BillFitzmaurice.info

billkatz wrote:Since it appears you have one set of braces half way - rather than cutting them out to put them at the recommended 1/3 and 2/3 - perhaps you could just add two more sets at 1/4 and 3/4. I believe the only downside to 3 sets of braces rather than 2 is weight. If I'm wrong, I'm sure someone will correct me. Without the final side on adding them won't be too difficult. As someone else said, the 3/5 will be the toughest.

+100! Make them out of 1/4" (6mm) plywood. Not a lot of added weight, but plenty of bracing.

Hey guys, sorry for the delayed reply but it's been a long weekend and I hadn't had time to check the forums before. I'll try to get to all the replies.

Grant Bunter wrote:The cab shouldn't vibrate at full volume with proper bracing, it should stay still.

And to help you visualise inches: 10cm is near enough to 4 inches (It's actually 10.1cm).
The acceptable allowance for variation in panel measurements is up to 1/8 of an inch, near enough to 3mm...

I meant vibrate as in if I put my hand on top would I feel it? If i left a bottle on top of it would it top? Not shaking out of place, simply constant vibration.

billkatz wrote:Since it appears you have one set of braces half way - rather than cutting them out to put them at the recommended 1/3 and 2/3 - perhaps you could just add two more sets at 1/4 and 3/4. I believe the only downside to 3 sets of braces rather than 2 is weight. If I'm wrong, I'm sure someone will correct me. Without the final side on adding them won't be too difficult. As someone else said, the 3/5 will be the toughest.

Tom Smit wrote:+1

DJPhatman wrote:

billkatz wrote:Since it appears you have one set of braces half way - rather than cutting them out to put them at the recommended 1/3 and 2/3 - perhaps you could just add two more sets at 1/4 and 3/4. I believe the only downside to 3 sets of braces rather than 2 is weight. If I'm wrong, I'm sure someone will correct me. Without the final side on adding them won't be too difficult. As someone else said, the 3/5 will be the toughest.

+100! Make them out of 1/4" (6mm) plywood. Not a lot of added weight, but plenty of bracing.

That was actually my first thought to try and jam a couple more on the back, through the horn. I was not thinking on adding to the front but yeah guess it makes sense as I can't reach panel 6 from behind.

Also I had 2 flange braces already cut, is it worth putting it there?

And finally, I have fairly cheap and easy access to birch ply 9mm that only has 3 layers. is that enough for bracing ?

If not it might just be easier to get 12mm as we'll have to buy more to start building the second one. It wont be those two extra braces that'll make the difference weightwise. (as the other 3 will have to have the braces this one doesn't).

And finally, I have fairly cheap and easy access to birch ply 9mm that only has 3 layers. is that enough for bracing ?

That will be fine.

little update, managed to get a couple more lower back braces in. couldn't reach far enough to reach top one but I figure it'll be enough as our width is not that larger than original.

Hopefully today I''ll be able to cut and install 2 more front braces.

Cheers

and a little update. We oficially have a Titan 48 ready for sanding / painting and of course... testing.

We didn't add the extra front braces (yet) as we would like to test it before to try and feel for any vibration.

some pics here. front cover is a bit messy as I halfway through decided to add more screws to it and didn't mark the distances properly. (it all fits properly)

also I know the hurricanes should be on the other side but my 5mm drill broke and had to use a smaller one and couldn't reach the holes from the back to open them enough to get the hurricane in there.

It's all been tested for leaks. we did find one in the baffle anchor which later was corrected with some glue on the inside and gasket on the outside. also found 2 on the backside near to top corner. also been glued over and retested and are now sealed.

anyway, should be able to turn it on over 10v later this week

very excited.

http://maisbaixo.com/Titan/final1.jpg
http://maisbaixo.com/Titan/final2.jpg

jmanso wrote:I know the hurricanes should be on the other side but my 5mm drill broke and had to use a smaller one and couldn't reach the holes from the back to open them enough to get the hurricane in there.

I can't see what you're referring to, but in any event hurricane nuts must be installed from the side of the panel opposite where the bolt goes into them. If installed backwards they will pull out.

we had to use these:

[img]
http://s1.kuantokusta.pt/img_upload/pro ... 002625.jpg
[/img]

as we couldn't find anything else similar.

these are meant to be nailed in but we clipped the tongs and just glued it in place.

I thought there were meant to go on the side of the flanges that are facing panel 2. yet we had no choice but to put them on the other side, that was facing the front access cover.
I added extra screws so not to place much tension on the glue when it's in use, and hopefully it should hold on with the 15+ screws I have there.

jmanso wrote:we had to use these:

[img]
http://s1.kuantokusta.pt/img_upload/pro ... 002625.jpg
[/img]

as we couldn't find anything else similar.

these are meant to be nailed in but we clipped the tongs and just glued it in place.

These are tee-nuts, not hurricane nuts. Next time to fit them, just use the bolt with a large washer on the end and tighten them up so that tightening the bolt 'pulls' the tee-nut into the wood. You may need to do this with the access cover on or the washer would get pulled into the driver hole and you'd end up with wonky nuts (which no-body wants to see )

EDIT: Hmm.. maybe not... you'd have a problem holding the pliers on whilst the tee-nut bites into the wood.

Look on the first page of my T30 16" build (2nd link) below. That's how I did it. This was in the driver baffle whilst it was outside of the cab, but you can get the idea.

escapemcp wrote:
These are tee-nuts, not hurricane nuts. Next time to fit them, just use the bolt with a large washer on the end and tighten them up so that tightening the bolt 'pulls' the tee-nut into the wood. You may need to do this with the access cover on or the washer would get pulled into the driver hole and you'd end up with wonky nuts (which no-body wants to see )

EDIT: Hmm.. maybe not... you'd have a problem holding the pliers on whilst the tee-nut bites into the wood.

