i built the HiVi - DIY 3.1A speakers kit awhile back and love them. i figured to get a matching center channel speaker i would just purchase the kit again and create the center from the same parts since it seemed to be a cheaper option, well before zreviews built and reviewed them.
i have ran through WinISD and got the box size (1.2cf) tuned to 43Hz. it looks like i can either do 2 x 2" ports or a single 3" port both options ~6" long give or take.
my current set up would require the center channel to be around 8" from the wall and figured having rear ports wouldn't do me any favors. i have the HiVi's about 12" from the wall and they seem to be just fine, but i don't really crank them up all that often.
current design attached, and although i don't much care for the look of the side port would it be worth doing this vs rear ports?
thoughts?
hopefully once i get to the XO i can get some help on using the XO that came with the kit designed for these speakers but adding a woofer to the mix.
thanks.
RM
i have ran through WinISD and got the box size (1.2cf) tuned to 43Hz. it looks like i can either do 2 x 2" ports or a single 3" port both options ~6" long give or take.
my current set up would require the center channel to be around 8" from the wall and figured having rear ports wouldn't do me any favors. i have the HiVi's about 12" from the wall and they seem to be just fine, but i don't really crank them up all that often.
current design attached, and although i don't much care for the look of the side port would it be worth doing this vs rear ports?
thoughts?
hopefully once i get to the XO i can get some help on using the XO that came with the kit designed for these speakers but adding a woofer to the mix.
thanks.
RM
Attachments
Symmetric driver placement with identical side-side ports will generate a counter-force which will reduce cabinet vibrations from the moving port air mass. Small mass = Small benefit.
You can also put dual symmetric rear ports to help balance the air pressures in the cabinet. Reduces cone rock.
You can also put dual symmetric rear ports to help balance the air pressures in the cabinet. Reduces cone rock.
I can't imagine there would be significant imbalance in cabinet pressure with a tuning of 43Hz - a standing wave requires 4 metres to develop and the cabinet is significantly smaller than that, therefore we expect the cabinet to pressurise evenly.
8" should be plenty of breathing space for the size of port proposed. When the gap from the wall to the speaker becomes smaller than the diameter of the port, the gap behaves as an extension of the port and the tuning frequency goes down. Also if the port is close enough and the air velocity high enough, a plasterboard/drywall wall might rattle
. With a gap many times the diameter of the port, it is a non-issue.
Side port does have one advantage in your application and that is the interior end of the port is further away from the woofers than it would be for straight rear ports. That will allow you to place some stuffing in the cabinet to attenuate frequencies that would excite the pipe resonances of the ports.
8" should be plenty of breathing space for the size of port proposed. When the gap from the wall to the speaker becomes smaller than the diameter of the port, the gap behaves as an extension of the port and the tuning frequency goes down. Also if the port is close enough and the air velocity high enough, a plasterboard/drywall wall might rattle
. With a gap many times the diameter of the port, it is a non-issue.Side port does have one advantage in your application and that is the interior end of the port is further away from the woofers than it would be for straight rear ports. That will allow you to place some stuffing in the cabinet to attenuate frequencies that would excite the pipe resonances of the ports.
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