BillFitzmaurice.info

I'm just going to assume from lack of response that everything looks as expected in the impedance sweeps. "No news is good news"

On the 2x6 SLA Pro shorties, I do wonder if the dip in impedance at 5kHz would possibly cause problems if I put 4 cabs on one channel (which would be a 1ohm dip). But, it's not a problem I have. Just a curiosity.

Otherwise, I've been listening and tweaking in the garage and I am really really liking what I am hearing. I still need to do an "official" outdoors initial system EQing on them, but still... I'm super happy with both the resultant clean clear output and overall sound quality I'm getting with a simple tune by ear. Everything is sounding great. 50's, 60's, 70's, 80's, etc... Country, Rock, Opera, EDM... Yes, the bottom end of some music is missing, but for this system and it's intended use it's absolutely not an issue at all.

I put Pandora on a 60's rock channel today while I was giving the "project space" a bit of a post project clean-up and organizing before start into the next mess... and it was fantastic. Nothing stood out too much and everything sounded very similar to earbuds, in that they just go louder and louder and louder without "sounding" loud. Tried some more modern rock with fatter more up-to-date bottom end too, with equally impressive results. Mostly lower level listening, but occasionally I'd turn a song up... and up a little more and then a little more. The volume was difficult to comprehend. It wasn't until I took a step outside the garage (it's my storage unit actually) and realized the whole complex is reverberating with clean concert like sound. Clean sound just doesn't "sound" loud, even when it is. And that's the sound I like. I love it! I'm really happy with this little trio of the 16" 3012LF T39 and pair of shorty 2x6 SLA Pro's. Quite happy.

Looking forward to the results of 4 x 30" T39 with full size SLA Pro's. Given what I've heard from the small system, I'm quite confident the larger system will cover my live band needs for quite some time.

Anyway, that's where that's at for the time being. I'll give an update on it when I put an outdoor RTA tune on it.

I went back to your build thread and your crossover looks good, so not sure about the dip.

Chris_Allen wrote: ↑Sat Apr 18, 2020 3:25 am I went back to your build thread and your crossover looks good, so not sure about the dip.

Thank you Chris. Much appreciated.

SethRocksYou wrote: ↑Sat Apr 18, 2020 3:02 am realized the whole complex is reverberating with clean concert like sound. Clean sound just doesn't "sound" loud, even when it is.

I've been talking about this for years to venues, etc. When you get rid of distortion and the piercing frequencies - volume becomes less of a factor. I always talk of this in terms of EQ.

My old band used to play at a venue where a lot of bands playing with just vocals in the PA were having to turn down. The amps onstage sitting on the stage were beaming right at the audience and just killing people. We played the same place where everything was in the PA and were much louder in terms of SPL than anyone else, yet never got asked to turn down.

Good EQ, Good Mix, through a great sounding system solves almost all of the problems in this business.

Bruce Weldy wrote: ↑Sat Apr 18, 2020 9:40 am
Good EQ, Good Mix, through a great sounding system solves almost all of the problems in this business.

You're so right Bruce. So much of it is in good EQ and mix. Slight changes can make a world of difference, better or worse.

I was looking at the pile of lumber I have that's supposed to become four 30" T39's and thought that I'd better get to it before it becomes one of those things "I'll do tomorrow". So I started pre-cutting everything and got all the pieces done for all four and pretty much ready to start step one, drawing out panel locations.
But then I took a look at the leftover lumber and thought to my self, "I bet I could make a whole TruckTuba with that and still have enough scrap to do all the bracing in the T39's".

So, I cut up all the pieces for a TruckTuba, 7½" panel width, 8½" cab width, 9½" overall on 1" stand off's/feet (driver will be down firing).
I glanced through the plans... seems like a really easy build.

Let's lay it out.
Here's where I ended up. Had I started before noon and not taken so many sit down breaks, it would have been an easy 1 day build.
It's interesting where action taken on a whim leads sometimes.

TruckTuba all buttoned up. Just have to trim the tongue off panel 7 and put a jack in. Well... all the finishing work too. .
If Bill says it will work okay, I'm going to fill the existing driver location and put two drivers in the side instead.

Since the cabinet will be laying flat, it would put the drivers rear firing on the passenger side, instead of down firing.

Cut the tongue off (would have been to the right of the new speaker location below), ran the flush cut bit around, and rounded the edges. It always looks so much better after that. Like a clean shave.

New driver location is coincidentally a perfect fit. I'm liking this option. I wont have to put feet under the box now. Hind sight; could have made it an inch wider now that I don't need to lift the box an inch to allow room for a down firing driver. Note to self if I do it again.

I cut a plug from one of the cutouts left over from the T39 build, glued it in place, and tacked it down. I'll get it blended in and no one will ever know it was there.

No reason why you can't do it that way, provided the depth is enough.

OD of the driver is 8.25", cab width 8.5"... Just barely. I had to be careful with the placement because the drivers are deep enough to interfere with the original driver location bracing. It worked out pretty well and each driver is about the same distance from panel 1's intersection with panels 2 & 7 (3.25 & 3.5").

Per your recommendation, I'm going to add a 3-4" gusset/brace between the drivers tying panel 1 into the sides and I'm also adding a 6/9 brace, 7/9 brace, and brace across the mouth similar to how the 10" sketchup indicates.

Just so everyone else isn't in the dark...
(Image skewed and no longer to scale)

6/9 brace installed. I didn't put one way down in there, but made this one longer than the one in the plans to span as much of the driver chamber as possible.

Sanded away the paint to let the PL bond directly to the wood.

Oooohhhh!!!

I really like this option!!
I may have to modify my truck Tuba to match!

Strange Kevin wrote: ↑Tue Apr 28, 2020 4:56 pm Oooohhhh!!!

I really like this option!!
I may have to modify my truck Tuba to match!

How wide did you build yours

7/9 brace and mouth brace are in. I decided to have them intersect. I went back and forth in my mind about whether or not to put a fancy arc in the mouth brace, or a handle, or just keep it simple and not do any of that stuff... I took the simple route. .
Tough to get a photo, and really it's not that interesting of a feature, but here it is anyway... Panel one's added support gusset/brace. Not the one alone on the left. The one to the right of that, between the drivers. .
Screw anchors are in. I'll have to trim them with a jig saw once the PL dries.

How wide did you build yours

Crazy enough. 8-1/2" total "width"

It's been so long I had to double check, all I could remember was it was built to just fit in my old mk3 vw golf without sticking up above where hatch opens.