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Post by Chuck Elliot on Jan 19, 2013 15:00:56 GMT -5
I’ve been working a couple of months on a DIY speaker to replace my Heresy III mains. The main design goals with this speaker were: - Get the overall efficiency above 100dB as I want to go tube at some point for the L/R.
- Use a larger horn than the Heresy uses to open up the mid-range.
- 2-way vs 3 way.
- DIY as I like to build stuff.
The speaker will use a pair of the Klipsch K28 woofers which are the same used by the Heresy III and the Faital HF140/LTH142 horn. Faital Parts: Bob Crites, who sells Klipsch replacement parts, built up a prototype of my design to prove out the validity of the design and I purchased the motorboards from him along with the horns. Prototype  Size compared to Heresy  I’ve sort of served as the GC on this project. I have limited woodworking skills and am having the cabinets built by a local cabinet maker. I have all the parts except the crossovers which are still under design. The cabinets are due next week, so I can start some finishing and assembly. I will add as I go along..... Chuck |
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Deleted
Deleted Member
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Post by Deleted on Jan 19, 2013 22:28:03 GMT -5
There ya go Chuck!!
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Post by Chuck Elliot on Jan 20, 2013 10:01:31 GMT -5
Size comparison between Klipsch K700 in Heresy and F142 horn:   |
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Post by bond007 on Jan 20, 2013 10:29:10 GMT -5
nice work great job on the speaker. man post some more pictures when you can.
cheers
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Post by flashjim on Jan 22, 2013 9:59:46 GMT -5
What's a motorboard?
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Post by Chuck Elliot on Jan 22, 2013 10:50:00 GMT -5
Motorboard is a term used to describe the front panel that the drivers("motors") are mounted to. |
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DYohn
Emo VIPs 
Posts: 18,487
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Post by DYohn on Jan 22, 2013 11:23:05 GMT -5
Looks good. Let us know how it sounds. (I haven't heard the term "motorboard" used in about 30 years. An old-school name for a speaker baffle. Now change those drivers from dynamics to field coil versions and we'll be back in the 40's.  ) |
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Post by jmason625 on Jan 22, 2013 13:03:48 GMT -5
keep us posted on progress
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Post by laserman35 on Jan 22, 2013 14:23:24 GMT -5
I loved eveything but the CIGS.
I can't wait for your review, I'm looking for a project like this for my self.
Please post specs and cost when finished.
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Post by Chuck Elliot on Jan 22, 2013 14:41:37 GMT -5
I loved eveything but the CIGS. I can't wait for your review, I'm looking for a project like this for my self. Please post specs and cost when finished. There are 2 standard frames of reference a breadbox and a pack of smokes. Since I haven't seen a breadbox since my grandmother's kitchen, I used the smokes. Cost so far for the pair: Horns and drivers (2 each): $800 K28 woofers ( 4 in total): $450 I expect the cabinets to come in around $800 for the pair. This is where a woodworker could save a pile. I specified "Euro-Ply" 15 ply plywood which also wasn't cheap at over $100 a 4x8 sheet. So my total is over $2K as I stand. I expect the crossovers may add another chunk.... I expect the cabinets by week's end, so I will have some more pictures. The first thing I need to do is finish the cabinets and mount the drivers. I've then got to do some impedance sweeps and SPL measurements to pass to a friend that's helping with the crossovers. |
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Post by laserman35 on Jan 22, 2013 15:13:52 GMT -5
I just can not stop hating the smokes, it has taken more of my friends and family than anything else.
And i do smoke a Cuban every other year or so.
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Post by flashjim on Jan 23, 2013 11:17:18 GMT -5
Motorboard is a term used to describe the front panel that the drivers("motors") are mounted to. Thanks! I had never heard of that term before. Keep the pictures coming! |
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Post by savjac on Jan 23, 2013 13:28:18 GMT -5
I do love this threads, those will be some powerful speakers. Looking forward to further updates.
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Post by jjmontague on Feb 1, 2013 9:45:51 GMT -5
Any updates? I'm interested in hearing about the crossover design you end up using. Nice work so far.
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Post by garym on Feb 1, 2013 10:38:31 GMT -5
cfelliot,
Did you use software to design the box or crossovers? Also, what was your source for those K28 drivers? I couldn't find bare drivers on Klipsch's site.
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traider79
Sensei
Getting used to new look
Posts: 434
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Post by traider79 on Feb 1, 2013 13:16:17 GMT -5
Chuck, This looks to be shaping up to be a great sounding project!
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Post by Chuck Elliot on Feb 1, 2013 15:40:53 GMT -5
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Post by The Mad Norseman on Feb 1, 2013 18:03:11 GMT -5
Those are looking gorgeous - keep the 'in progress' photos coming! I know a lot of us here are also looking forward to your sound review once they're all up and running for awhile...  |
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Post by Chuck Elliot on Feb 2, 2013 0:12:38 GMT -5
cfelliot, Did you use software to design the box or crossovers? Also, what was your source for those K28 drivers? I couldn't find bare drivers on Klipsch's site. The K28 woofer runs in a 2 ft^3 box in the Heresy. With 2, I just doubled it up to 4 ft^3. I wrote my own software to design the initial crossover which was 18dB @ 500Hz. I've decided to move that up t0 700Hz and perhaps go even steeper - say 24dB. My source for the K28s must remain secret - but I've seen them on ebay. Below is part of my starting crossover design, but I'm now working with Al @ ALKENG for the final design. Also the woofers were not originally K28s.  |
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Winger
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Wing-a-ling
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Post by Winger on Feb 2, 2013 9:36:28 GMT -5
You may find this site interesting, the Frequency Response Data (FRD) Consortium. www.pvconsultants.com/audio/frdgroup.htmThere are a host of DIY speaker design tools available. Everything from box modeling to crossover design to baffle diffraction and room response simulation. What do you plan to use for damping material? I've used Black Hole 5, which works great, but is spendy. There is another product called Whisper mat that works well too and is considerably cheaper. Both are sandwich construction foam products intended to damp sound wave transmission through the surfaces they're mounted to. Your cabinets appear to have some large un-braced surfaces and I think they'd benefit from some internal surface treatments. Also consider adding some additional bracing. If you do, to place the braces asymmetrically will brake the surfaces into different sizes and shapes. This spreads out the resonant modes of the cabinet and makes them less pronounced. Just a couple of thoughts. Happy designing  -Wing Follow-up: Seems there is more than one Whispermat product, with different applications. The one I'm referring to is not the flooring product. The Whispermat I've used is produced by Silent Source. Follow this link -->http://www.silentsource.com/barriers-whispermat.html |
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