A 3-way design/build journal.

Christof · « **Reply #20 on:** 7 Mar 2007, 01:41 pm »

The drivers are just arriving to Ricks vendor, he has to make test boxes for his lab and spend some time working with the xo's. Until he gets a better idea of how this design is going to go I will not have the cabinet dimensions to begin construction. In due time.

jono2channel · « **Reply #21 on:** 9 Mar 2007, 03:34 am »

Hi Christof

I just went back to your first post, and I was trying to figure out whey you didn't just go for the RC5? Definitely "eye candy" and I am sure they sound as good as they look. Are you trying to get something out of your custom build that would not be present in the RC5? Could you elaborate please? Thanks for the info. I am looking forward to hearing from you.

Jonathan

Christof · « **Reply #22 on:** 9 Mar 2007, 04:37 am »

Quote from: jono2channel on 9 Mar 2007, 03:34 am

.......Are you trying to get something out of your custom build that would not be present in the RC5? Could you elaborate please? Thanks for the info. I am looking forward to hearing from you.

Jonathan

I'm not trying to best the RC5 with this design but it will be very interesting to hear the subtle differences between this design and the RC5 when we are finished. I think the RC5 will have and edge in the low bass freq's but the ScanSpeak 6600 AirCirc tweeter could give the Seas tweeter a good run for it's money. Teh only special requirements I had were that this design be able to hold it's own in my listening room which is very large and I must be able to biamp. The truth be told if I was not a cabinet builder and had Rick not agreed to take on this commission I would have bought the RC5.

-c.

Rick Craig · « **Reply #23 on:** 9 Mar 2007, 06:29 pm »

Quote from: jono2channel on 9 Mar 2007, 03:34 am

Hi Christof

I just went back to your first post, and I was trying to figure out whey you didn't just go for the RC5? Definitely "eye candy" and I am sure they sound as good as they look. Are you trying to get something out of your custom build that would not be present in the RC5? Could you elaborate please? Thanks for the info. I am looking forward to hearing from you.

Jonathan

Chris desired to create his own cabinet design so that's when we started to discuss different drivers. With the RC5 the cabinet shape is integral to the performance of the speaker; as a result, it couldn't be adapted to his cabinets without a new crossover design.

I expect that the tonal characteristics will be very similar. As Chris noted there will be changes in the bass since the woofers are quite different.

Rick

Christof · « **Reply #24 on:** 3 Apr 2007, 05:38 pm »

Updated 4/3

Christof · « **Reply #25 on:** 11 Apr 2007, 09:34 pm »

Updated 4/11

Christof · « **Reply #26 on:** 21 Apr 2007, 12:10 pm »

Updated 4/20

Christof · « **Reply #27 on:** 24 Apr 2007, 09:47 pm »

Update 4/24

LadyDog · « **Reply #28 on:** 24 Apr 2007, 10:21 pm »

Quote

I shot a heap of pics in the shop today but I cannot locate the cord to my camera

Your such a tease!

Looking forward to the pics and the rest of the build.

mpauly · « **Reply #29 on:** 26 Apr 2007, 02:53 am »

I've seen lots of references to bend MDF with kerf cuts. Did you fill in the voids left in the kerfs with anything after the bend?

Christof · « **Reply #30 on:** 26 Apr 2007, 01:36 pm »

answered above

Christof · « **Reply #31 on:** 2 May 2007, 06:07 pm »

5/2

I've exceeded the max length for one post so I will continue the "journal" here

Added a few pics...more to come

To insure that the forms are all indentical and speed things up I made a template from Corian to use on the router table for shaping. You can see the kerf cuts that were made in the panels. They are spaced about 3/16" apart and leave about 1/16" at the bottom of the cut. I cheated and stacked 3 blades together with spacers. Each bend has about 15-20 cuts

Here are the panels before bending. Biscuits are used to keep everything in line but the joint relies primarily on PVA (yellow)glue and later fiberglass & resin.

The uncut side of the panel is steamed, the kerfs are filled up about 1/4 of the depth with PVA glue and the panel is slowly bent around the forms. Bar clamps are used top hold the panel and then band clamps pull the whole thing together.

This is what it looks like before the voids are filled with resin and the face is sanded smooth

Here is the same test enclosure as above after applying the matte blue laminate. The laminate was sanded to half thickness where the bends were made. Water-borne contact adhesive was applied and the laminate was wrapped while being heated.

Christof · « **Reply #32 on:** 8 May 2007, 02:31 pm »

Final crossover component decisions have been made. With all the buzz about XO components on the SP Tech circle & Ellis Audio circle I decided I should hold no punches and go all Sonicap with Sonicap Platinum bypass caps and aircores. Rick had some very encouraging words to say about the new SS6600 Aircirc tweeter used in this design. I'll leave it to him to post those comments

Rick did a fantastic job at keeping me within budget or pretty darn close anyway. I did make a couple upgrades at the last minute including the Platinum caps, all cardas internal hook-up wire, and Misic Post binding posts from Sonic Craft (sort of Cardas clones).

The prototype enclosures have been made with success and now it's time to build the real thing. Actually the prototypes turned out so well that they could be used for the real deal but I laminated them in regular blue hpl vs the white Microdot that I want for the final speakers. As a side note, if anyone is interested in the test enclosures shoot me a PM for more info.

