My build of a pair of HawthorneAudio Sterling Duets

[richidoo]

Lookin good Bob!

Do you get any low frequency vibration at the top of the baffle? I put a rear brace on my last OB, and it really killed the vibration.

http://www.audionervosa.com/index.php?topic=2505.msg27587#msg27587

Does that amp power the whole speaker?

[Bob in St. Louis]

Thank you Rich.

No, the vibrations are pretty well absorbed by the loose material inside, that does wonders for the vibrations. Although three layers of high quality plywood help too.  haha

The 300 watt amp is just for one driver. That being the 15" "Augie" on the bottom which is the driver that covers the lower octaves.

Bob

[Bob in St. Louis]

Not too much done this weekend.
But these are plywood braces. The original thought process was to have 1"x1.5" welded rectangular metal tubing (think race car chassis).
But when we couldn't find anybody to do it, I thought I'd make a quick plywood mockup version and see what it looks like. So this was mainly for Tony's benefit.


The amp boxes are primed, which is why they're white.

[richidoo]

Love the faux steel look, nice metallic paint color! Nice lap joints too!!! You da man!

Is it still warm there or do you work inside in heated shop?  I need a dust sucker BAD.

[Bob in St. Louis]

Thanks Rich!
Working in the basement. Much nicer than the garage. haha

"Lap joints", you talking about in the brace?
That line you see isn't actually a seam, it's a pencil line. I cut that brace from a sheet of plywood and has no joints at all. The fellow thinks the brace may be "too much", and may opt for a single diagonal "arm". Those lines are where I'd cut off the left 'leg' and bottom 'leg'.

I did my best to make the plywood look like steel tubing, with the size, shape, rounded corners, and paint color. This was a quick mockup of a welded steel tube brace to help him visualize what it would look like.
If fact, the other side of the brace isn't even painted, and when he came over the paint was still wet when he grabbed it. You can see the finger marks of you look close. 

I need some dust control too. <cough> 

Bob

[opnly bafld]

Lookin' good Bob. 
I think the brace/legs would look mo' betta if it was a triangle and it would be stronger than just the L shape.

[richidoo]

I saw those fingerprints but I wasn't gonna say anything  Blame it on the customer, that's classy Bob, real classy... 

I've been eyeing this dust box for a while, price is finally getting low enough to lure me.
http://www.rockler.com/product.cfm?page=30068&filter=dust

[Bob in St. Louis]

Thanks Lin! 
I agree. But of course, the customer is always right....to a limit.
I'll build whatever he wants, as long as I feel it's not a detriment. Personally, the thing is over built as it is, so any additional support at all will do nothing but help.

Just between you and me, I just want to build. I'll be the hand for the guy that can't, ya know. If he wants to split hairs, then so be it.

Rich, yea.....I had to get him a towel with some solvent on it to clean his hands off. 
The guy was cool enough to bring a bottle of 45(ish) year old Cognac for us to sip on while we talked about the next phases of the build. I'm not a Cognac guy, but loved what he had ("Camus Xo Borderie"). After five or six hours of chatting about audio stuff, we had lowered the level in his bottle by a third. 
After that, he didn't care about having paint on his fingers. 

Regarding the dust, I'd really like to plumb the shop properly. But of course, projects that improve projects always take a back burner to those projects that are projects themselves, if that makes sense.

Bob

[tmazz]

But of course, projects that improve projects always take a back burner to those projects that are projects themselves, if that makes sense.

Strangely, it does. 

[richidoo]

The only Cognac I've ever had was cheap stuff we used to pour into a big pot of lentil soup in college. We had a big pot on the stove for days at a time, until it was gone. To keep it "sterile" we would just pour in more booze.  It must have been cheap, I only paid $1/pot for all I could eat. Good thing it wasn't chicken soup.

I like the projects that improve projects too. What annoys me are the 'projects that enable projects,' like when I have to fix a tool before I can use it to fix something else with it. 

[Bob in St. Louis]

Didn't get too much finished this weekend. Today was about all I had to get much done, and one of "those" audio guys came over.
Of course we had to drink, listen, chat, etc..etc..etc...ha ha

So....
With regard to the bases.....
I got some sanding finished. Another coat of primer, some more sanding, a bit of spot putty, sanding, and another coat of primer and more sanding......

Also, there's been a few emails and PM's about the clearance between the driver magnet and the amp, so I thought I'd shoot a (fuzzy) picture.
That's about one honest inch between the magnet and the heat sinks of the amp.

That's about the best I can do with regard to progress for the weekend.
My son's 13th Birthday party is tomorrow, so no sawdust will be flying until next weekend.

Cheers.

[Bob in St. Louis]

Here's a pic of the crossovers Darrel Hawthorne built.
Just in case anybody was curious, they tip the scales at 6 pounds, 10.9 ounes....each. 

Bob

[richidoo]

I think you're OK with the heatsink. It is close, but otherwise well ventilated. I think the voice coil resistance will cause more heat internally than a warm heatsink nearby.  The magnet is ferrite, which resists high temps well, unlike the rare earths.

So how do you manage to keep those speaker posts tightened? Mine always come loose.

Happy BD to your son. My oldest is also 13, and he is wonderful.

[Bob in St. Louis]

I was more worried about the magnet being as close to the XO than I was the heatsink. Might have to build a lead umbrella for it.   

The best way to keep the posts tight would be to use banana connectors. haha
But seriously, I know what you mean, they do come "loose". Although I'd have to qualify that by saying they become "less tight", because I've never actually had one get loose enough to be audible to even allow the wire to be pulled out.

I have the same type on mine and notice that when I unscrew them, they're not very tight even though I barred down on them when I installed them.

Got the first sheet of veneer in the vacuum bag last night. Yipee!

Bob

[Barry (NJ)]

So how do you manage to keep those speaker posts tightened? Mine always come loose.

I have the same type on mine and notice that when I unscrew them, they're not very tight even though I barred down on them when I installed them.

Try a little dab of this on the binding-post threads