-Hobby- Posted August 19, 2009 Report Share Posted August 19, 2009 Forevrbumpn, I would like to get some input from you. I used the tutorial and built the line. I was blown away at the volume I could get from my 12" sub on only 600 watts. I did have 2 issues that I would like to correct. I found the enclosure was a lot more boomy than I anticipated and I have a driver unloading issue somewhere below 27hz. My subsonic filter settings on the amp are 15hz and 30hz. Right now its set to 30hz and as long as I dont go crazy with the volume Im ok. If I set it to 15 and hit a serious low note the driver unloads. Someone suggested that I tune it even lower, 22hz, then taper the line from the full port size at the beginning to 80% of the port size at the end. Also to keep my driver and port opening next to each other which they are currently not. When I saw you recommending opening the port at the end I started wondering if what I was about to build was correct. I was even recommended to use polyfill thru the line to try and control the driver. Heres a pict of the line I have now. Its for a TC-9 12" 10.46 ft 1/4 wave length and 78.5 sq in port. 6 1/4" X 12 1/2" port size. The corners are all 45'd as they should be, thats just a pict while I was in the process of building. Link to comment Share on other sites More sharing options...
kirill007 Posted August 20, 2009 Report Share Posted August 20, 2009 Using polyfill, doesn't helps controlling the driver, it's going to get worse if you use polyfill. Polyfill would make the port look bigger=more loading problems. Instead of tapering it, you could just shrink the port area.( to around 65-68sq inch) What is the cone area from the sub? measure from the middle of the dustcap to start of the surround. A Tline lowers the power handling from a sub(mechanical power handling.). If the spiders aren't stiff enough to control the cone, it's gonna overexcurt. Having the port and sub next to eachother won't help, mine is almost the same box as yours and my port and sub are nowhere near eachother. (i'm almost positive, that the guy at CA.com doesn't knows a lot about Tline's or Quarter wave boxes, not saying i know a lot, but i know a few basics) My box is tuned to 26hz, and when it gets around tuning frequency, like 26-29 hz or 22-24 hz the excursion is less then at around 34hz.(checkout my build.) Thinking is the root of all problems... You ALWAYS get what you pay for. Link to comment Share on other sites More sharing options...
Forevrbumpn Posted August 22, 2009 Author Report Share Posted August 22, 2009 I already know why its unloading.... a couple solutions for this, but neither are easy fixes The reason it is unloading is because of moving mass, aluminum is light, but heavier than paper/Kevlar cone, so the weight tends to throw itself beyond its limits- I cannot find specs on this sub, I have been looking for about 10 minutes- but I'am guessing its Fs is lower than your quarter wave your tuned at, and since its a heavy cone, and the suspension seems soft, its probably a higher Q designed sub yes, tune lower- At tuning the cone will move less, I bet the woofers broken in Fs is lower than the quarter wave measurement of the box 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. Link to comment Share on other sites More sharing options...
-Hobby- Posted August 22, 2009 Report Share Posted August 22, 2009 I already know why its unloading.... a couple solutions for this, but neither are easy fixes The reason it is unloading is because of moving mass, aluminum is light, but heavier than paper/Kevlar cone, so the weight tends to throw itself beyond its limits- I cannot find specs on this sub, I have been looking for about 10 minutes- but I'am guessing its Fs is lower than your quarter wave your tuned at, and since its a heavy cone, and the suspension seems soft, its probably a higher Q designed sub yes, tune lower- At tuning the cone will move less, I bet the woofers broken in Fs is lower than the quarter wave measurement of the box Heres a link for you , shows all the specs........TC-9 I have it tuned to the Fs and I believe the dia center of the surround to center of the surround was 10" just in case you want to check my math. Im pretty sure its right. As for fixing it, I was planning on building another one anyways that will fit into my new setup and be more finished and presentable. That was just for me to play around with and see just how well they worked. So should I tune lower and possibly taper the line. I dont have anything etched in stone at the moment. I just want the lows and not that awful unloading sound. Dont want to f the sub up either. Its broken in now, been played in a ported enclosure daily for more than a year. Link to comment Share on other sites More sharing options...
-Hobby- Posted August 22, 2009 Report Share Posted August 22, 2009 And what about the driver placement, Would putting the driver next to the opening help? I would rather not do it if I can help it. Makes the next design taller and shorter in length. Doesn't fit well with my plans . Link to comment Share on other sites More sharing options...
aznboi3644 Posted September 6, 2009 Report Share Posted September 6, 2009 I would rebuild the enclosure starting off around 150% sd down to 50-75% sd...it will help control the excursion Link to comment Share on other sites More sharing options...
qu1cks1lver56 Posted September 14, 2009 Report Share Posted September 14, 2009 foreverbumpn i am jealous as hell, that h/k receiver is amazing. i lucked up on one for $100, brought it home, and it had some kind of amp problem, everytime i turned it up for longer than 30 seconds it would shut itself off. i was pissed cuz those things have an amazing amp in them and sound great. First Gen Xterra: Always changing DNX 690HD RF 360.3RF T3002RF T4004RF T10001bdSilver Flute 6.5"s Tang Band 1" TweetersSundown X18 in 7cubes net tuned to 32hz Trust me .25 Blows your Load. Link to comment Share on other sites More sharing options...
Kasey Posted September 15, 2009 Report Share Posted September 15, 2009 If i where to use pvc pipe for a T-Line would it need to have turns in it or could it be a straight pice of pipe "Audio is not a hobby it's a lifestyle" _____________________________Refs_1_Refs_2_____________________________ Link to comment Share on other sites More sharing options...
aznboi3644 Posted September 16, 2009 Report Share Posted September 16, 2009 a speaker does not know if a pipe is bent or not...it is a speaker. You can use any tube...you can bend it or keep it straight...doesn't matter Link to comment Share on other sites More sharing options...
Kasey Posted September 16, 2009 Report Share Posted September 16, 2009 Cool that made that easy thanks "Audio is not a hobby it's a lifestyle" _____________________________Refs_1_Refs_2_____________________________ Link to comment Share on other sites More sharing options...
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