zobsky

Haven't got around to finishing these (other stuff to deal with over the summer),.. but here's the path I took with 2 way belles . There are some results etc on this forum too. http://www.diyaudio.com/forums/subwoofers/268959-zobsky-contemplates-variation-belle-klipsch.html

I use HF146 (the successor to HF144) with the XT1464 waveguide. I don't have any complaints at all. For what it's worth, the combination doesn't go to to 20 KHz but doesn't lack treble or sound rolled off, isn't annoying, shrill, peaky etc so I'm not concerned. It is useable as low as 550 - 600 Hz for home listening levels, probably at 800 Hz or above for higher power applications.

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 ?

Only certain variants of the econowave were DSP based (such as the gainphile one, .. I've messed around with active econowaves too).t. More often than not, they were designed to use passive crossovers. The "textbook" econowave crossovers were of two types: the low efficiency xover (meant for econowaving with low eff. woofers), and the high efficiency xover (less attenuation of the HF section). Most econowaves use a constant directivity waveguide of some sort, aiming for constant directivity You might find this post useful: http://audiokarma.org/forums/showpost.php?p=1856214&postcount=228 Lastly, if you can source this QSC waveguide, you will find it superior to the smaller pyle, dayton etc clones of the classic JBL CD waveguide http://www.parts-express.com/qsc-pl-000446gp-replacement-waveguide-horn-for-hpr152i-2-bolt--245-625

These are what I used to make a 2 way work. Not cheap, but not expensive (by hi-end standards, anyway). Active crossover is the the way forward, for me, at least, .. IMHO . https://community.klipsch.com/index.php?/topic/158061-ported-belle/

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

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, ...

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?

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

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.

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?

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

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.

If you have the compression driver available,.. Why not try a prototype with foam board using constrained dampening to minimize vibrations? http://www.diyaudio.com/forums/full-range/261427-presenting-trynergy-full-range-tractrix-synergy.html For that matter, there are plenty of synergy plans out there that could work in place of a k402 Disclaimer: I haven't built any of them - though I plan to custom design / fit one into my oversize belle top cabinet at some point Just another point of view . Hope this doesn't hurt anyone .

Don't get stuck up on TH not going past 50 Hz. 80 Hz is more like it, in reality. From a tech. standpoint, .. TH typically cover 1.5 to 2 octaves, so assuming you're NOT aiming for below 20 Hz, and design well, you should be good. Personally, I feel 25 - 30 Hz is a good design compromize for TH in terms of results, bandwidth and reasonable size. If the "subwoofer-riser" is an approach that you are dead set on, another approach would be to employ a quad of reasonably sized drivers (maybe 8" to 10") in a pair of PPSL bass reflex riser box . The driver size will ultimately determine the height of the riser.

If you have a smart phone or tablet, you could get by with this measurement mic and an RTA app such as "audiotools" http://www.parts-express.com/dayton-audio-imm-6-calibrated-measurement-microphone-for-iphone-ipad-tablet-and-android--390-810

Does this help ? https://community.klipsch.com/index.php?/topic/149442-lascala-sonic-detail-improvement-for-only-22098/

These are what I will be using http://www.parts-express.com/parts-express-speaker-cabinet-port-tube-4-5-16-id-adjustable--260-329?utm_source=google&utm_medium=cpc&utm_campaign=pla

Very cool. I look forward to seeing more of this. As I've said before, I would do the totally reversible bass reflex mod to any La Scalas I own. It's good that you have made yours reversible. If you add a sub, you might prefer the Belle Zillas without the reflex mod, or you might want to utilize it. Hi DizRotus, I'm assuming you run ported lascalas . If so, 1. What woofers do you use? 2. Do you further augument them with a sub? - If so, what frequency do you x-over to the sub ? - If not, -- a. what frequency do you tune the ports for. I can tune mine anywhere 45 Hz and below. 40 Hz seems to be the sweet spot for most folks who have tried the mod. -- b. do you feel the need for a sub at all? It would be awesome if I can get away with a TRUE 2 way FULL RANGE system (30 Hz to 15 KHz more or less , practically speaking) Thanks

Good call. It's nice to have options. Part of my issue as well, was not building the initial Belle horn with an open top: I would have to flip mine over. Also wondering what an aperiodic vent would do. I've always liked that 'sound'... oh well, maybe another time. Yeah. My strategy is to make the baffle for the top enclosure removable / replaceable in order to be able to try a variety of configurations (CD horn, tractrix horn, slot loaded midrange cone drivers, synergy etc ). It's certainly large enough ... for better or worse. I'm toying with the idea of using styrofoam blocks in case I need to reduce the internal volume of the total rear chamber volume. Bigger is not always better, in this case

Thanks. I have the option to seal off the bass horn back chamber in case the additional low frequency extension is unnecessary or I decide to implement a dedicated sub

Any updates?. Mine are getting there. Just need to route out the baffles. The entire saga is documented at http://www.diyaudio.com/forums/subwoofers/268959-zobsky-contemplates-variation-belle-klipsch.html . Here's a picture of one of my BelleZillas (with adjustable rear reflex ports) . Note the oversized (and yet unbraced) top chamber that will receive the 18sound XT1464 constant directivity waveguide ( http://www.eighteensound.it/PRODUCTS/Products/ProdID=180 )

If he's using the stamped frame 15c, the specs are Resonant Frequency (Fs)31 Hz DC Resistance (Re)3.68 ohms Voice Coil Inductance (Le)0.88 mH Mechanical Q (Qms)10.14 Electromagnetic Q (Qes)0.25 Total Q (Qts)0.25 Compliance Equivalent Volume (Vas)11.7 ft.³ Mechanical Compliance of Suspension (Cms)0.35 mm/N BL Product (BL)14.7 Tm Diaphragm Mass Inc. Airload (Mms)77g Maximum Linear Excursion (Xmax)2.4 mm Surface Area of Cone (Sd)856.3 cm²