FWIW a clean pair of Altec-Heath crossovers on Oz Ebay.
Altec crossover Heathkit AS-101 | eBay
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FWIW a clean pair of Altec-Heath crossovers on Oz Ebay.
Altec crossover Heathkit AS-101 | eBay
So, I'm replacing the caps. Got one done and just removed the other.
I noticed one thing that might be an issue with the "speaker of lower volume". That is the one that has the replaced 8-Ohm cap. Well I guess the previous owner figured 16-Ohms was close enough.
Attachment 1594Attachment 1595Attachment 1596
And to set the scene, we have Treasure of the Sierra Madre playing in the background.
The Treasure of the Sierra Madre (1948) Trailer - YouTube
We don't need no stinking badges! - YouTube
Oh, and one more little problem. It seems like the two of the caps were run to ground inadvertently.
Attachment 1597
All done. I invited Aretha over. She's sitting on my right speaker singing Chain of Fools at the moment. Gotta go and listen.
Or Blazing Saddles ! :biggrin2:
http://youtu.be/-lj056ao6GE
Now I'm working on inverting the LF drivers as recommended and after I removed the 4 mounting bolts the driver is not budging...I mean like it was glued in. Is there something I'm missing? FWIW, the surround looks good and I don't hear any rubbing in the VC.
Also, I took the back of the 806As. Should I keep going and or clean off the oxidation?
Attachment 1604
One more question. It seems my allotted 1mB of images files is full. I don't see anywhere in the attachment manager where I can delete them. How can I upload more pics?
So this cabinet doesn't even have a proper bass reflex port. The horn is only bolted at the top of the cab with two bolts, the bottom of the horn is just floating. The entire horn opening IS the "bass port". Wow. I have some work to do. It's scary how good these are going to sound.
BTW, I pried the LF driver from the baffle. It just had 40 years of surface tension holding it on.
You can see in this pic that the horns mounts on to the light wood on top. There is a 3/4" gap on the bottom, plus the gaps on the side. Woof...as they say.
DSCF0670 | Flickr - Photo Sharing!
Here is the horn with a piece of 3/4 MDF inserted:
DSCF0674 | Flickr - Photo Sharing!
And the driver:
DSCF0671 | Flickr - Photo Sharing!
Ummm, that gap around the horn IS the port. That is how it was designed and tuned.
Your strip of wood will mess with the tuning.
Early Valencias were the same.
Ron
* Yeah, those amps were a bit out of my range. hah.
Not uncommon with altec. The A7 uses this arrangement when the horn is stored inside the cab.
If you'll be taking measurements while experimenting, you might do so in it's natural state, as a baseline. Or just mod one at a time and a/b.
...yup, the drivers will stick themselves to the baffle. When the goop has run (over time, temp) it can rip pieces of the cork or baffle out. Gentle is good when they are stuck, saves headaches down the road. Gravity is a friend, but you have to be ready to catch or otherwise land ~30lb of woofer.
I think it needed some messing with, Ron...at least for my taste. The mids are so out in front, the lower frequencies lagged. I added the wood on the bottom of the horn and then put a few pieces of closed-cell foam on either side of the horn leaving about 14sqin per speaker of port. It seems to have helped the bottom end catch up quite a bit. Bass drums are punchier and bass guitar licks are bouncier. The foam might be narrowing the horn dispersion, but it seems to sound great.
DSCF0677 | Flickr - Photo Sharing!
Mine too...just a little. I'd love to build Bruce's 300b monoblocks, but at (4) 300b tubes per channel and $150ea for cheapies, I might have to wait till I hit the lottery.
So if I wanted to do some measurements, what would you recommend. I've never done anything like this before and I don't have a proper mic. Would my Macbook Air do? What software?
BTW, the drivers released with a little persuasion. Very little. Cork completely intact.