Transmission Line Enclosure

Hey guys whats up...Just wanted to post up a build I finished tonight. I'm sure Haemphyst will like this one. Took a few hours. It's not perfect but its pretty good and solid. The only thing I would have done different is add the 45s in the corners but my saw was being a f'in spaz and wouldn't cut no more than 4 inches on the 45 degree angle. Its 1/4 wave tuning is right around 31Hz. The sub in there right now is a Elemental Designs EHQS 12. The enclosure is originally designed for an old school JL 12W6. I haven't gotten a chance to test it out yet besides 20 seconds with 40 watts going towards it. From that listening test the lows are pretty good and seems like the lows have much more authority than the previous 2.5 cu ft @ 30Hz box the sub was in. I'll come back tomorrow after a thorough listening test.

aznboi3644 wrote: Hey guys whats up...Just wanted to post up a build I finished tonight.

ALWAYS like the pics!

aznboi3644 wrote: I'm sure Haemphyst will like this one.

I'm honored! Seriously, thanks for thinking of me!

aznboi3644 wrote: Took a few hours. It's not perfect but its pretty good and solid. The only thing I would have done different is add the 45s in the corners but my saw was being a f'in spaz and wouldn't cut no more than 4 inches on the 45 degree angle.

At subwoofer frequencies, a 45 won't add anything, acoustically... You can add them for structure, but if you are otherwise doing pretty well "solidity-wise", then you are probably OK...

aznboi3644 wrote: Its 1/4 wave tuning is right around 31Hz. The sub in there right now is a Elemental Designs EHQS 12. The enclosure is originally designed for an old school JL 12W6.

How did you figure the wavelength? That looks a little bit short for 31Hz. Post up a few specs (the ones you used in your calculations) lemme plug 'em in! Just as a cross check!

aznboi3644 wrote: I haven't gotten a chance to test it out yet besides 20 seconds with 40 watts going towards it. From that listening test the lows are pretty good and seems like the lows have much more authority than the previous 2.5 cu ft @ 30Hz box the sub was in.

That looks like... what... about 3 cubes, or maybe a little more? That's a BIG box! TLs will always sound deeper than a roughly equivalently sized vented enclosure...

aznboi3644 wrote: I'll come back tomorrow after a thorough listening test.

Cool! Let us know!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."

Whats up guys...I took a small vid today. my sister's camera has barely any memory on it so 29 seconds is all I got.As for how it sounds..._IN AWESOME. The tonality is a lot different from the 2.5 cu ft @ 30Hz box it the EHQS was in. This thing digs deep and has usable response down to 25Hz testing with sine waves...below that it unloads and doesn't have much output. It has a pretty flat response from 28 - 60Hz.   I really love how it sounds. It's easy to tell when the EHQS is reaching its mechanical limits as I can hear it bottoming out but that is only on certain beats but overall it slams hard and gets really low but still retains its punchiness and transients.30-35Hz tones are fun. Compared to the 2.5 cu ft ported...this T-Line rapes it hands down. Only thing is that the box is 38.5" wide and 21.75" deep lol. But I don't need cargo space.I think everyone should get to listen to a transmission line enclosure...it does really have a different sound to it.Anyways...heres a little vidAlso Haem...the box is 38.5" wide and 21.75" deep and 16.5 inches tall...external dimensions that is. Port width is 6.25" throughout. Just a little bit over 3 cu ft lol.Heres a pic of the sketch up

Today I put in the 12W6 and WOW...it is even BETTER. It's a lot louder than the EHQS 12. Slams the lows really really well. I went to a couple shops here and asked some people what they thought was in the back...test track was of course Euphoric Midnight Bass - Track 11 The first shop theres a guy with four 12's sealed off 2000 watts in his dodge avenger....he guessed I had two 15's and 1000 watts. Owner of the first shop is more experienced....he guessed one 12 and 800-1000 watts. Next shop a guy there guessed three 10's and 1000 watts. second guy at the next shop guessed a single 12 and 1000 watts. Sounds really good to me for a single 12 and 200-250 watts without impedance rise. Surprised the hell out of me. Tomorrow I'll take some more videos. This is one efficient enclosure. Enclosure is 38.5" wide, 21.75" deep, and 16.5" tall

Haem could you recheck the line tuning for me??

I get an EFFECTIVE line length of about 100 inches. 100*4=400 400 inches is right at about 32Hz, which is why you have so much fun with the 32-35Hz signals... This is a high Q line, meaning it's peaky. With a taper, it smooths the Q a bit, and makes the terminus's output a bit smoother. I would have modified it a bit to include a taper in the length, that'll help prevent standing waves - that's just me. Also, my personal opinion is that the terminus is a little too big. 15*6.25=93.75 square inches... too big for a 12 inch woofer. (The ideal unstuffed line aims for 25 to 50 percent of the driver's Sd - this terminus is close to 1.1 times )With that much terminus you are relying EXCULSIVELY on the air mass in the line to damp the woofer, which means minimal extension below resonance, and FAST unloading below resonance... I hope you have a subsonic! If it works for you, though, KEEP it... I'm just saying what I would have done with it!

sedate wrote: If my trunk wasn't so tiny I'd try one. That thing is really cool.

Hell, man! I did it in MY trunk - a two door Civic!! ANYBODY can do it!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."

Haem...this was my first T-line build. I only want to learn from it. If I were to design another T-Line but a tapered line. What should the starting area be if the terminus is 25-50% Sd???

aznboi3644 wrote: Haem...this was my first T-line build. I only want to learn from it.

No, dude... I totally respect that. I didn't mean to sound like I was tearing anything apart...

aznboi3644 wrote: If I were to design another T-Line but a tapered line. What should the starting area be if the terminus is 25-50% Sd???

If stuffing, I generally use 100 to 150% of the Sd, and it is wherever you start the line... If you are adding a box to house the woofer, then wherever you attach the line to that box would be 100 to 150% Sd... (I'm reading that back to myself, and it makes NO sense at all... I hope you know what I mean...) The difficulty comes in trying to decide whether to add a true taper, or a stepped taper. Acoustically, I prefer a true taper, even though it is SIGNIFICANLY harder to design and build. Then you have to decide whether you want to stuff or not... LOL Fun, fun, fun... Stuffing shortens the line, so your taper becomes tighter. Heavier stuffing shortens the line further, so your taper becomes even tighter! See where this leads? I sent a bunch of stuff to DYohn about a year or a year and a half ago... DYohn, you still got those files? Can you put 'em up on the downloads side? I'd like to get a copy of them back if possible, I had a HD crash, and I've lost 'em all...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."