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Quarter Wave / T-Line tutorial-UPDATED


Forevrbumpn

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I was acctualy going to use a single jl 6w3v3 6.5" sub in a t-line. but the mech-q @ 11 threw me for a loop, I thought it would be to stiff. but good luck on it, let us know how it turns out.

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////Alpine, Eclipse, Load Boss, Pheonix Gold, MB Quart,Digital Desings, Memphis, Stinger, Periphial, MTX, Visualogic

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Just thought I would share a tline I built for a guy on the weekend. I dont really build boxes any more, but this guy came back to me after a couple years in hiding, I couldn't say no...

Just one of my FLC 10"s Usually about a 500-600rms subwoofer. Being ran at 2ohms on a Hifonic's 1000w amp- seeing about 750rms.

Quarter-wave tuned to about 40hz, but plays well below. Installed in a 95' Jeep Grand Cherokee

1059623227_photobucket_46499_.jpg

^ Notice the slight angle to the line. I still wont say its quite a horn, but I guess you can. Starts off about 45sq inches, ends about 70sq inches.

I build my t lines this way because they seem to handle more power, and play more accurately

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Testing with no carpet yet. Just on 250rms, sounds great so far

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Finished.

To make the woofer fit, I had to grind out about 1/4" of the divider in the back

This box sounded great, lows as clean and powerful as a 15" or pair of 12s, and accuracy of a 10" cone.

This time, with this customer, I made sure he got an amp more powerful than needed, so everything can be toned down alot. Gain is low, no boosts in the deck at all, bass, loud, all Zero. Very clean, cone still barely moves 1/2" peak at the lowest freqs

sundown.jpg
I have a ritual called "terminator". I crouch in the shower in the "naked terminator" pose. With eyes closed I crouch for a minute and visualize either Arnie or the guy from the 2nd movie. I then start to hum the T2 theme. Slowly I rise to a standing position and open my eyes. It helps me get through my day. The only problem is if the shower curtain sticks to my terminator leg. It sorta ruins the fantasy.
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yep yep... This guy usually is the guy with the "Amp on special" But I talked him in to looking around for at least used with more clean power this time.

sundown.jpg
I have a ritual called "terminator". I crouch in the shower in the "naked terminator" pose. With eyes closed I crouch for a minute and visualize either Arnie or the guy from the 2nd movie. I then start to hum the T2 theme. Slowly I rise to a standing position and open my eyes. It helps me get through my day. The only problem is if the shower curtain sticks to my terminator leg. It sorta ruins the fantasy.
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Hey bumpn, should I build my home-theater t-line towers to exit towards the floor or the ceiling? I've got 6.5 foot ceilings to work with and its a 21" driver in each t-line.

I have a couple ideas worked out so i'm looking for other opinions. I intend to have the drivers mounted inside the t-line as well, rather than externally..

I'm thinking floor since if I ever move the ceilings could be a different height..

Hmm.. maybe I should face them backwards as well towards a wall to increase "mouth" area at the terminus..

MickyMcD - "Capable of making some serious trouser flapping volumes at where's-my-testicles frequencies, the Servo-Drives used to be fairly jaw dropping..."

Any time you have have a power wire next to your frame put some rubber hosing (or cut up an innertube) around it. The wire is bound to wiggle (due to driving or flex) and the casing will eventually wear through.

Hammerdown... 1%

no links to outside websites, business related FB/YT pages allowed.

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Just to chime in here - I wouldnt recommend too many people following the post. It isnt too accurate as many subs wont like it too well. Could exhibit an odd response, bad sound, ripple in response.. etc.

Expansion like in the images above gives the best sound normally, though it is much larger to reach proper line length. Also has better output, again at the cost of size. A tapered tline is normally a good balance of size, output, and sound.

If anyone wants designs like these or more visit my website http://tbhenclosures.com and fill out a design request, or feel free to shoot me an email with any questions you may have.

If youre going to do it, may as well do it right ;)

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Dude you've already been called out on the forums for spamming your website without prior authorization. Cut that shit out. 4 Posts all about your box design site. Good luck trying to get business here when we have ESTABLISHED and TRUSTED members offering great designs often for FREE.

May I suggest you post your ads on craigslist instead.

PS. following the design ideas in this thread has me doing 146.3 with a single DD 9512 in a trunk car.

