Altec 604-8G sanity check

Thermionics

Post Whore In Training
This project has been stalled out a while!

I’ve picked it back up recently, and as of this morning, I’ve installed the new front baffles and most of the bracing (before, there was effectively none).

Maybe you guys could cheer me on to the finish line?
 

MrEd

Senior Nobody
Man, I see the finish line just ahead...
Think about just how good those bad boys are gonna be 😊
 
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Thermionics

Post Whore In Training
You're further along than I am on my 604E cabinets (they're still being built by a friend in Oregon). Although I did finally start the veneering of the Altec 753c cabinets (teak to match the credenza). That ought to take me a week or so to complete. :|
 

John Frum

Secret Society Member
After picking up some shorter cap screws today, I intended to get the 604-8G drivers installed in the cabinets. Then, all that would be left would be to install the shelf braces, install Owens Corning 703 damping, and build and install the crossovers.

On the second driver installation, a t-nut came loose while tightening, despite being recessed and epoxied in/over. I’m not worried about seven cap screws holding the driver, but epoxy debris is caught between the cone and grill cloth, the t-nut is reflective and slightly pressing out from the grill cloth, and I’m afraid the screw/t-nut will rattle. Show-stopper.

My plan is to remove the front baffle, 604-8G and all, take loose the staples holding the upper corner of the grill cloth, remove the offending bolt/t-nut, remove the driver, re-staple the grill cloth, re-install the front baffle, and re-install the driver. I might take a bolt out of the other speaker to match…

The biggest pitfall I can foresee is damaging the grill cloth, necessitating re-covering one or both baffles. I wish I had done that myself to begin with rather than farming it out, but it’s still not an effort and expense to look forward to.

Nonetheless, I’ll keep moving.

2EF82822-69B5-4968-92B6-E58170E35AB5.jpeg
 

Thermionics

Post Whore In Training
After picking up some shorter cap screws today, I intended to get the 604-8G drivers installed in the cabinets. Then, all that would be left would be to install the shelf braces, install Owens Corning 703 damping, and build and install the crossovers.

On the second driver installation, a t-nut came loose while tightening, despite being recessed and epoxied in/over. I’m not worried about seven cap screws holding the driver, but epoxy debris is caught between the cone and grill cloth, the t-nut is reflective and slightly pressing out from the grill cloth, and I’m afraid the screw/t-nut will rattle. Show-stopper.

My plan is to remove the front baffle, 604-8G and all, take loose the staples holding the upper corner of the grill cloth, remove the offending bolt/t-nut, remove the driver, re-staple the grill cloth, re-install the front baffle, and re-install the driver. I might take a bolt out of the other speaker to match…

The biggest pitfall I can foresee is damaging the grill cloth, necessitating re-covering one or both baffles. I wish I had done that myself to begin with rather than farming it out, but it’s still not an effort and expense to look forward to.

Nonetheless, I’ll keep moving.

View attachment 39306
Not sure it is readily available where you are, but if you haven't already purchased the Owens Corning, you might want to look into using cotton (e.g. shredded denim jeans) batts. Easier to work with and no annoying fiberglass splinters.
 

Fran604g

Just Call Me Junior
After picking up some shorter cap screws today, I intended to get the 604-8G drivers installed in the cabinets. Then, all that would be left would be to install the shelf braces, install Owens Corning 703 damping, and build and install the crossovers.

On the second driver installation, a t-nut came loose while tightening, despite being recessed and epoxied in/over. I’m not worried about seven cap screws holding the driver, but epoxy debris is caught between the cone and grill cloth, the t-nut is reflective and slightly pressing out from the grill cloth, and I’m afraid the screw/t-nut will rattle. Show-stopper.

My plan is to remove the front baffle, 604-8G and all, take loose the staples holding the upper corner of the grill cloth, remove the offending bolt/t-nut, remove the driver, re-staple the grill cloth, re-install the front baffle, and re-install the driver. I might take a bolt out of the other speaker to match…

The biggest pitfall I can foresee is damaging the grill cloth, necessitating re-covering one or both baffles. I wish I had done that myself to begin with rather than farming it out, but it’s still not an effort and expense to look forward to.