Rick Craig · « **Reply #33 on:** 8 May 2007, 04:24 pm »

Quote from: Christof on 8 May 2007, 02:31 pm

Final crossover component decisions have been made. With all the buzz about XO components on the SP Tech circle & Ellis Audio circle I decided I should hold no punches and go all Sonicap with Sonicap Platinum bypass caps and aircores. Rick had some very encouraging words to say about the new SS6600 Aircirc tweeter used in this design. I'll leave it to him to post those comments Rick did a fantastic job at keeping me within budget or pretty darn close anyway. I did make a couple upgrades at the last minute including the Platinum caps, all cardas internal hook-up wire, and Misic Post binding posts from Sonic Craft (sort of Cardas clones).

The prototype enclosures have been made with success and now it's time to build the real thing. Actually the prototypes turned out so well that they could be used for the real deal but I laminated them in regular blue hpl vs the white Microdot that I want for the final speakers. As a side note, if anyone is interested in the test enclosures shoot me a PM for more info.

The crossover design is coming along very well. I'm very impressed with the AirCirc tweeter and it has the best off-axis extension of any 1" dome that I've tested

TomS · « **Reply #34 on:** 8 May 2007, 08:09 pm »

Quote from: Christof on 8 May 2007, 02:31 pm

I did make a couple upgrades at the last minute including the Platinum caps, all cardas internal hook-up wire, and Misic Post binding posts from Sonic Craft (sort of Cardas clones).

You're going to have to be really careful with the EP posts. Since they're soft, they strip VERY easily. I have them on my BEL amps and a couple were fouled when I got them. Tom

Rick Craig · « **Reply #35 on:** 11 May 2007, 02:24 pm »

Quote from: Christof on 8 May 2007, 02:31 pm

Final crossover component decisions have been made. With all the buzz about XO components on the SP Tech circle & Ellis Audio circle I decided I should hold no punches and go all Sonicap with Sonicap Platinum bypass caps and aircores. Rick had some very encouraging words to say about the new SS6600 Aircirc tweeter used in this design. I'll leave it to him to post those comments Rick did a fantastic job at keeping me within budget or pretty darn close anyway. I did make a couple upgrades at the last minute including the Platinum caps, all cardas internal hook-up wire, and Misic Post binding posts from Sonic Craft (sort of Cardas clones).

The prototype enclosures have been made with success and now it's time to build the real thing. Actually the prototypes turned out so well that they could be used for the real deal but I laminated them in regular blue hpl vs the white Microdot that I want for the final speakers. As a side note, if anyone is interested in the test enclosures shoot me a PM for more info.

The Sonicap Platinum caps are on backorder so we switched to Mundorf Supreme Silver / Gold caps.

Christof · « **Reply #36 on:** 18 May 2007, 02:38 am »

Got a PM from Rick stating that his work is completed, the design is done and now the ball is in my court.

Picked up another order of white MicroDot to finish the large bass cabs and I just need to select some nice walnut to resaw for the bass baffles. The rest of the pics of the initial cabinet build process will post in a few days.

A note for anyone trying to bend mdf...
I purchase mdf for my shop in bulk from a commercial vendor but I ran out after prototyping the initial enclosure. I went to a big box store and purchased a sheet of 3/4. This sheet was much lighter in color, cut much easier on my table saw and bent much easier. I'm not sure about this but I think the sheets from the HD/Menards type stores must be softwood and the better stuff from the commercial vendor seems like hardwood. If you have the option try to find the light colored mdf.

Christof · « **Reply #37 on:** 21 Jun 2007, 11:08 pm »

My how busy things get in the summer. I escaped my day job for a bit spent a little time on my project....actually, I went baffle shopping. As always I returned with more than I had intended but thats a pretty easy thing to do considering the selection I had to choose from. I returned from my buying trip with enough wood to build a boat.....I scored a 14" wide x 1" thick x 12' long solid piece of Bloodwood, 12" wide Purple Heart, extremely wide Bubinga, a few massive pieces of quilted maple, some Cocobolo, a few pieces of quarter sawn Padauk and some wicked American Black Cherry...quilted! All this for one pair of speakers

Ok, I'm raising my hand in the air and admiting that I have a problem, I'm a first class wood junky. I live only to support my habit. I am happy to say that I did pass on a slab of Redwood 3" thick, 49" wide and 11' long (sold). Someone in Chicago is going to have a beautiful custom table

. Anyway, with all this baffle material, Rick and I may have a little something in store for this fall/winter

MarkM · « **Reply #38 on:** 5 Sep 2007, 01:20 am »

Any updates on this project?

Christof · « **Reply #39 on:** 5 Sep 2007, 06:58 am »

Caught me sleeping on the job. Ok, not sleeping just too busy working on non-audio related commissions.

All the parts are now sitting in my woodshop waiting for the day

If you folks have not gotten a chance to check out the build quality of the SS6600 tweeter, you must.....this tweeter is a piece of art and Rick says it sounds damn good too!!!!

I was talking with Rick the other day about cabinets and there seems to be alot of interest in the Aurasounds mtm design that he is doing (for RMAF??) as well as the Seas Excel based design I am building. Both designs share more or less the same uncommon cabinet size so I started to kick around an idea. As long as I've made the jigs for constructing the bent cabinets, bracing and baffles then I might as well make a few extra pairs of mtm cabinets. When they are finished I'll decide which look best in my loft and if there is any interest I'll put the other cabinets up for grabs here or sell them as completed speaker through the gallery.

At this point I guess I better shut up and get busy.