Just to chime in here - I wouldnt recommend too many people following the post. It isnt too accurate as many subs wont like it too well. Could exhibit an odd response, bad sound, ripple in response.. etc.

Expansion like in the images above gives the best sound normally, though it is much larger to reach proper line length. Also has better output, again at the cost of size. A tapered tline is normally a good balance of size, output, and sound.

If anyone wants designs like these or more visit my website http://tbhenclosures.com and fill out a design request, or feel free to shoot me an email with any questions you may have.

If youre going to do it, may as well do it right ;)

Alpine F1 Status

DD CS6.5 x2 Front Stage

DD 9512H

DD M4a @ 2 ohm

DD S2b @ 8 ohm per channel

I run high ohn loads for MASSIVE headroom and cleaner SQ

270amp alt

D2400 up front

D3100 x2 batter in back

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Hey bumpn, should I build my home-theater t-line towers to exit towards the floor or the ceiling? I've got 6.5 foot ceilings to work with and its a 21" driver in each t-line.

I have a couple ideas worked out so i'm looking for other opinions. I intend to have the drivers mounted inside the t-line as well, rather than externally..

I'm thinking floor since if I ever move the ceilings could be a different height..

Hmm.. maybe I should face them backwards as well towards a wall to increase "mouth" area at the terminus..

ive seen a few t-lines for home audio with the port exit at the floor, and also facing backwards, like into a corner, i believe ken (bumpn) even had a youtube vid where he was testing a tline in his home and i think he had it in a corner, exit facing corner, i could be wrong though

@forevrbumpn

looks great,and as you say im sure it sounds great

right now as ive told you im stuck between tline or a 6th order, i know the 6th order would be more challenging though, but if i go with a tline i was thinking of doing a 55 - 60% taper overall, like the port exit would be 55 - 60% larger than the beginning. Yours seems to be around 60 - 65% (70 is roughly 65% larger than 45) so i think 55-60 my be alright. of course deciding the taper may not be as cut and dry as that, but ill have to see when i decided what im building. although ive had multiple people tell me tlines and 6th orders wont work well in a trunk car, lol

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  • 2 weeks later...

So based off of your measurements that you are saying, are you trying to create a line length that is tuned to 22 hz roughly?

Roughly, here are my notes and pics of the first box I had designed using sketchup. The problem with that box was that there was no way physically that the sub could have fit inside that box.

T-Line (eD 13Kv.2)

To calculate length of Freq divide 1130 / (Fs freq) = Full wave Length

To calculate Quarter Wave length divide (Full Wave Length / 4)

Take the SD (cone area) if in cm2 (squared centimeters) convert to in2 (squared inches)

1.) 1130 / 21.5Hz = 52.55 ft – rounded to 53 ft

2.) 53 ft / 4 = 13.25 ft Q-wave length

3.) SD =545cm2 which is 84.48in2. The line has to be 84in2

So based off of what I have, I'll need a line that is around 13 feet long with a port area of around 84sq inches.

Ok so I sketched up a drawing in google's sketchup. Now I didn't add the top to this but the box height with the top on is only 12inches high. So if HxWxD then the box is 12 x 45 1/2 x 27 3/4. The three drawings are of the same box just showing different measurments for what I wanted to illistrate. Now to get my 84sq of line I did a HxW of 10.5 x 8 = 84sq. So the lines wide is 8 inches high by 10 1/2 height.

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So based off what I had for the orignal design I tried to build the box as closely tuned to the subs's Fs as possible. I'm thinking this might be a home theater subwoofer. So should I just build the damn thing or what?

I'm finishing up my box today. I hope to hear it either tonight or sometime tomorrow but damn she sure is big.

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Almost done by pervitizm, on Flickr

2007 Chevy Suburban LT1

Pioneer AVH 5700 DVD

Diamond Audio D3 6 1/2 components

Kicker 06ZX650.4 amp

Kicker 06ZX2500.1 (x 2)

DC Sound Lab Level 4 18's with Level 5 coils

Autotek Mean Machine 400.1D (replaced)

Soon to come:

rims

body kit

flow master pipes

Confuscious say "he who say it can't be done shouldn't be bothering man busy doing it"

Now feel free to go crawl back under that rock and leave this to the professionals....

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