Build Thread: The Bombers (SR71's become 3-ways)

[lunchmoney]

Re: Build Thread: The Bombers (SR71's become 3-ways)

Not quite like a "Bomber", but same idea. I have SR71's with a "Blackbird" center.

I have small stands now for the SR71's, about 8 inches.

The subs each have a RSS370HF-8 driven by a Dayton SA1000 hooked in parallel. They are tuned to 22Hz.

I continue to be amazed by this setup. I have the bug to build again, but I am so happy with this that it will be for my daughter, not for me.

Lunchmoney helped with me with this build, and I am grateful to him.

Greg

Looks awesome!!!

It's not quite the same idea, as the goal of the Bombers is to have the 10's cover from about 400 hz and down... so they'll have that big midbass big speaker sound that you can't really achieve with 7" bookshelves plus subs, since the 7's are covering all the way down to sub territory.

I will also have a sub that will be crossed at 60 hz.

That being said, I'm sure your setup sounds amazing, and you're maintaining a true match between mains and center, which is something I'm sacrificing with the Bombers.

[lunchmoney]

Re: Build Thread: The Bombers (SR71's become 3-ways)

Build resumes tonight...

I will be trying one last thing to get the not-quite-furniture-grade plywood to work... I'll be trying deeper kerf cuts, leaving only about .060"...

[BeerParty]

Re: Build Thread: The Bombers (SR71's become 3-ways)

Build resumes tonight...

I will be trying one last thing to get the not-quite-furniture-grade plywood to work... I'll be trying deeper kerf cuts, leaving only about .060"...

Good luck.

Question - is your hesitation about using MDF weight or looks? I was thinking of using multiple layers of thin material (1/4" or 1/8") and then veneering.

[lunchmoney]

Re: Build Thread: The Bombers (SR71's become 3-ways)

So I decided to just cut the one turning I had made into four "1/4 rounds" by using a band saw, and simply accepting that 1/2 of a blade width would be sacrificed from each face of each quadrant... that's well within the tolerances of this build anyways :p

So now to the bandsaw... took a bit of finagling to jig up the piece to ride against the fence... double-sided tape is your friend... nice and slow, fortunately it cut through the douglas fir no problem...




Then cutting these 2 halves in half again was a breeze...




Next I needed to glue strips of 3/4 mdf to the quadrants as glue lugs... using a piece of 1/2" plywood as a guide, I double stick tape one of the mdf lugs to the 1/4 round...




When I pull away the piece of plywood the lug is left positioned perfectly...




Then I mark drill pilot holes for some wood screws through the lug and the 1/4 round...




Then I remove the lug, remove the double stick tape, drill clearance holes for the wood screws through the lugs, then glue and screw...




Then rinse and repeat for the other face of the 1/4 round...

[lunchmoney]

Re: Build Thread: The Bombers (SR71's become 3-ways)

Now to glue the 1/4 rounds to the baffles... first I double stuck taped the baffle to a stiff aluminum extrusion...




Then a bead of 3M PL construction adhesive on the 1/4 round...




Then clamp up... this went surprisingly well...






Then repeat for the other side. It was great how few clamps I needed, thanks to the aluminum extrusion... these joints are going to be SOLID...

[lunchmoney]

Re: Build Thread: The Bombers (SR71's become 3-ways)

Taking off the clamps this morning was an absolute joy... moments like this are why I do this...

Dry fit pictures here... the gaps you see between the front corners and the window braces are by design... making those gaps tight was going to be a real tolerancing challenge... I may end up gluing some shims in to close the gaps, but it's really not important, won't add any rigidity that isn't already there in spades...

WOW these baffles are rigid, and I'm not done bracing them...

[greywarden]

Re: Build Thread: The Bombers (SR71's become 3-ways)

That's pretty awesome looking! Looks like it will be strong

[john trials]

Re: Build Thread: The Bombers (SR71's become 3-ways)

That's pretty awesome looking! Looks like it will be strong

Agreed. It's cool to see such a different enclosure design. Lunch wasn't thinking outside the box...he was thinking ABOUT the box (haw haw!).

[D, Rose]

Re: Build Thread: The Bombers (SR71's become 3-ways)

Mr. Lunch, I must say I have some SERIOUS shop envy after going thru this thread! When I grow up I want to work in YOUR shop!!! You wouldn't happen to live within a half hour of Detroit, would you?:D We could make beautiful speakers together! Very cool build. I think that 1/8th hardboard would bend around that form easily, and with epoxy between the lams this set of cabs would be amazingly stiff.

[greywarden]

Re: Build Thread: The Bombers (SR71's become 3-ways)

He's a Nor'easter and I'm pretty sure that's where he works, but yes, envious nonetheless

[lunchmoney]

Re: Build Thread: The Bombers (SR71's become 3-ways)

Mr. Lunch, I must say I have some SERIOUS shop envy after going thru this thread! When I grow up I want to work in YOUR shop!!! You wouldn't happen to live within a half hour of Detroit, would you?:D We could make beautiful speakers together! Very cool build. I think that 1/8th hardboard would bend around that form easily, and with epoxy between the lams this set of cabs would be amazingly stiff.

Rhode Island, sir.

It's the shop here at Ximedica, a medical device design and engineering company. I'm the principal industrial designer here, and I use this shop at my leisure. I'm so spoiled I know.

[evilskillit]

Re: Build Thread: The Bombers (SR71's become 3-ways)

Rhode Island, sir.

It's the shop here at Ximedica, a medical device design and engineering company. I'm the principal industrial designer here, and I use this shop at my leisure. I'm so spoiled I know.

I initially read that as "a medieval device design and engineering company". I was going to say dang man, I want a trebuchet and a broad sword please.

[lunchmoney]

Re: Build Thread: The Bombers (SR71's become 3-ways)

I initially read that as "a medieval device design and engineering company". I was going to say dang man, I want a trebuchet and a broad sword please.

Trebuchet would be a sick name for a speaker

Do it!

copyright evilskillit 2012

[BeerParty]

Re: Build Thread: The Bombers (SR71's become 3-ways)

I initially read that as "a medieval device design and engineering company". I was going to say dang man, I want a trebuchet and a broad sword please.

Trebuchet would be a sick name for a speaker

Do it!

copyright evilskillit 2012

Trebuchets have big buckets, right? So what kind of speaker would it be? :D

[greywarden]

Re: Build Thread: The Bombers (SR71's become 3-ways)

I need to build a FUS RO DAH!!!