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Re: 4x T48 and 4x OT12 build
Posted: Wed Aug 21, 2024 9:32 am
by Bill Fitzmaurice
I use that U channel on the grilles I added to my car. There are plenty of sources for grille material, in various patterns and colors, many on Amazon.

Re: 4x T48 and 4x OT12 build
Posted: Wed Aug 21, 2024 9:55 am
by Bruce Weldy
Re: 4x T48 and 4x OT12 build
Posted: Thu Aug 22, 2024 11:11 pm
by dlv
Bruce Weldy wrote: ↑Wed Aug 21, 2024 9:55 am
This is where I got some grills way back...
Way back I'll bet they were cheaper.

Four T48 grills (23" x 30") from there would set me back $575 with shipping.
I'm leaning towards going with the 13ga flattened expanded steel I can get locally. It is $4 a sqft and everything else is looking a lot more with shipping. Including the c-channel edging I think it'll be about $35 per T48 if I go that way. Bonus is the local shop will cut it for a few dollars to the exact dimensions on their shear.
Re: 4x T48 and 4x OT12 build
Posted: Fri Aug 23, 2024 7:38 am
by dlv
Wondering about yet another thing. Appreciate you guys putting up with me.
Is there a guideline for how much open area a subwoofer grill should have?
For example 1/4" perforated has 40% open area. Flattened expanded metal ranges from 35% for 1/4" to 52% for 1/2".
Or does it just not matter?
Re: 4x T48 and 4x OT12 build
Posted: Fri Aug 23, 2024 1:17 pm
by Seth
Just thinking out loud here, a metal grill would traditionally protect the cone of a driver from damage. Since a grill wouldn't really protecting anything from impact damage in this case, perhaps take into consideration the possibility of softer solutions if they are able to better suit your cost/look/performance goals..
Re: 4x T48 and 4x OT12 build
Posted: Fri Aug 23, 2024 4:43 pm
by dlv
Thanks Seth. You're not wrong. However besides the fact folks around here like to dance in pointy cowboy boots and drink a bit too much sometimes, there's also mice. And pack rats. They're pretty thick around here. I literally had a rat run out of a sub port once when we went to load it from storage. Needless to say, we opened it up to see what the little bastard had done. Unfortunately that sub was toast.
Re: 4x T48 and 4x OT12 build
Posted: Sat Aug 24, 2024 2:11 am
by Seth
Another possibility would be to put the grill further back in the throat to cut down on the required square footage.
Re: 4x T48 and 4x OT12 build
Posted: Sat Aug 24, 2024 7:34 am
by Bill Fitzmaurice
That's what I'd do.
Re: 4x T48 and 4x OT12 build
Posted: Sat Aug 24, 2024 7:43 am
by dlv
Seth wrote: ↑Sat Aug 24, 2024 2:11 am
Another possibility would be to put the grill further back in the throat to cut down on the required square footage.
Yep that's brilliant! Could go right up against (and be attached to) the 6/10 braces and cross brace. Another "why didn't I think of that" moment. I'm gonna make one and see what it looks like.
Re: 4x T48 and 4x OT12 build
Posted: Sun Aug 25, 2024 10:14 pm
by dlv
Ok wondering if I made a mistake.
I put a pair of NL4 jacks in the top as well as the back so when the subs are up against a wall, so I've got an easy place to connect them. I put them in the driver chamber thinking easier to wire them up. It was.
The 1st sub is now closed up and I tested it. In my 1500 sq ft shop at 50v this thing was killing me. Dang it's loud! I can't wait to hear what the whole herd sounds like together!
But those two jacks in the driver chamber have a lot of air leakage around them no matter how tight they're screwed down. Lot of air pressure in that driver chamber. Would it have been better to locate them behind the driver chamber in-between it and panel 9? I think there's room there. Haven't cut the holes or closed up the other 3 subs yet so I could do that with them.
FWIW I plan to judiciously caulk the jacks in the final installation (cabinet is not yet painted) or maybe I'll try some gasket material behind the jacks. Curious what others do. Maybe this is normal and the caulk will take care of it. Thought I'd ask before going further with the other cabinets.
This is before I glued the final side on and started testing it but it shows where the jacks are.
Re: 4x T48 and 4x OT12 build
Posted: Mon Aug 26, 2024 5:38 am
by Bill Fitzmaurice
Putting jacks in the driver chamber isn't a good idea, the pressure there is very high. Placing them in the horn path is better as pressure there is much lower.
Re: 4x T48 and 4x OT12 build
Posted: Mon Aug 26, 2024 6:50 am
by dlv
Ok thanks for confirming Bill. I feared that was the answer. I'll do that in the other three cabs and chalk this up to another learning experience on the first cab. On this one I may PL the jacks in and take the risk that I'll never be able to remove them. They're accessible from behind the driver if I ever needed to fix a connection.
Re: 4x T48 and 4x OT12 build
Posted: Mon Aug 26, 2024 10:57 pm
by Tom Smit
dlv wrote: ↑Mon Aug 26, 2024 6:50 am
Ok thanks for confirming Bill. I feared that was the answer. I'll do that in the other three cabs and chalk this up to another learning experience on the first cab. On this one I may PL the jacks in and take the risk that I'll never be able to remove them. They're accessible from behind the driver if I ever needed to fix a connection.
Would you consider removing them, filling in the holes (cut out a patch and place in behind for a good seal), and relocating the jacks in panel 6? The repair will be covered with Duratex?
Re: 4x T48 and 4x OT12 build
Posted: Tue Aug 27, 2024 2:57 am
by Strange Kevin
I usualy put gasket tape on the back of speakon Jacks, although I haven't tried putting them in the drive chamber.
If your jacks are far enough from the driver, there may be room to build a small dog house behind the jacks to seal them from the main chamber.
Re: 4x T48 and 4x OT12 build
Posted: Tue Aug 27, 2024 7:51 am
by dlv
Strange Kevin wrote: ↑Tue Aug 27, 2024 2:57 am
If your jacks are far enough from the driver, there may be room to build a small dog house behind the jacks to seal them from the main chamber.
Oh I like that idea! I'm still gonna follow Bill's advice and put them in the horn on the other 3 cabs but that might work to fix this cab. I believe there is room for it. At least I'd be able to remove the jacks if I ever needed to replace one. Thanks Kevin!