A7-500 horn mounting frame

[altecman]

It's been a long time between drinks but have been busy. I just picked a full set of A7-500 parts e.g 808-8a, 416-8b, 511b and N501-8a but no boxes, picking up a pair of 825's soon. I know that I will eventually have to replace the diaphragms on the 808's soon but that can wait as they are in perfect condition. What I want to know is the length of the 511b horn mounting frame I intend to use 2 1/2"steel angle iron. I've seen pictures with the steel mounting frame instead of the more common wood as in earlier models - could someone measure their steel mounting frame and let me know. I want to restore these back to full A7-500 configuration. I'm almost tempted not to use the 825's as I have fitted this stuff into some JBL J bins, I think I'll lose the bass I am getting. I suppose it's a decision I'll have to make e.g use the 825's and add a sub to boost the bottom end.

[Audio_by_Goodwill]

I'm note sure how wide, as I don't have either. My plan was to use hard wood like, oak, or use steel shelf brackets. I really haven't thought about the length, if I go with wood.

<font color="#FFFFFF" size="1">[ November 27, 2008 02:27 PM: Message edited by: Audio_by_Goodwill ]</font>

[SD-50]

I was thinking about replacing the plywood L angle with a 3in. strip of hardwood that the spiked horn would rest on allowing for easy fore/back adjustment of horn position. Yet to find or make short spikes that can be bolted to the flange holes.
Horns won't vibrate off the top of cabs, each horn has about 8lbs of non-hardening modeling clay stuck to them.
Cheers

[mah]

Look at item No.21 in the page shown at this web link. I compared this item to an Altec 825 drawing and it is identical. I hope this is what you are looking for.
web page

[GM]

Originally posted by altecman:

I just picked a full set of A7-500 parts....... picking up a pair of 825's soon.

What I want to know is the length of the 511b horn mounting frame I intend to use 2 1/2"steel angle iron.

<font size="2" face="Verdana, Helvetica, sans-serif">AFAIK, a metal angle was not used on any A7-500s or any other model using the 825 cab, but you can work out the dims from its two piece wooden angle. The outer holes are for the 511: http://www.lansingheritage.org/image...ign/page14.jpg

GM

[altecman]

Thanks everyone for their imput, I know that the 825 cab only had wooden Horn mounting boards but I just wanted to use steel like in the later 828 versions. Looking at the later version and the one that was released a year or so I noticed that the steel frame was wider than those in the 825 drawings. I just wanted to get the correct dimension of the later version, in the end I supposed it doesn't matter, I'll just estimate.

[bfish]

Like the others, I'd only seen the wooden affair. After your last post, I looked at the "new" one that does indeed appear to be angle-iron;



Just by scaling the image, the angle looks to be an inch wider than the horn on each side.

Like you say though, it just doesn't matter. Especially since you'll not likely ever see a real life example of a factory steel angle to compare it to. Most certainly, no one here has one.

[GM]

Huh! Didn't notice that when I looked for detail differences back when it was first released. Actually, I've never seen a steel angle from the factory on even 828s, but then I hadn't seen that many, though I've seen some DIY ones used both as well as made/installed 3/16" x 1.5" x 2.5" x 28" long alum. angles to do double duty as horn mouth braces, though the main reason was so quick release pins could be used for installing/removing the horns for packing.

GM

[altecman]

Thanks for the input. What's the opinion of the white painted cabs I've seen on the net. I must say that they would look alot better in the lounge room than the more traditional battleship grey - at least the wife might like them!!

[GM]

You're welcome!

Do you mean Per Hasling's? Apparently he and I are the only ones who believe wings should be de riguer on A7s as well as tuned much lower than either stock or the 75"^2 vent many here prefer.

Anyway, they're your speakers, so decorate them however you or your SO prefers as long as it doesn't mess with their performance. Frankly, when I was actively building, big speakers were typically either painted with whatever was on the wall or wallpapered with whatever the SO chose. FWIW, butcher block, marble and bamboo in that order were the most often chosen, but then the leader hasn't stood the test of time except as a real butcher's block.

GM