transmission line sub

Boogeyman, that's a neat trick. The carpet is already laid and glued, so I'll have to tweak it a bit. I have enough carpet for a 2nd layer on the front though. The trick is to find something dynamat-ish to use, I don't have any of the real stuff. I'm sure the local hardware store will have something I can substitute.   I really like how it looks in my mind, simply raised bumps that doesn't involve chrome, neon lights, plexiglass, or anything that flashes : ) Oh how I hate some of the crap people put in cars... Interesting point you bring up about frequencies. My test CD has sine waves down to 25hz which was perfectly fine for the sub I had previously and all my home theater equipment. Looks like I need to build a new CD now hah, never thought I'd see the day! I too am really curious about how low it will go. That XA1000 is a wonderful little amp, I've only had it installed for a day now but I'm already in love. Everything from the heat sink and power terminals to the glowing Eclipse logo as a power light screams quality build. Oh and my favorite part is how hot it doesn't get. After a half hour of pushing it hard, the heat sink was barely warmer than the skin on my other arm. Sweet! I'll be around this weekend if you do make it, I can take you for a nice bike ride up Mt. Hamilton if you want? haha it's about one mile of elevation gain round trip. And as for rebuilding your enclosure, I thought it was the new reference all other subs were compared against based on the reviews you've been getting here. Anyhow, we'll see! Once you hear my components up front you'll be begging me to rip them out and set them on fire though, I'm nearly sure of it. -JustinMalcom: "This is the captain. We have a...little problem with our engine sequence, so we may experience some slight turbulence and then...explode."

Jayne: "We're gonna explode? I don't wanna explode.

step the eighth: install amp and enclosure, again striving for top quality I started with the power cable the same time as building the box because I had the materials and my cousin was around for free labor, so he did most of the wire running and taking the dash apart etc. It's really hard to see, but in the top left corner up against the body to the side of the battery is a small black box with a red button and red lever. This is a resettable fuse rated to 140amps. I got the idea from the broadcast vans we use at the radio station, they have similar (though much better quality) resettable fuses on all the battery related cables and I love the idea of being able to turn the power lead on/off at the flip of a switch, and not having to buy more fuses should I ever melt one. I'm using the side post of the yellow top, which some people say to be careful about due to the internal wiring being inferior to the top posts and not able to handle much current. To that I say, hmph. It's supplying the 40'some'odd amps I need for the amp, so it's all good. You'll notice however I didn't attach my winch to the side posts : ) Also you'll see split loom covering the new 4ga. wire in the engine compartment and you won't see the cute rubber grommet in the firewall. The next two photos are my cousin's handywork making a complete mess of my interior. Taking the dashboard apart to reach the power wire from the firewall, removing the rear seats and pulling up the carpet, and having a grand old time making a mess and cutting his fingers on everything sharp he can find. Below is the final amplifier installation. The 4ga. power cable is going directly to it for now, but I plan to add a distribution block at some point in the future to power the amp for the components, which also need replacing. Especially after this install, the components I have are sticking out like a sore thumb! Damn they sound bad... The last photo is what this project is all about. The transmission line is sitting happily in my cargo area, perfectly nestled against the spare tire and the wheel well, and between the rear seat and the molding along the floor. It ain't going anywhere! And I have to add, it's damn beautiful. The picture doesn't really do it justice because the project was finished too late at night and I had to use a flash : ( So where do I go from here? I wait for haemphyst to bring his laptop and TrueRTA gear up here for some measurements! I'd use mine but it was in my toolbag which was stolen a few weeks ago, curses! Seriously though, I'll use the belar spectrum analyzer I had earlier and check the response again. From there I can better tune the amplifier's crossover, but right now it's pretty darn close. I'm also beginning to read the many stickies about building a good front sound stage and proper mid-bass etc etc. That should be another fun little project, but that'll have to be another day. I'll keep playing around with what I have and post some results Soon™. -JustinMalcom: "This is the captain. We have a...little problem with our engine sequence, so we may experience some slight turbulence and then...explode."

Jayne: "We're gonna explode? I don't wanna explode.

nice build...No this makes me want to finish up my single 10 transmission line...I love being lazy though. That is a monster enclosure for a single 10 inch sub though. How much does that box weigh?? I know mine was quite hefty

I haven't a clue what it weighs, but it's probably in the range of 50-70lbs. I can move it myself a short distance, but the size is so awkward I can't get it off the ground and into the car, or onto the workbench by myself. Monster it is, but well worth it I think! I'm looking into replacing my RTA gear, so maybe in the next week or three I'll post some real measurements. The unit I used to have (before it was stolen) was the Phonic PAA2, a handheld 31-band RTA with built in mic and a few basic features like store/recall/average and EQ sugestions. If anybody has suggestions for a portable setup that is not terribly expensive, I'd love to hear it! I don't have a spare laptop to load software on though, so it's gotta be a self contained thing weather it's a rack-mount box or handheld device. If all else fails, I'll go find another PAA2 somewhere, it worked really well. -JustinMalcom: "This is the captain. We have a...little problem with our engine sequence, so we may experience some slight turbulence and then...explode."

Jayne: "We're gonna explode? I don't wanna explode.

So... How's it sound? We're all waiting! Forgot about the wife's birthday this weekend, (can you see me missing THAT? God help us all!) so I won't be there THIS week, but next week is a VERY much stronger possibility! That'll give you a little time to break things in! When I get up there, I'll be sure to bring my laptop, mic and mic pre-amp, tripod, soundcards, cables, and have the software all ready to go! Looking forward to it! By the way, that's a REALLY sharp looking install! (Except that dash... )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."

