Building the Wedge Bass OB 2x12, A Cautionary Tale ;-)

ebag4 · « **on:** 29 Jan 2016, 03:42 am »

I ran into an issue today during a build of a pair of Wedge shaped servo bass units, I have not seen this potential issue mentioned previously. This is likely because everyone else that has built these is sharper than I am, but I thought I would mention it in hope of keeping someone else from repeating the error.

As typical, I cut all of the parts needed to build a pair per drawings I put together (I only drew one unit). This is the first time I have built a set with non-parallel baffles. My plan was to build these as mirror images.

In order to round off the back side of the driver cutouts I had to partially rout out the driver cutout and complete the round over prior to putting the wedge together (I didn't want to complete the driver cutout until the units were glued together because part of the external cutout ran into the top/bottom boards), this meant I had to decide which side received the high driver and which was the low driver. Typically with parallel sides you can simply flip the baffle one direction or the other and get the layout you need, however with the wedge shape with the front and rear at a 10 degree angle, you do not have this option. With the wedge using a pair of drivers per unit on opposite sides, one high and one low, each of the 4 baffles are different from the other (based on the front/rear angle, driver location and whether it is the outside or inside the baffle).

Bottom portion of this:

This was not obvious to me until I put the unit together, at which point the damage had been done. I had to start over on one of the units. so save yourself some time, effort and money, be certain to do a temporary set up for both units before cutting your driver holes.

Best,
Ed

mlundy57 · « **Reply #1 on:** 29 Jan 2016, 06:45 am »

Ed,

Actually, the same thing happened to me, twice. I finally learned that after cutting the main pieces (fronts and sides) but before cutting any driver holes to stand them up side by side with the fronts facing me.

With the pieces in this position, label each piece for orientation (top, front, left, right (or inside/outside whatever works for you) so you don't get anything mixed up when you take them down to start glue up. Also mark where you want the driver openings to be. This way you will have your mirror image with the driver orientation the way you want it (in my case I wanted the inside drivers on the bottom.

Instead of taking the first pair apart I cutout enough pieces for two more figuring I'd end up with two mirrored pairs. Well, I didn't mark the pieces well enough and after gluing up the first one realized I now had three identical cabinets

.

This is when I thought about standing them up side by side then marking everything. I did get the fourth cabinet the way I wanted it so I had my mirrored pair. Of course I also have an identical pair glued up out in the garage. Once I get some spare time I'll cut the material for two more cabinets and make sure they are opposite the two I have. That way I'll have two completed pairs of cabinets.

These 12" dual cabinets are really tricky, not like the 3 x 8" wedge cabinets. With the 8" cabinets you can just glue them up. No need to worry about orientation until you are ready to attach the plinths and/or the block for the Neutrik connector. Once you get the main cabinets glued up you stand them up next to each other and they will either be in the mirror image orientation you want or not. If they are fine. If not, all you have to do is flip one of them upside down. Now attach the connector blocks and the plinths.

I naively thought the 12" cabinets would be this easy also.

Sorry for not mentioning this earlier. When I posted my thread on the 12" cabinets there didn't seem to be any real interest in them so I let it drop

.

Mike

ebag4 · « **Reply #2 on:** 29 Jan 2016, 07:53 am »

Thanks Mike, it makes me feel better that I wasn't the only one taken by surprise! Worse yet, it probably took me a half hour to convince myself that you couldn't simply flip them around to get the necessary layout.

Best,
Ed

Peter J · « **Reply #3 on:** 29 Jan 2016, 02:27 pm »

Ed and Mike, you're not alone. I've done similar a number of times. Mirror image stuff is maddening.

I think one's mind gets more accustomed to thinking in a little different way after a couple of those "on sh!t" moments, though, so the good news is there's way less possibility of a repeat performance!

Captainhemo · « **Reply #4 on:** 29 Jan 2016, 05:50 pm »

This is what we did with the NX Ottica/Treme baffle and wings. Might be tough to implement with what you guys are doing as cutting a deeper 1.5" rabbet at 10 degrees would be tough.
Doing this eliminates hving to cut the angle on the front of the wing (bafle in your case) and I'd think proably makes for a better joint ?

jay

ebag4 · « **Reply #5 on:** 8 Feb 2016, 01:57 am »

Jay, I like the idea of doing the joint that way, it would solve a few issues including hiding the joint since the seam would be routed.

Making progress...

I will work on the base next weekend.

