BillFitzmaurice.info

found out that chamber reducers are too big and need some trimming.

also found out that conversion to mm led to some minor discrepancies so have to trim the "corner" panels, 10 and 9 I think.

This probably explains the lip on the first build and why we had so many issues with panel 4.

Wont be happening now, hopefully

Hey everyone !

We've been working hard on our second titan and we will hopefully have it finished soon.

While we didn't take a lot of pics throughout the whole process, we went with pre-drilling everything and using screws instead of clamps this time and the results are 100x better.

We have no noticeable lip this time around, everything fit pretty much perfectly, and as many of you suggested we doubled the bracing both inside and on the front of the cab.

Having little to no woodworking skills I can't say how pleased I am with the result so far.

I took a few pics yesterday that I'd like to share with you.

We basically have everything but the second side panel glued.

Hopefully today or tomorrow I'll finish it

Cheers, and again thanks for all the help.

http://i.imgur.com/5X7fotI.jpg

http://i.imgur.com/F9LiPSM.jpg

http://i.imgur.com/0RJdpic.jpg

Nice job! It's funny to me how much I enjoy seeing pics of subs before the final side goes on. They always make me smile.

Building part is officially over !!!

still waiting on the warnex to arrive as well as the neutrik plugs and the jackplate, but everything else is finished.

Our first one now looks so crooked and poorly made next to this one that I almost want to scrap it and build a new one. But looks aren't everything and it still sounds awesome

I'm very happy on how much the screws helped with the final product.

honestly can't wait until I start the next build ! (probably 2x t24 now )

Here, have a pic

that one looks great man! very clean.

after a looooooooooooooooooooooongg time, it's time to bring this thread back, because all construction work is done !

it took such a long time because along the way we found out that the lab12 drivers weren't cutting it and switched to 18Sound 12NLW9300

which was a big change in budget so it took way more than originally planned.

anyway, we finished construction yesterday, and only have to leak test and paint the final 2 titans and it'll be done.

Here's some pics we took last evening



the two in the middle have white background so we can attach the label symbol like here:


anyway, thank you all for the help and time you all gave me, and I can't wait to test them out

Looking at the SPL chart for the 18Sound 12NLW9300 in the T30, and how little it adds to that, does it offer much more in the T-48 than the standard premium driver?? Or a similar 2 db in a few spots here and there?

Not only a little here and there on the SPL chart, but consider the benefit of a higher voltage limit overall.

David Raehn wrote:Not only a little here and there on the SPL chart, but consider the benefit of a higher voltage limit overall.

I'm past my personal Dunning Kruger point here, but isn't the output, as indicated by the SPL charts, the final arbiter? Personally, I don't read a driver's wattage capacity as "can handle" (RUFF, RUFF!), but rather as "requires _x_ to hit _y_ dBs". So *needing* 79 volts vs 49, in order to gain a few (sparse) spots of 2 dB, sounds like a lot of chasing up the cost/performance curve. The bigger advantage looks to be the 10 pound weight savings.

Unless, of course, the performance gains of this driver in the T48 vs the T30 are notably greater?

Rich4349 wrote: isn't the output, as indicated by the SPL charts, the final arbiter?

They're at 2.83v, unless noted otherwise.

Rich4349 wrote:Looking at the SPL chart for the 18Sound 12NLW9300 in the T30, and how little it adds to that, does it offer much more in the T-48 than the standard premium driver?? Or a similar 2 db in a few spots here and there?

The charts are based on each driver getting the same power. If the charts are relatively the same at equal power and the 18sound can handle 10 volts more, it will be louder. It can receive over 30% more wattage.

And yet, no one picked up on this:

jmanso wrote:honestly can't wait until I start the next build ! (probably 2x t24 now )<snip> it took such a long time because along the way we found out that the lab12 drivers weren't cutting it and switched to 18Sound 12NLW9300<snip>

jmanso, for less money that you spent on the Lab12s, you could have gotten a recommended 15" driver (Kappalite 3015LF, Kappa-15LFA, KappaPro-15LF, Definimax-4015LF or ULF-8, or a Lab-15) or a 3015LF comparable driver that are available around the EU! (hint-See the " Links to everything you need for your BFD-build, in Europe." sticky thread in "Tips, Techniques and Supplier Links").
The displacement difference between your 12" driver and a correct 15" driver is quite significant...

hey all!

The reason we changed drivers was not to have more spl,

it was after a looong and technical explanation from Sean Hennessey, after we blew a LAB12 driver (with every limiter in place),

and long story short, it was explained to me that:

"what this tells us, is a 40hz bassline is a prime candidate for roasting a coil, as the driver is consuming maximum thermal energy AND, moving very little (which means it cant coil effectivly)"


from this, Sean recommended me the 18sound drivers as they can take that sort of beating a lot better than the LAB12s,

also, they were the closest choice to retro-fit on both titans I had already built.


As for this:

jmanso, for less money that you spent on the Lab12s, you could have gotten a recommended 15" driver (Kappalite 3015LF, Kappa-15LFA, KappaPro-15LF, Definimax-4015LF or ULF-8, or a Lab-15) or a 3015LF comparable driver that are available around the EU! (hint-See the " Links to everything you need for your BFD-build, in Europe." sticky thread in "Tips, Techniques and Supplier Links").
The displacement difference between your 12" driver and a correct 15" driver is quite significant...

When we started this project about 2 years ago, we were very short on cash (we still are) and at that time, the LAB12 drivers were seriously cheaper than any other alternative (remember I live in Lisbon, Portugal).

Anyway, I'm still quite excited to finally be able to power this for the first time, will hopefully do so on the 15th.

Cheers

jmanso wrote: it was explained to me that:
"what this tells us, is a 40hz bassline is a prime candidate for roasting a coil, as the driver is consuming maximum thermal energy AND, moving very little (which means it cant coil effectivly)"

That's a myth, it never happens. Cone excursion will be at a minimum at specific frequencies, but unless your source is a sine wave generator a speaker never plays just one frequency. If you toast a coil it's from over-powering by one means or another. The LAB has a 400w coil, the NLW an 800w coil, it's as simple as that.

Bill Fitzmaurice wrote:

jmanso wrote: it was explained to me that:
"what this tells us, is a 40hz bassline is a prime candidate for roasting a coil, as the driver is consuming maximum thermal energy AND, moving very little (which means it cant coil effectivly)"

That's a myth, it never happens. Cone excursion will be at a minimum at specific frequencies, but unless your source is a sine wave generator a speaker never plays just one frequency. If you toast a coil it's from over-powering by one means or another. The LAB has a 400w coil, the NLW an 800w coil, it's as simple as that.

appreciate the clarification. In all honesty, I am but a leyman here, learning every day.

most of the sound we play does have a continuous sine at very low frequencies most of the time, like this for example:

https://www.youtube.com/watch?v=wi_bPp9La5g

but of course it's never continuously generated throughout the entire event.

Nevertheless, having already built the 12'' titans, and as the 12nlw9300 were at a sale at the time ( around 250€ each ) we felt it best to have the assurance of higher rated drivers.

It has been recommended on the forum to limit them around 5 ~10 v lower than stated on the plans for added safety.

My plan is to power them using this:
https://www.thomann.de/pt/the_tamp_tsa_4_1300.htm

I know it's a bit too much, I also know it's not a very good amp but money really is a factor and there's isnt any other choice below 500€ that I could find.
(Yes I checked ebay, no we don't have craigslist, similar Portugueses sites turned out blank, and second hand stores don't really carry amps that can do these kind of loads)