zobsky Posted July 5, 2015 Share Posted July 5, 2015 (edited) Well,not really a traditional belle - I intended to make it a 2 way, more or less, and decided to incorporate DJK's ported mod, .. so I shall name it BelleZilla . I've had this project thread going for a while on another forum but sometimes, I feel like it's been like a monologue. As much as I hate cross posting, I figured maybe I could contribute and learn a bit more wrt this project on this forum. The saga (starting from my initial impressions) is located at: http://www.diyaudio.com/forums/subwoofers/268959-zobsky-contemplates-variation-belle-klipsch-9.html#post4379829 In any case, the bottom of this design is a belle, running an eminence kappa 15c The top, OTOH, uses the Faital Pro HF146 on a constant directivity waveguide , the excellent (albeit ugly looking and grill cloth worthy) eighteensound XT1464 . The top cab is rear ported. I'm still tuning, .. and think there's some room for improvement in the bass , so I'm all ears here. The last posts in my other thread detail my experiences with the performance of the hybrid bass horn . I haven't yet tried it in conventional sealed back chamber mode. Edited July 5, 2015 by zobsky 3 Quote Link to comment Share on other sites More sharing options...
zobsky Posted July 5, 2015 Author Share Posted July 5, 2015 For what it's worth, a close up of the overbuilt braced top chamber . It connects to the horn rear chamber via a 7" diameter hole 1 Quote Link to comment Share on other sites More sharing options...
Don Richard Posted July 5, 2015 Share Posted July 5, 2015 If they sound as good as they look, you will be a happy man. Excellent! Quote Link to comment Share on other sites More sharing options...
totalcomfort Posted July 5, 2015 Share Posted July 5, 2015 Nicely done Quote Link to comment Share on other sites More sharing options...
zobsky Posted July 5, 2015 Author Share Posted July 5, 2015 Thanks. Has anyone else here run ported belles / la scalas with eminence kappa 15c (the woofers I use). If so, can you post thoughts / comparisons to other woofers wrt bass performance? Quote Link to comment Share on other sites More sharing options...
minermark Posted July 5, 2015 Share Posted July 5, 2015 Looks great, i think you have the thickness of the cabinet down pat. Should sound outstanding Quote Link to comment Share on other sites More sharing options...
spezjag Posted July 5, 2015 Share Posted July 5, 2015 (edited) Thanks. Has anyone else here run ported belles / la scalas with eminence kappa 15c (the woofers I use). If so, can you post thoughts / comparisons to other woofers wrt bass performance?zobsky - can you tell me why you are looking at the 15c, vice the 15a with the cast basket? Is there a demonstrated performance difference, or is it a matter of cost? Edited July 5, 2015 by spezjag Quote Link to comment Share on other sites More sharing options...
zobsky Posted July 6, 2015 Author Share Posted July 6, 2015 Thanks. Has anyone else here run ported belles / la scalas with eminence kappa 15c (the woofers I use). If so, can you post thoughts / comparisons to other woofers wrt bass performance? zobsky - can you tell me why you are looking at the 15c, vice the 15a with the cast basket? Is there a demonstrated performance difference, or is it a matter of cost? 1. Parts express had a single pair at a VERY tempting price on the 15c when I was looking. 2. This discussion: https://community.klipsch.com/index.php?/topic/149442-lascala-sonic-detail-improvement-for-only-22098/ 3. Not really a reason, but after I received the drivers, the specs seemed ideal for a ported lascala / belle The specs for the regular kappa 15a indicate a slightly higher Qts and more Xmax . I haven't looked into whether it is more suitable. Maybe someone else on this board can shed some light. On the other hand, if you are refering the kappa pro 15a (cast basket), the Qts seems a bit high for a bass horn. I haven't run simulations with it yet so I can't speaker with any authority FWIW,.. I was considering crites woofers till I came across the special on the kappa 15c woofers . If someone in the DFW area can loan me a pair for a few days, I'd be glad to compare and post my opinions. Quote Link to comment Share on other sites More sharing options...
Stevenarrow Posted July 7, 2015 Share Posted July 7, 2015 Nice job. What size ports and what internal volume are you using? Quote Link to comment Share on other sites More sharing options...
zobsky Posted July 8, 2015 Author Share Posted July 8, 2015 Nice job. What size ports and what internal volume are you using? twin 4.5" ports of variable length per cabinet. I still don't get the bass I expect, but I haven't given this project my full attention yet so I'll try and generate some SPL curves this evening or thereabouts (time permitting). Here are my notes regarding impedance, internal volumes etc http://www.diyaudio.com/forums/subwoofers/268959-zobsky-contemplates-variation-belle-klipsch-9.html#post4379851 Quote Link to comment Share on other sites More sharing options...
