Tuning Freq. Question about t-line boxes

[mbaty1]

I was coming up with a plan for a t-line box for an HX2, and have a couple questions....

The Fs of the speaker is 26hz, and I know you should generally tune to the speaker Fs, but is it OK to tune a little higher?

Reason I ask is that I would need a length of about 10.5 feet to get down to a 26 hz tune; however, when working with the dimensions I had, I could only work out about 8.5ft in line length... tuning to roughly 32hz by my calculations...

Would there be any adverse effects of making it this way? Would it actually help from bottoming out the speaker since it shouldn't dig down below it's capabilities?

Any input would be truly appreciated. I created a t-line for a couple 7 kv.2's and was amazed by the output, and the tuning was right around 35hz, so I'm thinking this should work out nicely and still be able to dig down fairly low. I guess the only true way to find out would be to make it and see how it sounds, but trying to get any info about effects of tuning higher than the speaker Fs when making a t-line.

Thanks for your time and assistance!

[mbaty1]

Anyone able to provide some input by chance? Here is a little bit more info if it helps.....

This speaker (Punch HX2) has an Qts of 0.39, so it is pretty close to spot on the mark for an "ideal" speaker to utilize (wish I had the other T/S specs of the speaker to verify), but since it was right at or slightly above the desired Qts, I wasn't sure if there would be any adverse effects to tuning slightly higher. I am going to run with this design and see how it works out. Figure it might not dig down quite as low as I would like, running slightly high tuning freq. should help prevent any damage to the speaker from over excursion and such. I wish I had a few extra inches of width to work with, but really limited to 34" wide.....

Current box works out to roughly (at work, don't have exact specs) 34" wide x 22 1/2" deep x 13 1/2" tall with a port/line area of 6.5"x12". The HX2 measures right at 10" from middle of surround to middle of surround, so working that out, I went 5x5=25 - 25 x pi = 78.53981.... (rounded down to 78) 78/12=6.5 which gave me my final port/line area of 78sq in so I went with 6.5"x12" to keep things simple.

If it is critical to reach closer to Fs of the speaker, I can try and modify the port dimensions (making it taller and skinnier) allowing me to possible get an additional line if I were to increase the depth of the box by another few inches. Just trying to get this hammered out before start construction.

Thanks for any input you may have!

[BanginOnABudget]

sorry nobody has replied to this, usually they are really helpful pretty quickly. your sub will be fine, it will be more of an SQ enclosure than a SPL one, you should try this calculator tho. http://dbdynamixaudio.com/62/dual-fold-on-axis-transmission-line-enclosure-calculator/

your tline design is fine, its perfect imho, not too tall but not too low, should have nice frequency responce.

you should go with a constant mouth tline like in the link, easier to build, and a tapered tline isnt going to have the same output.