Look on the first page of my T30 16" build (2nd link) below. That's how I did it. This was in the driver baffle whilst it was outside of the cab, but you can get the idea.

Thanks for the info, I didn't know they had a different name. we did that on the anchor, instead of predrilling 4 holes I just hammered one to mark and then glued using pretty much the same process you describe.

Couldn't do that on the outside because I cant reach the inside with an hammer much less a drill

The first cab is where you learn all the lessons for the second... if you can manage to get an air-tight working cab out of the process then that is a bonus (although usually achievable with a small amount of bodging!). I could have had a few issues when building the first cab that could have been showstoppers but (luckily) I caught them in time. It's one of the reasons why you shouldn't rush... mulling stuff over is as important as putting PL to ply.

escapemcp wrote:The first cab is where you learn all the lessons for the second... if you can manage to get an air-tight working cab out of the process then that is a bonus (although usually achievable with a small amount of bodging!). I could have had a few issues when building the first cab that could have been showstoppers but (luckily) I caught them in time. It's one of the reasons why you shouldn't rush... mulling stuff over is as important as putting PL to ply.

I feel like only the 3rd one will come out really nice to be honest. Still so much to learn.

We went head first on this project, having little to no experience or tools we found ourselves having to stop because we didnt have enough clamps, or because we needed a different size drill or something.

With every step we've learned something, and hopefully the end product will reflect the amount of work and learning it took us. Having said all that, we are quite pleased with how well everything fit together nicely and no apparent (large) mistakes were done.


can't wait to try it out.

It's official! it is finally finished !

After a lot of issues getting Warnex in Portugal we finally managed to get enough to do one coating.

Here it is, 2 layers of Latex primer tinted black, and a finishing coat of Black Warnex !




and the back side as well

Congratulations, you got there.

While that cab will be strong, as a cab, you should have made the effort to put in the extra braces in the horn mouth.

If it hasn't been explained already, if any of the panels can flex, that robs you of output. That loss of output can be up to 3dB, which = 1 whole cab.
You may or may not be able to feel that panel flex as vibration, but we don't want you to think that these cabs aren't great when it comes to output. Please, put in whatever extra braces you can manage.

On your other builds, just take a little extra time to make sure the panel edges are lined up. Using half inch ply means light cabs, but you want as much of that ply joining another piece as possible. I can see a lip on the panel 7 piece/side on the right side for example.

I write this, not trying to be critical, but just so you get nice strong cabs that perform as they should...

Grant Bunter wrote:Congratulations, you got there.

While that cab will be strong, as a cab, you should have made the effort to put in the extra braces in the horn mouth.

If it hasn't been explained already, if any of the panels can flex, that robs you of output. That loss of output can be up to 3dB, which = 1 whole cab.
You may or may not be able to feel that panel flex as vibration, but we don't want you to think that these cabs aren't great when it comes to output. Please, put in whatever extra braces you can manage.

On your other builds, just take a little extra time to make sure the panel edges are lined up. Using half inch ply means light cabs, but you want as much of that ply joining another piece as possible. I can see a lip on the panel 7 piece/side on the right side for example.

I write this, not trying to be critical, but just so you get nice strong cabs that perform as they should...

Let me start by saying that we truly appreciate every advice here, and take everything that is said very seriously.

Allow me to explain why we went ahead and painted.

We started by reinforcing the inner bracing all in as we could reach adding a few more inside the back panel, and one down in panel 4 i think (the one we had issues to begin with)

we then did a few tests in a friends house (outside) running the cab at different voltages for some ammount of time, ending in running almost full voltage (around 39v) for about 45min.

During all this we carefully tried to see if any panels were vibrating. and nowhere during our tests did we notice any vibration of any sort.

Also. We've had a party recently where we tried the titan using a pair of decent active PA Tops from a friend's band.

The room we were in is a decent room that holds around 100 people in front of the stage. when we were soundchecking we were soon warned by the resident tech that we couldnt go louder. at that point I measured a 40hz sine and it was measuring about 18v.

We ended up pushing a bit more when the party filled but could never go over 2/3 of max output or the needles on the turntables would start skipping.

I've yet to get an spl meter to have some more conservative measurements but all in all we were very impressed with the overall output and I think it goes right about the "advertised" values.

Regarding the lip. we've had all the panels pre-cut before building because we don't own a table saw and that caused a ton of warping on the second side.

also because we didn't pre-drill we had to use brute force and a lot of clamps to try to get everything in place. that lip was the result of this.

We intend to get a nail gun to address this on our next build, but we did reinforce that part with some extra glue just in case.

Also, everything was checked,double checked and triple checked using the tube method and all leaks were repaired (we had 2 I think)

Finally we had everything already sanded down and had to start painting soon risking the wood getting damaged.

Hope that addresses everything

I will surely get back here when we have measurements to see if everything is up to par.

Thanks.

Back again for more cabinet building

After stopping for a few months we're finally back in the workshop.

We decided to use what we've learned on the first build to try and address all issues we had with the build.

We are of course doubling the bracing, and more important we're pre-drilling everything and dryfitting with screws beforehand. (Many thanks to sine 143 for all the help provided and patience to answer all the questions I've nagged you on facebook).

We basically marked side panel, and then marked screw holes spaced 10cm apart.

Afterwards clamped 2 side panels together and drilled them both.
Afterwards I've dry fitted every panel to make sure they all align correctly.
After that I've secured the braces as well on position.

I didn't take a lot of pictures throughout the whole process but here's one of where I left off.

Overall looking much cleaner this build.