Stevenarrow Posted July 8, 2015 Share Posted July 8, 2015 Thanks, I read through your DIY thread. It is interesting, I am in nearly the same boat as you, with the same woofers. The numbers I am getting through simulation show that a slightly smaller volume 4 cu ft. with a 35-40 hz tuning seems best. I was planning to mock up a reflex box that had ports snap similar to a Cornwall. That said, I don't think you will ever get big bass from EDm or some hip hop as you mentioned. 1 Quote Link to comment Share on other sites More sharing options...
zobsky Posted July 8, 2015 Author Share Posted July 8, 2015 (edited) Cool. I'd be interested to read about your findings . I plan to utilize foam board to alter the internal volume (I'm out of styrofoam + it makes a mess when cut) . Maybe I should hook up the other belle in sealed mode to compare I'm using active x over (minidsp) but would anyone know if the stock belle / lascala used any contouring / bass compensation in the bass bin crossover or was it just a normal low pass? Edited July 8, 2015 by zobsky Quote Link to comment Share on other sites More sharing options...
Stevenarrow Posted July 8, 2015 Share Posted July 8, 2015 It would be interesting to see the sealed plots. Quote Link to comment Share on other sites More sharing options...
zobsky Posted July 9, 2015 Author Share Posted July 9, 2015 Here are some preliminary measurements. Before testing, I improved things somewhat by laying 80 lb of dumbells on the top cab(presumably, this has sealed the enclosure better). Port length hasn't made that much of a difference. I did manage to identify the major ranges that needed to be boosted and cut. In the final graph, note that I've also added in a 30 Hz low pass and a 600 Hz high pass Getting there, ... Quote Link to comment Share on other sites More sharing options...
Stevenarrow Posted July 9, 2015 Share Posted July 9, 2015 that's quite the jump with eq. Interesting comment on the sealing of the unit. Quote Link to comment Share on other sites More sharing options...
zobsky Posted July 9, 2015 Author Share Posted July 9, 2015 (edited) that's quite the jump with eq. Interesting comment on the sealing of the unit. Yes, .. the EQ gains indicated by the graph indicate that the cabinet alignment supports that frequency range. That said, I'm not quite sure why I can't hear much, if any, difference between different port lengths. I'll look into that later Yes, ... though I hadn't screwed in the top cab prior to this test, .. just clamped it in the front, presumably creating a wedge resulting in micro leak of some sort Edited July 9, 2015 by zobsky Quote Link to comment Share on other sites More sharing options...
Stevenarrow Posted July 14, 2015 Share Posted July 14, 2015 Just wondering. Perhaps using just one 4" diameter port at 4" would give a little more punch to the low-end. 4" should still provide enough area to not whistle. Quote Link to comment Share on other sites More sharing options...
Marvel Posted July 14, 2015 Share Posted July 14, 2015 Perhaps using just one 4" diameter port at 4" would give a little more punch to the low-end. 4" should still provide enough area to not whistle. That would raise the tuning... but make it a little tighter. Quote Link to comment Share on other sites More sharing options...
zobsky Posted July 14, 2015 Author Share Posted July 14, 2015 (edited) Just wondering. Perhaps using just one 4" diameter port at 4" would give a little more punch to the low-end. 4" should still provide enough area to not whistle. Correct, I did test the top cab with the port tubes removed (just for the sake of experimenting) i.e. nominally 2 x 3/4" long x 4" DIA holes . Punchier sound but not as low. This weekend, I disassembled the cabinets in preparation for veneering & finishing . What do folks around here use to trim veneer once it's glued to the substrate . I was planning to use a router with a flush trim bit but am a bit wary of tearout especially when trimming across the grain ? Edited July 14, 2015 by zobsky Quote Link to comment Share on other sites More sharing options...
Stevenarrow Posted July 14, 2015 Share Posted July 14, 2015 I use a small veneer trimmer. It is like a small scale router that counter top guys use for laminate. Alternately, a sharp knife and good substrate and only cut on the pull stroke with the veneer facing up to avoid splintering. Quote Link to comment Share on other sites More sharing options...
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