bcbrassard Posted January 31, 2014 Author Report Share Posted January 31, 2014 Ok, enclosure is 2.8947 currently, - the extra for port flare. Box is tuned at 44 hz. Precision ports calculator say that 2 3" ports at the length i have now would lower tuning to 34.5 ish. How can that be? Link to comment Share on other sites More sharing options...
bcbrassard Posted January 31, 2014 Author Report Share Posted January 31, 2014 OK, i just ran the numbers for displacement using the T1D2 15" with the lenght port i have now but a 3" instead of a 4" and the tuning turns out to be 38 hz. Way higher if using the 4" ports, like 47+ hz. WTF LOL Link to comment Share on other sites More sharing options...
Joe X Posted January 31, 2014 Report Share Posted January 31, 2014 Strange that the T1 15 is .54 cu ft and the T1 12 is listed as .099 cu ft. Well, enclosure is 3.117. That includes speaker displacement but not Aero Ports. I forgot, whats the formula to figure those out and do i need to subtract them from the 3.117? I imagine so. T1 15 is 0.547 and T1 12 is 0.308 Link to comment Share on other sites More sharing options...
bcbrassard Posted January 31, 2014 Author Report Share Posted January 31, 2014 Strange that the T1 15 is .54 cu ft and the T1 12 is listed as .099 cu ft. Well, enclosure is 3.117. That includes speaker displacement but not Aero Ports. I forgot, whats the formula to figure those out and do i need to subtract them from the 3.117? I imagine so. T1 15 is 0.547 and T1 12 is 0.308 Thanks, thats what i though! i got the info from RFs website. Link to comment Share on other sites More sharing options...
alaskanzx5 Posted January 31, 2014 Report Share Posted January 31, 2014 yeah I thought it was weird that the t1 has a higher displacement so I asked rf tech and they said its correct. them sitting side by side the size difference is tiny, wouldn't expect that big of a difference. t1500bdcp 2 t2d4 15" 1 t600.4 1 t400.2 1 set p1 tweets singer alt, tons of wiring, smd vm-1, 80prs, back seat delete, still in the works, aiming for a 145-147 with the ability to play 25hz up to 50hz. Link to comment Share on other sites More sharing options...
Joe X Posted January 31, 2014 Report Share Posted January 31, 2014 I have found in Rockford documentation very frequently confused peak volume displacement and driver displacement they used to list the same number and only recently have fixed this. Link to comment Share on other sites More sharing options...
alaskanzx5 Posted January 31, 2014 Report Share Posted January 31, 2014 those are 4" ports so as a rule of thumb its actually 4" of space. besides, he wants a lower tuning. the complaint isn't output its tuning. out of all the things listed here the following is what I think would help the most that don't require building a new box extending port externally (space it away from the inside of the back wall of the box while your at it) block a port (may get port noise but its easily reversible anyways) invert sub (increase box volume doing this which can slightly lower tuning) or any combination of them. besides those options I just don't see anything else helping now for a new box I would look at either doing a slot port or maybe a 6"aero port. box volume around 2-2.5cuft (Rockford recommended is 2-2.75 when I last talked to a rep but that was the t2 model), over powering that sub so a smaller volume can help with controlling its mechanical limit. and tuned to around 33-35hz. imo, 35hz would give you a good sound for a lot of different music. ports on one side of the box, from my understanding ports unload in the opposite corner then they are in. so if in the back driver corner is unloads into the front passenger side and vice versa. usually for numbers having the port on the driver side gives you better numbers on the meter. to make sure you can easily seal if off from the trunk real good make sure the design keeps the subs and port in the opening of the back seat. like if using aero ports have the sub to one side to where it kind of sits in the curved part of the trim that in front of the ports right now and have the port(s) sitting I in the curved part on the other side of the box. t1500bdcp 2 t2d4 15" 1 t600.4 1 t400.2 1 set p1 tweets singer alt, tons of wiring, smd vm-1, 80prs, back seat delete, still in the works, aiming for a 145-147 with the ability to play 25hz up to 50hz. Link to comment Share on other sites More sharing options...
bcbrassard Posted January 31, 2014 Author Report Share Posted January 31, 2014 thanks for all the help guys. Link to comment Share on other sites More sharing options...
alaskanzx5 Posted January 31, 2014 Report Share Posted January 31, 2014 no bad, was just pointing that out. fairly certain someone pointed that out already to. besides the trim is to the side a little and barely blocking the port. at most there might be some noise from air movement. t1500bdcp 2 t2d4 15" 1 t600.4 1 t400.2 1 set p1 tweets singer alt, tons of wiring, smd vm-1, 80prs, back seat delete, still in the works, aiming for a 145-147 with the ability to play 25hz up to 50hz. Link to comment Share on other sites More sharing options...
bcbrassard Posted February 1, 2014 Author Report Share Posted February 1, 2014 Ya i took the picture from the passanger side so it at a slight angle. The ports are free of obstructon, Barely but they are. I think i will buy some 3" Ports and make a ring adapter out of MDF to go over the 4" + holes and cut the ports to 9.75" to try. But if i block one 4" port then it tunes it at 33.5 HZ, so buy a Nerf ball and plug the ort to see what happens. Link to comment Share on other sites More sharing options...
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