babadono Posted April 7, 2016 Share Posted April 7, 2016 I don't know anything....but isn't the passive radiator a type of port? I do know my third cherry RSW-15 is in the back of the Subaru ready to go home with me tonight . Thanks Shodrewken. Quote Link to comment Share on other sites More sharing options...
Matthews Posted April 7, 2016 Author Share Posted April 7, 2016 but isn't the passive radiator a type of port? Indeed it is, "babadono" My goal was to remove the unwanted resonance (don't know the correct term). For an odd reason i cant put my finger on, I don't like passive radiators. I do know my third cherry RSW-15 is in the back of the Subaru ready to go home with me tonight . Awesome!!! Thunder in the skies tonight - Congrats on your new arrival Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted April 8, 2016 Share Posted April 8, 2016 Test mules don't need to be pretty. 3 Quote Link to comment Share on other sites More sharing options...
Matthews Posted April 8, 2016 Author Share Posted April 8, 2016 Experimental setup. This will be cut and a 90 added to extend the port tube with flared end venting downwards. Very happy with initial sound checks. 2 Quote Link to comment Share on other sites More sharing options...
MookieStl Posted April 8, 2016 Share Posted April 8, 2016 Even when I comes to test mules, some are prettier than others! You just have to make sure you point this end of the mule toward the wall. Still might want to dim the lights. 2 Quote Link to comment Share on other sites More sharing options...
Matthews Posted April 8, 2016 Author Share Posted April 8, 2016 Even when I comes to test mules, some are prettier than others! when it works, it works, Sir Mookie - thanks for stepping in to help out with the photo... 1 Quote Link to comment Share on other sites More sharing options...
Matthews Posted April 8, 2016 Author Share Posted April 8, 2016 (edited) QUESTION? - Is it correct that a longer port tube will tune the sub to an even lower frequency? On the other hand, shorten to tune a tad higher? I think tuning any lower than present is beyond my target. Thanks, Matt ♪ ♫ ♪ Edited April 8, 2016 by Matthews Quote Link to comment Share on other sites More sharing options...
jason str Posted April 8, 2016 Share Posted April 8, 2016 Yes. 1 Quote Link to comment Share on other sites More sharing options...
Shodrewken Posted April 8, 2016 Share Posted April 8, 2016 I don't know anything....but isn't the passive radiator a type of port? I do know my third cherry RSW-15 is in the back of the Subaru ready to go home with me tonight . Thanks Shodrewken. Not to steal the post, but no problem bud! Glad everything worked out. Enjoy that beast of a sub! 1 Quote Link to comment Share on other sites More sharing options...
Moderators Youthman Posted April 8, 2016 Moderators Share Posted April 8, 2016 For some reason having trouble loading pics. Resize them to around 1500px wide and you will be fine. 1 Quote Link to comment Share on other sites More sharing options...
mustang guy Posted April 8, 2016 Share Posted April 8, 2016 (edited) If that box is 3.72 f3, then with that 3" wide (I think) port: tuned to about 30Hz now 6" port would be about 25Hz tune 12" port would be about 20Hz The passive was tuned to 19 Hz, so I'd throw 12" at it and get a microphone to measure the results to see if ported is better than passive radiator-ated. Edited April 8, 2016 by mustang guy 1 Quote Link to comment Share on other sites More sharing options...
Matthews Posted April 8, 2016 Author Share Posted April 8, 2016 If that box is 3.72 f3, then with that 3" wide (I think) port: tuned to about 30Hz now 6" port would be about 25Hz tune 12" port would be about 20Hz Thanks Mustang, the new port is 4" wide and current tube length is 10". Going to experiment with shortening the tube couple of inches tonight. Don't have any measurement devices other then my ears. So far, my ears like what they are hearing, liking the port tube much better than the passive Quote Link to comment Share on other sites More sharing options...
Matthews Posted April 8, 2016 Author Share Posted April 8, 2016 testing, after picture snafu yesterday. Seems the gerbil crawled back on the wheel... Matt ♪ ♫ ♪ 1 Quote Link to comment Share on other sites More sharing options...
Matthews Posted April 8, 2016 Author Share Posted April 8, 2016 And so here is what I am going with. 4" port, 12 inches in length. 6 interior, 6 inches outside. There were just no good options at the hardware store to install a 90. All glued up and "the mule" is ready for another run of testing. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted April 8, 2016 Share Posted April 8, 2016 And flared at both ends, very nice. 1 Quote Link to comment Share on other sites More sharing options...
JiminSTL Posted April 8, 2016 Share Posted April 8, 2016 OK, Matt, my final offer . . . the same $250 I offered way back when, before you started all this stuff. I'll even come and pick it up . . . . Don't be one of those too proud to accept any offer of HELP. 1 Quote Link to comment Share on other sites More sharing options...
mustang guy Posted April 8, 2016 Share Posted April 8, 2016 12" is about a 25Hz tune for that box with a 4" port. For a 20Hz tune using a 4" port, you need 20". Quote Link to comment Share on other sites More sharing options...
Matthews Posted April 8, 2016 Author Share Posted April 8, 2016 OK, Matt, my final offer . . . the same $250 I offered way back when, before you started all this stuff. I'll even come and pick it up . . . . Don't be one of those too proud to accept any offer of HELP. LOL - you being silly, Jim Wouldn't let this subject go for twice of what I paid. Gonna have to do a little better than 250... 12" is about a 25Hz tune for that box with a 4" port. For a 20Hz tune using a 4" port, you need 20". I think that may be just the perfect tune, for my application. Perhaps exactly what I was shooting for? Hopefully a "hells yeah" in the coming days. Thanks Mustang... Quote Link to comment Share on other sites More sharing options...
JiminSTL Posted April 8, 2016 Share Posted April 8, 2016 Actually, I really admire the skill and precision of the types of work you do. Your consistently achieve superb results! 1 Quote Link to comment Share on other sites More sharing options...
Grizzog Posted April 8, 2016 Share Posted April 8, 2016 $251. But I'll need shipping. The extra dollar should cover it. 1 Quote Link to comment Share on other sites More sharing options...
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