BillFitzmaurice.info

The TT is something I've been wanting to create for a while, mainly from reading all the fantastic opinions on it being rather good for music. I wanted to do a long style on though rather than a proper table purely because of the small footprint, that and I wanted a bass cannon rather than a bass cube. So doing some reading and being pretty much unable to find Dayton or Tang band drivers in the UK means we've only one real choice, the JBL GTO 804. Picked one of those up a couple of weeks ago and broke it in immediately. Weekend after that I finally found a decent lumber yard and it turns out one of my old school friends works there. Picked up 8x 8'x4' sheets for a pretty damn fine £165. Also bought 3 hand saws.

They delivered the ply last Tuesday and another 3 saws. So we're up about £16 and probably won't have to buy another saw for a couple of years. Fine by me. Happy with the ply it's really nice hardwood faced stuff and is nice and flat too!

So today we cut some panels and I shook my head at how unbelievably non-straight the panel jig my build buddy built for the last speakers. I told him off and we made a new one which is fucking laser accurate. We were building for maybe 8 hours, started early afternoon and finished just before 10pm.



Arty shot!



I'm not entirely sure why he has to pose for photos but there we go, I'd not be without the man, he loves doing this shit.






Still surprised that this is supposedly going to make an awful lot of bass, it's tiny!



MAKE SURE IT IS AIRTIGHT!





...and that's where we left it. Panels 8/9/10 to go in as well as 5 and 6 which we left due to our allen key bolts being too fat for the holes on the JBL basket. Need to source some narrower ones along with the correct sized hurricane nuts. I thought we did pretty well today, all the panels are cut and just the braces to cut and install. Hopefully I'll be awake enough after work tomorrow to get those done and 8/9/10 installed then it's just 5/6 when I can get hold of fittings.

Not sure I would trust pink glue...

Coming together nicely. Be sure to post a review of how it sounds - I may be building a couple for myself here soon.

Pink is the '5 minute' version of the PL we've used on the Omni12s we built before. Used the 'slower' stuff on the T39s and had no issue with either aside from the fact it's ruining a lot of my wardrobe...

In reality it takes about 20 minutes to solidify. I had the TT stood upright by the garage door earlier and knocked it over. TIMBERRRRRR! Whoops. Certainly no problem with strength though as I picked it up and dusted it off and it was as it was mere seconds before being unceremoniously dumped on its face.

Yeah, when I first saw the GTO804 I was like ....that's only 5" diameter of actual cone....

It still delivers bass in droves.

Still in progress but finally got hold of the correct size bolts for the driver so hopefully I can get the last few panels in place then put that bad boy in there this evening...








Yes they have epoxy on them now, don't worry.

Today I started on one of a pair of T60s...






Never done a plunge cut before, never realised the saw could do that either! A few practice cuts on a trash bit of ply and it was on to the real deal.






Need lunch though before I carry on. I'll be spending the entire weekend on these so I'm keen to see how much I can get done in that time.

The wood you're using appears to be veneered. If that's the case under stress the veneer can separate from the substrate. To prevent that you need to use screws as well as adhesive.

There'll be screws EVERYWHERE...

Aye, but if the ply is soft enough you can screw them in past flush and a bit of bondo will sand down to invisible. If you can't bury the heads you'll have to countersink them, extra 10 minutes work.

Oh that wasn't me complaining, I mean there's currently an awful lot of screws gone into it.

Also remind me to do everything myself, my housemate rolled into the garage as I'd finished panel 3 and the spacer and 'helped' me pop it into place and glue it. I'd previously pre-drilled and countersunk everything and the dry fit was perfect. With his 'assistance' the panel was installed upside down, I did wonder why the ply had started to split in a couple of places despite being pre-drilled. Luckily the problem was noticed before the glue started to set so it was 'GETITOUTNOW' time.

Called it a day at that point and went to play with the plate amp I'd gotten for the TTLS. ZOMG!

TT was done after the last post referencing it and has been happily pounding the crap out of our games room since. Fantastic performance out of a piddly cheap driver. Work and people have eaten up my free time since then so the T60 is still awaiting panel 3 in the garage.

I have 3 weeks of holiday to take at some point so I reckon in the new year I'll use the cash saved since then to acquire more bits and get a second pair of OT12s built along with both T60s.

I've got an autotuba to get done too at some point. Then some Jacks, XF............. Gonna be loud next year.

Right, back on the T60s now as I've got some time off work. The annoying thing is that there's so many bloody birthdays I have to attend this week! I've got 3 events in 3 days so hopefully on Sunday I won't be too much of a mess to get some more done.

I have all the panels bar 12 cut and will start work on the braces first thing tomorrow. The hardest part of putting these together has honestly been marking and drilling holes for the driver. Is there a completely idiot proof way of doing this? I mean I pop the driver on the spacer, clamp that shit down and mark the holes with an awl then remove the driver and drill but my holes always seem to be ever so slightly out and I'm loathe to thread anything in at a slight angle so I may end up doing that panel (3) again.

Aside from that I've had no trouble, it's been a bit nippy but I'm certainly glad there's been less snow/ice than last week.

88h88 wrote:The hardest part of putting these together has honestly been marking and drilling holes for the driver. Is there a completely idiot proof way of doing this? I mean I pop the driver on the spacer, clamp that shit down and mark the holes with an awl then remove the driver and drill but my holes always seem to be ever so slightly out and I'm loathe to thread anything in at a slight angle so I may end up doing that panel (3) again.

This step is always my nemesis as well. I used to use the same method as you, but now I just place the driver on the spacer and drill straight through the holes in the driver.

88h88 wrote: The hardest part of putting these together has honestly been marking and drilling holes for the driver. Is there a completely idiot proof way of doing this? I mean I pop the driver on the spacer, clamp that shit down and mark the holes with an awl then remove the driver and drill but my holes always seem to be ever so slightly out and I'm loathe to thread anything in at a slight angle so I may end up doing that panel (3) again.

For marking the driver holes: http://www.flexbar.com/shop/pc/TRANSFER ... 9p3099.htm. They center the indent perfectly in the driver hole.

As for drilling the hole perfectly plumb, a drill press would do the job. If not then you could make yourself a jig that would do the job. Get yourself a nice 1" - 2" thick piece of brass drilled with a hole on a friends drill press (plumb) with the hole the diameter of your normal drill bit size for drilling driver holes. After you have your jig, you clamp it to your baffle centered on the hole and use it as a guide to drill your hole. Those transfer punches look like they would be great for centering the jig in the indent you just made with said transfer punches. It will turn your handheld drill into a precision plumb drilling guide.




You can buy them already made. Search for "square drill guide"

Used these brass guides many times before and they work great. Sometimes I will use them even with a drill press when drilling soft metals to ensure the drill bit doesn't wander during the initial bite.

I have to say this is my biggest head ache as well. Doesn't matter how accurate you think you are being, once the t-nuts are glued all bets are off.

I like the transfer punch idea.... I also like the drilling through the driver idea.... Never tried either though... I have always *just* got away with it. Sometimes it might take me like 30 minutes to get the driver in place with all threads started.

I think my next cab will be drilled through the driver and then the glue can set while the driver is attached. Those t-nut bastards are so fickle.

I would love to see a definitive guide. There must be a fool proof way.

On my last project (THTLP) I made 3 baffles before I was happy... Grrrr.