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Kappalite coaxials!!

#201
kringle77 said:
I looked up the 2" precision flared ports. A total length isn't listed but, Im assuming there is enough to get the 7.75"" of tuning length.
Click to expand...
what about PVC pipe? it's not flared, sure, but flaring just helps prevent chuffing and you can just use a slightly bigger port. I got a precision flared port once, and it wasn't simply flared at the mouth. This isn't necessarily a bad thing, I've read a paper that basically said that a flare that opens up in both directions from the centre of the thing was ideal - if I can recall, and could probably post that. My gripe was that I bought it to cut down into a specific length and that my math was based on a tube with a consistent diameter, and couldn't guarantee the tuning if I cut it and then sanded it down to a specific length. I mean, it probably wouldn't have deviated by much but I honestly couldn't have guaranteed anything.
 
#202
IMO, the whole flared thing is grossly over marketed. If a simple port is sized properly, it's a solution looking for a problem.

If it was that beneficial, you would see them on the unlimited budget touring pro audio cabinets too.
 
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#204
Alright, time to stop speculating and get to work!
This is my Eminence KL3015CX-8 cabinet build. I decided on a 2.29 cu-ft cab tuned to 38 Hz ported with 3" schedule 40 PVC pipe. A pair of 3" plugs allow this to be used ported or sealed. Ported has an F3 of 59.4 Hz and an F10 of 39.0 Hz. Sealed has an F3 of 74.5 Hz and a Qtc of .705 which is close to ideal. There aren't many drivers that can do both ported and sealed well at high power so I'm looking forward to seeing what this beast will do. Ported mode can take the full rated 400 watts down to 39 Hz and has a low group delay so the low end should be tight and solid. Eminence Designer screen shots:
Eminence KL3015CX-8 Vented.PNG

Eminence KL3015CX-8 Vented.PNG
Eminence KL3015CX-8 MaxPower.PNG

Eminence KL3015CX-8 GroupDelay.PNG
 
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#206
Here is the construction drawing, parts list, and start of assembly.
Eminence KL3015CX-8 Single.png

I have left over 18mm birch ply for the baffle, 12mm poplar ply for the rest of it, a quart of black Duratex, and 1-1/2" acoustic foam. Most of the rest was from Parts Express:
1 - Eminence KL3015CX-8 15" High Power Coaxial Woofer 8 Ohm $259.99
1 - Selenium D202Ti 1" Titanium Horn Driver 1-3/8"-18 TPI $43.99
1 - Switchcraft EHRRSLB Curved Rocker Switch I/O DPDT Black $6.53
2 - Penn-Elcom 30769 Compact PA Cabinet Handle 6" x 7" $7.33 ea
1 - 15" Waffle Style Black Steel Speaker Grill with Rubber Edge $8.29
1 - Penn-Elcom G0780KIT Large Speaker Grill Clamp Kit $6.94
1 - Eminence PX-LPAD Crossover LPad Attenuator $24.99
1 - Eminence PX-BII 2K6-2 2-Way Speaker Crossover Board 2,600 Hz $59.99
2 - Neutrik NL4MP-ST Speakon Connector 4 Pole Panel Mount $3.64 ea
1 - #10-32 Barbed Body Insert Nuts 50 Pcs. $8.78
Total with tax $450.80 I also picked up 1" #10-32 stainless cap head screws to mount the speaker, a tube of PL Premium adhesive, and a pack of 3.5" thick R-15 mineral wool batts for the extra insulation to stuff the cab. I think the PX-BII 2K6-2 crossover should work well with this driver pair. I used the Selenium D202Ti on an earlier build and liked how smooth and transparent it was; very nice driver for the price and it only weighs 2 lbs.

I drilled holes for and mounted the insert nuts before routing the baffle cutout. This prevented wood from extruding into the baffle cutout when mounting the nuts. Routing 3-1/2" holes for the port tubes didn't turn out so well. The trammel point rig was so tippy it jumped out of the center guide hole so I finished the holes with a saber saw and anchored the port tubes with PL premium. The first pic shows how the speaker, grill, and HF attenuator fit in the baffle. The next two show the front/bottom/right and back/top/left halves which will be joined in the final assembly. The drivers extend in 7" from the front and the port tubes extend in 6-3/8" in from the back.
KL3015CX Cab Baffle.jpg

KL3015CX Cab FBR Half.jpg

KL3015CX Cab BTL Half.jpg
 
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#211
kringle77 said:
Id love feedback on how the woofer sounds fullrange with no tweet!
Click to expand...
The 15" driver cuts off around 4Khz..so it's not full range by any stretch of the imagination. However...the coaxial design means that a specifically designed high frequency driver is placed behind the center dust cap of the 15" driver. The 15" cone then becomes a HF flare as well as a 15" woofer cone. There's a single point source for all the frequencies.
As it happens...I've also very interested in this cab / design too. I may build a pair of them in a few months as my 12" replacement cabs for my larger rig. Only 97db/w/m so a max spl of around 125db @ 400w. But it's such a small and movable cab.
 
#214
PraiseBassing said:
It is a coaxial driver, like the Altec. Coaxial's can be great full range systems. Just make sure you install a crossover and tweeter tho. The 10"/12"/15" speakers are only part of the full range system.
Click to expand...
We had four of the 15" Altecs, and two of the 12" version, back in the '70s, so I am way more than a bit familiar with the Altecs. :bassist: I think my brother still has a pair of 604-8Gs that he still uses.
 
#215
Jeff Scott said:
We had four of the 15" Altecs, and two of the 12" version, back in the '70s, so I am way more than a bit familiar with the Altecs. :bassist: I think my brother still has a pair of 604-8Gs that he still uses.
Click to expand...
Sorry if it came across as being snarky or rude. My point was that the Altecs look to come as a complete coaxial speaker, where the Eminence KL30XXCX speakers are the low frequency drivers only and need to be paired with a tweeter in order to produce a full range response.
 
#217
IMO, there's no such thing as the ideal speaker for bass, no different than the ideal tone for bass.

Different players have greatly different ideals, otherwise everyone would be playing the same bass, the same strings, the same amp and the same speakers... which is obviously not the case.
 
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#220
BassikLee said:
So much excursion it blew the damn cabinet apart. Might I suggest stronger glue and longer staples next time………

Looks GREAT!!!
Click to expand...
Yeah, probably should have let the glue dry and broke it in gently. Oh well, here goes and this time with PL Premium 8X...
The first pic is freshly glued. 18 gauge 1-1/4” brads in the nail gun really help pull the surfaces together tight. After trimming the excess adhesive and using a rasp to dress the joints, all edges are rounded with a 1/4" radius bit. Holes were filled with plastic wood and the box was given a finish sanding and wiped down with a tack cloth. At this point the raw wooden enclosure weighs 18.2 lbs.
KL3015CX Cab Raw Front.jpg

The port tubes were sprayed with 3 coats of black and the box was rolled with 3 coats of black Duratex. Front and back pics of the coated cabinet are shown.
KL3015CX Cab Duratex Front.jpg

KL3015CX Cab Duratex Back.jpg

When the Duratex dried, protective chevron corners were installed and 1-1/2" acoustic foam was applied to the interior.
KL3015CX Cab Corners&Foam.jpg
 
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