Yeah, the wife certainly takes priority. Sometimes I forget my mom's birthday. No wait, I *never* forget. I'm not going anywhere so don't skip your anniversary too while trying to visit San Jose. haha! Thankfully the dash is all back together now, but we must have missed something because there is a wicked squeak on the passenger's side that needs attention. There are three side effects I would have never thought about when beginning this project. First, and most obviously, my interior must have a dozen new rattles and squeaks in it from the sub trying to rip everything apart. Second, the carpet material gives everything a kind of "new car scent" because it smells like new carpet (pretty neat actually). And third, the quality of the low notes make the 2-way components I have up front sound absolutely terrible. I wasn't planning on replacing the components and adding an amplifier for at least a month or three. Sadly for my bank account, this will have to happen sooner than later. Alright alright, now onto how it sounds. HOLY CRAP I've never experienced low frequency extension like this in my car, home theater, any installation at work or anywhere else for that matter. The lowest notes are difficult to detect because they blend in with all the bumps and rumble of the road. When the engine is idling, it has very tiny inconsistencies that cause the RPMs to change ever so slightly. It's not a bad engine, just the normal kind of imperfect huumm.mm.mmm.mm that engines make. The sub hits so low I can't tell which from which. Is the engine sputtering, or is that the music? Is this road really bumpy all of a sudden? No, that *has* to be me, I drive this road every day. I simply don't know what to do with all the low notes, it's new territory for me to explore. When I was listening to it for the first time in the garage, I swear I looked at the garage door over ten times because I thought someone was opening it. I never hear the garage door opening while listening to music because it's simply not louder than my speakers. But I can always feel it moving because the thing is so heavy and rumbles around a bit. Well, not anymore! The damn sub kept tricking me into thinking it was opening from all the subsonic material I was hearing for the first time in my favorite songs. Unsettling at first, but awesome now that I'm used to it. I still haven't made a new test CD yet, but I can say that a playing few sine waves from 35hz down to 25hz make no appreciable difference in volume. I don't think the roll-off is going to start until the very low 20's which is exactly what I was hoping for. The low pass filter on the amp is set to about 55hz which is the highest I'd like to go, but it will have to sit higher for a while until I can get new components. There is a noticeable gap between the 55hz crossover I want and the point where the components start to kick in. This is very easy to hear with something like a bass guitar which spans the low octaves, but something like a kick drum sounds excellent because it's all below the crossover. Favorite new tracks are London Bridge by Fergie, Step Into The Arena by DJ Ernie, and Busy Child by The Crystal Method. London Bride has two bass rhythms where one is the typical boom boom flavor and the second is an awesome sub-30hz rumble. Step Into The Arena has some marching band drumline action mixed in with the techno driving-music for a really neat effect. There is also a synthed bass line that hits pretty low. Busy Child has a powerful bass introduction that often sounds boomy on a system that isn't setup correctly, but this install nailed it. Maroon 5's album Songs About Jane is a little bass heavy and kinda boomy in general, so it was nice to hear it being fairly tame and pleasant in the car. Jack Johnson's album Inbetween Dreams has very well balanced bass and played beautifully. Blue Man Group's Audio is one of my all time favorites and reproduced exceptionally. There is an ultra low frequency bass drum used in some of the tracks that is completely inaudible on most systems but the transmission line sure found it. I remember from the live performance how commanding that drum was when hit, and the sub did not dissapoint. I'm most likely going to grab a measurement microphone from Behringer to use with that Belar FFT I used earlier for some proper measurements, but that won't be for a little while. Until then, I'll be browsing and planning for a fresh mid/tweet install : ) -JustinMalcom: "This is the captain. We have a...little problem with our engine sequence, so we may experience some slight turbulence and then...explode."

Jayne: "We're gonna explode? I don't wanna explode.

i was looking for a sticky on tl enclosures but could not find one.  what are the benifits of them compared to ported or sealed enclosures?you can do it....

advanced MECP, lol does it really matter....

patience is a virtue

Upsides: very low frequency extension (reason I built it!) one full range woofer in a home setting can reach 40hz up to 18khz! can be designed to have a very flat response, or peaky if you like more efficient than sealed boxes mostly ignores Vas rating of a woofer (box size not dependent on this number) tunable after box it built, by using polyfill Downsides: often larger enclosures very complex to design compared to others little to no simulators available other than Martin J. King's worksheets less efficient than sealed or bandpass subsonic filter almost required similar to ported or bandpass boxes Others on this board will probably have their own points to add. -JustinMalcom: "This is the captain. We have a...little problem with our engine sequence, so we may experience some slight turbulence and then...explode."

Jayne: "We're gonna explode? I don't wanna explode.

so if i was building a sq system this could be a very good enclosure? i am only really fond of sealed enclosures, but would be willing to give one of these a try if it is worth it.   haemph  where are you located at.  i know tinker is in sj,  i am in ventura and am curious where about you are so i could see if i could possibly listen to your system. that is if it is still a tl box that you have.you can do it....

advanced MECP, lol does it really matter....

patience is a virtue

I built mine with the goal of sound quality from the very beginning, and I'm absolutely thrilled with the results. From my research into transmission lines in general, many people are very satisfied with them in this regard. The trick is to get the dimensions right for the woofer you choose. If you decide to go for it, I'll try to help you as best I can. wheeeee! -JustinMalcom: "This is the captain. We have a...little problem with our engine sequence, so we may experience some slight turbulence and then...explode."

Jayne: "We're gonna explode? I don't wanna explode.