Best,
Ed

Captainhemo · « **Reply #6 on:** 8 Feb 2016, 03:10 am »

Looking good Ed

Of course you still end up with a seam in the method we used for the NX series but it ends up being "in the radius" making it much easier to deal with. So long as you get decent glue squish out there will be no hint of seam after some sanding. Not sure how much it matters but I think it wouild result in a stronger joint as well being you have 2 surfaces you are gluing rather than just one if gluig a bevel to a face. It also aids in alignmment. A guy could increase the size of the braces by .5" on each side and use dados on the side panels making the whole thing very self aligning

Keep the pics coming, looking forward to seeing what you do for bases

jay

ebag4 · « **Reply #7 on:** 27 Mar 2016, 02:05 am »

We have finally had decent enough weather that I was able to make a little progress on this project. I borrowed some ideas from Keith's base, remember, imitation is the sincerest form of flattery.

Best,
Ed

mlundy57 · « **Reply #8 on:** 27 Mar 2016, 04:20 am »

I like the feet. One of these days I'll have time do do something different with mine also.

Mike

AKLegal · « **Reply #9 on:** 28 Mar 2016, 09:38 pm »

Quote from: Captainhemo on 29 Jan 2016, 05:50 pm

This is what we did with the NX Ottica/Treme baffle and wings. Might be tough to implement with what you guys are doing as cutting a deeper 1.5" rabbet at 10 degrees would be tough.
Doing this eliminates hving to cut the angle on the front of the wing (bafle in your case) and I'd think proably makes for a better joint ?

jay

I was wondering what the best way to do this would be. I had concerns about how a roundover would look with one side at an angle but I can hit it with the router first and then make the angle cut out. Its probably much easier to clamp this way too. Ive got to run out and get a dado blade set now.

mlundy57 · « **Reply #10 on:** 28 Mar 2016, 10:27 pm »

Quote from: AKLegal on 28 Mar 2016, 09:38 pm

Ive got to run out and get a dado blade set now.

I just bought one awhile back. Neat tool but it wasn't cheap. After futzing around getting it setup I wished I had spent the extra $75 and got the type that makes minor adjustments by twisting a dial. Much faster setups. You don't have to break the blade stack down and insert shims to dial it in. Just twist the dial.

Mike

Captainhemo · « **Reply #11 on:** 28 Mar 2016, 10:55 pm »

Quote from: mlundy57 on 28 Mar 2016, 10:27 pm

I just bought one awhile back. Neat tool but it wasn't cheap. After futzing around getting it setup I wished I had spent the extra $75 and got the type that makes minor adjustments by twisting a dial. Much faster setups. You don't have to break the blade stack down and insert shims to dial it in. Just twist the dial.

Mike

Ditto on that, pretty slick Mike

AKLegal , yeah, that's the way to do it, put your roundover on first then cut your rabbet so it meets the radius at 80 degrees (assuming an 80 degree wing) for a smooth transition from roundover to wing. Drawing a scale model can make it easier, do some test cuts !!!

jay

ebag4 · « **Reply #12 on:** 9 Apr 2016, 06:27 pm »

A little more progress, I hope to get these running this weekend. I continue to learn more about wrapping. More pics for your amusement:

Best,
Ed

Guy 13 · « **Reply #13 on:** 9 Apr 2016, 06:52 pm »

Ed,
really nice work.
I love the red and black.

Guy 13

DeeJayBump · « **Reply #14 on:** 9 Apr 2016, 07:42 pm »

Looking good, Ed. Nice work.

Captainhemo · « **Reply #15 on:** 9 Apr 2016, 07:48 pm »

man, those are looking pretty cool Ed

How far back until that base is 8.5" wide ?

jay

ebag4 · « **Reply #16 on:** 9 Apr 2016, 07:59 pm »

Thanks guys, much appreciated.

Jay, it is too far back...but I have a plan ( insert evil laugh here)...

Best,
Ed

ctviggen · « **Reply #17 on:** 9 Apr 2016, 08:36 pm »

That is super nice.

Danny Richie · « **Reply #18 on:** 10 Apr 2016, 03:15 am »

Man, those look great.

ebag4 · « **Reply #19 on:** 10 Apr 2016, 03:42 am »

Thanks, I have one of them running, here it is:

I'm going to have to adjust the settings on the servo, the bass is heavier in this configuration. I haven't done any real listening to them yet, but the difference in bass is immediate using the same amp settings.

Best,
Ed