BobK Posted January 13, 2016 Share Posted January 13, 2016 (edited) I read suggestions on this forum to get more bass from Chorus 1s is to use 7" port tubes. So I made four 7" tubes out of thick poster paper. Yes I went for fire Red Anyhow it did give the bass more Snap and if I put my hand by the ports I can now feel air pumping out where as with the holes I really did not feel much air. I did not even seal them, they are just in via friction fit. I rolled them up put them in the holes let them expand so they were tight then just taped the edges so it would not unroll. Just wondering what the relationship is between bass and port tube length and or diameter. Obviously the short (thickness of the wood 3/4") holes had less bass. But what would a tube 4" do vs 7" or 3" diameter vs 4" diameter? I used a calculator for 38hz and it was around 7" using 5 cubic feet for the chorus size. The Chorus has a K48 woofer that looks like it can go to 30hz. So why not use 30hz as the frequency? I think that gives around 9" tubes. Can anyone clarify the pros and cons of going to long for the port tube? Edited January 13, 2016 by BobK Quote Link to comment Share on other sites More sharing options...
billybob Posted January 13, 2016 Share Posted January 13, 2016 (edited) Guess it could get muddy or inaudible the difference. Going to try it? 38hz is getting pretty low over the stock 45hz(40?), with a - +3 db THE Given the depth of the box, 7 inch may be the optimum. But, easy to confirm given the poster paper. Let us know please,thanks! Edited January 13, 2016 by billybob Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted January 13, 2016 Share Posted January 13, 2016 Can anyone clarify the pros and cons of going to long for the port tube? Longer ports should tune the box lower. Shorter will probably give you more overall output. Quote Link to comment Share on other sites More sharing options...
WMcD Posted January 13, 2016 Share Posted January 13, 2016 Does anyone have the T-S parameters on the woofer so we can run a box response type thing? It seems to me we can assume the interior of the box is about 80% of the outside measurements (to account for the riser, thickness of walls, and displacement caused by the bass driver, horns, and ports. But maybe someone has more detailed information. WMcD 2 Quote Link to comment Share on other sites More sharing options...
Bob01464 Posted January 14, 2016 Share Posted January 14, 2016 Watching closely as I have much the same questions. Quote Link to comment Share on other sites More sharing options...
nd-irish147 Posted January 14, 2016 Share Posted January 14, 2016 I found this document in another post.... this should have the info you are looking for. K-1545-K-1548.pdf Quote Link to comment Share on other sites More sharing options...
wvu80 Posted January 14, 2016 Share Posted January 14, 2016 (edited) You don't get something for nothing. I would guess that as you get more lower bass extension you would lose efficiency. And there has to be a point at which the lower limits of the woofer are reached, no matter how long you make the port. The PDF indicates the range of the driver is 30Hz to 3000Hz. The box tune is 39Hz. http://www.klipsch.com.au/chorus-ii/details Edited January 14, 2016 by wvu80 1 Quote Link to comment Share on other sites More sharing options...
Bob01464 Posted January 14, 2016 Share Posted January 14, 2016 Found this in another post: I emailed Eminence about 15677 years ago and was told it is the K-48-E woofer with Fs 42 hz, qt.35, vas 166 liters, 97udb 1w/1m and 4 ohm impedance. Was used in the Chorus II I was told. Specs seem to be different from the PDF above. Chorus and Chorus II both use the same K-48 woofer. Can't confirm if they are actually accurate. Quote Link to comment Share on other sites More sharing options...
WMcD Posted January 14, 2016 Share Posted January 14, 2016 My contribution to the project is attached. Information on Chorus and k-48.pdf 2 Quote Link to comment Share on other sites More sharing options...
Bob01464 Posted January 14, 2016 Share Posted January 14, 2016 (edited) Wow great information. Seems that the PDF posted by nd-irish147 is pretty spot on. Thanks!!! Edited January 14, 2016 by Bob01464 Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted January 14, 2016 Share Posted January 14, 2016 Odd that the Fs of the cabinet is 37Hz and the measured +- 3 dB spec on the speaker is 45Hz. 1 Quote Link to comment Share on other sites More sharing options...
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