ports on bookshelf speakers

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I am going to build a set of 2-way bookshelf speakers using the 6.5" Vifa P17SJ-00-08 woofer and the D26AG-35-06 tweeter. Should I port these?

I tried simulating the response curves with WinISD and it seems like if I don't port, the lowest frequency response I can get is 85hz, but ported as low as 45hz.

If I do port the boxes, where should I place the port and how large should I make it- I'm not sure how to find out the neccessary parameters to determine this.

Thanks alot.

Brian
 
HI,
Download winisd from www.linearteam.org, free, great box program, it'll tell you the port diameter and length, or if you choose to change the dia. or length it'll compensate, it will also tell you if it just won't work. winisd also calculates square ports, you can find all the needed params at vifa's site or partsexpress.com. As to where to put the port, for bookshelves it's usually on the front, but not necessarily, some of the best bookshelf monitors have the ports on the back, like the Okara from North Creek. Personally I recommend placing ports on the back. I recommend doing some intensive reading of Vance Dickason's Loudspeaker cookbook.

Have fun!
 
Biff, the speakers you've got sound a lot like the drivers in the studio monitors I'm using now, which are ported, and claim response down to 45hz.

I've tried plugging the ports with socks, and the bass gets both quieter and tighter--by all means, port it, and then if you change your mind, lose a pair of socks into them! :D
 
Hello, sorry, I had a few drinks :drunk: before posting last night. I didn't notice that you already have winisd, but it still should calculate the port for you. If it's a question of getting the right parameters try the vifa site, just search the web for it. Once you have those you can build a test box and put a port on the front and back, plug one or the other to see which sounds best to you. You can then stuff the test port with drinking straws, and tune it by ear by moving the straws in or out to lengthen or shorten the port.
 
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