advice on t line enclosure

I had this TL enclosure designed to work with my Diamond Audio D612D2. I want to know what you guys think about it. Do you have any suggestions for improvement on the design? Any questions or comments will help me out a lot. I'm new to the TL enclosure and this will be my first one. I plan on leaving it unstuffed at first. I may add a little stuffing to see if it helps out the sound. The line length is around 106" or so. The link to the subs T/S parameters is listed in this link. http://www.diamondaudio.com/PDF/current/D6/D6WooferTechSheet.pdf

who designed that enclosure??

I had a friend of mine design it. He hasn't designed one before that is why I wanted to know if it is correct or not.

Stuff it. It's too short, I promise you. Also, a true TL will always be tapered. That is not tapered. 106 inches is WAY too long, unless you LIKE a major hump (about 12dB) in your response at 42Hz... Gah! Try this one... And this one... I sent those quite some time ago to DYohn, subsequently lost MY copies, and asked him to re-post them. I have an iso loaded 10" TL in my car, and they are very satisfying, but you WILL sacrifice output, and if incorrectly designed, you risk damaging your woofer(s) as well.It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

I have a specs for one that is tapered too. I haven't had time to draw up a design for it yet but I will post it when I get it done.

Here is the tapered design. It is approximately 83" long. It goes from 9" to 3" at the end. This is about 150% Sd to 50% Sd. It is 13" tall (not including the wood). I'm kind of worried about it being to short now. I hope it works because it was a pain to design.Thanks again for the help.

If you are afraid of it being too short, (which it is, but the OTHER one was also...) then you stuff it. Did you read the PDFs I linked to? Quite informative, and will guide you into the correct stuffing for that line, to "lengthen" it. I've been doing stuffed lines for quite some time, and they work really well.It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

So I should be fine if I stuff it. Does my taper look good? I read the articles and saw the impact that stuffing makes. I'm kind of confused on the line length. By using the basic formula for designing a TL I got 105" (Fs = 32.4). Then I used the alignment tables on www.quarter-wave.com to get my values. For the tapered line I used the value for Leff then adjusted it to get 6" less for a length of 83". Am I doing something wrong? I just curious what the correct length would be. Also, I plan on using 250w to power the sub. I don't expect a lot of output but I want better SQ from my sub over the slot port that Diamond gives (40Hz tuning is too high for me).

If lower tuning is what you desire, the the TL is the right path. If I remember correctly, the line in my car is 86 inches, but I am hitting 28 or 25 Hz, I don't exactly remember which. I put a subsonic on at 25, and have never bottomed yet. I think with that line, you'll be OK. Measure your total internal volume, and stuff with an EVENLY fluffed polyfill or Acoustastuff, (my preferred stuffing) to .5 pounds per cubic foot of total volume. I will often "taper" the fill also, starting less dense, and ending more dense.It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Alright then I'll use the tapered line plans. I'll mess around with the stuffing and see what I can come up with. I got it a couple of inches longer but that is all I can fit in my car. Can't wait to hear it. Thanks for the help. I'll posts some pics when it's done.