midbass). I told him I had some tempo 6's with solid midbass usually tuned down to 60-65hz.

Since I have no experience with ported enclosures at all I told him I want to keep it close to 32 but if you think it would really be better at something like 35, then I'd take his experienced advice over mine. (Mistake? Probably, I was put on the spot though and didn't have time to think it through). Based on the measurements I think its tuned to 38hz. (aero port)

SI suggests 2 cubes @ 32hz
(Not sure what the displacement of the sub woofer is)
But I calculated the interior dimensions of the box to 2.11ft^3, 13.5*23.5*11.5
the port is 4.2" in diameter and 10" long.

If anyone could confirm the 38hz number please let me know. I need to get it carpeted before I can test it out, but lets say I'm not happy with it (I'll know tomorrow). The box itself is pretty sick, (I'll post pics once some annoying tenants that are going to try and talk to me stop playing tennis).

If I'm not satisfied and want to keep the box and modify it down to 32hz how would I go about doing this? If my calculations are right then a 3.5" in diameter port (assuming box is 2.0 after displacement) would work, keeping the length to 10". Agree? Disagree? Alternatives (that would allow me to keep the box)? First thought was a 3.5" port that opens up (like a horn kind of) and will fit into the 4.2" hole

I know its longer than it probably needs to be

38hz to an SI Mag v3 is probably a mistake
Not sure what the displacement is of the subwoofer
13.5x23.5x11.5 with a 4.2 diameter 10" long port = 38 hz correct? (not accounting for displacement)
Is there a way I can keep the box and lower the tuning? Can I just find a 3.5" port that would fit into a 4.2" hole? Are there other alternatives?

02-26-2009, 02:12 PM
As Promised...


02-27-2009, 12:04 AM
bump for some input?