transmission line enclosure
Printed From: the12volt.comForum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=97630
Printed Date: May 05, 2024 at 11:27 PM
Topic: transmission line enclosure
Posted By: tubbs04
Subject: transmission line enclosure
Date Posted: October 02, 2007 at 7:24 PM
Replies:
Posted By: haemphyst
Date Posted: October 03, 2007 at 1:30 AM
Well, yes and no...
First of all, NEVER mention Bose in this forum again, unless you are considering trading up!
(Cause that's all you CAN do for it!) Bose does use TL designs, but the marketing geniuses over there thought that "Acoustimass" and (most recently) "Proprietary Waveguide Speaker Technology" sounded better! Nice, huh? Hell, I'd buy something called "Proprietary Waveguide Speaker Technology", if I didn't know better!! Sounds so... technical, and... scientific, doesn't it? LOL And now you know why 80% of their annual operating costs go directly to advertising, rather than R&D.
A port is just a device to tune an enclosure to a given resonance. Remove the enclosure, and buld the port SO big, that you can stick the woofer on the end of it, and there you are - a TL. Oversimplified, certainly, but basically... Instead of an air pump moving air through it, it's a speaker moving air through it.
OK, seriously though, the TL is more about organ pipes. It is designed with a single resonance in mind, like an organ pipe, and that resonance is VERY low, compared to a vented enclosure. Above the resonance nearly all of the sound being produced comes from the driver, as the frequency being produced gets lower, the pipe then begins to produce output, until the sound being produced is shared by the woofer and the terminus, but 90 degrees apart. 90 degrees, so it is additive, thus great authority "down low", much lower than an equivalently sized sealed or vented enclosure.
Just like a vented enclosure, though, a TL will unload below resonance, just as does a vented enclosure, so a subsonic filter is still necessary.
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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."
First of all, NEVER mention Bose in this forum again, unless you are considering trading up!
(Cause that's all you CAN do for it!) Bose does use TL designs, but the marketing geniuses over there thought that "Acoustimass" and (most recently) "Proprietary Waveguide Speaker Technology" sounded better! Nice, huh? Hell, I'd buy something called "Proprietary Waveguide Speaker Technology", if I didn't know better!! Sounds so... technical, and... scientific, doesn't it? LOL And now you know why 80% of their annual operating costs go directly to advertising, rather than R&D.
A port is just a device to tune an enclosure to a given resonance. Remove the enclosure, and buld the port SO big, that you can stick the woofer on the end of it, and there you are - a TL. Oversimplified, certainly, but basically... Instead of an air pump moving air through it, it's a speaker moving air through it.
OK, seriously though, the TL is more about organ pipes. It is designed with a single resonance in mind, like an organ pipe, and that resonance is VERY low, compared to a vented enclosure. Above the resonance nearly all of the sound being produced comes from the driver, as the frequency being produced gets lower, the pipe then begins to produce output, until the sound being produced is shared by the woofer and the terminus, but 90 degrees apart. 90 degrees, so it is additive, thus great authority "down low", much lower than an equivalently sized sealed or vented enclosure.
Just like a vented enclosure, though, a TL will unload below resonance, just as does a vented enclosure, so a subsonic filter is still necessary.
-------------
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."
Posted By: tubbs04
Date Posted: October 04, 2007 at 9:11 AM
Posted By: haemphyst
Date Posted: October 04, 2007 at 9:42 AM
Posted By: audiocableguy
Date Posted: October 04, 2007 at 10:47 AM
Posted By: haemphyst
Date Posted: October 04, 2007 at 10:49 AM
Posted By: audiocableguy
Date Posted: October 04, 2007 at 12:34 PM
Posted By: tubbs04
Date Posted: October 04, 2007 at 7:42 PM
Posted By: haemphyst
Date Posted: October 04, 2007 at 8:02 PM
Sorry... my mailbox was full... got some space now! 
Now, what are you asking about? I'm lost. (And I'm truly not trying to be obnoxious about that, either... I really am lost!) The TL is certainly NOT where you want to go for mid-bass - it's completely impractical there, due to their physical size. Are you asking about the whole system, and what I'd do, or are you asking about TL design?
TLs are also notoriously INefficient. VERY good extension, and generally meant to be a true subwoofer system, you'd rarely, if EVER cross them over higher than about 60Hz, which is where I am with mine right now. Output monsters, they ain't, though.
-------------
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."
Now, what are you asking about? I'm lost. (And I'm truly not trying to be obnoxious about that, either... I really am lost!) The TL is certainly NOT where you want to go for mid-bass - it's completely impractical there, due to their physical size. Are you asking about the whole system, and what I'd do, or are you asking about TL design?
TLs are also notoriously INefficient. VERY good extension, and generally meant to be a true subwoofer system, you'd rarely, if EVER cross them over higher than about 60Hz, which is where I am with mine right now. Output monsters, they ain't, though.
-------------
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."
Posted By: audiocableguy
Date Posted: October 04, 2007 at 8:20 PM
Posted By: audiocableguy
Date Posted: October 04, 2007 at 8:30 PM
Posted By: haemphyst
Date Posted: October 04, 2007 at 11:41 PM
Posted By: audiocableguy
Date Posted: October 04, 2007 at 11:48 PM
Posted By: haemphyst
Date Posted: October 04, 2007 at 11:52 PM
Posted By: tubbs04
Date Posted: October 05, 2007 at 1:25 PM
haemphyst wrote:
Sorry... my mailbox was full... got some space now!
Now, what are you asking about? I'm lost. (And I'm truly not trying to be obnoxious about that, either... I really am lost!) The TL is certainly NOT where you want to go for mid-bass - it's completely impractical there, due to their physical size. Are you asking about the whole system, and what I'd do, or are you asking about TL design?
TLs are also notoriously INefficient. VERY good extension, and generally meant to be a true subwoofer system, you'd rarely, if EVER cross them over higher than about 60Hz, which is where I am with mine right now. Output monsters, they ain't, though.
I was asking if a TL enclosure would help me with bringing bass up front... I simply asked bc I have no clue how they work or what they are designed for... You've answered that it wont help me... So thank you, thats one less headache for me hahaha...
And yes, the MA's aren't just the best, but the store I work for didn't have a MA demo vehicle, So I put my truck to use.. And I get a nice price so I can't really complain... Most cars around here just seem to just be crammed full of mis-matched speakers and other crap, So from what I'm normally exposed to, MA sounds pretty nice... I really wish there where some of the brands around here that ya'll know about, but it's northeast mississippi... we're behind on everything... hahaha
Thanks for the help!
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...don't crush the weasel...
Posted By: audiocableguy
Date Posted: October 05, 2007 at 9:25 PM
Posted By: DYohn
Date Posted: October 05, 2007 at 10:48 PM
Posted By: tubbs04
Date Posted: October 06, 2007 at 9:39 AM
Posted By: tubbs04
Date Posted: October 06, 2007 at 9:42 AM
Posted By: haemphyst
Date Posted: October 07, 2007 at 7:48 PM
Posted By: DYohn
Date Posted: October 07, 2007 at 10:53 PM