Next Project: Arc 40 CBT Array

[Kevin K.]

Here are this weekends updates. Got the upper back caps and top caps cut and glued to the enclosures. Finished the second harness other than securing it to the enclosure.



Prior to peeling the paper on the damping and sticking them in place, I epoxied the entire enclosure with hysol 9462. With all of the stress introduced to these panels to conform to shape, figured this would be worth the extra money for peace of mind. This stuff is ridiculously strong. Any of you remember the superglue commercial where they had a guy hanging from a hard hat that was glued to a high rise beam? This is the glue they really used.



Installed some extra pieces of foam in between the harness and enclosure to make sure we don't get any unwanted rattles. Tom, if you look closely you can see where I added dowels for the baffle alignment, you were right, it gets a little tough to keep everything aligned once you get all that slippery glue in between the panels, especially when you are bowing the panels. Had a hard time with the half scale enclosure so added this to the full scale. It worked great.



Next up was the part that had me sweating bullets all weekend. Attaching the baffles without splitting the veneer. Decided to kind of pretreat the baffles so to say. Applied veneer softener with a piece of cotton cloth and pre-shaped the baffles. Every couple of hours I would apply another light coat of the softener and add a little more to the bend. Seems to have worked, no unwanted cracks or splits after installation.







That's it for this weekend fellas. Will try to get the second enclosure caught up to the first one this week and then get started on the last of the outer panels this next weekend.

[Kevin K.]

Would like to add a couple of more things to this week's updates. This project is possible in part because of two men, one of whom, Rick Craig, is working with me directly to complete these. The other is the man behind the technology for the CBT arrays, Don Keele. I've had the distinct honor of meeting the man in person and he's about as good a guy as you will ever meet. I'm subscribed to Don's youtube channel because of my interest in the arrays and received a notification about an award he was just given, here is the link for those interested:

https://www.youtube.com/watch?v=H0QXezBg4iU&feature=em-subs_digest

I forwarded the link to Rick this weekend and when he replied, stated he'd just spoke with Don earlier in the day about his trip and learned that Don's wife has suffered a stroke. Please keep Don and his wife in your prayers and thoughts.

Thanks,
Kevin

[donradick]

Congratulations on the veneer hurdle. Veneer softener is pretty great stuff when you need it.

[Kevin K.]

Congratulations on the veneer hurdle. Veneer softener is pretty great stuff when you need it.

Thanks Don. The softener is great stuff. It's a little pricey, but very effective when it comes to getting the veneer to relax. One more baffle to go and then I'll feel like I completely cleared the hurdle.

[6thplanet]

No doubt man! Those are coming along nicely!

[neildavis]

Wow.

I watched one of the Keele CBT videos in which he pointed out that you can get the same benefits of the curved front baffle from DSP/delay. But he said the electronic version was a lot more complex. After looking at your build, I disagree. It took about 6 beers to build the amps shown below, which have 24 channels of DSP and 20 class-D power amps. Your build looks like it took more than a case of IPA!

Seriously, you have a nice project there, and I hope I can get an electronic delay version going by early next year for comparison. You're right--this is interesting technology and is opening up some exciting new possibilities for more realistic sounding loudspeakers.

I'm sorry to hear about Don's wife and wish them the best.

[Kevin K.]

Wow.

I watched one of the Keele CBT videos in which he pointed out that you can get the same benefits of the curved front baffle from DSP/delay. But he said the electronic version was a lot more complex. After looking at your build, I disagree. It took about 6 beers to build the amps shown below, which have 24 channels of DSP and 20 class-D power amps. Your build looks like it took more than a case of IPA!

Seriously, you have a nice project there, and I hope I can get an electronic delay version going by early next year for comparison. You're right--this is interesting technology and is opening up some exciting new possibilities for more realistic sounding loudspeakers.

I'm sorry to hear about Don's wife and wish them the best.

Holy cow Neil! If you accomplished that on a 6 pack, imagine what you could do if someone provided a case. Really cool stuff you got going on there and yea it would be awesome to do a comparison between the electronic delay and the curved front baffle delay. Perhaps some day we can arrange it. By the way, not all CBT arrays are this complex. I just have a habit of making my builds this way for some reason. No drama, no fun. Anyway, after these are finished, I'm looking forward to building some simple subwoofers. Surely I wont find a way to over-complicate those.

[andykriech]

Kevin, fantastic work!
Am I seeing your wiring harness correctly? Do you have them installed and the baffles glued on without having terminated each of the wire ends with the crimp-on terminals you showed earlier?

It would have seemed easier to have handled that extensive hand labor before installing. Hopefully, I am mistaken or you have a plan ;-)
Either way, it is doable, just a bit more awkward.

Keep up the exceptional work. This is a build for the ages.
Andy.

[Kevin K.]

Kevin, fantastic work!
Am I seeing your wiring harness correctly? Do you have them installed and the baffles glued on without having terminated each of the wire ends with the crimp-on terminals you showed earlier?

It would have seemed easier to have handled that extensive hand labor before installing. Hopefully, I am mistaken or you have a plan ;-)
Either way, it is doable, just a bit more awkward.

Keep up the exceptional work. This is a build for the ages.
Andy.

Thanks for the kind words Andy. Good catch, you have an eye for the details. Yea, I screwed up and left the terminals at the house (25 miles away) Sunday and decided to move forward with attaching the baffle. It's not as bad as it might look. I can get to the wires to strip and crimp from the front or sides. I'm using a set of the automatic wire strippers from PE and a set of ratcheting crimpers I've had for a while. Plenty of room for both.






Take care,
Kevin

[ani_101]

Great build progress Kevin. One question, did you veneer the baffle and then CNC or applied veneer later after cutting. If later what/how did you flush trip the veneer to the driver cut outs?

[Kevin K.]

Great build progress Kevin. One question, did you veneer the baffle and then CNC or applied veneer later after cutting. If later what/how did you flush trip the veneer to the driver cut outs?

Thanks Ani. I cold pressed the veneer to the mdf prior to cutting the driver cut outs. Used a 3/8" Onsrud Down-Cut Super "O" Flute cutter, part number 64-033. This is a great all around cutter for the CNC and it cut the veneer very clean. Here is a link if you're interested. http://www.cncrouterbitsxp.com/tools...s-614p2470.htm

They also carry the 64-031 which is the same cutter with a little shorter CEL. It's $13 bucks cheaper.

[Navy Guy]

Looking great Kevin!

[Kevin K.]

Looking great Kevin!

Thank you sir! Looking forward to your impression of these next year at MWAF. Wish it could be sooner, but not likely unless your planning a vacation to the Lone Star state.

[ani_101]

You will be dragging these to MWAF.... that's great - i need to make it there.... that's the only one in the midwest i haven't attended yet

[Kevin K.]

You will be dragging these to MWAF.... that's great - i need to make it there.... that's the only one in the midwest i haven't attended yet

Yep, my son and I will be driving up next year. We'll have these in tote and hopefully a couple of other projects as well. Not sure how MWAF compares to some of the other events, it's the only one I've attended so far. Been twice and had a blast both times. Lots of fantastic builds to look and listen to and lots of great guys to hang out with. Hope to see you there!