Buggered up handles

[rotebass]

Working on my first Tuba 30 build, I must say I've fired it up and I am quite happy with the results so far. I have been working on finishing touches before it is time to paint, but I ran into a snag while cutting out the handles. I started my night working on the handles on panel 12 and the jig saw made a mess of the plywood, on top of that I not happy with the over all shape of the handles. Is there anyway to remove and patch the area in question with another piece of plywood cut to size? If so, what adhesive would do the job best (I'm assuming PL)?

I'm hoping for a second chance to get do the job right, construction has been quite smooth so far despite my lack of experience.

[Tom Smit]

Is that the handhold in the panel, or is it the inlaid handlle installed in the corner?

[rotebass]

It is a handhold cut at the mouth end of the panel. I snapped a picture before leaving the shop earlier:

https://dl.dropbox.com/u/25226419/Photo ... 4%20PM.jpg

I have a few ideas on how to fix it, not sure what would be the best, or even if any of them would work. My first idea is to cut out the offending area and and try to make a patch as close to the right size as possible, PL it into place, then clamp it with a pair of 2x4 and some wax paper (2x4, wax paper, panel, wax paper, 2x4). Sand and hopefully try again...

Idea two is to set my circular saw at a 45' angle and set the depth to 1/2", clamp down my guide as to cut the width of the cab and about from the end of the panel, make the appropriate cuts in the two side panels. At this point I should have removed an area that is 20"x4" (the 19" internal panel with, plus the two 1/2" side panels). Next I could fashion a panel of the same size, with a corresponding 45' angle and glue and clamp it in place. I feel this option would probably result in a better looking, stronger patch, and probably take the same or possible even less time to get right that the first option. The 45' angle would maximise glueing area as well.

Woodworking is a new experience for me, I am learning a lot as I go. I'm glad I decided to try building this cab, but I am quite bummed to have made it this far and then messed up. Perhaps it's time to learn how to use a router?

[Tom Smit]

Heh, your "option two" sounds like the best, overall repair. And, since it was you who came up with it, you should do well.

When you go to cut out the new handhold, temporarily install/clamp a backer plate on top so that the panel will not suffer tear-out, but is instead supported by the temp plate on top of it.

[rotebass]

Thanks Tom, I'll post back tomorrow.

[DJPhatman]

Let this be a lesson to all to use the proper plywood.

If you look closely, you will see that the OP is using 4 ply plywood.

[rotebass]

Let this be a lesson to all to use the proper plywood.

If you look closely, you will see that the OP is using 4 ply plywood.

Don't trust the wood yard guys. I went into the lumber store, found some nice looking 5-ply spruce that was cut into 4x4 sheets, told the salesperson I wanted exactly that in a 4x8 sheet. Unfortunately my little Mazda 3 isn't built for hauling wood so I had them deliver to the shop while I was away at work.

The stuff that got delivered was a far cry from what was in the show room, made the decision that getting the wood back to the yard and replaced was a big hassle and this wood should be "good enough" for a practice build.

Do you reckon that a proper 5 ply would have produced better results while cutting those handles?

I plan to shop around for lumber next time around, I wanted to test the design and also get my construction chops up to snuff before I start building a herd. Initial tests show that the design lives up to it's name, I just want to finish this box off to get a complete idea of the construction process.

[netwerks]

Why dont you cut it closer to what you want and then fill it with bondo (may have to build it up in 2-3 applications) and sand it out. it will be fine. I would say you may want to have a look at the jigsaw blade you are using and make sure it is for wood, fine cuts.

[DJPhatman]

Do you reckon that a proper 5 ply would have produced better results while cutting those handles?

Quite possibly. A different method needs to be explored, also. My personal preference is to build a jig with the hole patterned into it, then use it as a guid for my router to make the hand-holds even and identical.

Why dont you cut it closer to what you want and then fill it with bondo (may have to build it up in 2-3 applications) and sand it out. it will be fine. I would say you may want to have a look at the jigsaw blade you are using and make sure it is for wood, fine cuts.

+2 All that tear-out indicates either a dull/improper blade, or bad technique. But, it is very fixable.

[Bruce Weldy]

I would say you may want to have a look at the jigsaw blade you are using and make sure it is for wood, fine cuts.

+1

And just important - make sure that you use a blade cutting on the downstroke if you cutting on the "good" side. You were obviously using a blake with the teeth pointing up instead down. That's why you got the tear out like that. If you don't have any other blades, cut from the other side.

[But it Hertz]

I feel your pain. The wood yards down here are a nightmare. Cloak & dagger all the way. I ended up in homedepot just so I could get started on my first build.

BUT I have learned my lesson. It's the right wood all the way for me from now on. You go to soooo much effort... it's crazy to do everything right except use the best wood. These words will be ringing in your ears when you come to finish the cab as well!!! Trust me.

I recently realised buying the best cutting tools really improves the quality of the job. Especially jigsaw and table saw blades.

Check your settings on the jigsaw. Mine has the ability to move the blade away from the wood on the up stroke. I have a pack of 10 blades with everything from metals to plastic to wood and I practice using different blades on scrap to find a combination of blade, technique and settings to get a good result.

Also, I just got a plunge router. I LOVE it. Get a hole cutting attachment as well and you will never look back.

