BillFitzmaurice.info

Fine looking cabs you got there.

Still looking forward to the finished project!
Do the speakers fit properly on the cargo rack?

bitSmasher wrote: ↑Fri May 25, 2018 7:22 pm Still looking forward to the finished project!
Do the speakers fit properly on the cargo rack?

The subs will be placed one in front of the other (output facing the ground), the cargo bed will have to be made a little longer to accommodate them both in this configuration. But then again, the TAT's are slim enough to leave space across the bed, to leave room for the amps, miniDSP and batteries.
I'm getting closer to the finished project, which is a good thing as it is already booked for 2 rentals so far...!

Tom Smit wrote: ↑Wed May 23, 2018 11:32 pm Fine looking cabs you got there.

Thanks Tom. That means a lot coming from an experienced builder!

Having stripped the box from the bike, it is clear that the space will be just sufficient for the project. I actually have to place the amps and the batteries UNDER the horns! This gives a better point of gravity, so it's not all bad!

Yesterday I finally go to the point where testing bike-speaker combination was a possibility. I just needed the last 3 feet of cable for the last top cab, but it was a success! Everything came together with ease, and there was no major hick ups in the assembly process...

So, the main question is whether the TAT's do the job playing outside on the bike. The short answer is NO...

They do a decent job, gotta give'em that. But filling my expectations for the capabilities of the sound bike, they do not. I know; they are not meant to be playing outside, they do not have the specified drivers, and so on.
There are plenty of reasons why they don't quite make it. The biggest reason probably is the sensitivity of the drivers of only 86 dB. I guess I have to settle OR build another cab...

Questions is what cab would do..? Suggestions are welcome!
Dimensions of platform is 620x910 mm (25x36 inch)

You could fit two 17.5" wide T39s within those dimensions, that would be the loudest combo of subs, loaded with 18sound twelves. You'd only get to 45hz at war volume though. How low do you need to go?

Hmm, making it down fireing..?
The T39 is 39" tall (in this case long), and I would be missing 3" on the platform... But IF going that direction, when why not make a 25" wide, double loaded with 10's..?

Padde298 wrote: ↑Mon Jul 09, 2018 7:57 am Hmm, making it down fireing..?
The T39 is 39" tall (in this case long), and I would be missing 3" on the platform... But IF going that direction, when why not make a 25" wide, double loaded with 10's..?

DB and extension would be the same (between 2 singles or 1 double of the same cab), you'd only be out flexibility of having 2 smaller cabs for other projects / gigs. The downward firing T-39(s) was my first thought, too!

T39 is what I'd do, with the horn mouth aimed at the ground not only for a bit better loading but also to keep out rain.

Shame about the disappointing first result...
Have you checked what voltage the amp is putting out, and tested it with other subs?
Double check your input signal and amp settings, and also test indoors with same settings.

I'll stick with previous advice that you need >60hz (or even >80hz) and attempting to achieve anything lower will result in compromise...

bitSmasher wrote: ↑Tue Jul 10, 2018 3:08 am Shame about the disappointing first result...

Disappointing maybe, but not surprising. AutoTuba is designed to take advantage of the cabin gain in a car.

Bill Fitzmaurice wrote: ↑Tue Jul 10, 2018 7:20 am Disappointing maybe, but not surprising. AutoTuba is designed to take advantage of the cabin gain in a car.

Yep, I know... And the Sound Bike project wasn't the initial intention for the TAT's. So no bad feelings there! They ended up there mostly due to their dimensions, and of course availability (having made them).

A while back I used them indoor at a party, where they did quite well. So they are quite capable of delivering outside the cabin of a car.

@Bitsmascher: I'll of course check everything! AND spend time dialing in the miniDSP and using REW trying to figure out what is going on.

In you're driving the car amp straight from MiniDSP, keep in mind the output is only 1v but the car amp will want 3~5v input... so you'll have to crank the gain right up
Same sort of thing when running a phone direct in to car amp, much lower level than what it's designed for

GREAT NEWS!!!

Got the entire set up assembled, and found a MAJOR mistake!!! The horns was connected out of phase..! TOTAL NEWBIE MISTAKE!!!
NOW the performance of the horns are QUITE impressive, even with out the gain of the cabin of the car!

@Bitsmasher: I encountered have this problem to some extend. But when going full volume on the cellphone over the BT module, the 8" drivers are getting just the power they can handle. So I guess it is OK this way. But the gain of the amp is WAY up!

Only this needed now is to fit some kind of LED flim-flam. More on that later!