tag:blogger.com,1999:blog-8689487740107692135.post2151632898020832213..comments2024-01-15T04:39:32.375-08:00Comments on Red Spade Audio: Rythmik dual opposed tapped horn subPaul Spencerhttp://www.blogger.com/profile/07514836858344391753noreply@blogger.comBlogger4125tag:blogger.com,1999:blog-8689487740107692135.post-87033299469552618452012-11-22T05:58:21.378-08:002012-11-22T05:58:21.378-08:00Eric, I have just created a custom version of T20 ...Eric, I have just created a custom version of T20 for a customer using different drivers. My own version has been built and measured and it performs well. Now installed under the floor. The design has progressed beyond the crude version shown there and is fully documented. You can't substitute the Rythmik 15" drivers without modifying the design - the box is likely to become larger. The 15" drivers gain about 2 dB in sensitivity, but this comes at the cost of a larger box. It's quite likely that the line would need a larger cross sectional area at the throat and mouth. You can contact me via the contact form link on the top right hand side, just under the blog header. Paul Spencerhttps://www.blogger.com/profile/07514836858344391753noreply@blogger.comtag:blogger.com,1999:blog-8689487740107692135.post-78472147167826080572012-11-22T05:45:36.522-08:002012-11-22T05:45:36.522-08:00Paul---Do you have and/or sell build plans for the...Paul---Do you have and/or sell build plans for these? Can the Rythmik 15" drivers be used in place of the 12's without any change in dimensions (except for the driver cut-out hole, of course)? Thanks---EJ.Eric Jerdenoreply@blogger.comtag:blogger.com,1999:blog-8689487740107692135.post-26003708160416802732012-02-22T17:45:14.669-08:002012-02-22T17:45:14.669-08:00Perhaps we can - if there is anything of interest ...Perhaps we can - if there is anything of interest let me know. <br /><br />I had a look at Patrick's post. If one models in free space then the result will not compare to other programs using a more typical half space loading. That is why I prefer to use half space simulations. Even better is to model the same drivers in a sealed box in Hornresp to make a proper comparison. When compared this way, T20 achieves 12 db higher output at 20 Hz compared to a sealed box considering both thermal and excursion limits down to 20 Hz. <br /><br />The subjective experience agrees with the simulations. Keeping the gain the same, the windows suddenly start rattling. They do this at 20 Hz but previously it was only ever an issue running test tones at xmax. The difference is dramatic. <br /><br />Tapped horns don't always justify themselves. Recendly I was looking at a tapped horn for some 18" pro woofers, hoping to extract more out of them than I could get in a vented box. I was not able to get enough improvement to make it worthwhile. I think their best use as a rule is as narrow band LFE devices. Their main limitation is that they won't effectively cover a wide bandwidth like a vented box. They won't do 20 - 80 Hz for example. 20 - 60 Hz is about as much as you will get and if you tune lower you also give up the top end.Paul Spencerhttps://www.blogger.com/profile/07514836858344391753noreply@blogger.comtag:blogger.com,1999:blog-8689487740107692135.post-57175179842361164552012-02-22T13:54:24.037-08:002012-02-22T13:54:24.037-08:00Paul, We use & sell & Rythmik subs as well...Paul, We use & sell & Rythmik subs as well - they are great in the lower octave. Like you, we use (& sell) pro woofers as well, providing higher output & better (hi-impact) sound in the upper bass octave.<br /><br />Maybe we can do some work together - we are in the US & online @ HDSound.us. <br /><br />When you say Tapped horns will "increase the sensitivity" 6dB, have you confirmed that your sub models are all in the same acoustic load (in free space)? See http://www.diyaudio.com/forums/subwoofers/114340-tapped-horn-dummies-10.html#post1597059ears4hirehttps://www.blogger.com/profile/05029753076708723115noreply@blogger.com