6.5" speaker for bass?

[tomdarch]

(snip)
This is for 2 of these drivers. Tune it to ~48hz or so using 2 tubes 1.5" in diameter by 4.5" long. Some of you may recognize that as being a standard size empty toilet paper roll. Shouldn't have much trouble finding a couple of those.
(snip)

Does it matter what direction the ports point? I would assume that having them open to same face as the drivers would be most convenient, but I have no idea if this would be a problem acoustically.

Also, while using toilet paper tubes a certain "hacker elegance" je ne sais quoi, I'm thinking that using PVC pipe for a bit more "robustness" should work well. 1 1/2" Schedule 40 PVC has an inside diameter of 1.61" - would that make any noticeable difference vs. 1.5"? (I have some 1 1/2" sched 40 on hand, vs buying some sched. 80)

I'm putting together some sketches based on Will's dimensions (and the 1/2" baltic birch ply I've got in the basement) that I can post if anyone is interested.

 

[will33]

That's fine. The slighly larger ports would have to be slightly longer to reach the same tuning., but, that's a small difference and still falls under "try different lengths and tune it by ear", anything between roughly 2 and 7 inches long. Only caveat is both ports have to be the same length, can't have one 4" and one 6" in there.

 

[LeDuck]

My Polk RT5 loudspeakers have internal ports of unequal length in order to get rid of internal resonances.

Saying that reflex ports must be equal length means the person doesn't understand loudspeaker design. If you KNOW what you are doing then you can vary the port length.

I improved the RT5 sound even further by turning the ports into resistive flow vents with open cell foam plugs. My sound level meter and my ears both agree on this one. Speaker now has more of a "transmission line" sound and bass goes a bit deeper. That means it has better bass definition, which T-Line speakers are famous for.

Parts Express sells a lot of 6.5" speakers that could be used for bass practice amps. The Dayton Classic 6.5" woofer can be had for under $30 delivered.