You'll be turning out quality "I can't believe I did that myself" cabs before you know it. A router also allows you to build things with slight overhangs and trim later making perfect edges.

[rotebass]

Why dont you cut it closer to what you want and then fill it with bondo (may have to build it up in 2-3 applications) and sand it out. it will be fine. I would say you may want to have a look at the jigsaw blade you are using and make sure it is for wood, fine cuts.

I considered Bondo, I was worried about strength (20" T30 with a Lab 12 has a bit of weight). Also, I would like to practice the job so I can "get it right" on the practice box, then move on to building a nice set.

Quite possibly. A different method needs to be explored, also. My personal preference is to build a jig with the hole patterned into it, then use it as a guid for my router to make the hand-holds even and identical.

I have lots of off cuts and access to a router, maybe it is time to learn

+2 All that tear-out indicates either a dull/improper blade, or bad technique. But, it is very fixable.

And just important - make sure that you use a blade cutting on the downstroke if you cutting on the "good" side. You were obviously using a blake with the teeth pointing up instead down. That's why you got the tear out like that. If you don't have any other blades, cut from the other side.

These are all things that are very possible, I did use the jig saw for a few other cuts with no problems, perhaps I just got lucky on those cuts.

I feel your pain. The wood yards down here are a nightmare. Cloak & dagger all the way. I ended up in homedepot just so I could get started on my first build.

BUT I have learned my lesson. It's the right wood all the way for me from now on. You go to soooo much effort... it's crazy to do everything right except use the best wood. These words will be ringing in your ears when you come to finish the cab as well!!! Trust me.

This pretty much echoes my feelings going into the project. I wasn't even sure I was going to be able to build the box and get acceptable results, I have managed to get this far with no major problems (the driver chamber even passed the leak test on my first go). I've learned a lot on this project, my prior experience in woodworking extends are far as building a swingset for my son last summer, and helping my dad frame in his basement back when I was a teenager.

[rotebass]

I really wanted to wait until I was done and make a build thread, but I really want to share this.

http://dl.dropbox.com/u/25226419/545445 ... 2392_n.jpg

Speaker on top was a Turbosound TXD-12M, not exactly cream of the Turbosound crop (and certainly not as good as the 712m's that I usually work with) but it was lying around the work space and made for a good test speaker. I ran each cab off of a channel of an XTI4000, limiter set to -6 for the Tuba, placed the cabs in the middle of a stage facing towards a 1250 seat auditorium (~30 ft. to either side wall and ~20 to the back wall, so take cancellation into consideration), sat in various positions as well as listened up close.

My observations were as follows:
- The Tuba was still craving more power when the Turbosound was running out of steam.
- Horn bass really does sound different than bass reflex cabs, I'm not willing to say that one is better than the other at this point because they both have pros and cons. I can see why people miss the harmonic content of a bass reflex, but love the output I'm getting out of the Tuba so far.
- Don't put your head near the horn mouth.

I mentioned earlier that the leak test in the driver chamber was successful, I did find a leak around the speakon jacks which have since been sealed, I'm not sure how much of a difference they would have made that far down the horn path but any improvement is worth the couple minutes of effort. Two tracks that were particularly pleasing to listen to are Where's my Keys by Deadmau5 and Firepower by Datsik. I haven't done any measurements on the cab yet (was waiting for my reg. code to come for TrueRTA) and I might have to wait until spring before I can get a really nice day to test, but even some Moombah and Tech House tracks with low bass seemed to come out well on the Tuba.

[But it Hertz]

Interesting musings on performance!

What other subs do you run? What can you compare this T30 with?

I think this is the best looking tuba because of the huge mouth. There's something very aesthetic about that design.

You should definitely do a build thread. I read every word and pour over every photo on all the build threads I find!

Keep up the good work.

[rotebass]

Interesting musings on performance!

What other subs do you run? What can you compare this T30 with?

I think this is the best looking tuba because of the huge mouth. There's something very aesthetic about that design.

You should definitely do a build thread. I read every word and pour over every photo on all the build threads I find!

Keep up the good work.

Standard rig for my consists of SRX728, we have 10 available depending on the size of the job, also 718 for small jobs. Also have experience with the 2x18 offerings from EV (X Array and QRX), Transparent Audio, Adamson and (unfortunately) Yorkville. The SRX will probably be used for comparison, my original thoughts going into the project were that the Tuba would get close to the 718, now I'm thinking it will be at least as good and possibly capable of more output. We all know that SRX are power hogs, but they perform quite well assuming you can get the power to the speaker.

I agree about the aesthetics, even with my inferior woodworking, I think the box will turn out quite well once I slap a few coats of finish on it. Future projects can only get better (knocking on wood). The box is sized right that I should be able to fit two subs and two PRX512 in the back of the Mazda, with room to spare for Laptop and my NI Kontrol S2, cabling, etc.

I plan on doing a thread when the project is finished. I didn't document every step, I spent about 2 hours a night after putting the boy to bed and every night before leaving I snapped a picture of the progress. What I can do is try to document some of the pitfalls I encountered to try to help future novice builders save some time (2 hours sanding the driver cut out to correct size, going to have to rethink that step next time around lol).