Nonetheless, I’ll keep moving.

View attachment 39306
Are you sure you don't have my life? There's always that one damned T-nut! 🤪 Seriously though, your cabinets look beautiful. I like really like the combination of grille cloth and finish shade you chose. Very nice!
 

John Frum

Secret Society Member
Since Friday, I’ve removed both front baffles, retrieved the offending cap nut and t-nut, re-stapled the grill cloth, installed the rest of my bracing, installed most of my damping, spruced up the cabinets, and re-installed my front baffles.

Next up, building the Markwart crossovers!

I bought 2” thick Owens Corning 703, thinking it would be easier to work with than the pink stuff. No, it’s just as awful. And 2” is too thick for the sides, requiring me to split it. Should have used a cotton/denim product like Ultratouch insulation or U-Haul moving blankets. Might yet.

4CB1052F-2BB7-4AE3-A510-A18E6607ABCA.jpeg0ACE7558-7B77-4E67-B517-764495A69D77.jpeg
 
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John Frum

Secret Society Member
I couldn’t stand the 703, and ripped it out. I still have three pieces to make acoustic panels out of or what-have-you, but I’m already tired of dealing with it.

The U-Haul blankets are now installed four layers deep over the the back, top, bottom, brace, and one side. Both drivers are installed, and the only hold-up now is crossovers. Those are coming right along, just waiting on me to have a couple of hours.

I bought some new Altec badges from eBay, and have been trying to decide if using them on this project is cheesy or cool. I’m leaning towards cool.

What I find out is that I don’t do projects for myself when there’s myriad household tasks that are far more important. And there’s ALWAYS tasks that are far more important - I’m drowning in them. But instead of doing something pleasurable, or something needful, I get paralyzed and do nothing at all - a bad scene.

The biggest factor that has gotten me unstalled (besides the encouragement of youse folks) has been simply giving myself permission.

The title of the thread becomes increasingly ironic.

9311A1A8-EE4E-4B75-96DD-47C6D46FC28F.jpeg692EDA84-60AA-499E-A894-36486E354A73.jpeg519D288D-6DDA-4AA6-BEE8-2699332876EF.jpeg
 

John Frum

Secret Society Member
Kat, I've used that in some Bozak restoration and I did not care for it. Way too loose. Not dense enough and just falls apart. The Cotton batting link I attached above seems more applicable.
I think the U-Haul blankets are much the same thing as the batting you link to, in roughly 1/8” thickness. Here, if they’re not doing what I intend, the prescription would be more blankets.

I’ve caught flack already in other quarters for my minimal bracing, by modern standards, and I assume that the same nattering nabobs would take issue with my damping. I’m worried about choking the life completely out of the cabinets, and it’s easier to add more than remove.
 
I think the U-Haul blankets are much the same thing as the batting you link to, in roughly 1/8” thickness. Here, if they’re not doing what I intend, the prescription would be more blankets.

I’ve caught flack already in other quarters for my minimal bracing, by modern standards, and I assume that the same nattering nabobs would take issue with my damping. I’m worried about choking the life completely out of the cabinets, and it’s easier to add more than remove.

I just went with a single diagonal brace on the sides and back of my 6 cu ft. cabinets I built recently. Don't tell the other quarters! Only difference on mine is I fastened the braces on edge to the plywood, so they would have less deflection.

Definitely not a case where one size fits all, good on ya for playing around with the variables!
 

Audionut

Next Round Is On Me
I think the U-Haul blankets are much the same thing as the batting you link to, in roughly 1/8” thickness. Here, if they’re not doing what I intend, the prescription would be more blankets.

I’ve caught flack already in other quarters for my minimal bracing, by modern standards, and I assume that the same nattering nabobs would take issue with my damping. I’m worried about choking the life completely out of the cabinets, and it’s easier to add more than remove.
The denim from the depot is the ticket for insulation. Easy to cut and staple to the walls.
I could probably add some additional bracing by new build standards, but I’m quite happy with the sound so…
 
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